gecko-dev/layout/painting/nsDisplayList.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/*
* structures that represent things to be painted (ordered in z-order),
* used during painting and hit testing
*/
#ifndef NSDISPLAYLIST_H_
#define NSDISPLAYLIST_H_
#include "DisplayItemClipChain.h"
#include "DisplayListClipState.h"
#include "FrameMetrics.h"
#include "HitTestInfo.h"
#include "ImgDrawResult.h"
#include "LayerState.h"
#include "RetainedDisplayListHelpers.h"
#include "Units.h"
#include "gfxContext.h"
#include "mozilla/ArenaAllocator.h"
#include "mozilla/Array.h"
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/EffectCompositor.h"
#include "mozilla/EnumSet.h"
#include "mozilla/EnumeratedArray.h"
#include "mozilla/Logging.h"
#include "mozilla/Maybe.h"
#include "mozilla/MotionPathUtils.h"
#include "mozilla/RefPtr.h"
#include "mozilla/TemplateLib.h"
#include "mozilla/TimeStamp.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/dom/EffectsInfo.h"
#include "mozilla/dom/RemoteBrowser.h"
#include "mozilla/gfx/UserData.h"
#include "mozilla/layers/BSPTree.h"
#include "mozilla/layers/LayerAttributes.h"
#include "mozilla/layers/ScrollableLayerGuid.h"
#include "nsAutoLayoutPhase.h"
#include "nsCOMPtr.h"
#include "nsCSSRenderingBorders.h"
#include "nsContainerFrame.h"
#include "nsDisplayItemTypes.h"
#include "nsDisplayListInvalidation.h"
#include "nsPoint.h"
#include "nsPresArena.h"
#include "nsRect.h"
#include "nsRegion.h"
#include "nsClassHashtable.h"
#include "nsTHashSet.h"
#include "nsTHashMap.h"
#include <algorithm>
#include <unordered_set>
// XXX Includes that could be avoided by moving function implementations to the
// cpp file.
#include "gfxPlatform.h"
class gfxContext;
class nsIContent;
class nsIScrollableFrame;
class nsSubDocumentFrame;
class nsCaret;
struct WrFiltersHolder;
namespace nsStyleTransformMatrix {
class TransformReferenceBox;
}
namespace mozilla {
enum class nsDisplayOwnLayerFlags;
class nsDisplayCompositorHitTestInfo;
class nsDisplayScrollInfoLayer;
class PresShell;
class StickyScrollContainer;
namespace layers {
struct FrameMetrics;
class RenderRootStateManager;
class Layer;
class ImageContainer;
class StackingContextHelper;
class WebRenderScrollData;
class WebRenderLayerScrollData;
class WebRenderLayerManager;
} // namespace layers
namespace wr {
class DisplayListBuilder;
} // namespace wr
namespace dom {
class Selection;
} // namespace dom
enum class DisplayListArenaObjectId {
#define DISPLAY_LIST_ARENA_OBJECT(name_) name_,
#include "nsDisplayListArenaTypes.h"
#undef DISPLAY_LIST_ARENA_OBJECT
COUNT
};
extern LazyLogModule sDisplayListLog;
#define DL_LOG(lvl, ...) MOZ_LOG(sDisplayListLog, lvl, (__VA_ARGS__))
#define DL_LOGI(...) DL_LOG(LogLevel::Info, __VA_ARGS__)
#define DL_LOGD(...) DL_LOG(LogLevel::Debug, __VA_ARGS__)
#define DL_LOGV(...) DL_LOG(LogLevel::Verbose, __VA_ARGS__)
#define DL_LOG_TEST(lvl) MOZ_LOG_TEST(sDisplayListLog, lvl)
/*
* An nsIFrame can have many different visual parts. For example an image frame
* can have a background, border, and outline, the image itself, and a
* translucent selection overlay. In general these parts can be drawn at
* discontiguous z-levels; see CSS2.1 appendix E:
* http://www.w3.org/TR/CSS21/zindex.html
*
* We construct a display list for a frame tree that contains one item
* for each visual part. The display list is itself a tree since some items
* are containers for other items; however, its structure does not match
* the structure of its source frame tree. The display list items are sorted
* by z-order. A display list can be used to paint the frames, to determine
* which frame is the target of a mouse event, and to determine what areas
* need to be repainted when scrolling. The display lists built for each task
* may be different for efficiency; in particular some frames need special
* display list items only for event handling, and do not create these items
* when the display list will be used for painting (the common case). For
* example, when painting we avoid creating nsDisplayBackground items for
* frames that don't display a visible background, but for event handling
* we need those backgrounds because they are not transparent to events.
*
* We could avoid constructing an explicit display list by traversing the
* frame tree multiple times in clever ways. However, reifying the display list
* reduces code complexity and reduces the number of times each frame must be
* traversed to one, which seems to be good for performance. It also means
* we can share code for painting, event handling and scroll analysis.
*
* Display lists are short-lived; content and frame trees cannot change
* between a display list being created and destroyed. Display lists should
* not be created during reflow because the frame tree may be in an
* inconsistent state (e.g., a frame's stored overflow-area may not include
* the bounds of all its children). However, it should be fine to create
* a display list while a reflow is pending, before it starts.
*
* A display list covers the "extended" frame tree; the display list for
* a frame tree containing FRAME/IFRAME elements can include frames from
* the subdocuments.
*
* Display item's coordinates are relative to their nearest reference frame
* ancestor. Both the display root and any frame with a transform act as a
* reference frame for their frame subtrees.
*/
/**
* An active scrolled root (ASR) is similar to an animated geometry root (AGR).
* The differences are:
* - ASRs are only created for async-scrollable scroll frames. This is a
* (hopefully) temporary restriction. In the future we will want to create
* ASRs for all the things that are currently creating AGRs, and then
* replace AGRs with ASRs and rename them from "active scrolled root" to
* "animated geometry root".
* - ASR objects are created during display list construction by the nsIFrames
* that induce ASRs. This is done using AutoCurrentActiveScrolledRootSetter.
* The current ASR is returned by
* nsDisplayListBuilder::CurrentActiveScrolledRoot().
* - There is no way to go from an nsIFrame pointer to the ASR of that frame.
* If you need to look up an ASR after display list construction, you need
* to store it while the AutoCurrentActiveScrolledRootSetter that creates it
* is on the stack.
*/
struct ActiveScrolledRoot {
static already_AddRefed<ActiveScrolledRoot> CreateASRForFrame(
const ActiveScrolledRoot* aParent, nsIScrollableFrame* aScrollableFrame,
bool aIsRetained);
static const ActiveScrolledRoot* PickAncestor(
const ActiveScrolledRoot* aOne, const ActiveScrolledRoot* aTwo) {
MOZ_ASSERT(IsAncestor(aOne, aTwo) || IsAncestor(aTwo, aOne));
return Depth(aOne) <= Depth(aTwo) ? aOne : aTwo;
}
static const ActiveScrolledRoot* PickDescendant(
const ActiveScrolledRoot* aOne, const ActiveScrolledRoot* aTwo) {
MOZ_ASSERT(IsAncestor(aOne, aTwo) || IsAncestor(aTwo, aOne));
return Depth(aOne) >= Depth(aTwo) ? aOne : aTwo;
}
static bool IsAncestor(const ActiveScrolledRoot* aAncestor,
const ActiveScrolledRoot* aDescendant);
static bool IsProperAncestor(const ActiveScrolledRoot* aAncestor,
const ActiveScrolledRoot* aDescendant);
static nsCString ToString(const ActiveScrolledRoot* aActiveScrolledRoot);
// Call this when inserting an ancestor.
void IncrementDepth() { mDepth++; }
/**
* Find the view ID (or generate a new one) for the content element
* corresponding to the ASR.
*/
layers::ScrollableLayerGuid::ViewID GetViewId() const {
if (!mViewId.isSome()) {
mViewId = Some(ComputeViewId());
}
return *mViewId;
}
RefPtr<const ActiveScrolledRoot> mParent;
nsIScrollableFrame* mScrollableFrame;
NS_INLINE_DECL_REFCOUNTING(ActiveScrolledRoot)
private:
ActiveScrolledRoot()
: mScrollableFrame(nullptr), mDepth(0), mRetained(false) {}
~ActiveScrolledRoot();
static void DetachASR(ActiveScrolledRoot* aASR) {
aASR->mParent = nullptr;
aASR->mScrollableFrame = nullptr;
NS_RELEASE(aASR);
}
NS_DECLARE_FRAME_PROPERTY_WITH_DTOR(ActiveScrolledRootCache,
ActiveScrolledRoot, DetachASR)
static uint32_t Depth(const ActiveScrolledRoot* aActiveScrolledRoot) {
return aActiveScrolledRoot ? aActiveScrolledRoot->mDepth : 0;
}
layers::ScrollableLayerGuid::ViewID ComputeViewId() const;
// This field is lazily populated in GetViewId(). We don't want to do the
// work of populating if webrender is disabled, because it is often not
// needed.
mutable Maybe<layers::ScrollableLayerGuid::ViewID> mViewId;
uint32_t mDepth;
bool mRetained;
};
enum class nsDisplayListBuilderMode : uint8_t {
Painting,
PaintForPrinting,
EventDelivery,
FrameVisibility,
TransformComputation,
GenerateGlyph,
};
class nsDisplayList;
class nsDisplayWrapList;
class nsDisplayTableBackgroundSet;
class nsDisplayTableItem;
/**
* This manages a display list and is passed as a parameter to
* nsIFrame::BuildDisplayList.
* It contains the parameters that don't change from frame to frame and manages
* the display list memory using an arena. It also establishes the reference
* coordinate system for all display list items. Some of the parameters are
* available from the prescontext/presshell, but we copy them into the builder
* for faster/more convenient access.
*/
class nsDisplayListBuilder {
/**
* This manages status of a 3d context to collect visible rects of
* descendants and passing a dirty rect.
*
* Since some transforms maybe singular, passing visible rects or
* the dirty rect level by level from parent to children may get a
* wrong result, being different from the result of appling with
* effective transform directly.
*
* nsIFrame::BuildDisplayListForStackingContext() uses
* AutoPreserves3DContext to install an instance on the builder.
*
* \see AutoAccumulateTransform, AutoAccumulateRect,
* AutoPreserves3DContext, Accumulate, GetCurrentTransform,
* StartRoot.
*/
class Preserves3DContext {
public:
Preserves3DContext()
: mAccumulatedRectLevels(0), mAllowAsyncAnimation(true) {}
Preserves3DContext(const Preserves3DContext& aOther)
: mAccumulatedTransform(),
mAccumulatedRect(),
mAccumulatedRectLevels(0),
mVisibleRect(aOther.mVisibleRect),
mAllowAsyncAnimation(aOther.mAllowAsyncAnimation) {}
// Accmulate transforms of ancestors on the preserves-3d chain.
gfx::Matrix4x4 mAccumulatedTransform;
// Accmulate visible rect of descendants in the preserves-3d context.
nsRect mAccumulatedRect;
// How far this frame is from the root of the current 3d context.
int mAccumulatedRectLevels;
nsRect mVisibleRect;
// Allow async animation for this 3D context.
bool mAllowAsyncAnimation;
};
public:
using ViewID = layers::ScrollableLayerGuid::ViewID;
/**
* @param aReferenceFrame the frame at the root of the subtree; its origin
* is the origin of the reference coordinate system for this display list
* @param aMode encodes what the builder is being used for.
* @param aBuildCaret whether or not we should include the caret in any
* display lists that we make.
*/
nsDisplayListBuilder(nsIFrame* aReferenceFrame,
nsDisplayListBuilderMode aMode, bool aBuildCaret,
bool aRetainingDisplayList = false);
~nsDisplayListBuilder();
void BeginFrame();
void EndFrame();
void AddTemporaryItem(nsDisplayItem* aItem) {
mTemporaryItems.AppendElement(aItem);
}
WindowRenderer* GetWidgetWindowRenderer(nsView** aView = nullptr);
layers::WebRenderLayerManager* GetWidgetLayerManager(
nsView** aView = nullptr);
/**
* @return true if the display is being built in order to determine which
* frame is under the mouse position.
*/
bool IsForEventDelivery() const {
return mMode == nsDisplayListBuilderMode::EventDelivery;
}
/**
* @return true if the display list is being built for painting. This
* includes both painting to a window or other buffer and painting to
* a print/pdf destination.
*/
bool IsForPainting() const {
return mMode == nsDisplayListBuilderMode::Painting ||
mMode == nsDisplayListBuilderMode::PaintForPrinting;
}
/**
* @return true if the display list is being built specifically for printing.
*/
bool IsForPrinting() const {
return mMode == nsDisplayListBuilderMode::PaintForPrinting;
}
/**
* @return true if the display list is being built for determining frame
* visibility.
*/
bool IsForFrameVisibility() const {
return mMode == nsDisplayListBuilderMode::FrameVisibility;
}
/**
* @return true if the display list is being built for creating the glyph
* mask from text items.
*/
bool IsForGenerateGlyphMask() const {
return mMode == nsDisplayListBuilderMode::GenerateGlyph;
}
bool IsForContent() const { return mIsForContent; }
bool BuildCompositorHitTestInfo() const {
return mBuildCompositorHitTestInfo;
}
/**
* @return true if "painting is suppressed" during page load and we
* should paint only the background of the document.
*/
bool IsBackgroundOnly() {
NS_ASSERTION(mPresShellStates.Length() > 0,
"don't call this if we're not in a presshell");
return CurrentPresShellState()->mIsBackgroundOnly;
}
/**
* @return the root of given frame's (sub)tree, whose origin
* establishes the coordinate system for the child display items.
*/
const nsIFrame* FindReferenceFrameFor(const nsIFrame* aFrame,
nsPoint* aOffset = nullptr) const;
const Maybe<nsPoint>& AdditionalOffset() const { return mAdditionalOffset; }
/**
* @return the root of the display list's frame (sub)tree, whose origin
* establishes the coordinate system for the display list
*/
nsIFrame* RootReferenceFrame() const { return mReferenceFrame; }
/**
* @return a point pt such that adding pt to a coordinate relative to aFrame
* makes it relative to ReferenceFrame(), i.e., returns
* aFrame->GetOffsetToCrossDoc(ReferenceFrame()). The returned point is in
* the appunits of aFrame.
*/
const nsPoint ToReferenceFrame(const nsIFrame* aFrame) const {
nsPoint result;
FindReferenceFrameFor(aFrame, &result);
return result;
}
/**
* When building the display list, the scrollframe aFrame will be "ignored"
* for the purposes of clipping, and its scrollbars will be hidden. We use
* this to allow RenderOffscreen to render a whole document without beign
* clipped by the viewport or drawing the viewport scrollbars.
*/
void SetIgnoreScrollFrame(nsIFrame* aFrame) { mIgnoreScrollFrame = aFrame; }
/**
* Get the scrollframe to ignore, if any.
*/
nsIFrame* GetIgnoreScrollFrame() { return mIgnoreScrollFrame; }
void SetIsRelativeToLayoutViewport();
bool IsRelativeToLayoutViewport() const {
return mIsRelativeToLayoutViewport;
}
/**
* Get the ViewID of the nearest scrolling ancestor frame.
*/
ViewID GetCurrentScrollParentId() const { return mCurrentScrollParentId; }
/**
* Get and set the flag that indicates if scroll parents should have layers
* forcibly created. This flag is set when a deeply nested scrollframe has
* a displayport, and for scroll handoff to work properly the ancestor
* scrollframes should also get their own scrollable layers.
*/
void ForceLayerForScrollParent() { mForceLayerForScrollParent = true; }
/**
* Set the flag that indicates there is a non-minimal display port in the
* current subtree. This is used to determine display port expiry.
*/
void SetContainsNonMinimalDisplayPort() {
mContainsNonMinimalDisplayPort = true;
}
/**
* Get the ViewID and the scrollbar flags corresponding to the scrollbar for
* which we are building display items at the moment.
*/
ViewID GetCurrentScrollbarTarget() const { return mCurrentScrollbarTarget; }
Maybe<layers::ScrollDirection> GetCurrentScrollbarDirection() const {
return mCurrentScrollbarDirection;
}
/**
* Returns true if building a scrollbar, and the scrollbar will not be
* layerized.
*/
bool IsBuildingNonLayerizedScrollbar() const {
return mIsBuildingScrollbar && !mCurrentScrollbarWillHaveLayer;
}
/**
* Calling this setter makes us include all out-of-flow descendant
* frames in the display list, wherever they may be positioned (even
* outside the dirty rects).
*/
void SetIncludeAllOutOfFlows() { mIncludeAllOutOfFlows = true; }
bool GetIncludeAllOutOfFlows() const { return mIncludeAllOutOfFlows; }
/**
* Calling this setter makes us exclude all leaf frames that aren't
* selected.
*/
void SetSelectedFramesOnly() { mSelectedFramesOnly = true; }
bool GetSelectedFramesOnly() { return mSelectedFramesOnly; }
/**
* @return Returns true if we should include the caret in any display lists
* that we make.
*/
bool IsBuildingCaret() const { return mBuildCaret; }
bool IsRetainingDisplayList() const { return mRetainingDisplayList; }
bool IsPartialUpdate() const { return mPartialUpdate; }
void SetPartialUpdate(bool aPartial) { mPartialUpdate = aPartial; }
bool IsBuilding() const { return mIsBuilding; }
void SetIsBuilding(bool aIsBuilding) { mIsBuilding = aIsBuilding; }
bool InInvalidSubtree() const { return mInInvalidSubtree; }
/**
* Allows callers to selectively override the regular paint suppression
* checks, so that methods like GetFrameForPoint work when painting is
* suppressed.
*/
void IgnorePaintSuppression() { mIgnoreSuppression = true; }
/**
* @return Returns if this builder will ignore paint suppression.
*/
bool IsIgnoringPaintSuppression() { return mIgnoreSuppression; }
/**
* Call this if we're doing normal painting to the window.
*/
void SetPaintingToWindow(bool aToWindow) { mIsPaintingToWindow = aToWindow; }
bool IsPaintingToWindow() const { return mIsPaintingToWindow; }
/**
* Call this if we're using high quality scaling for image decoding.
* It is also implied by IsPaintingToWindow.
*/
void SetUseHighQualityScaling(bool aUseHighQualityScaling) {
mUseHighQualityScaling = aUseHighQualityScaling;
}
bool UseHighQualityScaling() const {
return mIsPaintingToWindow || mUseHighQualityScaling;
}
/**
* Call this if we're doing painting for WebRender
*/
void SetPaintingForWebRender(bool aForWebRender) {
mIsPaintingForWebRender = true;
}
bool IsPaintingForWebRender() const { return mIsPaintingForWebRender; }
/**
* Call this to prevent descending into subdocuments.
*/
void SetDescendIntoSubdocuments(bool aDescend) {
mDescendIntoSubdocuments = aDescend;
}
bool GetDescendIntoSubdocuments() { return mDescendIntoSubdocuments; }
/**
* Get dirty rect relative to current frame (the frame that we're calling
* BuildDisplayList on right now).
*/
const nsRect& GetVisibleRect() { return mVisibleRect; }
const nsRect& GetDirtyRect() { return mDirtyRect; }
void SetVisibleRect(const nsRect& aVisibleRect) {
mVisibleRect = aVisibleRect;
}
void IntersectVisibleRect(const nsRect& aVisibleRect) {
mVisibleRect.IntersectRect(mVisibleRect, aVisibleRect);
}
void SetDirtyRect(const nsRect& aDirtyRect) { mDirtyRect = aDirtyRect; }
void IntersectDirtyRect(const nsRect& aDirtyRect) {
mDirtyRect.IntersectRect(mDirtyRect, aDirtyRect);
}
const nsIFrame* GetCurrentFrame() { return mCurrentFrame; }
const nsIFrame* GetCurrentReferenceFrame() { return mCurrentReferenceFrame; }
const nsPoint& GetCurrentFrameOffsetToReferenceFrame() const {
return mCurrentOffsetToReferenceFrame;
}
void Check() { mPool.Check(); }
/**
* Returns true if merging and flattening of display lists should be
* performed while computing visibility.
*/
bool AllowMergingAndFlattening() { return mAllowMergingAndFlattening; }
void SetAllowMergingAndFlattening(bool aAllow) {
mAllowMergingAndFlattening = aAllow;
}
void SetCompositorHitTestInfo(const gfx::CompositorHitTestInfo& aInfo) {
mCompositorHitTestInfo = aInfo;
}
const gfx::CompositorHitTestInfo& GetCompositorHitTestInfo() const {
return mCompositorHitTestInfo;
}
/**
* Builds a new nsDisplayCompositorHitTestInfo for the frame |aFrame| if
* needed, and adds it to the top of |aList|.
*/
void BuildCompositorHitTestInfoIfNeeded(nsIFrame* aFrame,
nsDisplayList* aList);
bool IsInsidePointerEventsNoneDoc() {
return CurrentPresShellState()->mInsidePointerEventsNoneDoc;
}
bool IsTouchEventPrefEnabledDoc() {
return CurrentPresShellState()->mTouchEventPrefEnabledDoc;
}
bool GetAncestorHasApzAwareEventHandler() const {
return mAncestorHasApzAwareEventHandler;
}
void SetAncestorHasApzAwareEventHandler(bool aValue) {
mAncestorHasApzAwareEventHandler = aValue;
}
bool HaveScrollableDisplayPort() const { return mHaveScrollableDisplayPort; }
void SetHaveScrollableDisplayPort() { mHaveScrollableDisplayPort = true; }
void ClearHaveScrollableDisplayPort() { mHaveScrollableDisplayPort = false; }
bool SetIsCompositingCheap(bool aCompositingCheap) {
bool temp = mIsCompositingCheap;
mIsCompositingCheap = aCompositingCheap;
return temp;
}
bool IsCompositingCheap() const { return mIsCompositingCheap; }
/**
* Display the caret if needed.
*/
bool DisplayCaret(nsIFrame* aFrame, nsDisplayList* aList) {
nsIFrame* frame = GetCaretFrame();
if (aFrame == frame && !IsBackgroundOnly()) {
frame->DisplayCaret(this, aList);
return true;
}
return false;
}
/**
* Get the frame that the caret is supposed to draw in.
* If the caret is currently invisible, this will be null.
*/
nsIFrame* GetCaretFrame() { return mCaretFrame; }
/**
* Get the rectangle we're supposed to draw the caret into.
*/
const nsRect& GetCaretRect() { return mCaretRect; }
/**
* Get the caret associated with the current presshell.
*/
nsCaret* GetCaret();
/**
* Returns the root scroll frame for the current PresShell, if the PresShell
* is ignoring viewport scrolling.
*/
nsIFrame* GetPresShellIgnoreScrollFrame() {
return CurrentPresShellState()->mPresShellIgnoreScrollFrame;
}
/**
* Notify the display list builder that we're entering a presshell.
* aReferenceFrame should be a frame in the new presshell.
* aPointerEventsNoneDoc should be set to true if the frame generating this
* document is pointer-events:none.
*/
void EnterPresShell(const nsIFrame* aReferenceFrame,
bool aPointerEventsNoneDoc = false);
/**
* For print-preview documents, we sometimes need to build display items for
* the same frames multiple times in the same presentation, with different
* clipping. Between each such batch of items, call
* ResetMarkedFramesForDisplayList to make sure that the results of
* MarkFramesForDisplayList do not carry over between batches.
*/
void ResetMarkedFramesForDisplayList(const nsIFrame* aReferenceFrame);
/**
* Notify the display list builder that we're leaving a presshell.
*/
void LeavePresShell(const nsIFrame* aReferenceFrame,
nsDisplayList* aPaintedContents);
void IncrementPresShellPaintCount(PresShell* aPresShell);
/**
* Returns true if we're currently building a display list that's
* directly or indirectly under an nsDisplayTransform.
*/
bool IsInTransform() const { return mInTransform; }
bool InEventsOnly() const { return mInEventsOnly; }
/**
* Indicate whether or not we're directly or indirectly under and
* nsDisplayTransform or SVG foreignObject.
*/
void SetInTransform(bool aInTransform) { mInTransform = aInTransform; }
/**
* Returns true if we're currently building a display list that's
* under an nsDisplayFilters.
*/
bool IsInFilter() const { return mInFilter; }
/**
* Return true if we're currently building a display list for a
* nested presshell.
*/
bool IsInSubdocument() const { return mPresShellStates.Length() > 1; }
void SetDisablePartialUpdates(bool aDisable) {
mDisablePartialUpdates = aDisable;
}
bool DisablePartialUpdates() const { return mDisablePartialUpdates; }
void SetPartialBuildFailed(bool aFailed) { mPartialBuildFailed = aFailed; }
bool PartialBuildFailed() const { return mPartialBuildFailed; }
bool IsInActiveDocShell() const { return mIsInActiveDocShell; }
void SetInActiveDocShell(bool aActive) { mIsInActiveDocShell = aActive; }
/**
* Return true if we're currently building a display list for the presshell
* of a chrome document, or if we're building the display list for a popup.
*/
bool IsInChromeDocumentOrPopup() const {
return mIsInChromePresContext || mIsBuildingForPopup;
}
/**
* @return true if images have been set to decode synchronously.
*/
bool ShouldSyncDecodeImages() const { return mSyncDecodeImages; }
/**
* Indicates whether we should synchronously decode images. If true, we decode
* and draw whatever image data has been loaded. If false, we just draw
* whatever has already been decoded.
*/
void SetSyncDecodeImages(bool aSyncDecodeImages) {
mSyncDecodeImages = aSyncDecodeImages;
}
nsDisplayTableBackgroundSet* SetTableBackgroundSet(
nsDisplayTableBackgroundSet* aTableSet) {
nsDisplayTableBackgroundSet* old = mTableBackgroundSet;
mTableBackgroundSet = aTableSet;
return old;
}
nsDisplayTableBackgroundSet* GetTableBackgroundSet() const {
return mTableBackgroundSet;
}
void FreeClipChains();
/*
* Frees the temporary display items created during merging.
*/
void FreeTemporaryItems();
/**
* Helper method to generate background painting flags based on the
* information available in the display list builder.
*/
uint32_t GetBackgroundPaintFlags();
/**
* Helper method to generate nsImageRenderer flags based on the information
* available in the display list builder.
*/
uint32_t GetImageRendererFlags() const;
/**
* Helper method to generate image decoding flags based on the
* information available in the display list builder.
*/
uint32_t GetImageDecodeFlags() const;
/**
* Subtracts aRegion from *aVisibleRegion. We avoid letting
* aVisibleRegion become overcomplex by simplifying it if necessary.
*/
void SubtractFromVisibleRegion(nsRegion* aVisibleRegion,
const nsRegion& aRegion);
/**
* Mark the frames in aFrames to be displayed if they intersect aDirtyRect
* (which is relative to aDirtyFrame). If the frames have placeholders
* that might not be displayed, we mark the placeholders and their ancestors
* to ensure that display list construction descends into them
* anyway. nsDisplayListBuilder will take care of unmarking them when it is
* destroyed.
*/
void MarkFramesForDisplayList(nsIFrame* aDirtyFrame,
const nsFrameList& aFrames);
void MarkFrameForDisplay(nsIFrame* aFrame, const nsIFrame* aStopAtFrame);
void MarkFrameForDisplayIfVisible(nsIFrame* aFrame,
const nsIFrame* aStopAtFrame);
void AddFrameMarkedForDisplayIfVisible(nsIFrame* aFrame);
void ClearFixedBackgroundDisplayData();
/**
* Mark all child frames that Preserve3D() as needing display.
* Because these frames include transforms set on their parent, dirty rects
* for intermediate frames may be empty, yet child frames could still be
* visible.
*/
void MarkPreserve3DFramesForDisplayList(nsIFrame* aDirtyFrame);
/**
* Returns true if we need to descend into this frame when building
* the display list, even though it doesn't intersect the dirty
* rect, because it may have out-of-flows that do so.
*/
bool ShouldDescendIntoFrame(nsIFrame* aFrame, bool aVisible) const {
return aFrame->HasAnyStateBits(NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO) ||
(aVisible && aFrame->ForceDescendIntoIfVisible()) ||
GetIncludeAllOutOfFlows();
}
/**
* Returns the list of registered theme geometries.
*/
nsTArray<nsIWidget::ThemeGeometry> GetThemeGeometries() const {
nsTArray<nsIWidget::ThemeGeometry> geometries;
for (const auto& data : mThemeGeometries.Values()) {
geometries.AppendElements(*data);
}
return geometries;
}
/**
* Notifies the builder that a particular themed widget exists
* at the given rectangle within the currently built display list.
* For certain appearance values (currently only StyleAppearance::Toolbar and
* StyleAppearance::WindowTitlebar) this gets called during every display list
* construction, for every themed widget of the right type within the
* display list, except for themed widgets which are transformed or have
* effects applied to them (e.g. CSS opacity or filters).
*
* @param aWidgetType the -moz-appearance value for the themed widget
* @param aItem the item associated with the theme geometry
* @param aRect the device-pixel rect relative to the widget's displayRoot
* for the themed widget
*/
void RegisterThemeGeometry(uint8_t aWidgetType, nsDisplayItem* aItem,
const LayoutDeviceIntRect& aRect) {
if (!mIsPaintingToWindow) {
return;
}
nsTArray<nsIWidget::ThemeGeometry>* geometries =
mThemeGeometries.GetOrInsertNew(aItem);
geometries->AppendElement(nsIWidget::ThemeGeometry(aWidgetType, aRect));
}
/**
* Removes theme geometries associated with the given display item |aItem|.
*/
void UnregisterThemeGeometry(nsDisplayItem* aItem) {
mThemeGeometries.Remove(aItem);
}
/**
* Adjusts mWindowDraggingRegion to take into account aFrame. If aFrame's
* -moz-window-dragging value is |drag|, its border box is added to the
* collected dragging region; if the value is |no-drag|, the border box is
* subtracted from the region; if the value is |default|, that frame does
* not influence the window dragging region.
*/
void AdjustWindowDraggingRegion(nsIFrame* aFrame);
LayoutDeviceIntRegion GetWindowDraggingRegion() const;
void RemoveModifiedWindowRegions();
void ClearRetainedWindowRegions();
const nsTHashMap<nsPtrHashKey<dom::RemoteBrowser>, dom::EffectsInfo>&
GetEffectUpdates() const {
return mEffectsUpdates;
}
void AddEffectUpdate(dom::RemoteBrowser* aBrowser,
const dom::EffectsInfo& aUpdate);
/**
* Allocate memory in our arena. It will only be freed when this display list
* builder is destroyed. This memory holds nsDisplayItems and
* DisplayItemClipChain objects.
*
* Destructors are called as soon as the item is no longer used.
*/
void* Allocate(size_t aSize, DisplayListArenaObjectId aId) {
return mPool.Allocate(aId, aSize);
}
void* Allocate(size_t aSize, DisplayItemType aType) {
static_assert(size_t(DisplayItemType::TYPE_ZERO) ==
size_t(DisplayListArenaObjectId::CLIPCHAIN),
"");
#define DECLARE_DISPLAY_ITEM_TYPE(name_, ...) \
static_assert(size_t(DisplayItemType::TYPE_##name_) == \
size_t(DisplayListArenaObjectId::name_), \
"");
#include "nsDisplayItemTypesList.h"
#undef DECLARE_DISPLAY_ITEM_TYPE
return Allocate(aSize, DisplayListArenaObjectId(size_t(aType)));
}
void Destroy(DisplayListArenaObjectId aId, void* aPtr) {
return mPool.Free(aId, aPtr);
}
void Destroy(DisplayItemType aType, void* aPtr) {
return Destroy(DisplayListArenaObjectId(size_t(aType)), aPtr);
}
/**
* Allocate a new ActiveScrolledRoot in the arena. Will be cleaned up
* automatically when the arena goes away.
*/
ActiveScrolledRoot* AllocateActiveScrolledRoot(
const ActiveScrolledRoot* aParent, nsIScrollableFrame* aScrollableFrame);
/**
* Allocate a new DisplayItemClipChain object in the arena. Will be cleaned
* up automatically when the arena goes away.
*/
const DisplayItemClipChain* AllocateDisplayItemClipChain(
const DisplayItemClip& aClip, const ActiveScrolledRoot* aASR,
const DisplayItemClipChain* aParent);
/**
* Intersect two clip chains, allocating the new clip chain items in this
* builder's arena. The result is parented to aAncestor, and no intersections
* happen past aAncestor's ASR.
* That means aAncestor has to be living in this builder's arena already.
* aLeafClip1 and aLeafClip2 only need to outlive the call to this function,
* their values are copied into the newly-allocated intersected clip chain
* and this function does not hold on to any pointers to them.
*/
const DisplayItemClipChain* CreateClipChainIntersection(
const DisplayItemClipChain* aAncestor,
const DisplayItemClipChain* aLeafClip1,
const DisplayItemClipChain* aLeafClip2);
/**
* Same as above, except aAncestor is computed as the nearest common
* ancestor of the two provided clips.
*/
const DisplayItemClipChain* CreateClipChainIntersection(
const DisplayItemClipChain* aLeafClip1,
const DisplayItemClipChain* aLeafClip2);
/**
* Clone the supplied clip chain's chain items into this builder's arena.
*/
const DisplayItemClipChain* CopyWholeChain(
const DisplayItemClipChain* aClipChain);
const ActiveScrolledRoot* GetFilterASR() const { return mFilterASR; }
/**
* Merges the display items in |aMergedItems| and returns a new temporary
* display item.
* The display items in |aMergedItems| have to be mergeable with each other.
*/
nsDisplayWrapList* MergeItems(nsTArray<nsDisplayWrapList*>& aItems);
/**
* A helper class used to temporarily set nsDisplayListBuilder properties for
* building display items.
* aVisibleRect and aDirtyRect are relative to aForChild.
*/
class AutoBuildingDisplayList {
public:
AutoBuildingDisplayList(nsDisplayListBuilder* aBuilder, nsIFrame* aForChild,
const nsRect& aVisibleRect,
const nsRect& aDirtyRect)
: AutoBuildingDisplayList(aBuilder, aForChild, aVisibleRect, aDirtyRect,
aForChild->IsTransformed()) {}
AutoBuildingDisplayList(nsDisplayListBuilder* aBuilder, nsIFrame* aForChild,
const nsRect& aVisibleRect,
const nsRect& aDirtyRect,
const bool aIsTransformed);
void SetReferenceFrameAndCurrentOffset(const nsIFrame* aFrame,
const nsPoint& aOffset) {
mBuilder->mCurrentReferenceFrame = aFrame;
mBuilder->mCurrentOffsetToReferenceFrame = aOffset;
}
void SetAdditionalOffset(const nsPoint& aOffset) {
MOZ_ASSERT(!mBuilder->mAdditionalOffset);
mBuilder->mAdditionalOffset = Some(aOffset);
mBuilder->mCurrentOffsetToReferenceFrame += aOffset;
}
void RestoreBuildingInvisibleItemsValue() {
mBuilder->mBuildingInvisibleItems = mPrevBuildingInvisibleItems;
}
~AutoBuildingDisplayList() {
mBuilder->mCurrentFrame = mPrevFrame;
mBuilder->mCurrentReferenceFrame = mPrevReferenceFrame;
mBuilder->mCurrentOffsetToReferenceFrame = mPrevOffset;
mBuilder->mVisibleRect = mPrevVisibleRect;
mBuilder->mDirtyRect = mPrevDirtyRect;
mBuilder->mAncestorHasApzAwareEventHandler =
mPrevAncestorHasApzAwareEventHandler;
mBuilder->mBuildingInvisibleItems = mPrevBuildingInvisibleItems;
mBuilder->mInInvalidSubtree = mPrevInInvalidSubtree;
mBuilder->mAdditionalOffset = mPrevAdditionalOffset;
mBuilder->mCompositorHitTestInfo = mPrevCompositorHitTestInfo;
}
private:
nsDisplayListBuilder* mBuilder;
const nsIFrame* mPrevFrame;
const nsIFrame* mPrevReferenceFrame;
nsPoint mPrevOffset;
Maybe<nsPoint> mPrevAdditionalOffset;
nsRect mPrevVisibleRect;
nsRect mPrevDirtyRect;
gfx::CompositorHitTestInfo mPrevCompositorHitTestInfo;
bool mPrevAncestorHasApzAwareEventHandler;
bool mPrevBuildingInvisibleItems;
bool mPrevInInvalidSubtree;
};
/**
* A helper class to temporarily set the value of mInTransform.
*/
class AutoInTransformSetter {
public:
AutoInTransformSetter(nsDisplayListBuilder* aBuilder, bool aInTransform)
: mBuilder(aBuilder), mOldValue(aBuilder->mInTransform) {
aBuilder->mInTransform = aInTransform;
}
~AutoInTransformSetter() { mBuilder->mInTransform = mOldValue; }
private:
nsDisplayListBuilder* mBuilder;
bool mOldValue;
};
class AutoInEventsOnly {
public:
AutoInEventsOnly(nsDisplayListBuilder* aBuilder, bool aInEventsOnly)
: mBuilder(aBuilder), mOldValue(aBuilder->mInEventsOnly) {
aBuilder->mInEventsOnly |= aInEventsOnly;
}
~AutoInEventsOnly() { mBuilder->mInEventsOnly = mOldValue; }
private:
nsDisplayListBuilder* mBuilder;
bool mOldValue;
};
/**
* A helper class to temporarily set the value of mFilterASR and
* mInFilter.
*/
class AutoEnterFilter {
public:
AutoEnterFilter(nsDisplayListBuilder* aBuilder, bool aUsingFilter)
: mBuilder(aBuilder),
mOldValue(aBuilder->mFilterASR),
mOldInFilter(aBuilder->mInFilter) {
if (!aBuilder->mFilterASR && aUsingFilter) {
aBuilder->mFilterASR = aBuilder->CurrentActiveScrolledRoot();
aBuilder->mInFilter = true;
}
}
~AutoEnterFilter() {
mBuilder->mFilterASR = mOldValue;
mBuilder->mInFilter = mOldInFilter;
}
private:
nsDisplayListBuilder* mBuilder;
const ActiveScrolledRoot* mOldValue;
bool mOldInFilter;
};
/**
* A helper class to temporarily set the value of mCurrentScrollParentId.
*/
class AutoCurrentScrollParentIdSetter {
public:
AutoCurrentScrollParentIdSetter(nsDisplayListBuilder* aBuilder,
ViewID aScrollId)
: mBuilder(aBuilder),
mOldValue(aBuilder->mCurrentScrollParentId),
mOldForceLayer(aBuilder->mForceLayerForScrollParent),
mOldContainsNonMinimalDisplayPort(
mBuilder->mContainsNonMinimalDisplayPort) {
// If this AutoCurrentScrollParentIdSetter has the same scrollId as the
// previous one on the stack, then that means the scrollframe that
// created this isn't actually scrollable and cannot participate in
// scroll handoff. We set mCanBeScrollParent to false to indicate this.
mCanBeScrollParent = (mOldValue != aScrollId);
aBuilder->mCurrentScrollParentId = aScrollId;
aBuilder->mForceLayerForScrollParent = false;
aBuilder->mContainsNonMinimalDisplayPort = false;
}
bool ShouldForceLayerForScrollParent() const {
// Only scrollframes participating in scroll handoff can be forced to
// layerize
return mCanBeScrollParent && mBuilder->mForceLayerForScrollParent;
}
bool GetContainsNonMinimalDisplayPort() const {
// Only for scrollframes participating in scroll handoff can we return
// true.
return mCanBeScrollParent && mBuilder->mContainsNonMinimalDisplayPort;
}
~AutoCurrentScrollParentIdSetter() {
mBuilder->mCurrentScrollParentId = mOldValue;
if (mCanBeScrollParent) {
// If this flag is set, caller code is responsible for having dealt
// with the current value of mBuilder->mForceLayerForScrollParent, so
// we can just restore the old value.
mBuilder->mForceLayerForScrollParent = mOldForceLayer;
} else {
// Otherwise we need to keep propagating the force-layerization flag
// upwards to the next ancestor scrollframe that does participate in
// scroll handoff.
mBuilder->mForceLayerForScrollParent |= mOldForceLayer;
}
mBuilder->mContainsNonMinimalDisplayPort |=
mOldContainsNonMinimalDisplayPort;
}
private:
nsDisplayListBuilder* mBuilder;
ViewID mOldValue;
bool mOldForceLayer;
bool mOldContainsNonMinimalDisplayPort;
bool mCanBeScrollParent;
};
/**
* Used to update the current active scrolled root on the display list
* builder, and to create new active scrolled roots.
*/
class AutoCurrentActiveScrolledRootSetter {
public:
explicit AutoCurrentActiveScrolledRootSetter(nsDisplayListBuilder* aBuilder)
: mBuilder(aBuilder),
mSavedActiveScrolledRoot(aBuilder->mCurrentActiveScrolledRoot),
mContentClipASR(aBuilder->ClipState().GetContentClipASR()),
mDescendantsStartIndex(aBuilder->mActiveScrolledRoots.Length()),
mUsed(false) {}
~AutoCurrentActiveScrolledRootSetter() {
mBuilder->mCurrentActiveScrolledRoot = mSavedActiveScrolledRoot;
}
void SetCurrentActiveScrolledRoot(
const ActiveScrolledRoot* aActiveScrolledRoot);
void EnterScrollFrame(nsIScrollableFrame* aScrollableFrame) {
MOZ_ASSERT(!mUsed);
ActiveScrolledRoot* asr = mBuilder->AllocateActiveScrolledRoot(
mBuilder->mCurrentActiveScrolledRoot, aScrollableFrame);
mBuilder->mCurrentActiveScrolledRoot = asr;
mUsed = true;
}
void InsertScrollFrame(nsIScrollableFrame* aScrollableFrame);
private:
nsDisplayListBuilder* mBuilder;
/**
* The builder's mCurrentActiveScrolledRoot at construction time which
* needs to be restored at destruction time.
*/
const ActiveScrolledRoot* mSavedActiveScrolledRoot;
/**
* If there's a content clip on the builder at construction time, then
* mContentClipASR is that content clip's ASR, otherwise null. The
* assumption is that the content clip doesn't get relaxed while this
* object is on the stack.
*/
const ActiveScrolledRoot* mContentClipASR;
/**
* InsertScrollFrame needs to mutate existing ASRs (those that were
* created while this object was on the stack), and mDescendantsStartIndex
* makes it easier to skip ASRs that were created in the past.
*/
size_t mDescendantsStartIndex;
/**
* Flag to make sure that only one of SetCurrentActiveScrolledRoot /
* EnterScrollFrame / InsertScrollFrame is called per instance of this
* class.
*/
bool mUsed;
};
/**
* Keeps track of the innermost ASR that can be used as the ASR for a
* container item that wraps all items that were created while this
* object was on the stack.
* The rule is: all child items of the container item need to have
* clipped bounds with respect to the container ASR.
*/
class AutoContainerASRTracker {
public:
explicit AutoContainerASRTracker(nsDisplayListBuilder* aBuilder);
const ActiveScrolledRoot* GetContainerASR() {
return mBuilder->mCurrentContainerASR;
}
~AutoContainerASRTracker() {
mBuilder->mCurrentContainerASR = ActiveScrolledRoot::PickAncestor(
mBuilder->mCurrentContainerASR, mSavedContainerASR);
}
private:
nsDisplayListBuilder* mBuilder;
const ActiveScrolledRoot* mSavedContainerASR;
};
/**
* A helper class to temporarily set the value of mCurrentScrollbarTarget
* and mCurrentScrollbarFlags.
*/
class AutoCurrentScrollbarInfoSetter {
public:
AutoCurrentScrollbarInfoSetter(
nsDisplayListBuilder* aBuilder, ViewID aScrollTargetID,
const Maybe<layers::ScrollDirection>& aScrollbarDirection,
bool aWillHaveLayer)
: mBuilder(aBuilder) {
aBuilder->mIsBuildingScrollbar = true;
aBuilder->mCurrentScrollbarTarget = aScrollTargetID;
aBuilder->mCurrentScrollbarDirection = aScrollbarDirection;
aBuilder->mCurrentScrollbarWillHaveLayer = aWillHaveLayer;
}
~AutoCurrentScrollbarInfoSetter() {
// No need to restore old values because scrollbars cannot be nested.
mBuilder->mIsBuildingScrollbar = false;
mBuilder->mCurrentScrollbarTarget =
layers::ScrollableLayerGuid::NULL_SCROLL_ID;
mBuilder->mCurrentScrollbarDirection.reset();
mBuilder->mCurrentScrollbarWillHaveLayer = false;
}
private:
nsDisplayListBuilder* mBuilder;
};
/**
* A helper class to temporarily set mBuildingExtraPagesForPageNum.
*/
class MOZ_RAII AutoPageNumberSetter {
public:
AutoPageNumberSetter(nsDisplayListBuilder* aBuilder, const uint8_t aPageNum)
: mBuilder(aBuilder),
mOldPageNum(aBuilder->GetBuildingExtraPagesForPageNum()) {
mBuilder->SetBuildingExtraPagesForPageNum(aPageNum);
}
~AutoPageNumberSetter() {
mBuilder->SetBuildingExtraPagesForPageNum(mOldPageNum);
}
private:
nsDisplayListBuilder* mBuilder;
uint8_t mOldPageNum;
};
/**
* A helper class to track current effective transform for items.
*
* For frames that is Combines3DTransformWithAncestors(), we need to
* apply all transforms of ancestors on the same preserves3D chain
* on the bounds of current frame to the coordination of the 3D
* context root. The 3D context root computes it's bounds from
* these transformed bounds.
*/
class AutoAccumulateTransform {
public:
explicit AutoAccumulateTransform(nsDisplayListBuilder* aBuilder)
: mBuilder(aBuilder),
mSavedTransform(aBuilder->mPreserves3DCtx.mAccumulatedTransform) {}
~AutoAccumulateTransform() {
mBuilder->mPreserves3DCtx.mAccumulatedTransform = mSavedTransform;
}
void Accumulate(const gfx::Matrix4x4& aTransform) {
mBuilder->mPreserves3DCtx.mAccumulatedTransform =
aTransform * mBuilder->mPreserves3DCtx.mAccumulatedTransform;
}
const gfx::Matrix4x4& GetCurrentTransform() {
return mBuilder->mPreserves3DCtx.mAccumulatedTransform;
}
void StartRoot() {
mBuilder->mPreserves3DCtx.mAccumulatedTransform = gfx::Matrix4x4();
}
private:
nsDisplayListBuilder* mBuilder;
gfx::Matrix4x4 mSavedTransform;
};
/**
* A helper class to collect bounds rects of descendants.
*
* For a 3D context root, it's bounds is computed from the bounds of
* descendants. If we transform bounds frame by frame applying
* transforms, the bounds may turn to empty for any singular
* transform on the path, but it is not empty for the accumulated
* transform.
*/
class AutoAccumulateRect {
public:
explicit AutoAccumulateRect(nsDisplayListBuilder* aBuilder)
: mBuilder(aBuilder),
mSavedRect(aBuilder->mPreserves3DCtx.mAccumulatedRect) {
aBuilder->mPreserves3DCtx.mAccumulatedRect = nsRect();
aBuilder->mPreserves3DCtx.mAccumulatedRectLevels++;
}
~AutoAccumulateRect() {
mBuilder->mPreserves3DCtx.mAccumulatedRect = mSavedRect;
mBuilder->mPreserves3DCtx.mAccumulatedRectLevels--;
}
private:
nsDisplayListBuilder* mBuilder;
nsRect mSavedRect;
};
void AccumulateRect(const nsRect& aRect) {
mPreserves3DCtx.mAccumulatedRect.UnionRect(mPreserves3DCtx.mAccumulatedRect,
aRect);
}
const nsRect& GetAccumulatedRect() {
return mPreserves3DCtx.mAccumulatedRect;
}
/**
* The level is increased by one for items establishing 3D rendering
* context and starting a new accumulation.
*/
int GetAccumulatedRectLevels() {
return mPreserves3DCtx.mAccumulatedRectLevels;
}
struct OutOfFlowDisplayData {
OutOfFlowDisplayData(
const DisplayItemClipChain* aContainingBlockClipChain,
const DisplayItemClipChain* aCombinedClipChain,
const ActiveScrolledRoot* aContainingBlockActiveScrolledRoot,
const nsRect& aVisibleRect, const nsRect& aDirtyRect)
: mContainingBlockClipChain(aContainingBlockClipChain),
mCombinedClipChain(aCombinedClipChain),
mContainingBlockActiveScrolledRoot(
aContainingBlockActiveScrolledRoot),
mVisibleRect(aVisibleRect),
mDirtyRect(aDirtyRect) {}
const DisplayItemClipChain* mContainingBlockClipChain;
const DisplayItemClipChain*
mCombinedClipChain; // only necessary for the special case of top layer
const ActiveScrolledRoot* mContainingBlockActiveScrolledRoot;
// If this OutOfFlowDisplayData is associated with the ViewportFrame
// of a document that has a resolution (creating separate visual and
// layout viewports with their own coordinate spaces), these rects
// are in layout coordinates. Similarly, GetVisibleRectForFrame() in
// such a case returns a quantity in layout coordinates.
nsRect mVisibleRect;
nsRect mDirtyRect;
static nsRect ComputeVisibleRectForFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame,
const nsRect& aVisibleRect,
const nsRect& aDirtyRect,
nsRect* aOutDirtyRect);
nsRect GetVisibleRectForFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, nsRect* aDirtyRect) {
return ComputeVisibleRectForFrame(aBuilder, aFrame, mVisibleRect,
mDirtyRect, aDirtyRect);
}
};
NS_DECLARE_FRAME_PROPERTY_DELETABLE(OutOfFlowDisplayDataProperty,
OutOfFlowDisplayData)
struct DisplayListBuildingData {
nsIFrame* mModifiedAGR = nullptr;
nsRect mDirtyRect;
};
NS_DECLARE_FRAME_PROPERTY_DELETABLE(DisplayListBuildingRect,
DisplayListBuildingData)
NS_DECLARE_FRAME_PROPERTY_DELETABLE(DisplayListBuildingDisplayPortRect,
nsRect)
static OutOfFlowDisplayData* GetOutOfFlowData(nsIFrame* aFrame) {
if (!aFrame->GetParent()) {
return nullptr;
}
return aFrame->GetParent()->GetProperty(OutOfFlowDisplayDataProperty());
}
nsPresContext* CurrentPresContext();
OutOfFlowDisplayData* GetCurrentFixedBackgroundDisplayData() {
auto& displayData = CurrentPresShellState()->mFixedBackgroundDisplayData;
return displayData ? displayData.ptr() : nullptr;
}
/**
* Accumulates the bounds of box frames that have moz-appearance
* -moz-win-exclude-glass style. Used in setting glass margins on
* Windows.
*
* We set the window opaque region (from which glass margins are computed)
* to the intersection of the glass region specified here and the opaque
* region computed during painting. So the excluded glass region actually
* *limits* the extent of the opaque area reported to Windows. We limit it
* so that changes to the computed opaque region (which can vary based on
* region optimizations and the placement of UI elements) outside the
* -moz-win-exclude-glass area don't affect the glass margins reported to
* Windows; changing those margins willy-nilly can cause the Windows 7 glass
* haze effect to jump around disconcertingly.
*/
void AddWindowExcludeGlassRegion(nsIFrame* aFrame, const nsRect& aBounds) {
mWindowExcludeGlassRegion.Add(aFrame, aBounds);
}
/**
* Returns the window exclude glass region.
*/
nsRegion GetWindowExcludeGlassRegion() const {
return mWindowExcludeGlassRegion.ToRegion();
}
/**
* Accumulates opaque stuff into the window opaque region.
*/
void AddWindowOpaqueRegion(nsIFrame* aFrame, const nsRect& aBounds) {
if (IsRetainingDisplayList()) {
mRetainedWindowOpaqueRegion.Add(aFrame, aBounds);
return;
}
mWindowOpaqueRegion.Or(mWindowOpaqueRegion, aBounds);
}
/**
* Returns the window opaque region built so far. This may be incomplete
* since the opaque region is built during layer construction.
*/
const nsRegion GetWindowOpaqueRegion() {
return IsRetainingDisplayList() ? mRetainedWindowOpaqueRegion.ToRegion()
: mWindowOpaqueRegion;
}
void SetGlassDisplayItem(nsDisplayItem* aItem);
void ClearGlassDisplayItem() { mGlassDisplayItem = nullptr; }
nsDisplayItem* GetGlassDisplayItem() { return mGlassDisplayItem; }
bool NeedToForceTransparentSurfaceForItem(nsDisplayItem* aItem);
/**
* mContainsBlendMode is true if we processed a display item that
* has a blend mode attached. We do this so we can insert a
* nsDisplayBlendContainer in the parent stacking context.
*/
void SetContainsBlendMode(bool aContainsBlendMode) {
mContainsBlendMode = aContainsBlendMode;
}
bool ContainsBlendMode() const { return mContainsBlendMode; }
/**
* mContainsBackdropFilter is true if we proccessed a display item that
* has a backdrop filter set. We track this so we can insert a
* nsDisplayBackdropRootContainer in the stacking context of the nearest
* ancestor that forms a backdrop root.
*/
void SetContainsBackdropFilter(bool aContainsBackdropFilter) {
mContainsBackdropFilter = aContainsBackdropFilter;
}
bool ContainsBackdropFilter() const { return mContainsBackdropFilter; }
DisplayListClipState& ClipState() { return mClipState; }
const ActiveScrolledRoot* CurrentActiveScrolledRoot() {
return mCurrentActiveScrolledRoot;
}
const ActiveScrolledRoot* CurrentAncestorASRStackingContextContents() {
return mCurrentContainerASR;
}
/**
* Add the current frame to the will-change budget if possible and
* remeber the outcome. Subsequent calls to IsInWillChangeBudget
* will return the same value as return here.
*/
bool AddToWillChangeBudget(nsIFrame* aFrame, const nsSize& aSize);
/**
* This will add the current frame to the will-change budget the first
* time it is seen. On subsequent calls this will return the same
* answer. This effectively implements a first-come, first-served
* allocation of the will-change budget.
*/
bool IsInWillChangeBudget(nsIFrame* aFrame, const nsSize& aSize);
/**
* Clears the will-change budget status for the given |aFrame|.
* This will also remove the frame from will-change budgets.
*/
void ClearWillChangeBudgetStatus(nsIFrame* aFrame);
/**
* Removes the given |aFrame| from will-change budgets.
*/
void RemoveFromWillChangeBudgets(const nsIFrame* aFrame);
/**
* Clears the will-change budgets.
*/
void ClearWillChangeBudgets();
void EnterSVGEffectsContents(nsIFrame* aEffectsFrame,
nsDisplayList* aHoistedItemsStorage);
void ExitSVGEffectsContents();
bool ShouldBuildScrollInfoItemsForHoisting() const;
void AppendNewScrollInfoItemForHoisting(
nsDisplayScrollInfoLayer* aScrollInfoItem);
/**
* A helper class to install/restore nsDisplayListBuilder::mPreserves3DCtx.
*
* mPreserves3DCtx is used by class AutoAccumulateTransform &
* AutoAccumulateRect to passing data between frames in the 3D
* context. If a frame create a new 3D context, it should restore
* the value of mPreserves3DCtx before returning back to the parent.
* This class do it for the users.
*/
class AutoPreserves3DContext {
public:
explicit AutoPreserves3DContext(nsDisplayListBuilder* aBuilder)
: mBuilder(aBuilder), mSavedCtx(aBuilder->mPreserves3DCtx) {}
~AutoPreserves3DContext() { mBuilder->mPreserves3DCtx = mSavedCtx; }
private:
nsDisplayListBuilder* mBuilder;
Preserves3DContext mSavedCtx;
};
const nsRect GetPreserves3DRect() const {
return mPreserves3DCtx.mVisibleRect;
}
void SavePreserves3DRect() { mPreserves3DCtx.mVisibleRect = mVisibleRect; }
void SavePreserves3DAllowAsyncAnimation(bool aValue) {
mPreserves3DCtx.mAllowAsyncAnimation = aValue;
}
bool GetPreserves3DAllowAsyncAnimation() const {
return mPreserves3DCtx.mAllowAsyncAnimation;
}
bool IsBuildingInvisibleItems() const { return mBuildingInvisibleItems; }
void SetBuildingInvisibleItems(bool aBuildingInvisibleItems) {
mBuildingInvisibleItems = aBuildingInvisibleItems;
}
void SetBuildingExtraPagesForPageNum(uint8_t aPageNum) {
mBuildingExtraPagesForPageNum = aPageNum;
}
uint8_t GetBuildingExtraPagesForPageNum() const {
return mBuildingExtraPagesForPageNum;
}
bool HitTestIsForVisibility() const { return mVisibleThreshold.isSome(); }
float VisibilityThreshold() const {
MOZ_DIAGNOSTIC_ASSERT(HitTestIsForVisibility());
return mVisibleThreshold.valueOr(1.0f);
}
void SetHitTestIsForVisibility(float aVisibleThreshold) {
mVisibleThreshold = Some(aVisibleThreshold);
}
bool ShouldBuildAsyncZoomContainer() const {
return mBuildAsyncZoomContainer;
}
void UpdateShouldBuildAsyncZoomContainer();
void UpdateShouldBuildBackdropRootContainer();
bool ShouldRebuildDisplayListDueToPrefChange();
/**
* Represents a region composed of frame/rect pairs.
* WeakFrames are used to track whether a rect still belongs to the region.
* Modified frames and rects are removed and re-added to the region if needed.
*/
struct WeakFrameRegion {
/**
* A wrapper to store WeakFrame and the pointer to the underlying frame.
* This is needed because WeakFrame does not store the frame pointer after
* the frame has been deleted.
*/
struct WeakFrameWrapper {
explicit WeakFrameWrapper(nsIFrame* aFrame)
: mWeakFrame(new WeakFrame(aFrame)), mFrame(aFrame) {}
UniquePtr<WeakFrame> mWeakFrame;
void* mFrame;
};
nsTHashSet<void*> mFrameSet;
nsTArray<WeakFrameWrapper> mFrames;
nsTArray<pixman_box32_t> mRects;
template <typename RectType>
void Add(nsIFrame* aFrame, const RectType& aRect) {
if (mFrameSet.Contains(aFrame)) {
return;
}
mFrameSet.Insert(aFrame);
mFrames.AppendElement(WeakFrameWrapper(aFrame));
mRects.AppendElement(nsRegion::RectToBox(aRect));
}
void Clear() {
mFrameSet.Clear();
mFrames.Clear();
mRects.Clear();
}
void RemoveModifiedFramesAndRects();
size_t SizeOfExcludingThis(MallocSizeOf) const;
typedef gfx::ArrayView<pixman_box32_t> BoxArrayView;
nsRegion ToRegion() const { return nsRegion(BoxArrayView(mRects)); }
LayoutDeviceIntRegion ToLayoutDeviceIntRegion() const {
return LayoutDeviceIntRegion(BoxArrayView(mRects));
}
};
void AddScrollFrameToNotify(nsIScrollableFrame* aScrollFrame);
void NotifyAndClearScrollFrames();
// Helper class to find what link spec (if any) to associate with a frame,
// recording it in the builder, and generate the corresponding DisplayItem.
// This also takes care of generating a named destination for internal links
// if the element has an id or name attribute.
class Linkifier {
public:
Linkifier(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
~Linkifier() {
if (mBuilderToReset) {
mBuilderToReset->mLinkSpec.Truncate(0);
}
}
void MaybeAppendLink(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame);
private:
nsDisplayListBuilder* mBuilderToReset = nullptr;
nsDisplayList* mList;
};
/**
* Returns the nearest ancestor frame to aFrame that is considered to have
* (or will have) animated geometry. This can return aFrame.
*/
nsIFrame* FindAnimatedGeometryRootFrameFor(nsIFrame* aFrame);
/**
* Returns true if this is a retained builder and reuse stacking contexts
* mode is enabled by pref.
*/
bool IsReusingStackingContextItems() const {
return mIsReusingStackingContextItems;
}
/**
* Adds display item |aItem| to the reuseable display items set.
*/
void AddReusableDisplayItem(nsDisplayItem* aItem);
/**
* Removes display item |aItem| from the reuseable display items set.
* This is needed because display items are sometimes deleted during
* display list building.
* Called by |nsDisplayItem::Destroy()| when the item has been reused.
*/
void RemoveReusedDisplayItem(nsDisplayItem* aItem);
/**
* Clears the reuseable display items set.
*/
void ClearReuseableDisplayItems();
/**
* Marks the given display item |aItem| as reused, and updates the necessary
* display list builder state.
*/
void ReuseDisplayItem(nsDisplayItem* aItem);
private:
bool MarkOutOfFlowFrameForDisplay(nsIFrame* aDirtyFrame, nsIFrame* aFrame,
const nsRect& aVisibleRect,
const nsRect& aDirtyRect);
friend class nsDisplayBackgroundImage;
friend struct RetainedDisplayListBuilder;
/**
* Returns whether a frame acts as an animated geometry root, optionally
* returning the next ancestor to check.
*/
bool IsAnimatedGeometryRoot(nsIFrame* aFrame, nsIFrame** aParent = nullptr);
struct PresShellState {
PresShell* mPresShell;
#ifdef DEBUG
Maybe<nsAutoLayoutPhase> mAutoLayoutPhase;
#endif
Maybe<OutOfFlowDisplayData> mFixedBackgroundDisplayData;
uint32_t mFirstFrameMarkedForDisplay;
uint32_t mFirstFrameWithOOFData;
bool mIsBackgroundOnly;
// This is a per-document flag turning off event handling for all content
// in the document, and is set when we enter a subdocument for a pointer-
// events:none frame.
bool mInsidePointerEventsNoneDoc;
bool mTouchEventPrefEnabledDoc;
nsIFrame* mPresShellIgnoreScrollFrame;
};
PresShellState* CurrentPresShellState() {
NS_ASSERTION(mPresShellStates.Length() > 0,
"Someone forgot to enter a presshell");
return &mPresShellStates[mPresShellStates.Length() - 1];
}
void AddSizeOfExcludingThis(nsWindowSizes&) const;
struct FrameWillChangeBudget {
FrameWillChangeBudget() : mPresContext(nullptr), mUsage(0) {}
FrameWillChangeBudget(const nsPresContext* aPresContext, uint32_t aUsage)
: mPresContext(aPresContext), mUsage(aUsage) {}
const nsPresContext* mPresContext;
uint32_t mUsage;
};
nsIFrame* const mReferenceFrame;
nsIFrame* mIgnoreScrollFrame;
using Arena = nsPresArena<32768, DisplayListArenaObjectId,
size_t(DisplayListArenaObjectId::COUNT)>;
Arena mPool;
AutoTArray<PresShellState, 8> mPresShellStates;
AutoTArray<nsIFrame*, 400> mFramesMarkedForDisplay;
AutoTArray<nsIFrame*, 40> mFramesMarkedForDisplayIfVisible;
AutoTArray<nsIFrame*, 20> mFramesWithOOFData;
nsClassHashtable<nsPtrHashKey<nsDisplayItem>,
nsTArray<nsIWidget::ThemeGeometry>>
mThemeGeometries;
DisplayListClipState mClipState;
const ActiveScrolledRoot* mCurrentActiveScrolledRoot;
const ActiveScrolledRoot* mCurrentContainerASR;
// mCurrentFrame is the frame that we're currently calling (or about to call)
// BuildDisplayList on.
const nsIFrame* mCurrentFrame;
// The reference frame for mCurrentFrame.
const nsIFrame* mCurrentReferenceFrame;
// The offset from mCurrentFrame to mCurrentReferenceFrame.
nsPoint mCurrentOffsetToReferenceFrame;
Maybe<nsPoint> mAdditionalOffset;
// will-change budget tracker
typedef uint32_t DocumentWillChangeBudget;
nsTHashMap<nsPtrHashKey<const nsPresContext>, DocumentWillChangeBudget>
mDocumentWillChangeBudgets;
// Any frame listed in this set is already counted in the budget
// and thus is in-budget.
nsTHashMap<nsPtrHashKey<const nsIFrame>, FrameWillChangeBudget>
mFrameWillChangeBudgets;
uint8_t mBuildingExtraPagesForPageNum;
nsTHashMap<nsPtrHashKey<dom::RemoteBrowser>, dom::EffectsInfo>
mEffectsUpdates;
// Relative to mCurrentFrame.
nsRect mVisibleRect;
nsRect mDirtyRect;
// Tracked regions used for retained display list.
WeakFrameRegion mWindowExcludeGlassRegion;
WeakFrameRegion mRetainedWindowDraggingRegion;
WeakFrameRegion mRetainedWindowNoDraggingRegion;
// Window opaque region is calculated during layer building.
WeakFrameRegion mRetainedWindowOpaqueRegion;
// Optimized versions for non-retained display list.
LayoutDeviceIntRegion mWindowDraggingRegion;
LayoutDeviceIntRegion mWindowNoDraggingRegion;
nsRegion mWindowOpaqueRegion;
// The display item for the Windows window glass background, if any
// Set during full display list builds or during display list merging only,
// partial display list builds don't touch this.
nsDisplayItem* mGlassDisplayItem;
// If we've encountered a glass item yet, only used during partial display
// list builds.
bool mHasGlassItemDuringPartial;
nsIFrame* mCaretFrame;
nsRect mCaretRect;
// A temporary list that we append scroll info items to while building
// display items for the contents of frames with SVG effects.
// Only non-null when ShouldBuildScrollInfoItemsForHoisting() is true.
// This is a pointer and not a real nsDisplayList value because the
// nsDisplayList class is defined below this class, so we can't use it here.
nsDisplayList* mScrollInfoItemsForHoisting;
nsTArray<RefPtr<ActiveScrolledRoot>> mActiveScrolledRoots;
std::unordered_set<const DisplayItemClipChain*, DisplayItemClipChainHasher,
DisplayItemClipChainEqualer>
mClipDeduplicator;
DisplayItemClipChain* mFirstClipChainToDestroy;
nsTArray<nsDisplayItem*> mTemporaryItems;
nsDisplayListBuilderMode mMode;
nsDisplayTableBackgroundSet* mTableBackgroundSet;
ViewID mCurrentScrollParentId;
ViewID mCurrentScrollbarTarget;
Maybe<layers::ScrollDirection> mCurrentScrollbarDirection;
Preserves3DContext mPreserves3DCtx;
nsTArray<nsIFrame*> mSVGEffectsFrames;
// When we are inside a filter, the current ASR at the time we entered the
// filter. Otherwise nullptr.
const ActiveScrolledRoot* mFilterASR;
std::unordered_set<nsIScrollableFrame*> mScrollFramesToNotify;
nsCString mLinkSpec; // Destination of link currently being emitted, if any.
nsTHashSet<nsCString> mDestinations; // Destination names emitted.
bool mContainsBlendMode;
bool mIsBuildingScrollbar;
bool mCurrentScrollbarWillHaveLayer;
bool mBuildCaret;
bool mRetainingDisplayList;
bool mPartialUpdate;
bool mIgnoreSuppression;
bool mIncludeAllOutOfFlows;
bool mDescendIntoSubdocuments;
bool mSelectedFramesOnly;
bool mAllowMergingAndFlattening;
// True when we're building a display list that's directly or indirectly
// under an nsDisplayTransform
bool mInTransform;
bool mInEventsOnly;
bool mInFilter;
bool mInPageSequence;
bool mIsInChromePresContext;
bool mSyncDecodeImages;
bool mIsPaintingToWindow;
bool mUseHighQualityScaling;
bool mIsPaintingForWebRender;
bool mIsCompositingCheap;
bool mAncestorHasApzAwareEventHandler;
// True when the first async-scrollable scroll frame for which we build a
// display list has a display port. An async-scrollable scroll frame is one
// which WantsAsyncScroll().
bool mHaveScrollableDisplayPort;
bool mWindowDraggingAllowed;
bool mIsBuildingForPopup;
bool mForceLayerForScrollParent;
bool mContainsNonMinimalDisplayPort;
bool mAsyncPanZoomEnabled;
bool mBuildingInvisibleItems;
bool mIsBuilding;
bool mInInvalidSubtree;
bool mBuildCompositorHitTestInfo;
bool mDisablePartialUpdates;
bool mPartialBuildFailed;
bool mIsInActiveDocShell;
bool mBuildAsyncZoomContainer;
bool mContainsBackdropFilter;
bool mIsRelativeToLayoutViewport;
bool mUseOverlayScrollbars;
bool mAlwaysLayerizeScrollbars;
Maybe<float> mVisibleThreshold;
gfx::CompositorHitTestInfo mCompositorHitTestInfo;
bool mIsForContent;
bool mIsReusingStackingContextItems;
// Stores reusable items collected during display list preprocessing.
nsTHashSet<nsDisplayItem*> mReuseableItems;
};
class nsDisplayItem;
class nsPaintedDisplayItem;
class nsDisplayList;
class RetainedDisplayList;
// All types are defined in nsDisplayItemTypes.h
#define NS_DISPLAY_DECL_NAME(n, e) \
const char* Name() const override { return n; } \
constexpr static DisplayItemType ItemType() { return DisplayItemType::e; } \
\
private: \
void* operator new(size_t aSize, nsDisplayListBuilder* aBuilder) { \
return aBuilder->Allocate(aSize, DisplayItemType::e); \
} \
\
template <typename T, typename F, typename... Args> \
friend T* mozilla::MakeDisplayItemWithIndex( \
nsDisplayListBuilder* aBuilder, F* aFrame, const uint16_t aIndex, \
Args&&... aArgs); \
\
public:
#define NS_DISPLAY_ALLOW_CLONING() \
template <typename T> \
friend T* mozilla::MakeClone(nsDisplayListBuilder* aBuilder, \
const T* aItem); \
\
nsDisplayWrapList* Clone(nsDisplayListBuilder* aBuilder) const override { \
return MakeClone(aBuilder, this); \
}
template <typename T>
MOZ_ALWAYS_INLINE T* MakeClone(nsDisplayListBuilder* aBuilder, const T* aItem) {
static_assert(std::is_base_of<nsDisplayWrapList, T>::value,
"Display item type should be derived from nsDisplayWrapList");
T* item = new (aBuilder) T(aBuilder, *aItem);
item->SetType(T::ItemType());
return item;
}
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
void AssertUniqueItem(nsDisplayItem* aItem);
#endif
/**
* Returns true, if a display item of given |aType| needs to be built within
* opacity:0 container.
*/
bool ShouldBuildItemForEvents(const DisplayItemType aType);
/**
* Initializes the hit test information of |aItem| if the item type supports it.
*/
void InitializeHitTestInfo(nsDisplayListBuilder* aBuilder,
nsPaintedDisplayItem* aItem,
const DisplayItemType aType);
template <typename T, typename F, typename... Args>
MOZ_ALWAYS_INLINE T* MakeDisplayItemWithIndex(nsDisplayListBuilder* aBuilder,
F* aFrame, const uint16_t aIndex,
Args&&... aArgs) {
static_assert(std::is_base_of<nsDisplayItem, T>::value,
"Display item type should be derived from nsDisplayItem");
static_assert(std::is_base_of<nsIFrame, F>::value,
"Frame type should be derived from nsIFrame");
const DisplayItemType type = T::ItemType();
if (aBuilder->InEventsOnly() && !ShouldBuildItemForEvents(type)) {
// This item is not needed for events.
return nullptr;
}
T* item = new (aBuilder) T(aBuilder, aFrame, std::forward<Args>(aArgs)...);
if (type != DisplayItemType::TYPE_GENERIC) {
item->SetType(type);
}
item->SetPerFrameIndex(aIndex);
item->SetExtraPageForPageNum(aBuilder->GetBuildingExtraPagesForPageNum());
nsPaintedDisplayItem* paintedItem = item->AsPaintedDisplayItem();
if (paintedItem) {
InitializeHitTestInfo(aBuilder, paintedItem, type);
}
if (aBuilder->InInvalidSubtree() ||
item->FrameForInvalidation()->IsFrameModified()) {
item->SetModifiedFrame(true);
}
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
if (aBuilder->IsRetainingDisplayList() && aBuilder->IsBuilding()) {
AssertUniqueItem(item);
}
// Verify that InInvalidSubtree matches invalidation frame's modified state.
if (aBuilder->InInvalidSubtree()) {
MOZ_DIAGNOSTIC_ASSERT(
AnyContentAncestorModified(item->FrameForInvalidation()));
}
DebugOnly<bool> isContainerType =
(GetDisplayItemFlagsForType(type) & TYPE_IS_CONTAINER);
MOZ_ASSERT(item->HasChildren() == isContainerType,
"Container items must have container display item flag set.");
#endif
if (aBuilder->IsForPainting() && aBuilder->IsForContent()) {
DL_LOGV("Created display item %p (%s) (frame: %p)", item, item->Name(),
aFrame);
}
return item;
}
template <typename T, typename F, typename... Args>
MOZ_ALWAYS_INLINE T* MakeDisplayItem(nsDisplayListBuilder* aBuilder, F* aFrame,
Args&&... aArgs) {
return MakeDisplayItemWithIndex<T>(aBuilder, aFrame, 0,
std::forward<Args>(aArgs)...);
}
/**
* nsDisplayItems are put in singly-linked lists rooted in an nsDisplayList.
* nsDisplayItemLink holds the link. The lists are linked from lowest to
* highest in z-order.
*/
class nsDisplayItemLink {
// This is never instantiated directly, so no need to count constructors and
// destructors.
protected:
nsDisplayItemLink() : mAbove(nullptr) {}
nsDisplayItemLink(const nsDisplayItemLink&) : mAbove(nullptr) {}
~nsDisplayItemLink() { MOZ_RELEASE_ASSERT(!mAbove); }
nsDisplayItem* mAbove;
friend class nsDisplayList;
};
/*
* nsDisplayItemBase is a base-class for all display items. It is mainly
* responsible for handling the frame-display item 1:n relationship, as well as
* storing the state needed for display list merging.
*
* Display items are arena-allocated during display list construction.
*
* Display items can be containers --- i.e., they can perform hit testing
* and painting by recursively traversing a list of child items.
*
* Display items belong to a list at all times (except temporarily as they
* move from one list to another).
*/
class nsDisplayItem : public nsDisplayItemLink {
public:
using Layer = layers::Layer;
using LayerManager = layers::LayerManager;
using WebRenderLayerManager = layers::WebRenderLayerManager;
using StackingContextHelper = layers::StackingContextHelper;
using ViewID = layers::ScrollableLayerGuid::ViewID;
/**
* Downcasts this item to nsPaintedDisplayItem, if possible.
*/
virtual nsPaintedDisplayItem* AsPaintedDisplayItem() { return nullptr; }
virtual const nsPaintedDisplayItem* AsPaintedDisplayItem() const {
return nullptr;
}
/**
* Downcasts this item to nsDisplayWrapList, if possible.
*/
virtual nsDisplayWrapList* AsDisplayWrapList() { return nullptr; }
virtual const nsDisplayWrapList* AsDisplayWrapList() const { return nullptr; }
/**
* Create a clone of this item.
*/
virtual nsDisplayWrapList* Clone(nsDisplayListBuilder* aBuilder) const {
return nullptr;
}
/**
* Frees the memory allocated for this display item.
* The given display list builder must have allocated this display item.
*/
virtual void Destroy(nsDisplayListBuilder* aBuilder) {
const DisplayItemType type = GetType();
if (aBuilder->IsForPainting() && aBuilder->IsForContent()) {
DL_LOGV("Destroying display item %p (%s)", this, Name());
}
if (IsReusedItem()) {
aBuilder->RemoveReusedDisplayItem(this);
}
this->~nsDisplayItem();
aBuilder->Destroy(type, this);
}
/**
* Returns the frame that this display item was created for.
* Never returns null.
*/
inline nsIFrame* Frame() const {
MOZ_ASSERT(mFrame, "Trying to use display item after deletion!");
return mFrame;
}
/**
* Called when the display item is prepared for deletion. The display item
* should not be used after calling this function.
*/
virtual void RemoveFrame(nsIFrame* aFrame) {
MOZ_ASSERT(aFrame);
if (mFrame && aFrame == mFrame) {
mFrame = nullptr;
SetDeletedFrame();
}
}
/**
* A display item can depend on multiple different frames for invalidation.
*/
virtual nsIFrame* GetDependentFrame() { return nullptr; }
/**
* Returns the frame that provides the style data, and should
* be checked when deciding if this display item can be reused.
*/
virtual nsIFrame* FrameForInvalidation() const { return Frame(); }
/**
* Returns the printable name of this display item.
*/
virtual const char* Name() const = 0;
/**
* Some consecutive items should be rendered together as a unit, e.g.,
* outlines for the same element. For this, we need a way for items to
* identify their type. We use the type for other purposes too.
*/
DisplayItemType GetType() const {
MOZ_ASSERT(mType != DisplayItemType::TYPE_ZERO,
"Display item should have a valid type!");
return mType;
}
/**
* Pairing this with the Frame() pointer gives a key that
* uniquely identifies this display item in the display item tree.
*/
uint32_t GetPerFrameKey() const {
// The top 8 bits are the page index
// The middle 16 bits of the per frame key uniquely identify the display
// item when there are more than one item of the same type for a frame.
// The low 8 bits are the display item type.
return (static_cast<uint32_t>(mExtraPageForPageNum)
<< (TYPE_BITS + (sizeof(mPerFrameIndex) * 8))) |
(static_cast<uint32_t>(mPerFrameIndex) << TYPE_BITS) |
static_cast<uint32_t>(mType);
}
/**
* Returns true if this item was reused during display list merging.
*/
bool IsReused() const { return mItemFlags.contains(ItemFlag::ReusedItem); }
void SetReused(bool aReused) { SetItemFlag(ItemFlag::ReusedItem, aReused); }
/**
* Returns true if this item can be reused during display list merging.
*/
bool CanBeReused() const {
return !mItemFlags.contains(ItemFlag::CantBeReused);
}
void SetCantBeReused() { mItemFlags += ItemFlag::CantBeReused; }
bool CanBeCached() const {
return !mItemFlags.contains(ItemFlag::CantBeCached);
}
void SetCantBeCached() { mItemFlags += ItemFlag::CantBeCached; }
bool IsOldItem() const { return !!mOldList; }
/**
* Returns true if the frame of this display item is in a modified subtree.
*/
bool HasModifiedFrame() const {
return mItemFlags.contains(ItemFlag::ModifiedFrame);
}
void SetModifiedFrame(bool aModified) {
SetItemFlag(ItemFlag::ModifiedFrame, aModified);
}
bool HasDeletedFrame() const;
/**
* Set the nsDisplayList that this item belongs to, and what index it is
* within that list.
* Temporary state for merging used by RetainedDisplayListBuilder.
*/
void SetOldListIndex(nsDisplayList* aList, OldListIndex aIndex,
uint32_t aListKey, uint32_t aNestingDepth) {
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
mOldListKey = aListKey;
mOldNestingDepth = aNestingDepth;
#endif
mOldList = reinterpret_cast<uintptr_t>(aList);
mOldListIndex = aIndex;
}
bool GetOldListIndex(nsDisplayList* aList, uint32_t aListKey,
OldListIndex* aOutIndex) {
if (mOldList != reinterpret_cast<uintptr_t>(aList)) {
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
MOZ_CRASH_UNSAFE_PRINTF(
"Item found was in the wrong list! type %d "
"(outer type was %d at depth %d, now is %d)",
GetPerFrameKey(), mOldListKey, mOldNestingDepth, aListKey);
#endif
return false;
}
*aOutIndex = mOldListIndex;
return true;
}
/**
* Returns the display list containing the children of this display item.
* The children may be in a different coordinate system than this item.
*/
virtual RetainedDisplayList* GetChildren() const { return nullptr; }
bool HasChildren() const { return GetChildren(); }
/**
* Display items with children may return true here. This causes the
* display list iterator to descend into the child display list.
*/
virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) {
return false;
}
virtual bool CreatesStackingContextHelper() { return false; }
/**
* Returns true if this item can be moved asynchronously on the compositor,
* see RetainedDisplayListBuilder.cpp comments.
*/
virtual bool CanMoveAsync() { return false; }
protected:
// This is never instantiated directly (it has pure virtual methods), so no
// need to count constructors and destructors.
nsDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame);
nsDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const ActiveScrolledRoot* aActiveScrolledRoot);
/**
* The custom copy-constructor is implemented to prevent copying the saved
* state of the item.
* This is currently only used when creating temporary items for merging.
*/
nsDisplayItem(nsDisplayListBuilder* aBuilder, const nsDisplayItem& aOther)
: mFrame(aOther.mFrame),
mItemFlags(aOther.mItemFlags),
mType(aOther.mType),
mExtraPageForPageNum(aOther.mExtraPageForPageNum),
mPerFrameIndex(aOther.mPerFrameIndex),
mBuildingRect(aOther.mBuildingRect),
mToReferenceFrame(aOther.mToReferenceFrame),
mActiveScrolledRoot(aOther.mActiveScrolledRoot),
mClipChain(aOther.mClipChain) {
MOZ_COUNT_CTOR(nsDisplayItem);
// TODO: It might be better to remove the flags that aren't copied.
if (aOther.ForceNotVisible()) {
mItemFlags += ItemFlag::ForceNotVisible;
}
if (mFrame->In3DContextAndBackfaceIsHidden()) {
mItemFlags += ItemFlag::BackfaceHidden;
}
if (aOther.Combines3DTransformWithAncestors()) {
mItemFlags += ItemFlag::Combines3DTransformWithAncestors;
}
}
virtual ~nsDisplayItem() {
MOZ_COUNT_DTOR(nsDisplayItem);
if (mFrame) {
mFrame->RemoveDisplayItem(this);
}
}
void SetType(const DisplayItemType aType) { mType = aType; }
void SetPerFrameIndex(const uint16_t aIndex) { mPerFrameIndex = aIndex; }
// Display list building for printing can build duplicate
// container display items when they contain a mixture of
// OOF and normal content that is spread across multiple
// pages. We include the page number for the duplicates
// to make our GetPerFrameKey unique.
void SetExtraPageForPageNum(const uint8_t aPageNum) {
mExtraPageForPageNum = aPageNum;
}
void SetDeletedFrame();
public:
nsDisplayItem() = delete;
nsDisplayItem(const nsDisplayItem&) = delete;
/**
* Invalidate cached information that depends on this node's contents, after
* a mutation of those contents.
*
* Specifically, if you mutate an |nsDisplayItem| in a way that would change
* the WebRender display list items generated for it, you should call this
* method.
*
* If a |RestoreState| method exists to restore some piece of state, that's a
* good indication that modifications to said state should be accompanied by a
* call to this method. Opacity flattening's effects on
* |nsDisplayBackgroundColor| items are one example.
*/
virtual void InvalidateItemCacheEntry() {}
struct HitTestState {
explicit HitTestState() = default;
~HitTestState() {
NS_ASSERTION(mItemBuffer.Length() == 0,
"mItemBuffer should have been cleared");
}
// Handling transform items for preserve 3D frames.
bool mInPreserves3D = false;
// When hit-testing for visibility, we may hit an fully opaque item in a
// nested display list. We want to stop at that point, without looking
// further on other items.
bool mHitOccludingItem = false;
float mCurrentOpacity = 1.0f;
AutoTArray<nsDisplayItem*, 100> mItemBuffer;
};
uint8_t GetFlags() const { return GetDisplayItemFlagsForType(GetType()); }
virtual bool IsContentful() const { return GetFlags() & TYPE_IS_CONTENTFUL; }
/**
* This is called after we've constructed a display list for event handling.
* When this is called, we've already ensured that aRect intersects the
* item's bounds and that clipping has been taking into account.
*
* @param aRect the point or rect being tested, relative to the reference
* frame. If the width and height are both 1 app unit, it indicates we're
* hit testing a point, not a rect.
* @param aState must point to a HitTestState. If you don't have one,
* just create one with the default constructor and pass it in.
* @param aOutFrames each item appends the frame(s) in this display item that
* the rect is considered over (if any) to aOutFrames.
*/
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) {}
virtual nsIFrame* StyleFrame() const { return mFrame; }
/**
* Compute the used z-index of our frame; returns zero for elements to which
* z-index does not apply, and for z-index:auto.
* @note This can be overridden, @see nsDisplayWrapList::SetOverrideZIndex.
*/
virtual int32_t ZIndex() const;
/**
* The default bounds is the frame border rect.
* @param aSnap *aSnap is set to true if the returned rect will be
* snapped to nearest device pixel edges during actual drawing.
* It might be set to false and snap anyway, so code computing the set of
* pixels affected by this display item needs to round outwards to pixel
* boundaries when *aSnap is set to false.
* This does not take the item's clipping into account.
* @return a rectangle relative to aBuilder->ReferenceFrame() that
* contains the area drawn by this display item
*/
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const {
*aSnap = false;
return nsRect(ToReferenceFrame(), Frame()->GetSize());
}
/**
* Returns the untransformed bounds of this display item.
*/
virtual nsRect GetUntransformedBounds(nsDisplayListBuilder* aBuilder,
bool* aSnap) const {
return GetBounds(aBuilder, aSnap);
}
virtual nsRegion GetTightBounds(nsDisplayListBuilder* aBuilder,
bool* aSnap) const {
*aSnap = false;
return nsRegion();
}
/**
* Returns true if nothing will be rendered inside aRect, false if uncertain.
* aRect is assumed to be contained in this item's bounds.
*/
virtual bool IsInvisibleInRect(const nsRect& aRect) const { return false; }
/**
* Returns the result of GetBounds intersected with the item's clip.
* The intersection is approximate since rounded corners are not taking into
* account.
*/
nsRect GetClippedBounds(nsDisplayListBuilder* aBuilder) const;
nsRect GetBorderRect() const {
return nsRect(ToReferenceFrame(), Frame()->GetSize());
}
nsRect GetPaddingRect() const {
return Frame()->GetPaddingRectRelativeToSelf() + ToReferenceFrame();
}
nsRect GetContentRect() const {
return Frame()->GetContentRectRelativeToSelf() + ToReferenceFrame();
}
/**
* Checks if the frame(s) owning this display item have been marked as
* invalid, and needing repainting.
*/
virtual bool IsInvalid(nsRect& aRect) const {
bool result = mFrame ? mFrame->IsInvalid(aRect) : false;
aRect += ToReferenceFrame();
return result;
}
/**
* Creates and initializes an nsDisplayItemGeometry object that retains the
* current areas covered by this display item. These need to retain enough
* information such that they can be compared against a future nsDisplayItem
* of the same type, and determine if repainting needs to happen.
*
* Subclasses wishing to store more information need to override both this
* and ComputeInvalidationRegion, as well as implementing an
* nsDisplayItemGeometry subclass.
*
* The default implementation tracks both the display item bounds, and the
* frame's border rect.
*/
virtual nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) {
return new nsDisplayItemGenericGeometry(this, aBuilder);
}
/**
* Compares an nsDisplayItemGeometry object from a previous paint against the
* current item. Computes if the geometry of the item has changed, and the
* invalidation area required for correct repainting.
*
* The existing geometry will have been created from a display item with a
* matching GetPerFrameKey()/mFrame pair to the current item.
*
* The default implementation compares the display item bounds, and the
* frame's border rect, and invalidates the entire bounds if either rect
* changes.
*
* @param aGeometry The geometry of the matching display item from the
* previous paint.
* @param aInvalidRegion Output param, the region to invalidate, or
* unchanged if none.
*/
virtual void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const {
const nsDisplayItemGenericGeometry* geometry =
static_cast<const nsDisplayItemGenericGeometry*>(aGeometry);
bool snap;
if (!geometry->mBounds.IsEqualInterior(GetBounds(aBuilder, &snap)) ||
!geometry->mBorderRect.IsEqualInterior(GetBorderRect())) {
aInvalidRegion->Or(GetBounds(aBuilder, &snap), geometry->mBounds);
}
}
/**
* An alternative default implementation of ComputeInvalidationRegion,
* that instead invalidates only the changed area between the two items.
*/
void ComputeInvalidationRegionDifference(
nsDisplayListBuilder* aBuilder,
const nsDisplayItemBoundsGeometry* aGeometry,
nsRegion* aInvalidRegion) const {
bool snap;
nsRect bounds = GetBounds(aBuilder, &snap);
if (!aGeometry->mBounds.IsEqualInterior(bounds)) {
nscoord radii[8];
if (aGeometry->mHasRoundedCorners || Frame()->GetBorderRadii(radii)) {
aInvalidRegion->Or(aGeometry->mBounds, bounds);
} else {
aInvalidRegion->Xor(aGeometry->mBounds, bounds);
}
}
}
/**
* This function is called when an item's list of children has been modified
* by RetainedDisplayListBuilder.
*/
virtual void InvalidateCachedChildInfo(nsDisplayListBuilder* aBuilder) {}
virtual void AddSizeOfExcludingThis(nsWindowSizes&) const {}
/**
* @param aSnap set to true if the edges of the rectangles of the opaque
* region would be snapped to device pixels when drawing
* @return a region of the item that is opaque --- that is, every pixel
* that is visible is painted with an opaque
* color. This is useful for determining when one piece
* of content completely obscures another so that we can do occlusion
* culling.
* This does not take clipping into account.
* This must return a simple region (1 rect) for painting display lists.
* It is only allowed to be a complex region for hit testing.
*/
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const {
*aSnap = false;
return nsRegion();
}
/**
* @return Some(nscolor) if the item is guaranteed to paint every pixel in its
* bounds with the same (possibly translucent) color
*/
virtual Maybe<nscolor> IsUniform(nsDisplayListBuilder* aBuilder) const {
return Nothing();
}
/**
* @return true if the contents of this item are rendered fixed relative
* to the nearest viewport.
*/
virtual bool ShouldFixToViewport(nsDisplayListBuilder* aBuilder) const {
return false;
}
/**
* Returns true if all layers that can be active should be forced to be
* active. Requires setting the pref layers.force-active=true.
*/
static bool ForceActiveLayers();
#ifdef MOZ_DUMP_PAINTING
/**
* Mark this display item as being painted via
* FrameLayerBuilder::DrawPaintedLayer.
*/
bool Painted() const { return mItemFlags.contains(ItemFlag::Painted); }
/**
* Check if this display item has been painted.
*/
void SetPainted() { mItemFlags += ItemFlag::Painted; }
#endif
void SetIsGlassItem() { mItemFlags += ItemFlag::IsGlassItem; }
bool IsGlassItem() { return mItemFlags.contains(ItemFlag::IsGlassItem); }
/**
* Function to create the WebRenderCommands.
* We should check if the layer state is
* active first and have an early return if the layer state is
* not active.
*
* @return true if successfully creating webrender commands.
*/
virtual bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) {
return false;
}
/**
* Updates the provided aLayerData with any APZ-relevant scroll data
* that is specific to this display item. This is stuff that would normally
* be put on the layer during BuildLayer, but this is only called in
* layers-free webrender mode, where we don't have layers.
*
* This function returns true if and only if it has APZ-relevant scroll data
* to provide. Note that the arguments passed in may be nullptr, in which case
* the function should still return true if and only if it has APZ-relevant
* scroll data, but obviously in this case it can't actually put the
* data onto aLayerData, because there isn't one.
*
* This function assumes that aData and aLayerData will either both be null,
* or will both be non-null. The caller is responsible for enforcing this.
*/
virtual bool UpdateScrollData(layers::WebRenderScrollData* aData,
layers::WebRenderLayerScrollData* aLayerData) {
return false;
}
/**
* Returns true if this item needs to have its geometry updated, despite
* returning empty invalidation region.
*/
virtual bool NeedsGeometryUpdates() const { return false; }
/**
* Some items such as those calling into the native themed widget machinery
* have to be painted on the content process. In this case it is best to avoid
* allocating layers that serializes and forwards the work to the compositor.
*/
virtual bool MustPaintOnContentSide() const { return false; }
/**
* If this has a child list where the children are in the same coordinate
* system as this item (i.e., they have the same reference frame),
* return the list.
*/
virtual RetainedDisplayList* GetSameCoordinateSystemChildren() const {
return nullptr;
}
virtual void UpdateBounds(nsDisplayListBuilder* aBuilder) {}
/**
* Do UpdateBounds() for items with frames establishing or extending
* 3D rendering context.
*
* This function is called by UpdateBoundsFor3D() of
* nsDisplayTransform(), and it is called by
* BuildDisplayListForStackingContext() on transform items
* establishing 3D rendering context.
*
* The bounds of a transform item with the frame establishing 3D
* rendering context should be computed by calling
* DoUpdateBoundsPreserves3D() on all descendants that participate
* the same 3d rendering context.
*/
virtual void DoUpdateBoundsPreserves3D(nsDisplayListBuilder* aBuilder) {}
/**
* Returns the building rectangle used by nsDisplayListBuilder when
* this item was constructed.
*/
const nsRect& GetBuildingRect() const { return mBuildingRect; }
void SetBuildingRect(const nsRect& aBuildingRect) {
if (aBuildingRect == mBuildingRect) {
// Avoid unnecessary paint rect recompution when the
// building rect is staying the same.
return;
}
mBuildingRect = aBuildingRect;
}
/**
* Returns the building rect for the children, relative to their
* reference frame. Can be different from mBuildingRect for
* nsDisplayTransform, since the reference frame for the children is different
* from the reference frame for the item itself.
*/
virtual const nsRect& GetBuildingRectForChildren() const {
return mBuildingRect;
}
virtual void WriteDebugInfo(std::stringstream& aStream) {}
nsDisplayItem* GetAbove() { return mAbove; }
/**
* Returns the result of aBuilder->ToReferenceFrame(GetUnderlyingFrame())
*/
const nsPoint& ToReferenceFrame() const {
NS_ASSERTION(mFrame, "No frame?");
return mToReferenceFrame;
}
/**
* Returns the reference frame for display item children of this item.
*/
virtual const nsIFrame* ReferenceFrameForChildren() const { return nullptr; }
/**
* Checks if this display item (or any children) contains content that might
* be rendered with component alpha (e.g. subpixel antialiasing). Returns the
* bounds of the area that needs component alpha, or an empty rect if nothing
* in the item does.
*/
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) const {
return nsRect();
}
/**
* Check if we can add async animations to the layer for this display item.
*/
virtual bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) {
return false;
}
virtual bool SupportsOptimizingToImage() const { return false; }
virtual const DisplayItemClip& GetClip() const;
void IntersectClip(nsDisplayListBuilder* aBuilder,
const DisplayItemClipChain* aOther, bool aStore);
virtual void SetActiveScrolledRoot(
const ActiveScrolledRoot* aActiveScrolledRoot) {
mActiveScrolledRoot = aActiveScrolledRoot;
}
const ActiveScrolledRoot* GetActiveScrolledRoot() const {
return mActiveScrolledRoot;
}
virtual void SetClipChain(const DisplayItemClipChain* aClipChain,
bool aStore);
const DisplayItemClipChain* GetClipChain() const { return mClipChain; }
bool BackfaceIsHidden() const {
return mItemFlags.contains(ItemFlag::BackfaceHidden);
}
bool Combines3DTransformWithAncestors() const {
return mItemFlags.contains(ItemFlag::Combines3DTransformWithAncestors);
}
bool ForceNotVisible() const {
return mItemFlags.contains(ItemFlag::ForceNotVisible);
}
bool In3DContextAndBackfaceIsHidden() const {
return mItemFlags.contains(ItemFlag::BackfaceHidden) &&
mItemFlags.contains(ItemFlag::Combines3DTransformWithAncestors);
}
bool HasDifferentFrame(const nsDisplayItem* aOther) const {
return mFrame != aOther->mFrame;
}
bool HasHitTestInfo() const {
return mItemFlags.contains(ItemFlag::HasHitTestInfo);
}
bool HasSameTypeAndClip(const nsDisplayItem* aOther) const {
return GetPerFrameKey() == aOther->GetPerFrameKey() &&
GetClipChain() == aOther->GetClipChain();
}
bool HasSameContent(const nsDisplayItem* aOther) const {
return mFrame->GetContent() == aOther->Frame()->GetContent();
}
virtual void NotifyUsed(nsDisplayListBuilder* aBuilder) {}
virtual Maybe<nsRect> GetClipWithRespectToASR(
nsDisplayListBuilder* aBuilder, const ActiveScrolledRoot* aASR) const;
virtual const nsRect& GetUntransformedPaintRect() const {
return GetBuildingRect();
}
nsRect GetPaintRect(nsDisplayListBuilder* aBuilder, gfxContext* aCtx);
virtual const HitTestInfo& GetHitTestInfo() { return HitTestInfo::Empty(); }
enum class ReuseState : uint8_t {
None,
// Set during display list building.
Reusable,
// Set during display list preprocessing.
PreProcessed,
// Set during partial display list build.
Reused,
};
void SetReusable() {
MOZ_ASSERT(mReuseState == ReuseState::None ||
mReuseState == ReuseState::Reused);
mReuseState = ReuseState::Reusable;
}
bool IsReusable() const { return mReuseState == ReuseState::Reusable; }
void SetPreProcessed() {
MOZ_ASSERT(mReuseState == ReuseState::Reusable);
mReuseState = ReuseState::PreProcessed;
}
bool IsPreProcessed() const {
return mReuseState == ReuseState::PreProcessed;
}
void SetReusedItem() {
MOZ_ASSERT(mReuseState == ReuseState::PreProcessed);
mReuseState = ReuseState::Reused;
}
bool IsReusedItem() const { return mReuseState == ReuseState::Reused; }
void ResetReuseState() { mReuseState = ReuseState::None; }
ReuseState GetReuseState() const { return mReuseState; }
nsIFrame* mFrame; // 8
private:
enum class ItemFlag : uint16_t {
CantBeReused,
CantBeCached,
DeletedFrame,
ModifiedFrame,
ReusedItem,
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
MergedItem,
PreProcessedItem,
#endif
BackfaceHidden,
Combines3DTransformWithAncestors,
ForceNotVisible,
HasHitTestInfo,
IsGlassItem,
#ifdef MOZ_DUMP_PAINTING
// True if this frame has been painted.
Painted,
#endif
};
EnumSet<ItemFlag, uint16_t> mItemFlags; // 2
DisplayItemType mType = DisplayItemType::TYPE_ZERO; // 1
uint8_t mExtraPageForPageNum = 0; // 1
uint16_t mPerFrameIndex = 0; // 2
ReuseState mReuseState = ReuseState::None;
OldListIndex mOldListIndex; // 4
uintptr_t mOldList = 0; // 8
// This is the rectangle that nsDisplayListBuilder was using as the visible
// rect to decide which items to construct.
nsRect mBuildingRect;
protected:
void SetItemFlag(ItemFlag aFlag, const bool aValue) {
if (aValue) {
mItemFlags += aFlag;
} else {
mItemFlags -= aFlag;
}
}
void SetHasHitTestInfo() { mItemFlags += ItemFlag::HasHitTestInfo; }
// Result of ToReferenceFrame(mFrame), if mFrame is non-null
nsPoint mToReferenceFrame;
RefPtr<const ActiveScrolledRoot> mActiveScrolledRoot;
RefPtr<const DisplayItemClipChain> mClipChain;
#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED
public:
bool IsMergedItem() const {
return mItemFlags.contains(ItemFlag::MergedItem);
}
bool IsPreProcessedItem() const {
return mItemFlags.contains(ItemFlag::PreProcessedItem);
}
void SetMergedPreProcessed(bool aMerged, bool aPreProcessed) {
SetItemFlag(ItemFlag::MergedItem, aMerged);
SetItemFlag(ItemFlag::PreProcessedItem, aPreProcessed);
}
uint32_t mOldListKey = 0;
uint32_t mOldNestingDepth = 0;
#endif
};
class nsPaintedDisplayItem : public nsDisplayItem {
public:
nsPaintedDisplayItem* AsPaintedDisplayItem() final { return this; }
const nsPaintedDisplayItem* AsPaintedDisplayItem() const final {
return this;
}
/**
* Returns true if this display item would return true from ApplyOpacity
* without actually applying the opacity. Otherwise returns false.
*/
virtual bool CanApplyOpacity(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const {
return false;
}
/**
* Returns true if this item supports PaintWithClip, where the clipping
* is used directly as the primitive geometry instead of needing an explicit
* clip.
*/
virtual bool CanPaintWithClip(const DisplayItemClip& aClip) { return false; }
/**
* Same as |Paint()|, except provides a clip to use the geometry to draw with.
* Must not be called unless |CanPaintWithClip()| returned true.
*/
virtual void PaintWithClip(nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
const DisplayItemClip& aClip) {
MOZ_ASSERT_UNREACHABLE("PaintWithClip() is not implemented!");
}
/**
* Paint this item to some rendering context.
*/
virtual void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) = 0;
/**
* External storage used by |DisplayItemCache| to avoid hashmap lookups.
* If an item is reused and has the cache index set, it means that
* |DisplayItemCache| has assigned a cache slot for the item.
*/
Maybe<uint16_t>& CacheIndex() { return mCacheIndex; }
void InvalidateItemCacheEntry() override {
// |nsPaintedDisplayItem|s may have |DisplayItemCache| entries
// that no longer match after a mutation. The cache will notice
// on its own that the entry is no longer in use, and free it.
mCacheIndex = Nothing();
}
const HitTestInfo& GetHitTestInfo() final { return mHitTestInfo; }
void InitializeHitTestInfo(nsDisplayListBuilder* aBuilder) {
mHitTestInfo.Initialize(aBuilder, Frame());
SetHasHitTestInfo();
}
protected:
nsPaintedDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsPaintedDisplayItem(aBuilder, aFrame,
aBuilder->CurrentActiveScrolledRoot()) {}
nsPaintedDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const ActiveScrolledRoot* aActiveScrolledRoot)
: nsDisplayItem(aBuilder, aFrame, aActiveScrolledRoot) {}
nsPaintedDisplayItem(nsDisplayListBuilder* aBuilder,
const nsPaintedDisplayItem& aOther)
: nsDisplayItem(aBuilder, aOther), mHitTestInfo(aOther.mHitTestInfo) {}
protected:
HitTestInfo mHitTestInfo;
Maybe<uint16_t> mCacheIndex;
};
/**
* Manages a singly-linked list of display list items.
*
* mSentinel is the sentinel list value, the first value in the null-terminated
* linked list of items. mTop is the last item in the list (whose 'above'
* pointer is null). This class has no virtual methods. So list objects are just
* two pointers.
*
* Stepping upward through this list is very fast. Stepping downward is very
* slow so we don't support it. The methods that need to step downward
* (HitTest()) internally build a temporary array of all
* the items while they do the downward traversal, so overall they're still
* linear time. We have optimized for efficient AppendToTop() of both
* items and lists, with minimal codesize. AppendToBottom() is efficient too.
*/
class nsDisplayList {
public:
class Iterator {
public:
constexpr Iterator() : mCurrent(nullptr), mEnd(nullptr) {}
~Iterator() = default;
Iterator(const Iterator& aOther) = default;
Iterator& operator=(const Iterator& aOther) = default;
explicit Iterator(const nsDisplayList* aList)
: mCurrent(aList->GetBottom()), mEnd(nullptr) {}
explicit Iterator(nsDisplayItem* aStart)
: mCurrent(aStart), mEnd(nullptr) {}
Iterator& operator++() {
mCurrent = Next();
return *this;
}
nsDisplayItem* operator*() {
MOZ_ASSERT(mCurrent);
return mCurrent;
}
bool operator==(const Iterator& aOther) const {
return mCurrent == aOther.mCurrent;
}
bool operator!=(const Iterator& aOther) const {
return !operator==(aOther);
}
bool HasNext() const { return mCurrent != nullptr; }
nsDisplayItem* GetNext() {
MOZ_ASSERT(HasNext());
auto* next = mCurrent;
operator++();
return next;
}
protected:
Iterator(nsDisplayItem* aStart, nsDisplayItem* aEnd)
: mCurrent(aStart), mEnd(aEnd) {}
nsDisplayItem* Next() const {
if (!mCurrent) {
return nullptr;
}
auto* next = mCurrent->GetAbove();
if (next == mEnd) {
return nullptr;
}
return next;
}
private:
nsDisplayItem* mCurrent;
nsDisplayItem* mEnd;
};
class Range final : public Iterator {
public:
Range(nsDisplayItem* aStart, nsDisplayItem* aEnd)
: Iterator(aStart, aEnd) {}
};
Iterator begin() const { return Iterator(this); }
constexpr Iterator end() const { return Iterator(); }
/**
* Create an empty list.
*/
nsDisplayList() : mLength(0), mForceTransparentSurface(false) {
mTop = &mSentinel;
mSentinel.mAbove = nullptr;
}
virtual ~nsDisplayList() {
MOZ_RELEASE_ASSERT(!mSentinel.mAbove, "Nonempty list left over?");
}
nsDisplayList(nsDisplayList&& aOther) {
mForceTransparentSurface = aOther.mForceTransparentSurface;
if (aOther.mSentinel.mAbove) {
AppendToTop(&aOther);
} else {
mTop = &mSentinel;
mLength = 0;
}
}
nsDisplayList& operator=(nsDisplayList&& aOther) {
if (this != &aOther) {
if (aOther.mSentinel.mAbove) {
nsDisplayList tmp;
tmp.AppendToTop(&aOther);
aOther.AppendToTop(this);
AppendToTop(&tmp);
} else {
mTop = &mSentinel;
mLength = 0;
}
mForceTransparentSurface = aOther.mForceTransparentSurface;
}
return *this;
}
nsDisplayList(const nsDisplayList&) = delete;
nsDisplayList& operator=(const nsDisplayList& aOther) = delete;
/**
* Append an item to the top of the list. The item must not currently
* be in a list and cannot be null.
*/
void AppendToTop(nsDisplayItem* aItem) {
if (!aItem) {
return;
}
MOZ_ASSERT(!aItem->mAbove, "Already in a list!");
mTop->mAbove = aItem;
mTop = aItem;
mLength++;
}
template <typename T, typename F, typename... Args>
void AppendNewToTop(nsDisplayListBuilder* aBuilder, F* aFrame,
Args&&... aArgs) {
AppendNewToTopWithIndex<T>(aBuilder, aFrame, 0,
std::forward<Args>(aArgs)...);
}
template <typename T, typename F, typename... Args>
void AppendNewToTopWithIndex(nsDisplayListBuilder* aBuilder, F* aFrame,
const uint16_t aIndex, Args&&... aArgs) {
nsDisplayItem* item = MakeDisplayItemWithIndex<T>(
aBuilder, aFrame, aIndex, std::forward<Args>(aArgs)...);
if (item) {
AppendToTop(item);
}
}
/**
* Append a new item to the bottom of the list. The item must be non-null
* and not already in a list.
*/
void AppendToBottom(nsDisplayItem* aItem) {
if (!aItem) {
return;
}
MOZ_ASSERT(!aItem->mAbove, "Already in a list!");
aItem->mAbove = mSentinel.mAbove;
mSentinel.mAbove = aItem;
if (mTop == &mSentinel) {
mTop = aItem;
}
mLength++;
}
template <typename T, typename F, typename... Args>
void AppendNewToBottom(nsDisplayListBuilder* aBuilder, F* aFrame,
Args&&... aArgs) {
AppendNewToBottomWithIndex<T>(aBuilder, aFrame, 0,
std::forward<Args>(aArgs)...);
}
template <typename T, typename F, typename... Args>
void AppendNewToBottomWithIndex(nsDisplayListBuilder* aBuilder, F* aFrame,
const uint16_t aIndex, Args&&... aArgs) {
nsDisplayItem* item = MakeDisplayItemWithIndex<T>(
aBuilder, aFrame, aIndex, std::forward<Args>(aArgs)...);
if (item) {
AppendToBottom(item);
}
}
/**
* Removes all items from aList and appends them to the top of this list
*/
void AppendToTop(nsDisplayList* aList) {
if (aList->mSentinel.mAbove) {
mTop->mAbove = aList->mSentinel.mAbove;
mTop = aList->mTop;
aList->mTop = &aList->mSentinel;
aList->mSentinel.mAbove = nullptr;
mLength += aList->mLength;
aList->mLength = 0;
}
}
/**
* Removes all items from aList and prepends them to the bottom of this list
*/
void AppendToBottom(nsDisplayList* aList) {
if (aList->mSentinel.mAbove) {
aList->mTop->mAbove = mSentinel.mAbove;
mSentinel.mAbove = aList->mSentinel.mAbove;
if (mTop == &mSentinel) {
mTop = aList->mTop;
}
aList->mTop = &aList->mSentinel;
aList->mSentinel.mAbove = nullptr;
mLength += aList->mLength;
aList->mLength = 0;
}
}
/**
* Remove an item from the bottom of the list and return it.
*/
nsDisplayItem* RemoveBottom();
/**
* Remove all items from the list and call their destructors.
*/
virtual void DeleteAll(nsDisplayListBuilder* aBuilder);
/**
* @return the item at the top of the list, or null if the list is empty
*/
nsDisplayItem* GetTop() const {
return mTop != &mSentinel ? static_cast<nsDisplayItem*>(mTop) : nullptr;
}
/**
* @return the item at the bottom of the list, or null if the list is empty
*/
nsDisplayItem* GetBottom() const { return mSentinel.mAbove; }
bool IsEmpty() const { return mTop == &mSentinel; }
/**
* @return the number of items in the list
*/
uint32_t Count() const { return mLength; }
/**
* Stable sort the list by the z-order of GetUnderlyingFrame() on
* each item. 'auto' is counted as zero.
* It is assumed that the list is already in content document order.
*/
void SortByZOrder();
/**
* Stable sort the list by the tree order of the content of
* GetUnderlyingFrame() on each item. z-index is ignored.
* @param aCommonAncestor a common ancestor of all the content elements
* associated with the display items, for speeding up tree order
* checks, or nullptr if not known; it's only a hint, if it is not an
* ancestor of some elements, then we lose performance but not correctness
*/
void SortByContentOrder(nsIContent* aCommonAncestor);
/**
* Sort the display list using a stable sort. Take care, because some of the
* items might be nsDisplayLists themselves.
* aComparator(Item item1, Item item2) should return true if item1 should go
* before item2.
* We sort the items into increasing order.
*/
template <typename Item, typename Comparator>
void Sort(const Comparator& aComparator) {
if (Count() < 2) {
// Only sort lists with more than one item.
return;
}
// Some casual local browsing testing suggests that a local preallocated
// array of 20 items should be able to avoid a lot of dynamic allocations
// here.
AutoTArray<Item, 20> items;
while (nsDisplayItem* item = RemoveBottom()) {
items.AppendElement(Item(item));
}
std::stable_sort(items.begin(), items.end(), aComparator);
for (Item& item : items) {
AppendToTop(item);
}
}
/**
* Returns true if any display item requires the surface to be transparent.
*/
bool NeedsTransparentSurface() const { return mForceTransparentSurface; }
/**
* Paint the list to the rendering context. We assume that (0,0) in aCtx
* corresponds to the origin of the reference frame. For best results,
* aCtx's current transform should make (0,0) pixel-aligned. The
* rectangle in aDirtyRect is painted, which *must* be contained in the
* dirty rect used to construct the display list.
*
* If aFlags contains PAINT_USE_WIDGET_LAYERS and
* ShouldUseWidgetLayerManager() is set, then we will paint using
* the reference frame's widget's layer manager (and ctx may be null),
* otherwise we will use a temporary BasicLayerManager and ctx must
* not be null.
*
* If PAINT_EXISTING_TRANSACTION is set, the reference frame's widget's
* layer manager has already had BeginTransaction() called on it and
* we should not call it again.
*
* This must only be called on the root display list of the display list
* tree.
*
* We return the layer manager used for painting --- mainly so that
* callers can dump its layer tree if necessary.
*/
enum {
PAINT_DEFAULT = 0,
PAINT_USE_WIDGET_LAYERS = 0x01,
PAINT_EXISTING_TRANSACTION = 0x04,
PAINT_IDENTICAL_DISPLAY_LIST = 0x08
};
void PaintRoot(nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
uint32_t aFlags, Maybe<double> aDisplayListBuildTime);
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
int32_t aAppUnitsPerDevPixel);
/**
* Get the bounds. Takes the union of the bounds of all children.
* The result is not cached.
*/
nsRect GetClippedBounds(nsDisplayListBuilder* aBuilder) const;
/**
* Get this list's bounds, respecting clips relative to aASR. The result is
* the union of each item's clipped bounds with respect to aASR. That means
* that if an item can move asynchronously with an ASR that is a descendant
* of aASR, then the clipped bounds with respect to aASR will be the clip of
* that item for aASR, because the item can move anywhere inside that clip.
* If there is an item in this list which is not bounded with respect to
* aASR (i.e. which does not have "finite bounds" with respect to aASR),
* then this method trigger an assertion failure.
* The optional aBuildingRect out argument can be set to non-null if the
* caller is also interested to know the building rect. This can be used
* to get the visible rect efficiently without traversing the display list
* twice.
*/
nsRect GetClippedBoundsWithRespectToASR(
nsDisplayListBuilder* aBuilder, const ActiveScrolledRoot* aASR,
nsRect* aBuildingRect = nullptr) const;
/**
* Returns the opaque region of this display list.
*/
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder) {
nsRegion result;
bool snap;
for (nsDisplayItem* item : *this) {
result.OrWith(item->GetOpaqueRegion(aBuilder, &snap));
}
return result;
}
/**
* Returns the bounds of the area that needs component alpha.
*/
nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) const {
nsRect bounds;
for (nsDisplayItem* item : *this) {
bounds.UnionRect(bounds, item->GetComponentAlphaBounds(aBuilder));
}
return bounds;
}
/**
* Find the topmost display item that returns a non-null frame, and return
* the frame.
*/
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
nsDisplayItem::HitTestState* aState,
nsTArray<nsIFrame*>* aOutFrames) const;
/**
* Compute the union of the visible rects of the items in the list. The
* result is not cached.
*/
nsRect GetBuildingRect() const;
void SetNeedsTransparentSurface() { mForceTransparentSurface = true; }
void RestoreState() { mForceTransparentSurface = false; }
private:
nsDisplayItemLink mSentinel;
nsDisplayItemLink* mTop;
uint32_t mLength;
// This is set to true by FrameLayerBuilder if any display item in this
// list needs to force the surface containing this list to be transparent.
bool mForceTransparentSurface;
};
/**
* This is passed as a parameter to nsIFrame::BuildDisplayList. That method
* will put any generated items onto the appropriate list given here. It's
* basically just a collection with one list for each separate stacking layer.
* The lists themselves are external to this object and thus can be shared
* with others. Some of the list pointers may even refer to the same list.
*/
class nsDisplayListSet {
public:
/**
* @return a list where one should place the border and/or background for
* this frame (everything from steps 1 and 2 of CSS 2.1 appendix E)
*/
nsDisplayList* BorderBackground() const { return mBorderBackground; }
/**
* @return a list where one should place the borders and/or backgrounds for
* block-level in-flow descendants (step 4 of CSS 2.1 appendix E)
*/
nsDisplayList* BlockBorderBackgrounds() const {
return mBlockBorderBackgrounds;
}
/**
* @return a list where one should place descendant floats (step 5 of
* CSS 2.1 appendix E)
*/
nsDisplayList* Floats() const { return mFloats; }
/**
* @return a list where one should place the (pseudo) stacking contexts
* for descendants of this frame (everything from steps 3, 7 and 8
* of CSS 2.1 appendix E)
*/
nsDisplayList* PositionedDescendants() const { return mPositioned; }
/**
* @return a list where one should place the outlines
* for this frame and its descendants (step 9 of CSS 2.1 appendix E)
*/
nsDisplayList* Outlines() const { return mOutlines; }
/**
* @return a list where one should place all other content
*/
nsDisplayList* Content() const { return mContent; }
void DeleteAll(nsDisplayListBuilder* aBuilder) {
BorderBackground()->DeleteAll(aBuilder);
BlockBorderBackgrounds()->DeleteAll(aBuilder);
Floats()->DeleteAll(aBuilder);
PositionedDescendants()->DeleteAll(aBuilder);
Outlines()->DeleteAll(aBuilder);
Content()->DeleteAll(aBuilder);
}
nsDisplayListSet(nsDisplayList* aBorderBackground,
nsDisplayList* aBlockBorderBackgrounds,
nsDisplayList* aFloats, nsDisplayList* aContent,
nsDisplayList* aPositionedDescendants,
nsDisplayList* aOutlines)
: mBorderBackground(aBorderBackground),
mBlockBorderBackgrounds(aBlockBorderBackgrounds),
mFloats(aFloats),
mContent(aContent),
mPositioned(aPositionedDescendants),
mOutlines(aOutlines) {}
/**
* A copy constructor that lets the caller override the BorderBackground
* list.
*/
nsDisplayListSet(const nsDisplayListSet& aLists,
nsDisplayList* aBorderBackground)
: mBorderBackground(aBorderBackground),
mBlockBorderBackgrounds(aLists.BlockBorderBackgrounds()),
mFloats(aLists.Floats()),
mContent(aLists.Content()),
mPositioned(aLists.PositionedDescendants()),
mOutlines(aLists.Outlines()) {}
/**
* Move all display items in our lists to top of the corresponding lists in
* the destination.
*/
void MoveTo(const nsDisplayListSet& aDestination) const;
private:
// This class is only used on stack, so we don't have to worry about leaking
// it. Don't let us be heap-allocated!
void* operator new(size_t sz) noexcept(true);
protected:
nsDisplayList* mBorderBackground;
nsDisplayList* mBlockBorderBackgrounds;
nsDisplayList* mFloats;
nsDisplayList* mContent;
nsDisplayList* mPositioned;
nsDisplayList* mOutlines;
};
/**
* A specialization of nsDisplayListSet where the lists are actually internal
* to the object, and all distinct.
*/
struct nsDisplayListCollection : public nsDisplayListSet {
explicit nsDisplayListCollection(nsDisplayListBuilder* aBuilder)
: nsDisplayListSet(&mLists[0], &mLists[1], &mLists[2], &mLists[3],
&mLists[4], &mLists[5]) {}
explicit nsDisplayListCollection(nsDisplayListBuilder* aBuilder,
nsDisplayList* aBorderBackground)
: nsDisplayListSet(aBorderBackground, &mLists[1], &mLists[2], &mLists[3],
&mLists[4], &mLists[5]) {}
/**
* Sort all lists by content order.
*/
void SortAllByContentOrder(nsIContent* aCommonAncestor) {
for (auto& mList : mLists) {
mList.SortByContentOrder(aCommonAncestor);
}
}
/**
* Serialize this display list collection into a display list with the items
* in the correct Z order.
* @param aOutList the result display list
* @param aContent the content element to use for content ordering
*/
void SerializeWithCorrectZOrder(nsDisplayList* aOutResultList,
nsIContent* aContent);
private:
// This class is only used on stack, so we don't have to worry about leaking
// it. Don't let us be heap-allocated!
void* operator new(size_t sz) noexcept(true);
nsDisplayList mLists[6];
};
/**
* A display list that also retains the partial build
* information (in the form of a DAG) used to create it.
*
* Display lists built from a partial list aren't necessarily
* in the same order as a full build, and the DAG retains
* the information needing to interpret the current
* order correctly.
*/
class RetainedDisplayList : public nsDisplayList {
public:
RetainedDisplayList() = default;
RetainedDisplayList(RetainedDisplayList&& aOther) {
AppendToTop(&aOther);
mDAG = std::move(aOther.mDAG);
}
~RetainedDisplayList() override {
MOZ_ASSERT(mOldItems.IsEmpty(), "Must empty list before destroying");
}
RetainedDisplayList& operator=(RetainedDisplayList&& aOther) {
MOZ_ASSERT(!Count(), "Can only move into an empty list!");
MOZ_ASSERT(mOldItems.IsEmpty(), "Can only move into an empty list!");
AppendToTop(&aOther);
mDAG = std::move(aOther.mDAG);
mOldItems = std::move(aOther.mOldItems);
return *this;
}
RetainedDisplayList& operator=(nsDisplayList&& aOther) {
MOZ_ASSERT(!Count(), "Can only move into an empty list!");
MOZ_ASSERT(mOldItems.IsEmpty(), "Can only move into an empty list!");
AppendToTop(&aOther);
return *this;
}
void DeleteAll(nsDisplayListBuilder* aBuilder) override {
for (OldItemInfo& i : mOldItems) {
if (i.mItem && i.mOwnsItem) {
i.mItem->Destroy(aBuilder);
MOZ_ASSERT(!GetBottom(),
"mOldItems should not be owning items if we also have items "
"in the normal list");
}
}
mOldItems.Clear();
mDAG.Clear();
nsDisplayList::DeleteAll(aBuilder);
}
void AddSizeOfExcludingThis(nsWindowSizes&) const;
DirectedAcyclicGraph<MergedListUnits> mDAG;
// Temporary state initialized during the preprocess pass
// of RetainedDisplayListBuilder and then used during merging.
nsTArray<OldItemInfo> mOldItems;
};
class nsDisplayContainer final : public nsDisplayItem {
public:
nsDisplayContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const ActiveScrolledRoot* aActiveScrolledRoot,
nsDisplayList* aList);
~nsDisplayContainer() override { MOZ_COUNT_DTOR(nsDisplayContainer); }
NS_DISPLAY_DECL_NAME("nsDisplayContainer", TYPE_CONTAINER)
void Destroy(nsDisplayListBuilder* aBuilder) override {
mChildren.DeleteAll(aBuilder);
nsDisplayItem::Destroy(aBuilder);
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) const override;
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
Maybe<nscolor> IsUniform(nsDisplayListBuilder* aBuilder) const override {
return Nothing();
}
RetainedDisplayList* GetChildren() const override { return &mChildren; }
RetainedDisplayList* GetSameCoordinateSystemChildren() const override {
return GetChildren();
}
Maybe<nsRect> GetClipWithRespectToASR(
nsDisplayListBuilder* aBuilder,
const ActiveScrolledRoot* aASR) const override;
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return true;
}
void SetClipChain(const DisplayItemClipChain* aClipChain,
bool aStore) override {
MOZ_ASSERT_UNREACHABLE("nsDisplayContainer does not support clipping");
}
void UpdateBounds(nsDisplayListBuilder* aBuilder) override;
private:
mutable RetainedDisplayList mChildren;
nsRect mBounds;
};
/**
* Use this class to implement not-very-frequently-used display items
* that are not opaque, do not receive events, and are bounded by a frame's
* border-rect.
*
* This should not be used for display items which are created frequently,
* because each item is one or two pointers bigger than an item from a
* custom display item class could be, and fractionally slower. However it does
* save code size. We use this for infrequently-used item types.
*/
class nsDisplayGeneric : public nsPaintedDisplayItem {
public:
typedef void (*PaintCallback)(nsIFrame* aFrame, gfx::DrawTarget* aDrawTarget,
const nsRect& aDirtyRect, nsPoint aFramePt);
// XXX: should be removed eventually
typedef void (*OldPaintCallback)(nsIFrame* aFrame, gfxContext* aCtx,
const nsRect& aDirtyRect, nsPoint aFramePt);
nsDisplayGeneric(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
PaintCallback aPaint, const char* aName,
DisplayItemType aType)
: nsPaintedDisplayItem(aBuilder, aFrame),
mPaint(aPaint),
mOldPaint(nullptr),
mName(aName) {
MOZ_COUNT_CTOR(nsDisplayGeneric);
SetType(aType);
}
// XXX: should be removed eventually
nsDisplayGeneric(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
OldPaintCallback aOldPaint, const char* aName,
DisplayItemType aType)
: nsPaintedDisplayItem(aBuilder, aFrame),
mPaint(nullptr),
mOldPaint(aOldPaint),
mName(aName) {
MOZ_COUNT_CTOR(nsDisplayGeneric);
SetType(aType);
}
constexpr static DisplayItemType ItemType() {
return DisplayItemType::TYPE_GENERIC;
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayGeneric)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
MOZ_ASSERT(!!mPaint != !!mOldPaint);
if (mPaint) {
mPaint(mFrame, aCtx->GetDrawTarget(), GetPaintRect(aBuilder, aCtx),
ToReferenceFrame());
} else {
mOldPaint(mFrame, aCtx, GetPaintRect(aBuilder, aCtx), ToReferenceFrame());
}
}
const char* Name() const override { return mName; }
// This override is needed because GetType() for nsDisplayGeneric subclasses
// does not match TYPE_GENERIC that was used to allocate the object.
void Destroy(nsDisplayListBuilder* aBuilder) override {
this->~nsDisplayGeneric();
aBuilder->Destroy(DisplayItemType::TYPE_GENERIC, this);
}
protected:
void* operator new(size_t aSize, nsDisplayListBuilder* aBuilder) {
return aBuilder->Allocate(aSize, DisplayItemType::TYPE_GENERIC);
}
template <typename T, typename F, typename... Args>
friend T* MakeDisplayItemWithIndex(nsDisplayListBuilder* aBuilder, F* aFrame,
const uint16_t aIndex, Args&&... aArgs);
PaintCallback mPaint;
OldPaintCallback mOldPaint; // XXX: should be removed eventually
const char* mName;
};
#if defined(MOZ_REFLOW_PERF_DSP) && defined(MOZ_REFLOW_PERF)
/**
* This class implements painting of reflow counts. Ideally, we would simply
* make all the frame names be those returned by nsIFrame::GetFrameName
* (except that tosses in the content tag name!) and support only one color
* and eliminate this class altogether in favor of nsDisplayGeneric, but for
* the time being we can't pass args to a PaintCallback, so just have a
* separate class to do the right thing. Sadly, this alsmo means we need to
* hack all leaf frame classes to handle this.
*
* XXXbz the color thing is a bit of a mess, but 0 basically means "not set"
* here... I could switch it all to nscolor, but why bother?
*/
class nsDisplayReflowCount : public nsPaintedDisplayItem {
public:
nsDisplayReflowCount(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const char* aFrameName, uint32_t aColor = 0)
: nsPaintedDisplayItem(aBuilder, aFrame),
mFrameName(aFrameName),
mColor(aColor) {
MOZ_COUNT_CTOR(nsDisplayReflowCount);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayReflowCount)
NS_DISPLAY_DECL_NAME("nsDisplayReflowCount", TYPE_REFLOW_COUNT)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
protected:
const char* mFrameName;
nscolor mColor;
};
# define DO_GLOBAL_REFLOW_COUNT_DSP(_name) \
PR_BEGIN_MACRO \
if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \
PresShell()->IsPaintingFrameCounts()) { \
aLists.Outlines()->AppendNewToTop<mozilla::nsDisplayReflowCount>( \
aBuilder, this, _name); \
} \
PR_END_MACRO
# define DO_GLOBAL_REFLOW_COUNT_DSP_COLOR(_name, _color) \
PR_BEGIN_MACRO \
if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \
PresShell()->IsPaintingFrameCounts()) { \
aLists.Outlines()->AppendNewToTop<mozilla::nsDisplayReflowCount>( \
aBuilder, this, _name, _color); \
} \
PR_END_MACRO
/*
Macro to be used for classes that don't actually implement BuildDisplayList
*/
# define DECL_DO_GLOBAL_REFLOW_COUNT_DSP(_class, _super) \
void BuildDisplayList(nsDisplayListBuilder* aBuilder, \
const nsRect& aDirtyRect, \
const nsDisplayListSet& aLists) { \
DO_GLOBAL_REFLOW_COUNT_DSP(#_class); \
_super::BuildDisplayList(aBuilder, aDirtyRect, aLists); \
}
#else // MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF
# define DO_GLOBAL_REFLOW_COUNT_DSP(_name)
# define DO_GLOBAL_REFLOW_COUNT_DSP_COLOR(_name, _color)
# define DECL_DO_GLOBAL_REFLOW_COUNT_DSP(_class, _super)
#endif // MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF
class nsDisplayCaret : public nsPaintedDisplayItem {
public:
nsDisplayCaret(nsDisplayListBuilder* aBuilder, nsIFrame* aCaretFrame);
#ifdef NS_BUILD_REFCNT_LOGGING
~nsDisplayCaret() override;
#endif
NS_DISPLAY_DECL_NAME("Caret", TYPE_CARET)
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
protected:
RefPtr<nsCaret> mCaret;
nsRect mBounds;
};
/**
* The standard display item to paint the CSS borders of a frame.
*/
class nsDisplayBorder : public nsPaintedDisplayItem {
public:
nsDisplayBorder(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayBorder)
NS_DISPLAY_DECL_NAME("Border", TYPE_BORDER)
bool IsInvisibleInRect(const nsRect& aRect) const override;
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override;
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
nsRegion GetTightBounds(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override {
*aSnap = true;
return CalculateBounds<nsRegion>(*mFrame->StyleBorder());
}
protected:
template <typename T>
T CalculateBounds(const nsStyleBorder& aStyleBorder) const {
nsRect borderBounds(ToReferenceFrame(), mFrame->GetSize());
if (aStyleBorder.IsBorderImageSizeAvailable()) {
borderBounds.Inflate(aStyleBorder.GetImageOutset());
return borderBounds;
}
nsMargin border = aStyleBorder.GetComputedBorder();
T result;
if (border.top > 0) {
result = nsRect(borderBounds.X(), borderBounds.Y(), borderBounds.Width(),
border.top);
}
if (border.right > 0) {
result.OrWith(nsRect(borderBounds.XMost() - border.right,
borderBounds.Y(), border.right,
borderBounds.Height()));
}
if (border.bottom > 0) {
result.OrWith(nsRect(borderBounds.X(),
borderBounds.YMost() - border.bottom,
borderBounds.Width(), border.bottom));
}
if (border.left > 0) {
result.OrWith(nsRect(borderBounds.X(), borderBounds.Y(), border.left,
borderBounds.Height()));
}
nscoord radii[8];
if (mFrame->GetBorderRadii(radii)) {
if (border.left > 0 || border.top > 0) {
nsSize cornerSize(radii[eCornerTopLeftX], radii[eCornerTopLeftY]);
result.OrWith(nsRect(borderBounds.TopLeft(), cornerSize));
}
if (border.top > 0 || border.right > 0) {
nsSize cornerSize(radii[eCornerTopRightX], radii[eCornerTopRightY]);
result.OrWith(
nsRect(borderBounds.TopRight() - nsPoint(cornerSize.width, 0),
cornerSize));
}
if (border.right > 0 || border.bottom > 0) {
nsSize cornerSize(radii[eCornerBottomRightX],
radii[eCornerBottomRightY]);
result.OrWith(nsRect(borderBounds.BottomRight() -
nsPoint(cornerSize.width, cornerSize.height),
cornerSize));
}
if (border.bottom > 0 || border.left > 0) {
nsSize cornerSize(radii[eCornerBottomLeftX], radii[eCornerBottomLeftY]);
result.OrWith(
nsRect(borderBounds.BottomLeft() - nsPoint(0, cornerSize.height),
cornerSize));
}
}
return result;
}
nsRect mBounds;
};
/**
* A simple display item that just renders a solid color across the
* specified bounds. For canvas frames (in the CSS sense) we split off the
* drawing of the background color into this class (from nsDisplayBackground
* via nsDisplayCanvasBackground). This is done so that we can always draw a
* background color to avoid ugly flashes of white when we can't draw a full
* frame tree (ie when a page is loading). The bounds can differ from the
* frame's bounds -- this is needed when a frame/iframe is loading and there
* is not yet a frame tree to go in the frame/iframe so we use the subdoc
* frame of the parent document as a standin.
*/
class nsDisplaySolidColorBase : public nsPaintedDisplayItem {
public:
nsDisplaySolidColorBase(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nscolor aColor)
: nsPaintedDisplayItem(aBuilder, aFrame), mColor(aColor) {}
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplaySolidColorGeometry(this, aBuilder, mColor);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override {
const nsDisplaySolidColorGeometry* geometry =
static_cast<const nsDisplaySolidColorGeometry*>(aGeometry);
if (mColor != geometry->mColor) {
bool dummy;
aInvalidRegion->Or(geometry->mBounds, GetBounds(aBuilder, &dummy));
return;
}
ComputeInvalidationRegionDifference(aBuilder, geometry, aInvalidRegion);
}
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override {
*aSnap = false;
nsRegion result;
if (NS_GET_A(mColor) == 255) {
result = GetBounds(aBuilder, aSnap);
}
return result;
}
Maybe<nscolor> IsUniform(nsDisplayListBuilder* aBuilder) const override {
return Some(mColor);
}
protected:
nscolor mColor;
};
class nsDisplaySolidColor : public nsDisplaySolidColorBase {
public:
nsDisplaySolidColor(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aBounds, nscolor aColor,
bool aCanBeReused = true)
: nsDisplaySolidColorBase(aBuilder, aFrame, aColor), mBounds(aBounds) {
NS_ASSERTION(NS_GET_A(aColor) > 0,
"Don't create invisible nsDisplaySolidColors!");
MOZ_COUNT_CTOR(nsDisplaySolidColor);
if (!aCanBeReused) {
SetCantBeReused();
}
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplaySolidColor)
NS_DISPLAY_DECL_NAME("SolidColor", TYPE_SOLID_COLOR)
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
void WriteDebugInfo(std::stringstream& aStream) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
int32_t ZIndex() const override {
if (mOverrideZIndex) {
return mOverrideZIndex.value();
}
return nsDisplaySolidColorBase::ZIndex();
}
void SetOverrideZIndex(int32_t aZIndex) { mOverrideZIndex = Some(aZIndex); }
private:
nsRect mBounds;
Maybe<int32_t> mOverrideZIndex;
};
/**
* A display item that renders a solid color over a region. This is not
* exposed through CSS, its only purpose is efficient invalidation of
* the find bar highlighter dimmer.
*/
class nsDisplaySolidColorRegion : public nsPaintedDisplayItem {
public:
nsDisplaySolidColorRegion(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRegion& aRegion, nscolor aColor)
: nsPaintedDisplayItem(aBuilder, aFrame),
mRegion(aRegion),
mColor(gfx::sRGBColor::FromABGR(aColor)) {
NS_ASSERTION(NS_GET_A(aColor) > 0,
"Don't create invisible nsDisplaySolidColorRegions!");
MOZ_COUNT_CTOR(nsDisplaySolidColorRegion);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplaySolidColorRegion)
NS_DISPLAY_DECL_NAME("SolidColorRegion", TYPE_SOLID_COLOR_REGION)
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplaySolidColorRegionGeometry(this, aBuilder, mRegion,
mColor);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override {
const nsDisplaySolidColorRegionGeometry* geometry =
static_cast<const nsDisplaySolidColorRegionGeometry*>(aGeometry);
if (mColor == geometry->mColor) {
aInvalidRegion->Xor(geometry->mRegion, mRegion);
} else {
aInvalidRegion->Or(geometry->mRegion.GetBounds(), mRegion.GetBounds());
}
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
protected:
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
void WriteDebugInfo(std::stringstream& aStream) override;
private:
nsRegion mRegion;
gfx::sRGBColor mColor;
};
enum class AppendedBackgroundType : uint8_t {
None,
Background,
ThemedBackground,
};
/**
* A display item to paint one background-image for a frame. Each background
* image layer gets its own nsDisplayBackgroundImage.
*/
class nsDisplayBackgroundImage : public nsPaintedDisplayItem {
public:
struct InitData {
nsDisplayListBuilder* builder;
ComputedStyle* backgroundStyle;
nsCOMPtr<imgIContainer> image;
nsRect backgroundRect;
nsRect fillArea;
nsRect destArea;
uint32_t layer;
bool isRasterImage;
bool shouldFixToViewport;
};
/**
* aLayer signifies which background layer this item represents.
* aIsThemed should be the value of aFrame->IsThemed.
* aBackgroundStyle should be the result of
* nsCSSRendering::FindBackground, or null if FindBackground returned false.
* aBackgroundRect is relative to aFrame.
*/
static InitData GetInitData(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
uint16_t aLayer, const nsRect& aBackgroundRect,
ComputedStyle* aBackgroundStyle);
explicit nsDisplayBackgroundImage(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, const InitData& aInitData,
nsIFrame* aFrameForBounds = nullptr);
~nsDisplayBackgroundImage() override;
NS_DISPLAY_DECL_NAME("Background", TYPE_BACKGROUND)
/**
* This will create and append new items for all the layers of the
* background. Returns the type of background that was appended.
* aAllowWillPaintBorderOptimization should usually be left at true, unless
* aFrame has special border drawing that causes opaque borders to not
* actually be opaque.
*/
static AppendedBackgroundType AppendBackgroundItemsToTop(
nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aBackgroundRect, nsDisplayList* aList,
bool aAllowWillPaintBorderOptimization = true,
ComputedStyle* aComputedStyle = nullptr,
const nsRect& aBackgroundOriginRect = nsRect(),
nsIFrame* aSecondaryReferenceFrame = nullptr,
Maybe<nsDisplayListBuilder::AutoBuildingDisplayList>*
aAutoBuildingDisplayList = nullptr);
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
Maybe<nscolor> IsUniform(nsDisplayListBuilder* aBuilder) const override;
bool CanApplyOpacity(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const override;
/**
* GetBounds() returns the background painting area.
*/
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
/**
* Return the background positioning area.
* (GetBounds() returns the background painting area.)
* Can be called only when mBackgroundStyle is non-null.
*/
nsRect GetPositioningArea() const;
/**
* Returns true if existing rendered pixels of this display item may need
* to be redrawn if the positioning area size changes but its position does
* not.
* If false, only the changed painting area needs to be redrawn when the
* positioning area size changes but its position does not.
*/
bool RenderingMightDependOnPositioningAreaSizeChange() const;
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplayBackgroundGeometry(this, aBuilder);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
bool ShouldFixToViewport(nsDisplayListBuilder* aBuilder) const override {
return mShouldFixToViewport;
}
nsRect GetDestRect() const { return mDestRect; }
nsIFrame* GetDependentFrame() override { return mDependentFrame; }
void SetDependentFrame(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) {
if (!aBuilder->IsRetainingDisplayList() || mDependentFrame == aFrame) {
return;
}
mDependentFrame = aFrame;
if (aFrame) {
mDependentFrame->AddDisplayItem(this);
}
}
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mDependentFrame) {
mDependentFrame = nullptr;
}
nsPaintedDisplayItem::RemoveFrame(aFrame);
}
// Match https://w3c.github.io/paint-timing/#contentful-image
bool IsContentful() const override {
const auto& styleImage =
mBackgroundStyle->StyleBackground()->mImage.mLayers[mLayer].mImage;
return styleImage.IsSizeAvailable() && styleImage.FinalImage().IsUrl();
}
protected:
bool CanBuildWebRenderDisplayItems(layers::WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const;
nsRect GetBoundsInternal(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrameForBounds = nullptr);
void PaintInternal(nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
const nsRect& aBounds, nsRect* aClipRect);
// Cache the result of nsCSSRendering::FindBackground. Always null if
// mIsThemed is true or if FindBackground returned false.
RefPtr<ComputedStyle> mBackgroundStyle;
nsCOMPtr<imgIContainer> mImage;
nsIFrame* mDependentFrame;
nsRect mBackgroundRect; // relative to the reference frame
nsRect mFillRect;
nsRect mDestRect;
/* Bounds of this display item */
nsRect mBounds;
uint16_t mLayer;
bool mIsRasterImage;
/* Whether the image should be treated as fixed to the viewport. */
bool mShouldFixToViewport;
};
/**
* A display item to paint background image for table. For table parts, such
* as row, row group, col, col group, when drawing its background, we'll
* create separate background image display item for its containning cell.
* Those background image display items will reference to same DisplayItemData
* if we keep the mFrame point to cell's ancestor frame. We don't want to this
* happened bacause share same DisplatItemData will cause many bugs. So that
* we let mFrame point to cell frame and store the table type of the ancestor
* frame. And use mFrame and table type as key to generate DisplayItemData to
* avoid sharing DisplayItemData.
*
* Also store ancestor frame as mStyleFrame for all rendering informations.
*/
class nsDisplayTableBackgroundImage : public nsDisplayBackgroundImage {
public:
nsDisplayTableBackgroundImage(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, const InitData& aData,
nsIFrame* aCellFrame);
~nsDisplayTableBackgroundImage() override;
NS_DISPLAY_DECL_NAME("TableBackgroundImage", TYPE_TABLE_BACKGROUND_IMAGE)
bool IsInvalid(nsRect& aRect) const override;
nsIFrame* FrameForInvalidation() const override { return mStyleFrame; }
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mStyleFrame) {
mStyleFrame = nullptr;
SetDeletedFrame();
}
nsDisplayBackgroundImage::RemoveFrame(aFrame);
}
protected:
nsIFrame* StyleFrame() const override { return mStyleFrame; }
nsIFrame* mStyleFrame;
};
/**
* A display item to paint the native theme background for a frame.
*/
class nsDisplayThemedBackground : public nsPaintedDisplayItem {
public:
nsDisplayThemedBackground(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aBackgroundRect);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayThemedBackground)
NS_DISPLAY_DECL_NAME("ThemedBackground", TYPE_THEMED_BACKGROUND)
void Init(nsDisplayListBuilder* aBuilder);
void Destroy(nsDisplayListBuilder* aBuilder) override {
aBuilder->UnregisterThemeGeometry(this);
nsPaintedDisplayItem::Destroy(aBuilder);
}
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
Maybe<nscolor> IsUniform(nsDisplayListBuilder* aBuilder) const override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool MustPaintOnContentSide() const override { return true; }
/**
* GetBounds() returns the background painting area.
*/
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
/**
* Return the background positioning area.
* (GetBounds() returns the background painting area.)
* Can be called only when mBackgroundStyle is non-null.
*/
nsRect GetPositioningArea() const;
/**
* Return whether our frame's document does not have the state
* NS_DOCUMENT_STATE_WINDOW_INACTIVE.
*/
bool IsWindowActive() const;
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplayThemedBackgroundGeometry(this, aBuilder);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
void WriteDebugInfo(std::stringstream& aStream) override;
protected:
nsRect GetBoundsInternal();
void PaintInternal(nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
const nsRect& aBounds, nsRect* aClipRect);
nsRect mBackgroundRect;
nsRect mBounds;
nsITheme::Transparency mThemeTransparency;
StyleAppearance mAppearance;
};
class nsDisplayTableThemedBackground : public nsDisplayThemedBackground {
public:
nsDisplayTableThemedBackground(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame,
const nsRect& aBackgroundRect,
nsIFrame* aAncestorFrame)
: nsDisplayThemedBackground(aBuilder, aFrame, aBackgroundRect),
mAncestorFrame(aAncestorFrame) {
if (aBuilder->IsRetainingDisplayList()) {
mAncestorFrame->AddDisplayItem(this);
}
}
~nsDisplayTableThemedBackground() override {
if (mAncestorFrame) {
mAncestorFrame->RemoveDisplayItem(this);
}
}
NS_DISPLAY_DECL_NAME("TableThemedBackground",
TYPE_TABLE_THEMED_BACKGROUND_IMAGE)
nsIFrame* FrameForInvalidation() const override { return mAncestorFrame; }
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mAncestorFrame) {
mAncestorFrame = nullptr;
SetDeletedFrame();
}
nsDisplayThemedBackground::RemoveFrame(aFrame);
}
protected:
nsIFrame* StyleFrame() const override { return mAncestorFrame; }
nsIFrame* mAncestorFrame;
};
class nsDisplayBackgroundColor : public nsPaintedDisplayItem {
public:
nsDisplayBackgroundColor(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aBackgroundRect,
const ComputedStyle* aBackgroundStyle,
const nscolor& aColor)
: nsPaintedDisplayItem(aBuilder, aFrame),
mBackgroundRect(aBackgroundRect),
mHasStyle(aBackgroundStyle),
mDependentFrame(nullptr),
mColor(gfx::sRGBColor::FromABGR(aColor)) {
if (mHasStyle) {
mBottomLayerClip =
aBackgroundStyle->StyleBackground()->BottomLayer().mClip;
} else {
MOZ_ASSERT(aBuilder->IsForEventDelivery());
}
}
~nsDisplayBackgroundColor() override {
if (mDependentFrame) {
mDependentFrame->RemoveDisplayItem(this);
}
}
NS_DISPLAY_DECL_NAME("BackgroundColor", TYPE_BACKGROUND_COLOR)
bool HasBackgroundClipText() const {
MOZ_ASSERT(mHasStyle);
return mBottomLayerClip == StyleGeometryBox::Text;
}
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
void PaintWithClip(nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
const DisplayItemClip& aClip) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
Maybe<nscolor> IsUniform(nsDisplayListBuilder* aBuilder) const override;
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
bool CanApplyOpacity(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const override;
float GetOpacity() const { return mColor.a; }
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override {
*aSnap = true;
return mBackgroundRect;
}
bool CanPaintWithClip(const DisplayItemClip& aClip) override {
if (HasBackgroundClipText()) {
return false;
}
if (aClip.GetRoundedRectCount() > 1) {
return false;
}
return true;
}
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplaySolidColorGeometry(this, aBuilder, mColor.ToABGR());
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override {
const nsDisplaySolidColorGeometry* geometry =
static_cast<const nsDisplaySolidColorGeometry*>(aGeometry);
if (mColor.ToABGR() != geometry->mColor) {
bool dummy;
aInvalidRegion->Or(geometry->mBounds, GetBounds(aBuilder, &dummy));
return;
}
ComputeInvalidationRegionDifference(aBuilder, geometry, aInvalidRegion);
}
nsIFrame* GetDependentFrame() override { return mDependentFrame; }
void SetDependentFrame(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) {
if (!aBuilder->IsRetainingDisplayList() || mDependentFrame == aFrame) {
return;
}
mDependentFrame = aFrame;
if (aFrame) {
mDependentFrame->AddDisplayItem(this);
}
}
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mDependentFrame) {
mDependentFrame = nullptr;
}
nsPaintedDisplayItem::RemoveFrame(aFrame);
}
void WriteDebugInfo(std::stringstream& aStream) override;
bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) override;
protected:
const nsRect mBackgroundRect;
const bool mHasStyle;
StyleGeometryBox mBottomLayerClip;
nsIFrame* mDependentFrame;
gfx::sRGBColor mColor;
};
class nsDisplayTableBackgroundColor : public nsDisplayBackgroundColor {
public:
nsDisplayTableBackgroundColor(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, const nsRect& aBackgroundRect,
const ComputedStyle* aBackgroundStyle,
const nscolor& aColor, nsIFrame* aAncestorFrame)
: nsDisplayBackgroundColor(aBuilder, aFrame, aBackgroundRect,
aBackgroundStyle, aColor),
mAncestorFrame(aAncestorFrame) {
if (aBuilder->IsRetainingDisplayList()) {
mAncestorFrame->AddDisplayItem(this);
}
}
~nsDisplayTableBackgroundColor() override {
if (mAncestorFrame) {
mAncestorFrame->RemoveDisplayItem(this);
}
}
NS_DISPLAY_DECL_NAME("TableBackgroundColor", TYPE_TABLE_BACKGROUND_COLOR)
nsIFrame* FrameForInvalidation() const override { return mAncestorFrame; }
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mAncestorFrame) {
mAncestorFrame = nullptr;
SetDeletedFrame();
}
nsDisplayBackgroundColor::RemoveFrame(aFrame);
}
bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) override {
return false;
}
protected:
nsIFrame* mAncestorFrame;
};
/**
* The standard display item to paint the outer CSS box-shadows of a frame.
*/
class nsDisplayBoxShadowOuter final : public nsPaintedDisplayItem {
public:
nsDisplayBoxShadowOuter(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsPaintedDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayBoxShadowOuter);
mBounds = GetBoundsInternal();
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayBoxShadowOuter)
NS_DISPLAY_DECL_NAME("BoxShadowOuter", TYPE_BOX_SHADOW_OUTER)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
bool IsInvisibleInRect(const nsRect& aRect) const override;
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
bool CanApplyOpacity(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const override {
return CanBuildWebRenderDisplayItems();
}
bool CanBuildWebRenderDisplayItems() const;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
nsRect GetBoundsInternal();
private:
nsRect mBounds;
};
/**
* The standard display item to paint the inner CSS box-shadows of a frame.
*/
class nsDisplayBoxShadowInner : public nsPaintedDisplayItem {
public:
nsDisplayBoxShadowInner(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsPaintedDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayBoxShadowInner);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayBoxShadowInner)
NS_DISPLAY_DECL_NAME("BoxShadowInner", TYPE_BOX_SHADOW_INNER)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplayBoxShadowInnerGeometry(this, aBuilder);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override {
const nsDisplayBoxShadowInnerGeometry* geometry =
static_cast<const nsDisplayBoxShadowInnerGeometry*>(aGeometry);
if (!geometry->mPaddingRect.IsEqualInterior(GetPaddingRect())) {
// nsDisplayBoxShadowInner is based around the padding rect, but it can
// touch pixels outside of this. We should invalidate the entire bounds.
bool snap;
aInvalidRegion->Or(geometry->mBounds, GetBounds(aBuilder, &snap));
}
}
static bool CanCreateWebRenderCommands(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame,
const nsPoint& aReferenceOffset);
static void CreateInsetBoxShadowWebRenderCommands(
wr::DisplayListBuilder& aBuilder, const StackingContextHelper& aSc,
nsRect& aVisibleRect, nsIFrame* aFrame, const nsRect& aBorderRect);
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
};
/**
* The standard display item to paint the CSS outline of a frame.
*/
class nsDisplayOutline final : public nsPaintedDisplayItem {
public:
nsDisplayOutline(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsPaintedDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayOutline);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayOutline)
NS_DISPLAY_DECL_NAME("Outline", TYPE_OUTLINE)
bool MustPaintOnContentSide() const override {
MOZ_ASSERT(IsThemedOutline(),
"The only fallback path we have is for themed outlines");
return true;
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool IsInvisibleInRect(const nsRect& aRect) const override;
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
private:
nsRect GetInnerRect() const;
bool IsThemedOutline() const;
bool HasRadius() const;
};
/**
* A class that lets you receive events within the frame bounds but never
* paints.
*/
class nsDisplayEventReceiver final : public nsDisplayItem {
public:
nsDisplayEventReceiver(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayEventReceiver);
}
MOZ_COUNTED_DTOR_FINAL(nsDisplayEventReceiver)
NS_DISPLAY_DECL_NAME("EventReceiver", TYPE_EVENT_RECEIVER)
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) final;
};
/**
* Similar to nsDisplayEventReceiver in that it is used for hit-testing. However
* this gets built when we're doing widget painting and we need to send the
* compositor some hit-test info for a frame. This is effectively a dummy item
* whose sole purpose is to carry the hit-test info to the compositor.
*/
class nsDisplayCompositorHitTestInfo final : public nsDisplayItem {
public:
nsDisplayCompositorHitTestInfo(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayCompositorHitTestInfo);
mHitTestInfo.Initialize(aBuilder, aFrame);
SetHasHitTestInfo();
}
nsDisplayCompositorHitTestInfo(
nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, const nsRect& aArea,
const gfx::CompositorHitTestInfo& aHitTestFlags)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayCompositorHitTestInfo);
mHitTestInfo.SetAreaAndInfo(aArea, aHitTestFlags);
mHitTestInfo.InitializeScrollTarget(aBuilder);
SetHasHitTestInfo();
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayCompositorHitTestInfo)
NS_DISPLAY_DECL_NAME("CompositorHitTestInfo", TYPE_COMPOSITOR_HITTEST_INFO)
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
int32_t ZIndex() const override;
void SetOverrideZIndex(int32_t aZIndex);
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override {
*aSnap = false;
return nsRect();
}
const HitTestInfo& GetHitTestInfo() final { return mHitTestInfo; }
private:
HitTestInfo mHitTestInfo;
Maybe<int32_t> mOverrideZIndex;
};
/**
* A class that lets you wrap a display list as a display item.
*
* GetUnderlyingFrame() is troublesome for wrapped lists because if the wrapped
* list has many items, it's not clear which one has the 'underlying frame'.
* Thus we force the creator to specify what the underlying frame is. The
* underlying frame should be the root of a stacking context, because sorting
* a list containing this item will not get at the children.
*
* In some cases (e.g., clipping) we want to wrap a list but we don't have a
* particular underlying frame that is a stacking context root. In that case
* we allow the frame to be nullptr. Callers to GetUnderlyingFrame must
* detect and handle this case.
*/
class nsDisplayWrapList : public nsPaintedDisplayItem {
public:
/**
* Takes all the items from aList and puts them in our list.
*/
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayItem* aItem);
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
bool aClearClipChain = false);
nsDisplayWrapList(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsPaintedDisplayItem(aBuilder, aFrame),
mFrameActiveScrolledRoot(aBuilder->CurrentActiveScrolledRoot()),
mOverrideZIndex(0),
mHasZIndexOverride(false) {
MOZ_COUNT_CTOR(nsDisplayWrapList);
mBaseBuildingRect = GetBuildingRect();
mListPtr = &mList;
mOriginalClipChain = mClipChain;
}
nsDisplayWrapList() = delete;
/**
* A custom copy-constructor that does not copy mList, as this would mutate
* the other item.
*/
nsDisplayWrapList(const nsDisplayWrapList& aOther) = delete;
nsDisplayWrapList(nsDisplayListBuilder* aBuilder,
const nsDisplayWrapList& aOther)
: nsPaintedDisplayItem(aBuilder, aOther),
mListPtr(&mList),
mFrameActiveScrolledRoot(aOther.mFrameActiveScrolledRoot),
mMergedFrames(aOther.mMergedFrames.Clone()),
mBounds(aOther.mBounds),
mBaseBuildingRect(aOther.mBaseBuildingRect),
mOriginalClipChain(aOther.mClipChain),
mOverrideZIndex(aOther.mOverrideZIndex),
mHasZIndexOverride(aOther.mHasZIndexOverride),
mClearingClipChain(aOther.mClearingClipChain) {
MOZ_COUNT_CTOR(nsDisplayWrapList);
}
~nsDisplayWrapList() override;
const nsDisplayWrapList* AsDisplayWrapList() const final { return this; }
nsDisplayWrapList* AsDisplayWrapList() final { return this; }
void Destroy(nsDisplayListBuilder* aBuilder) override {
mList.DeleteAll(aBuilder);
nsPaintedDisplayItem::Destroy(aBuilder);
}
/**
* Creates a new nsDisplayWrapList that holds a pointer to the display list
* owned by the given nsDisplayItem. The new nsDisplayWrapList will be added
* to the bottom of this item's contents.
*/
void MergeDisplayListFromItem(nsDisplayListBuilder* aBuilder,
const nsDisplayWrapList* aItem);
/**
* Call this if the wrapped list is changed.
*/
void UpdateBounds(nsDisplayListBuilder* aBuilder) override {
// Clear the clip chain up to the asr, but don't store it, so that we'll
// recover it when we reuse the item.
if (mClearingClipChain) {
const DisplayItemClipChain* clip = mOriginalClipChain;
while (clip && ActiveScrolledRoot::IsAncestor(GetActiveScrolledRoot(),
clip->mASR)) {
clip = clip->mParent;
}
SetClipChain(clip, false);
}
nsRect buildingRect;
mBounds = mListPtr->GetClippedBoundsWithRespectToASR(
aBuilder, mActiveScrolledRoot, &buildingRect);
// The display list may contain content that's visible outside the visible
// rect (i.e. the current dirty rect) passed in when the item was created.
// This happens when the dirty rect has been restricted to the visual
// overflow rect of a frame for some reason (e.g. when setting up dirty
// rects in nsDisplayListBuilder::MarkOutOfFlowFrameForDisplay), but that
// frame contains placeholders for out-of-flows that aren't descendants of
// the frame.
buildingRect.UnionRect(mBaseBuildingRect, buildingRect);
SetBuildingRect(buildingRect);
}
void SetClipChain(const DisplayItemClipChain* aClipChain,
bool aStore) override {
nsDisplayItem::SetClipChain(aClipChain, aStore);
if (aStore) {
mOriginalClipChain = mClipChain;
}
}
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
Maybe<nscolor> IsUniform(nsDisplayListBuilder* aBuilder) const override;
/**
* Checks if the given display item can be merged with this item.
* @return true if the merging is possible, otherwise false.
*/
virtual bool CanMerge(const nsDisplayItem* aItem) const { return false; }
/**
* Try to merge with the other item (which is below us in the display
* list). This gets used by nsDisplayClip to coalesce clipping operations
* (optimization), by nsDisplayOpacity to merge rendering for the same
* content element into a single opacity group (correctness), and will be
* used by nsDisplayOutline to merge multiple outlines for the same element
* (also for correctness).
*/
virtual void Merge(const nsDisplayItem* aItem) {
MOZ_ASSERT(CanMerge(aItem));
MOZ_ASSERT(Frame() != aItem->Frame());
MergeFromTrackingMergedFrames(static_cast<const nsDisplayWrapList*>(aItem));
}
/**
* Returns the underlying frames of all display items that have been
* merged into this one (excluding this item's own underlying frame)
* to aFrames.
*/
const nsTArray<nsIFrame*>& GetMergedFrames() const { return mMergedFrames; }
bool HasMergedFrames() const { return !mMergedFrames.IsEmpty(); }
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return true;
}
bool IsInvalid(nsRect& aRect) const override {
if (mFrame->IsInvalid(aRect) && aRect.IsEmpty()) {
return true;
}
nsRect temp;
for (uint32_t i = 0; i < mMergedFrames.Length(); i++) {
if (mMergedFrames[i]->IsInvalid(temp) && temp.IsEmpty()) {
aRect.SetEmpty();
return true;
}
aRect = aRect.Union(temp);
}
aRect += ToReferenceFrame();
return !aRect.IsEmpty();
}
nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) const override;
RetainedDisplayList* GetSameCoordinateSystemChildren() const override {
return mListPtr;
}
RetainedDisplayList* GetChildren() const override { return mListPtr; }
int32_t ZIndex() const override {
return (mHasZIndexOverride) ? mOverrideZIndex
: nsPaintedDisplayItem::ZIndex();
}
void SetOverrideZIndex(int32_t aZIndex) {
mHasZIndexOverride = true;
mOverrideZIndex = aZIndex;
}
/**
* This creates a copy of this item, but wrapping aItem instead of
* our existing list. Only gets called if this item returned nullptr
* for GetUnderlyingFrame(). aItem is guaranteed to return non-null from
* GetUnderlyingFrame().
*/
nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) {
MOZ_ASSERT_UNREACHABLE("We never returned nullptr for GetUnderlyingFrame!");
return nullptr;
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override {
return CreateWebRenderCommandsNewClipListOption(
aBuilder, aResources, aSc, aManager, aDisplayListBuilder, true);
}
// Same as the above but with the option to pass the aNewClipList argument to
// WebRenderCommandBuilder::CreateWebRenderCommandsFromDisplayList.
bool CreateWebRenderCommandsNewClipListOption(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder, bool aNewClipList);
const ActiveScrolledRoot* GetFrameActiveScrolledRoot() {
return mFrameActiveScrolledRoot;
}
protected:
void MergeFromTrackingMergedFrames(const nsDisplayWrapList* aOther) {
mBounds.UnionRect(mBounds, aOther->mBounds);
nsRect buildingRect;
buildingRect.UnionRect(GetBuildingRect(), aOther->GetBuildingRect());
SetBuildingRect(buildingRect);
mMergedFrames.AppendElement(aOther->mFrame);
mMergedFrames.AppendElements(aOther->mMergedFrames.Clone());
}
RetainedDisplayList mList;
RetainedDisplayList* mListPtr;
// The active scrolled root for the frame that created this
// wrap list.
RefPtr<const ActiveScrolledRoot> mFrameActiveScrolledRoot;
// The frames from items that have been merged into this item, excluding
// this item's own frame.
nsTArray<nsIFrame*> mMergedFrames;
nsRect mBounds;
// Displaylist building rect contributed by this display item itself.
// Our mBuildingRect may include the visible areas of children.
nsRect mBaseBuildingRect;
RefPtr<const DisplayItemClipChain> mOriginalClipChain;
int32_t mOverrideZIndex;
bool mHasZIndexOverride;
bool mClearingClipChain = false;
};
class nsDisplayWrapper : public nsDisplayWrapList {
public:
NS_DISPLAY_DECL_NAME("WrapList", TYPE_WRAP_LIST)
nsDisplayWrapper(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
bool aClearClipChain = false)
: nsDisplayWrapList(aBuilder, aFrame, aList, aActiveScrolledRoot,
aClearClipChain) {}
nsDisplayWrapper(const nsDisplayWrapper& aOther) = delete;
nsDisplayWrapper(nsDisplayListBuilder* aBuilder,
const nsDisplayWrapList& aOther)
: nsDisplayWrapList(aBuilder, aOther) {}
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
private:
NS_DISPLAY_ALLOW_CLONING()
friend class nsDisplayListBuilder;
friend class nsDisplayWrapList;
};
/**
* We call WrapDisplayList on the in-flow lists: BorderBackground(),
* BlockBorderBackgrounds() and Content().
* We call WrapDisplayItem on each item of Outlines(), PositionedDescendants(),
* and Floats(). This is done to support special wrapping processing for frames
* that may not be in-flow descendants of the current frame.
*/
class nsDisplayItemWrapper {
public:
// This is never instantiated directly (it has pure virtual methods), so no
// need to count constructors and destructors.
bool WrapBorderBackground() { return true; }
virtual nsDisplayItem* WrapList(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, nsDisplayList* aList) = 0;
virtual nsDisplayItem* WrapItem(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) = 0;
nsresult WrapLists(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsDisplayListSet& aIn, const nsDisplayListSet& aOut);
nsresult WrapListsInPlace(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsDisplayListSet& aLists);
protected:
nsDisplayItemWrapper() = default;
};
/**
* The standard display item to paint a stacking context with translucency
* set by the stacking context root frame's 'opacity' style.
*/
class nsDisplayOpacity : public nsDisplayWrapList {
public:
nsDisplayOpacity(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
bool aForEventsOnly, bool aNeedsActiveLayer);
nsDisplayOpacity(nsDisplayListBuilder* aBuilder,
const nsDisplayOpacity& aOther)
: nsDisplayWrapList(aBuilder, aOther),
mOpacity(aOther.mOpacity),
mForEventsOnly(aOther.mForEventsOnly),
mNeedsActiveLayer(aOther.mNeedsActiveLayer),
mChildOpacityState(ChildOpacityState::Unknown) {
MOZ_COUNT_CTOR(nsDisplayOpacity);
// We should not try to merge flattened opacities.
MOZ_ASSERT(aOther.mChildOpacityState != ChildOpacityState::Applied);
}
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayOpacity)
NS_DISPLAY_DECL_NAME("Opacity", TYPE_OPACITY)
void InvalidateCachedChildInfo(nsDisplayListBuilder* aBuilder) override {
mChildOpacityState = ChildOpacityState::Unknown;
}
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
bool CanMerge(const nsDisplayItem* aItem) const override {
// items for the same content element should be merged into a single
// compositing group
// aItem->GetUnderlyingFrame() returns non-null because it's
// nsDisplayOpacity
return HasDifferentFrame(aItem) && HasSameTypeAndClip(aItem) &&
HasSameContent(aItem);
}
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplayOpacityGeometry(this, aBuilder, mOpacity);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
bool IsInvalid(nsRect& aRect) const override {
if (mForEventsOnly) {
return false;
}
return nsDisplayWrapList::IsInvalid(aRect);
}
bool CanApplyOpacity(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const override;
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return false;
}
bool CanApplyOpacityToChildren(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder,
float aInheritedOpacity);
bool NeedsGeometryUpdates() const override {
// For flattened nsDisplayOpacity items, ComputeInvalidationRegion() only
// handles invalidation for changed |mOpacity|. In order to keep track of
// the current bounds of the item for invalidation, nsDisplayOpacityGeometry
// for the corresponding DisplayItemData needs to be updated, even if the
// reported invalidation region is empty.
return mChildOpacityState == ChildOpacityState::Deferred;
}
/**
* Returns true if ShouldFlattenAway() applied opacity to children.
*/
bool OpacityAppliedToChildren() const {
return mChildOpacityState == ChildOpacityState::Applied;
}
static bool NeedsActiveLayer(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame);
void WriteDebugInfo(std::stringstream& aStream) override;
bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
float GetOpacity() const { return mOpacity; }
bool CreatesStackingContextHelper() override { return true; }
private:
NS_DISPLAY_ALLOW_CLONING()
bool CanApplyToChildren(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder);
bool ApplyToMask();
float mOpacity;
bool mForEventsOnly : 1;
enum class ChildOpacityState : uint8_t {
// Our child list has changed since the last time ApplyToChildren was
// called.
Unknown,
// Our children defer opacity handling to us.
Deferred,
// Opacity is applied to our children.
Applied
};
bool mNeedsActiveLayer : 1;
#ifndef __GNUC__
ChildOpacityState mChildOpacityState : 2;
#else
ChildOpacityState mChildOpacityState;
#endif
};
class nsDisplayBlendMode : public nsDisplayWrapList {
public:
nsDisplayBlendMode(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, StyleBlend aBlendMode,
const ActiveScrolledRoot* aActiveScrolledRoot,
const bool aIsForBackground);
nsDisplayBlendMode(nsDisplayListBuilder* aBuilder,
const nsDisplayBlendMode& aOther)
: nsDisplayWrapList(aBuilder, aOther),
mBlendMode(aOther.mBlendMode),
mIsForBackground(aOther.mIsForBackground) {
MOZ_COUNT_CTOR(nsDisplayBlendMode);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayBlendMode)
NS_DISPLAY_DECL_NAME("BlendMode", TYPE_BLEND_MODE)
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override {
// We don't need to compute an invalidation region since we have
// LayerTreeInvalidation
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
bool CanMerge(const nsDisplayItem* aItem) const override;
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return false;
}
gfx::CompositionOp BlendMode();
bool CreatesStackingContextHelper() override { return true; }
protected:
StyleBlend mBlendMode;
bool mIsForBackground;
private:
NS_DISPLAY_ALLOW_CLONING()
};
class nsDisplayTableBlendMode : public nsDisplayBlendMode {
public:
nsDisplayTableBlendMode(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, StyleBlend aBlendMode,
const ActiveScrolledRoot* aActiveScrolledRoot,
nsIFrame* aAncestorFrame, const bool aIsForBackground)
: nsDisplayBlendMode(aBuilder, aFrame, aList, aBlendMode,
aActiveScrolledRoot, aIsForBackground),
mAncestorFrame(aAncestorFrame) {
if (aBuilder->IsRetainingDisplayList()) {
mAncestorFrame->AddDisplayItem(this);
}
}
nsDisplayTableBlendMode(nsDisplayListBuilder* aBuilder,
const nsDisplayTableBlendMode& aOther)
: nsDisplayBlendMode(aBuilder, aOther),
mAncestorFrame(aOther.mAncestorFrame) {
if (aBuilder->IsRetainingDisplayList()) {
mAncestorFrame->AddDisplayItem(this);
}
}
~nsDisplayTableBlendMode() override {
if (mAncestorFrame) {
mAncestorFrame->RemoveDisplayItem(this);
}
}
NS_DISPLAY_DECL_NAME("TableBlendMode", TYPE_TABLE_BLEND_MODE)
nsIFrame* FrameForInvalidation() const override { return mAncestorFrame; }
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mAncestorFrame) {
mAncestorFrame = nullptr;
SetDeletedFrame();
}
nsDisplayBlendMode::RemoveFrame(aFrame);
}
protected:
nsIFrame* mAncestorFrame;
private:
NS_DISPLAY_ALLOW_CLONING()
};
class nsDisplayBlendContainer : public nsDisplayWrapList {
public:
static nsDisplayBlendContainer* CreateForMixBlendMode(
nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot);
static nsDisplayBlendContainer* CreateForBackgroundBlendMode(
nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsIFrame* aSecondaryFrame, nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayBlendContainer)
NS_DISPLAY_DECL_NAME("BlendContainer", TYPE_BLEND_CONTAINER)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool CanMerge(const nsDisplayItem* aItem) const override {
// Items for the same content element should be merged into a single
// compositing group.
return HasDifferentFrame(aItem) && HasSameTypeAndClip(aItem) &&
HasSameContent(aItem) &&
mIsForBackground ==
static_cast<const nsDisplayBlendContainer*>(aItem)
->mIsForBackground;
}
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return false;
}
bool CreatesStackingContextHelper() override { return true; }
protected:
nsDisplayBlendContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
bool aIsForBackground);
nsDisplayBlendContainer(nsDisplayListBuilder* aBuilder,
const nsDisplayBlendContainer& aOther)
: nsDisplayWrapList(aBuilder, aOther),
mIsForBackground(aOther.mIsForBackground) {
MOZ_COUNT_CTOR(nsDisplayBlendContainer);
}
// Used to distinguish containers created at building stacking
// context or appending background.
bool mIsForBackground;
private:
NS_DISPLAY_ALLOW_CLONING()
};
class nsDisplayTableBlendContainer : public nsDisplayBlendContainer {
public:
NS_DISPLAY_DECL_NAME("TableBlendContainer", TYPE_TABLE_BLEND_CONTAINER)
nsIFrame* FrameForInvalidation() const override { return mAncestorFrame; }
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mAncestorFrame) {
mAncestorFrame = nullptr;
SetDeletedFrame();
}
nsDisplayBlendContainer::RemoveFrame(aFrame);
}
protected:
nsDisplayTableBlendContainer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
bool aIsForBackground, nsIFrame* aAncestorFrame)
: nsDisplayBlendContainer(aBuilder, aFrame, aList, aActiveScrolledRoot,
aIsForBackground),
mAncestorFrame(aAncestorFrame) {
if (aBuilder->IsRetainingDisplayList()) {
mAncestorFrame->AddDisplayItem(this);
}
}
nsDisplayTableBlendContainer(nsDisplayListBuilder* aBuilder,
const nsDisplayTableBlendContainer& aOther)
: nsDisplayBlendContainer(aBuilder, aOther),
mAncestorFrame(aOther.mAncestorFrame) {}
~nsDisplayTableBlendContainer() override {
if (mAncestorFrame) {
mAncestorFrame->RemoveDisplayItem(this);
}
}
nsIFrame* mAncestorFrame;
private:
NS_DISPLAY_ALLOW_CLONING()
};
/**
* nsDisplayOwnLayer constructor flags. If we nest this class inside
* nsDisplayOwnLayer then we can't forward-declare it up at the top of this
* file and that makes it hard to use in all the places that we need to use it.
*/
enum class nsDisplayOwnLayerFlags {
None = 0,
GenerateSubdocInvalidations = 1 << 0,
GenerateScrollableLayer = 1 << 1,
};
MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(nsDisplayOwnLayerFlags)
/**
* A display item that has no purpose but to ensure its contents get
* their own layer.
*/
class nsDisplayOwnLayer : public nsDisplayWrapList {
public:
enum OwnLayerType {
OwnLayerForTransformWithRoundedClip,
OwnLayerForStackingContext,
OwnLayerForImageBoxFrame,
OwnLayerForScrollbar,
OwnLayerForScrollThumb,
OwnLayerForSubdoc,
OwnLayerForBoxFrame
};
/**
* @param aFlags eGenerateSubdocInvalidations :
* Add UserData to the created ContainerLayer, so that invalidations
* for this layer are send to our nsPresContext.
* eGenerateScrollableLayer : only valid on nsDisplaySubDocument (and
* subclasses), indicates this layer is to be a scrollable layer, so call
* ComputeFrameMetrics, etc.
* @param aScrollTarget when eVerticalScrollbar or eHorizontalScrollbar
* is set in the flags, this parameter should be the ViewID of the
* scrollable content this scrollbar is for.
*/
nsDisplayOwnLayer(
nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
nsDisplayOwnLayerFlags aFlags = nsDisplayOwnLayerFlags::None,
const layers::ScrollbarData& aScrollbarData = layers::ScrollbarData{},
bool aForceActive = true, bool aClearClipChain = false);
nsDisplayOwnLayer(nsDisplayListBuilder* aBuilder,
const nsDisplayOwnLayer& aOther)
: nsDisplayWrapList(aBuilder, aOther),
mFlags(aOther.mFlags),
mScrollbarData(aOther.mScrollbarData),
mForceActive(aOther.mForceActive),
mWrAnimationId(aOther.mWrAnimationId) {
MOZ_COUNT_CTOR(nsDisplayOwnLayer);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayOwnLayer)
NS_DISPLAY_DECL_NAME("OwnLayer", TYPE_OWN_LAYER)
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool UpdateScrollData(layers::WebRenderScrollData* aData,
layers::WebRenderLayerScrollData* aLayerData) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
GetChildren()->Paint(aBuilder, aCtx,
mFrame->PresContext()->AppUnitsPerDevPixel());
}
bool CanMerge(const nsDisplayItem* aItem) const override {
// Don't allow merging, each sublist must have its own layer
return false;
}
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return false;
}
void WriteDebugInfo(std::stringstream& aStream) override;
nsDisplayOwnLayerFlags GetFlags() { return mFlags; }
bool IsScrollThumbLayer() const;
bool IsScrollbarContainer() const;
bool IsRootScrollbarContainer() const;
bool IsZoomingLayer() const;
bool IsFixedPositionLayer() const;
bool IsStickyPositionLayer() const;
bool HasDynamicToolbar() const;
bool CreatesStackingContextHelper() override { return true; }
protected:
nsDisplayOwnLayerFlags mFlags;
/**
* If this nsDisplayOwnLayer represents a scroll thumb layer or a
* scrollbar container layer, mScrollbarData stores information
* about the scrollbar. Otherwise, mScrollbarData will be
* default-constructed (in particular with mDirection == Nothing())
* and can be ignored.
*/
layers::ScrollbarData mScrollbarData;
bool mForceActive;
uint64_t mWrAnimationId;
};
/**
* A display item for subdocuments. This is more or less the same as
* nsDisplayOwnLayer, except that it always populates the FrameMetrics instance
* on the ContainerLayer it builds.
*/
class nsDisplaySubDocument : public nsDisplayOwnLayer {
public:
nsDisplaySubDocument(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsSubDocumentFrame* aSubDocFrame, nsDisplayList* aList,
nsDisplayOwnLayerFlags aFlags);
~nsDisplaySubDocument() override;
NS_DISPLAY_DECL_NAME("SubDocument", TYPE_SUBDOCUMENT)
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
virtual nsSubDocumentFrame* SubDocumentFrame() { return mSubDocFrame; }
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return mShouldFlatten;
}
void SetShouldFlattenAway(bool aShouldFlatten) {
mShouldFlatten = aShouldFlatten;
}
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
nsIFrame* FrameForInvalidation() const override;
void RemoveFrame(nsIFrame* aFrame) override;
void Disown();
protected:
ViewID mScrollParentId;
bool mForceDispatchToContentRegion{};
bool mShouldFlatten;
nsSubDocumentFrame* mSubDocFrame;
};
/**
* A display item used to represent sticky position elements. The contents
* gets its own layer and creates a stacking context, and the layer will have
* position-related metadata set on it.
*/
class nsDisplayStickyPosition : public nsDisplayOwnLayer {
public:
nsDisplayStickyPosition(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
const ActiveScrolledRoot* aContainerASR,
bool aClippedToDisplayPort);
nsDisplayStickyPosition(nsDisplayListBuilder* aBuilder,
const nsDisplayStickyPosition& aOther)
: nsDisplayOwnLayer(aBuilder, aOther),
mContainerASR(aOther.mContainerASR),
mClippedToDisplayPort(aOther.mClippedToDisplayPort) {
MOZ_COUNT_CTOR(nsDisplayStickyPosition);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayStickyPosition)
const DisplayItemClip& GetClip() const override {
return DisplayItemClip::NoClip();
}
bool IsClippedToDisplayPort() const { return mClippedToDisplayPort; }
NS_DISPLAY_DECL_NAME("StickyPosition", TYPE_STICKY_POSITION)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
GetChildren()->Paint(aBuilder, aCtx,
mFrame->PresContext()->AppUnitsPerDevPixel());
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool UpdateScrollData(layers::WebRenderScrollData* aData,
layers::WebRenderLayerScrollData* aLayerData) override;
const ActiveScrolledRoot* GetContainerASR() const { return mContainerASR; }
bool CreatesStackingContextHelper() override { return true; }
bool CanMoveAsync() override { return true; }
private:
NS_DISPLAY_ALLOW_CLONING()
void CalculateLayerScrollRanges(StickyScrollContainer* aStickyScrollContainer,
float aAppUnitsPerDevPixel, float aScaleX,
float aScaleY,
LayerRectAbsolute& aStickyOuter,
LayerRectAbsolute& aStickyInner);
StickyScrollContainer* GetStickyScrollContainer();
// This stores the ASR that this sticky container item would have assuming it
// has no fixed descendants. This may be the same as the ASR returned by
// GetActiveScrolledRoot(), or it may be a descendant of that.
RefPtr<const ActiveScrolledRoot> mContainerASR;
// This flag tracks if this sticky item is just clipped to the enclosing
// scrollframe's displayport, or if there are additional clips in play. In
// the former case, we can skip setting the displayport clip as the scrolled-
// clip of the corresponding layer. This allows sticky items to remain
// unclipped when the enclosing scrollframe is scrolled past the displayport.
// i.e. when the rest of the scrollframe checkerboards, the sticky item will
// not. This makes sense to do because the sticky item has abnormal scrolling
// behavior and may still be visible even if the rest of the scrollframe is
// checkerboarded. Note that the sticky item will still be subject to the
// scrollport clip.
bool mClippedToDisplayPort;
};
class nsDisplayFixedPosition : public nsDisplayOwnLayer {
public:
nsDisplayFixedPosition(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
const ActiveScrolledRoot* aScrollTargetASR);
nsDisplayFixedPosition(nsDisplayListBuilder* aBuilder,
const nsDisplayFixedPosition& aOther)
: nsDisplayOwnLayer(aBuilder, aOther),
mScrollTargetASR(aOther.mScrollTargetASR),
mIsFixedBackground(aOther.mIsFixedBackground) {
MOZ_COUNT_CTOR(nsDisplayFixedPosition);
}
static nsDisplayFixedPosition* CreateForFixedBackground(
nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsIFrame* aSecondaryFrame, nsDisplayBackgroundImage* aImage,
const uint16_t aIndex, const ActiveScrolledRoot* aScrollTargetASR);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayFixedPosition)
NS_DISPLAY_DECL_NAME("FixedPosition", TYPE_FIXED_POSITION)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
GetChildren()->Paint(aBuilder, aCtx,
mFrame->PresContext()->AppUnitsPerDevPixel());
}
bool ShouldFixToViewport(nsDisplayListBuilder* aBuilder) const override {
return mIsFixedBackground;
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool UpdateScrollData(layers::WebRenderScrollData* aData,
layers::WebRenderLayerScrollData* aLayerData) override;
void WriteDebugInfo(std::stringstream& aStream) override;
protected:
// For background-attachment:fixed
nsDisplayFixedPosition(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aScrollTargetASR);
ViewID GetScrollTargetId();
RefPtr<const ActiveScrolledRoot> mScrollTargetASR;
bool mIsFixedBackground;
private:
NS_DISPLAY_ALLOW_CLONING()
};
class nsDisplayTableFixedPosition : public nsDisplayFixedPosition {
public:
NS_DISPLAY_DECL_NAME("TableFixedPosition", TYPE_TABLE_FIXED_POSITION)
nsIFrame* FrameForInvalidation() const override { return mAncestorFrame; }
void RemoveFrame(nsIFrame* aFrame) override {
if (aFrame == mAncestorFrame) {
mAncestorFrame = nullptr;
SetDeletedFrame();
}
nsDisplayFixedPosition::RemoveFrame(aFrame);
}
protected:
nsDisplayTableFixedPosition(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, nsIFrame* aAncestorFrame,
const ActiveScrolledRoot* aScrollTargetASR);
nsDisplayTableFixedPosition(nsDisplayListBuilder* aBuilder,
const nsDisplayTableFixedPosition& aOther)
: nsDisplayFixedPosition(aBuilder, aOther),
mAncestorFrame(aOther.mAncestorFrame) {}
~nsDisplayTableFixedPosition() override {
if (mAncestorFrame) {
mAncestorFrame->RemoveDisplayItem(this);
}
}
nsIFrame* mAncestorFrame;
private:
NS_DISPLAY_ALLOW_CLONING()
};
/**
* This creates an empty scrollable layer. It has no child layers.
* It is used to record the existence of a scrollable frame in the layer
* tree.
*/
class nsDisplayScrollInfoLayer : public nsDisplayWrapList {
public:
nsDisplayScrollInfoLayer(nsDisplayListBuilder* aBuilder,
nsIFrame* aScrolledFrame, nsIFrame* aScrollFrame,
const gfx::CompositorHitTestInfo& aHitInfo,
const nsRect& aHitArea);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayScrollInfoLayer)
NS_DISPLAY_DECL_NAME("ScrollInfoLayer", TYPE_SCROLL_INFO_LAYER)
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override {
*aSnap = false;
return nsRegion();
}
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
return;
}
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return false;
}
void WriteDebugInfo(std::stringstream& aStream) override;
UniquePtr<layers::ScrollMetadata> ComputeScrollMetadata(
nsDisplayListBuilder* aBuilder,
layers::WebRenderLayerManager* aLayerManager);
bool UpdateScrollData(layers::WebRenderScrollData* aData,
layers::WebRenderLayerScrollData* aLayerData) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
protected:
nsIFrame* mScrollFrame;
nsIFrame* mScrolledFrame;
ViewID mScrollParentId;
gfx::CompositorHitTestInfo mHitInfo;
nsRect mHitArea;
};
/**
* nsDisplayZoom is used for subdocuments that have a different full zoom than
* their parent documents. This item creates a container layer.
*/
class nsDisplayZoom : public nsDisplaySubDocument {
public:
/**
* @param aFrame is the root frame of the subdocument.
* @param aList contains the display items for the subdocument.
* @param aAPD is the app units per dev pixel ratio of the subdocument.
* @param aParentAPD is the app units per dev pixel ratio of the parent
* document.
* @param aFlags eGenerateSubdocInvalidations :
* Add UserData to the created ContainerLayer, so that invalidations
* for this layer are send to our nsPresContext.
*/
nsDisplayZoom(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsSubDocumentFrame* aSubDocFrame, nsDisplayList* aList,
int32_t aAPD, int32_t aParentAPD,
nsDisplayOwnLayerFlags aFlags = nsDisplayOwnLayerFlags::None);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayZoom)
NS_DISPLAY_DECL_NAME("Zoom", TYPE_ZOOM)
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
// Get the app units per dev pixel ratio of the child document.
int32_t GetChildAppUnitsPerDevPixel() { return mAPD; }
// Get the app units per dev pixel ratio of the parent document.
int32_t GetParentAppUnitsPerDevPixel() { return mParentAPD; }
private:
int32_t mAPD, mParentAPD;
};
/**
* nsDisplayAsyncZoom is used for APZ zooming. It wraps the contents of the
* root content document's scroll frame, including fixed position content. It
* does not contain the scroll frame's scrollbars. It is clipped to the scroll
* frame's scroll port clip. It is not scrolled; only its non-fixed contents
* are scrolled. This item creates a container layer.
*/
class nsDisplayAsyncZoom : public nsDisplayOwnLayer {
public:
nsDisplayAsyncZoom(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
layers::FrameMetrics::ViewID aViewID);
nsDisplayAsyncZoom(nsDisplayListBuilder* aBuilder,
const nsDisplayAsyncZoom& aOther)
: nsDisplayOwnLayer(aBuilder, aOther), mViewID(aOther.mViewID) {
MOZ_COUNT_CTOR(nsDisplayAsyncZoom);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayAsyncZoom();
#endif
NS_DISPLAY_DECL_NAME("AsyncZoom", TYPE_ASYNC_ZOOM)
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
bool UpdateScrollData(layers::WebRenderScrollData* aData,
layers::WebRenderLayerScrollData* aLayerData) override;
protected:
layers::FrameMetrics::ViewID mViewID;
};
/**
* A base class for different effects types.
*/
class nsDisplayEffectsBase : public nsDisplayWrapList {
public:
nsDisplayEffectsBase(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot,
bool aClearClipChain = false);
nsDisplayEffectsBase(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
nsDisplayEffectsBase(nsDisplayListBuilder* aBuilder,
const nsDisplayEffectsBase& aOther)
: nsDisplayWrapList(aBuilder, aOther),
mEffectsBounds(aOther.mEffectsBounds) {
MOZ_COUNT_CTOR(nsDisplayEffectsBase);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayEffectsBase)
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return false;
}
gfxRect BBoxInUserSpace() const;
gfxPoint UserSpaceOffset() const;
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
protected:
bool ValidateSVGFrame();
// relative to mFrame
nsRect mEffectsBounds;
};
/**
* A display item to paint a stacking context with 'mask' and 'clip-path'
* effects set by the stacking context root frame's style. The 'mask' and
* 'clip-path' properties may both contain multiple masks and clip paths,
* respectively.
*
* Note that 'mask' and 'clip-path' may just contain CSS simple-images and CSS
* basic shapes, respectively. That is, they don't necessarily reference
* resources such as SVG 'mask' and 'clipPath' elements.
*/
class nsDisplayMasksAndClipPaths : public nsDisplayEffectsBase {
public:
nsDisplayMasksAndClipPaths(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot);
nsDisplayMasksAndClipPaths(nsDisplayListBuilder* aBuilder,
const nsDisplayMasksAndClipPaths& aOther)
: nsDisplayEffectsBase(aBuilder, aOther),
mDestRects(aOther.mDestRects.Clone()) {
MOZ_COUNT_CTOR(nsDisplayMasksAndClipPaths);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayMasksAndClipPaths)
NS_DISPLAY_DECL_NAME("Mask", TYPE_MASK)
bool CanMerge(const nsDisplayItem* aItem) const override;
void Merge(const nsDisplayItem* aItem) override {
nsDisplayWrapList::Merge(aItem);
const nsDisplayMasksAndClipPaths* other =
static_cast<const nsDisplayMasksAndClipPaths*>(aItem);
mEffectsBounds.UnionRect(
mEffectsBounds,
other->mEffectsBounds + other->mFrame->GetOffsetTo(mFrame));
}
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplayMasksAndClipPathsGeometry(this, aBuilder);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
#ifdef MOZ_DUMP_PAINTING
void PrintEffects(nsACString& aTo);
#endif
bool IsValidMask();
void PaintWithContentsPaintCallback(
nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
const std::function<void()>& aPaintChildren);
/*
* Paint mask onto aMaskContext in mFrame's coordinate space and
* return whether the mask layer was painted successfully.
*/
bool PaintMask(nsDisplayListBuilder* aBuilder, gfxContext* aMaskContext,
bool aHandleOpacity, bool* aMaskPainted = nullptr);
const nsTArray<nsRect>& GetDestRects() { return mDestRects; }
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
Maybe<nsRect> GetClipWithRespectToASR(
nsDisplayListBuilder* aBuilder,
const ActiveScrolledRoot* aASR) const override;
bool CreatesStackingContextHelper() override { return true; }
private:
NS_DISPLAY_ALLOW_CLONING()
nsTArray<nsRect> mDestRects;
};
class nsDisplayBackdropRootContainer : public nsDisplayWrapList {
public:
nsDisplayBackdropRootContainer(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame, nsDisplayList* aList,
const ActiveScrolledRoot* aActiveScrolledRoot)
: nsDisplayWrapList(aBuilder, aFrame, aList, aActiveScrolledRoot, true) {
MOZ_COUNT_CTOR(nsDisplayBackdropRootContainer);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayBackdropRootContainer)
NS_DISPLAY_DECL_NAME("BackdropRootContainer", TYPE_BACKDROP_ROOT_CONTAINER)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return !aBuilder->IsPaintingForWebRender();
}
bool CreatesStackingContextHelper() override { return true; }
};
class nsDisplayBackdropFilters : public nsDisplayWrapList {
public:
nsDisplayBackdropFilters(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, const nsRect& aBackdropRect)
: nsDisplayWrapList(aBuilder, aFrame, aList),
mBackdropRect(aBackdropRect) {
MOZ_COUNT_CTOR(nsDisplayBackdropFilters);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayBackdropFilters)
NS_DISPLAY_DECL_NAME("BackdropFilter", TYPE_BACKDROP_FILTER)
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
static bool CanCreateWebRenderCommands(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame);
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override {
return !aBuilder->IsPaintingForWebRender();
}
bool CreatesStackingContextHelper() override { return true; }
private:
nsRect mBackdropRect;
};
/**
* A display item to paint a stacking context with filter effects set by the
* stacking context root frame's style.
*
* Note that the filters may just be simple CSS filter functions. That is,
* they won't necessarily be references to SVG 'filter' elements.
*/
class nsDisplayFilters : public nsDisplayEffectsBase {
public:
nsDisplayFilters(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
nsDisplayFilters(nsDisplayListBuilder* aBuilder,
const nsDisplayFilters& aOther)
: nsDisplayEffectsBase(aBuilder, aOther),
mEffectsBounds(aOther.mEffectsBounds) {
MOZ_COUNT_CTOR(nsDisplayFilters);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayFilters)
NS_DISPLAY_DECL_NAME("Filter", TYPE_FILTER)
bool CanMerge(const nsDisplayItem* aItem) const override {
// Items for the same content element should be merged into a single
// compositing group.
return HasDifferentFrame(aItem) && HasSameTypeAndClip(aItem) &&
HasSameContent(aItem);
}
void Merge(const nsDisplayItem* aItem) override {
nsDisplayWrapList::Merge(aItem);
const nsDisplayFilters* other = static_cast<const nsDisplayFilters*>(aItem);
mEffectsBounds.UnionRect(
mEffectsBounds,
other->mEffectsBounds + other->mFrame->GetOffsetTo(mFrame));
}
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override {
*aSnap = false;
return mEffectsBounds + ToReferenceFrame();
}
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplayFiltersGeometry(this, aBuilder);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override;
#ifdef MOZ_DUMP_PAINTING
void PrintEffects(nsACString& aTo);
#endif
void PaintWithContentsPaintCallback(
nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
const std::function<void(gfxContext* aContext)>& aPaintChildren);
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool CanCreateWebRenderCommands() const;
bool CanApplyOpacity(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const override {
return CanCreateWebRenderCommands();
}
bool CreatesStackingContextHelper() override { return true; }
private:
NS_DISPLAY_ALLOW_CLONING()
// relative to mFrame
nsRect mEffectsBounds;
nsRect mVisibleRect;
};
/* A display item that applies a transformation to all of its descendant
* elements. This wrapper should only be used if there is a transform applied
* to the root element.
*
* The reason that a "bounds" rect is involved in transform calculations is
* because CSS-transforms allow percentage values for the x and y components
* of <translation-value>s, where percentages are percentages of the element's
* border box.
*
* INVARIANT: The wrapped frame is transformed or we supplied a transform getter
* function.
* INVARIANT: The wrapped frame is non-null.
*/
class nsDisplayTransform : public nsPaintedDisplayItem {
using Matrix4x4 = gfx::Matrix4x4;
using Matrix4x4Flagged = gfx::Matrix4x4Flagged;
using TransformReferenceBox = nsStyleTransformMatrix::TransformReferenceBox;
public:
enum class PrerenderDecision : uint8_t { No, Full, Partial };
enum {
WithTransformGetter,
};
/* Constructor accepts a display list, empties it, and wraps it up. It also
* ferries the underlying frame to the nsDisplayItem constructor.
*/
nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, const nsRect& aChildrenBuildingRect);
nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, const nsRect& aChildrenBuildingRect,
PrerenderDecision aPrerenderDecision);
nsDisplayTransform(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, const nsRect& aChildrenBuildingRect,
decltype(WithTransformGetter));
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayTransform)
NS_DISPLAY_DECL_NAME("nsDisplayTransform", TYPE_TRANSFORM)
void UpdateBounds(nsDisplayListBuilder* aBuilder) override;
/**
* This function updates bounds for items with a frame establishing
* 3D rendering context.
*/
void UpdateBoundsFor3D(nsDisplayListBuilder* aBuilder);
void DoUpdateBoundsPreserves3D(nsDisplayListBuilder* aBuilder) override;
void Destroy(nsDisplayListBuilder* aBuilder) override {
GetChildren()->DeleteAll(aBuilder);
nsPaintedDisplayItem::Destroy(aBuilder);
}
nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) const override;
RetainedDisplayList* GetChildren() const override { return &mChildren; }
nsRect GetUntransformedBounds(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override {
*aSnap = false;
return mChildBounds;
}
const nsRect& GetUntransformedPaintRect() const override {
return mChildrenBuildingRect;
}
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override;
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override;
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override;
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx,
const Maybe<gfx::Polygon>& aPolygon);
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
bool UpdateScrollData(layers::WebRenderScrollData* aData,
layers::WebRenderLayerScrollData* aLayerData) override;
nsDisplayItemGeometry* AllocateGeometry(
nsDisplayListBuilder* aBuilder) override {
return new nsDisplayTransformGeometry(
this, aBuilder, GetTransformForRendering(),
mFrame->PresContext()->AppUnitsPerDevPixel());
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override {
const nsDisplayTransformGeometry* geometry =
static_cast<const nsDisplayTransformGeometry*>(aGeometry);
// This code is only called for flattened, inactive transform items.
// Only check if the transform has changed. The bounds invalidation should
// be handled by the children themselves.
if (!geometry->mTransform.FuzzyEqual(GetTransformForRendering())) {
bool snap;
aInvalidRegion->Or(GetBounds(aBuilder, &snap), geometry->mBounds);
}
}
const nsIFrame* ReferenceFrameForChildren() const override {
// If we were created using a transform-getter, then we don't
// belong to a transformed frame, and aren't a reference frame
// for our children.
if (!mHasTransformGetter) {
return mFrame;
}
return nsPaintedDisplayItem::ReferenceFrameForChildren();
}
const nsRect& GetBuildingRectForChildren() const override {
return mChildrenBuildingRect;
}
enum { INDEX_MAX = UINT32_MAX >> TYPE_BITS };
/**
* We include the perspective matrix from our containing block for the
* purposes of visibility calculations, but we exclude it from the transform
* we set on the layer (for rendering), since there will be an
* nsDisplayPerspective created for that.
*/
const Matrix4x4Flagged& GetTransform() const;
const Matrix4x4Flagged& GetInverseTransform() const;
bool ShouldSkipTransform(nsDisplayListBuilder* aBuilder) const;
Matrix4x4 GetTransformForRendering(
LayoutDevicePoint* aOutOrigin = nullptr) const;
/**
* Return the transform that is aggregation of all transform on the
* preserves3d chain.
*/
const Matrix4x4& GetAccumulatedPreserved3DTransform(
nsDisplayListBuilder* aBuilder);
float GetHitDepthAtPoint(nsDisplayListBuilder* aBuilder,
const nsPoint& aPoint);
/**
* TransformRect takes in as parameters a rectangle (in aFrame's coordinate
* space) and returns the smallest rectangle (in aFrame's coordinate space)
* containing the transformed image of that rectangle. That is, it takes
* the four corners of the rectangle, transforms them according to the
* matrix associated with the specified frame, then returns the smallest
* rectangle containing the four transformed points.
*
* @param untransformedBounds The rectangle (in app units) to transform.
* @param aFrame The frame whose transformation should be applied. This
* function raises an assertion if aFrame is null or doesn't have a
* transform applied to it.
* @param aRefBox the reference box to use, which would usually be just
* TransformReferemceBox(aFrame), but callers may override it if
* needed.
*/
static nsRect TransformRect(const nsRect& aUntransformedBounds,
const nsIFrame* aFrame,
TransformReferenceBox& aRefBox);
/* UntransformRect is like TransformRect, except that it inverts the
* transform.
*/
static bool UntransformRect(const nsRect& aTransformedBounds,
const nsRect& aChildBounds,
const nsIFrame* aFrame, nsRect* aOutRect);
bool UntransformRect(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
nsRect* aOutRect) const;
bool UntransformBuildingRect(nsDisplayListBuilder* aBuilder,
nsRect* aOutRect) const {
return UntransformRect(aBuilder, GetBuildingRect(), aOutRect);
}
static gfx::Point3D GetDeltaToTransformOrigin(const nsIFrame* aFrame,
TransformReferenceBox&,
float aAppUnitsPerPixel);
/*
* Returns true if aFrame has perspective applied from its containing
* block.
* Returns the matrix to append to apply the persective (taking
* perspective-origin into account), relative to aFrames coordinate
* space).
* aOutMatrix is assumed to be the identity matrix, and isn't explicitly
* cleared.
*/
static bool ComputePerspectiveMatrix(const nsIFrame* aFrame,
float aAppUnitsPerPixel,
Matrix4x4& aOutMatrix);
struct MOZ_STACK_CLASS FrameTransformProperties {
FrameTransformProperties(const nsIFrame* aFrame,
TransformReferenceBox& aRefBox,
float aAppUnitsPerPixel);
FrameTransformProperties(const StyleTranslate& aTranslate,
const StyleRotate& aRotate,
const StyleScale& aScale,
const StyleTransform& aTransform,
const Maybe<ResolvedMotionPathData>& aMotion,
const gfx::Point3D& aToTransformOrigin)
: mFrame(nullptr),
mTranslate(aTranslate),
mRotate(aRotate),
mScale(aScale),
mTransform(aTransform),
mMotion(aMotion),
mToTransformOrigin(aToTransformOrigin) {}
bool HasTransform() const {
return !mTranslate.IsNone() || !mRotate.IsNone() || !mScale.IsNone() ||
!mTransform.IsNone() || mMotion.isSome();
}
const nsIFrame* mFrame;
const StyleTranslate& mTranslate;
const StyleRotate& mRotate;
const StyleScale& mScale;
const StyleTransform& mTransform;
const Maybe<ResolvedMotionPathData> mMotion;
const gfx::Point3D mToTransformOrigin;
};
/**
* Given a frame with the transform property or an SVG transform,
* returns the transformation matrix for that frame.
*
* @param aFrame The frame to get the matrix from.
* @param aOrigin Relative to which point this transform should be applied.
* @param aAppUnitsPerPixel The number of app units per graphics unit.
* @param aBoundsOverride [optional] If this is nullptr (the default), the
* computation will use the value of TransformReferenceBox(aFrame).
* Otherwise, it will use the value of aBoundsOverride. This is
* mostly for internal use and in most cases you will not need to
* specify a value.
* @param aFlags OFFSET_BY_ORIGIN The resulting matrix will be translated
* by aOrigin. This translation is applied *before* the CSS transform.
* @param aFlags INCLUDE_PRESERVE3D_ANCESTORS The computed transform will
* include the transform of any ancestors participating in the same
* 3d rendering context.
* @param aFlags INCLUDE_PERSPECTIVE The resulting matrix will include the
* perspective transform from the containing block if applicable.
*/
enum {
OFFSET_BY_ORIGIN = 1 << 0,
INCLUDE_PRESERVE3D_ANCESTORS = 1 << 1,
INCLUDE_PERSPECTIVE = 1 << 2,
};
static Matrix4x4 GetResultingTransformMatrix(const nsIFrame* aFrame,
const nsPoint& aOrigin,
float aAppUnitsPerPixel,
uint32_t aFlags);
static Matrix4x4 GetResultingTransformMatrix(
const FrameTransformProperties& aProperties, TransformReferenceBox&,
float aAppUnitsPerPixel);
struct PrerenderInfo {
bool CanUseAsyncAnimations() const {
return mDecision != PrerenderDecision::No && mHasAnimations;
}
PrerenderDecision mDecision = PrerenderDecision::No;
bool mHasAnimations = true;
};
/**
* Decide whether we should prerender some or all of the contents of the
* transformed frame even when it's not completely visible (yet).
* Return PrerenderDecision::Full if the entire contents should be
* prerendered, PrerenderDecision::Partial if some but not all of the
* contents should be prerendered, or PrerenderDecision::No if only the
* visible area should be rendered.
* |mNoAffectDecisionInPreserve3D| is set if the prerender decision should not
* affect the decision on other frames in the preserve 3d tree.
* |aDirtyRect| is updated to the area that should be prerendered.
*/
static PrerenderInfo ShouldPrerenderTransformedContent(
nsDisplayListBuilder* aBuilder, nsIFrame* aFrame, nsRect* aDirtyRect);
bool CanUseAsyncAnimations(nsDisplayListBuilder* aBuilder) override;
bool MayBeAnimated(nsDisplayListBuilder* aBuilder) const;
void WriteDebugInfo(std::stringstream& aStream) override;
bool CanMoveAsync() override {
return EffectCompositor::HasAnimationsForCompositor(
mFrame, DisplayItemType::TYPE_TRANSFORM);
}
/**
* This item is an additional item as the boundary between parent
* and child 3D rendering context.
* \see nsIFrame::BuildDisplayListForStackingContext().
*/
bool IsTransformSeparator() const { return mIsTransformSeparator; }
/**
* This item is the boundary between parent and child 3D rendering
* context.
*/
bool IsLeafOf3DContext() const {
return (IsTransformSeparator() ||
(!mFrame->Extend3DContext() && Combines3DTransformWithAncestors()));
}
/**
* The backing frame of this item participates a 3D rendering
* context.
*/
bool IsParticipating3DContext() const {
return mFrame->Extend3DContext() || Combines3DTransformWithAncestors();
}
bool IsPartialPrerender() const {
return mPrerenderDecision == PrerenderDecision::Partial;
}
/**
* Mark this item as created together with `nsDisplayPerspective`.
* \see nsIFrame::BuildDisplayListForStackingContext().
*/
void MarkWithAssociatedPerspective() { mHasAssociatedPerspective = true; }
void AddSizeOfExcludingThis(nsWindowSizes&) const override;
bool CreatesStackingContextHelper() override { return true; }
private:
void ComputeBounds(nsDisplayListBuilder* aBuilder);
nsRect TransformUntransformedBounds(nsDisplayListBuilder* aBuilder,
const Matrix4x4Flagged& aMatrix) const;
void UpdateUntransformedBounds(nsDisplayListBuilder* aBuilder);
void SetReferenceFrameToAncestor(nsDisplayListBuilder* aBuilder);
void Init(nsDisplayListBuilder* aBuilder, nsDisplayList* aChildren);
static Matrix4x4 GetResultingTransformMatrixInternal(
const FrameTransformProperties& aProperties,
TransformReferenceBox& aRefBox, const nsPoint& aOrigin,
float aAppUnitsPerPixel, uint32_t aFlags);
void Collect3DTransformLeaves(nsDisplayListBuilder* aBuilder,
nsTArray<nsDisplayTransform*>& aLeaves);
using TransformPolygon = layers::BSPPolygon<nsDisplayTransform>;
void CollectSorted3DTransformLeaves(nsDisplayListBuilder* aBuilder,
nsTArray<TransformPolygon>& aLeaves);
mutable Maybe<Matrix4x4Flagged> mTransform;
mutable Maybe<Matrix4x4Flagged> mInverseTransform;
// Accumulated transform of ancestors on the preserves-3d chain.
UniquePtr<Matrix4x4> mTransformPreserves3D;
nsRect mChildrenBuildingRect;
mutable RetainedDisplayList mChildren;
// The untransformed bounds of |mChildren|.
nsRect mChildBounds;
// The transformed bounds of this display item.
nsRect mBounds;
PrerenderDecision mPrerenderDecision : 8;
// This item is a separator between 3D rendering contexts, and
// mTransform have been presetted by the constructor.
// This also forces us not to extend the 3D context. Since we don't create a
// transform item, a container layer, for every frame in a preserves3d
// context, the transform items of a child preserves3d context may extend the
// parent context unintendedly if the root of the child preserves3d context
// doesn't create a transform item.
bool mIsTransformSeparator : 1;
// True if we have a transform getter.
bool mHasTransformGetter : 1;
// True if this item is created together with `nsDisplayPerspective`
// from the same CSS stacking context.
bool mHasAssociatedPerspective : 1;
};
/* A display item that applies a perspective transformation to a single
* nsDisplayTransform child item. We keep this as a separate item since the
* perspective-origin is relative to an ancestor of the transformed frame, and
* APZ can scroll the child separately.
*/
class nsDisplayPerspective : public nsPaintedDisplayItem {
public:
nsDisplayPerspective(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
~nsDisplayPerspective() override = default;
NS_DISPLAY_DECL_NAME("nsDisplayPerspective", TYPE_PERSPECTIVE)
void Destroy(nsDisplayListBuilder* aBuilder) override {
mList.DeleteAll(aBuilder);
nsPaintedDisplayItem::Destroy(aBuilder);
}
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) override {
return GetChildren()->HitTest(aBuilder, aRect, aState, aOutFrames);
}
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const override {
*aSnap = false;
return GetChildren()->GetClippedBoundsWithRespectToASR(aBuilder,
mActiveScrolledRoot);
}
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const override {}
nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
bool* aSnap) const override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
RetainedDisplayList* GetSameCoordinateSystemChildren() const override {
return &mList;
}
RetainedDisplayList* GetChildren() const override { return &mList; }
nsRect GetComponentAlphaBounds(
nsDisplayListBuilder* aBuilder) const override {
return GetChildren()->GetComponentAlphaBounds(aBuilder);
}
void DoUpdateBoundsPreserves3D(nsDisplayListBuilder* aBuilder) override {
if (GetChildren()->GetTop()) {
static_cast<nsDisplayTransform*>(GetChildren()->GetTop())
->DoUpdateBoundsPreserves3D(aBuilder);
}
}
bool CreatesStackingContextHelper() override { return true; }
private:
mutable RetainedDisplayList mList;
};
class nsDisplayTextGeometry;
/**
* This class adds basic support for limiting the rendering (in the inline axis
* of the writing mode) to the part inside the specified edges.
* The two members, mVisIStartEdge and mVisIEndEdge, are relative to the edges
* of the frame's scrollable overflow rectangle and are the amount to suppress
* on each side.
*
* Setting none, both or only one edge is allowed.
* The values must be non-negative.
* The default value for both edges is zero, which means everything is painted.
*/
class nsDisplayText final : public nsPaintedDisplayItem {
public:
nsDisplayText(nsDisplayListBuilder* aBuilder, nsTextFrame* aFrame);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayText)
NS_DISPLAY_DECL_NAME("Text", TYPE_TEXT)
nsRect GetBounds(nsDisplayListBuilder* aBuilder, bool* aSnap) const final {
*aSnap = false;
return mBounds;
}
void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*>* aOutFrames) final {
if (nsRect(ToReferenceFrame(), mFrame->GetSize()).Intersects(aRect)) {
aOutFrames->AppendElement(mFrame);
}
}
bool CreateWebRenderCommands(wr::DisplayListBuilder& aBuilder,
wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) final;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) final;
nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) const final {
if (gfxPlatform::GetPlatform()->RespectsFontStyleSmoothing()) {
// On OS X, web authors can turn off subpixel text rendering using the
// CSS property -moz-osx-font-smoothing. If they do that, we don't need
// to use component alpha layers for the affected text.
if (mFrame->StyleFont()->mFont.smoothing == NS_FONT_SMOOTHING_GRAYSCALE) {
return nsRect();
}
}
bool snap;
return GetBounds(aBuilder, &snap);
}
nsDisplayItemGeometry* AllocateGeometry(nsDisplayListBuilder* aBuilder) final;
void ComputeInvalidationRegion(nsDisplayListBuilder* aBuilder,
const nsDisplayItemGeometry* aGeometry,
nsRegion* aInvalidRegion) const final;
void RenderToContext(gfxContext* aCtx, nsDisplayListBuilder* aBuilder,
const nsRect& aVisibleRect, float aOpacity = 1.0f,
bool aIsRecording = false);
bool CanApplyOpacity(WebRenderLayerManager* aManager,
nsDisplayListBuilder* aBuilder) const final;
void WriteDebugInfo(std::stringstream& aStream) final;
static nsDisplayText* CheckCast(nsDisplayItem* aItem) {
return (aItem->GetType() == DisplayItemType::TYPE_TEXT)
? static_cast<nsDisplayText*>(aItem)
: nullptr;
}
struct ClipEdges {
ClipEdges(const nsIFrame* aFrame, const nsPoint& aToReferenceFrame,
nscoord aVisIStartEdge, nscoord aVisIEndEdge) {
nsRect r = aFrame->ScrollableOverflowRect() + aToReferenceFrame;
if (aFrame->GetWritingMode().IsVertical()) {
mVisIStart = aVisIStartEdge > 0 ? r.y + aVisIStartEdge : nscoord_MIN;
mVisIEnd = aVisIEndEdge > 0
? std::max(r.YMost() - aVisIEndEdge, mVisIStart)
: nscoord_MAX;
} else {
mVisIStart = aVisIStartEdge > 0 ? r.x + aVisIStartEdge : nscoord_MIN;
mVisIEnd = aVisIEndEdge > 0
? std::max(r.XMost() - aVisIEndEdge, mVisIStart)
: nscoord_MAX;
}
}
void Intersect(nscoord* aVisIStart, nscoord* aVisISize) const {
nscoord end = *aVisIStart + *aVisISize;
*aVisIStart = std::max(*aVisIStart, mVisIStart);
*aVisISize = std::max(std::min(end, mVisIEnd) - *aVisIStart, 0);
}
nscoord mVisIStart;
nscoord mVisIEnd;
};
nscoord& VisIStartEdge() { return mVisIStartEdge; }
nscoord& VisIEndEdge() { return mVisIEndEdge; }
private:
nsRect mBounds;
nsRect mVisibleRect;
// Lengths measured from the visual inline start and end sides
// (i.e. left and right respectively in horizontal writing modes,
// regardless of bidi directionality; top and bottom in vertical modes).
nscoord mVisIStartEdge;
nscoord mVisIEndEdge;
};
/**
* A display item that for webrender to handle SVG
*/
class nsDisplaySVGWrapper : public nsDisplayWrapList {
public:
nsDisplaySVGWrapper(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplaySVGWrapper)
NS_DISPLAY_DECL_NAME("SVGWrapper", TYPE_SVG_WRAPPER)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
GetChildren()->Paint(aBuilder, aCtx,
mFrame->PresContext()->AppUnitsPerDevPixel());
}
bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override;
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
};
/**
* A display item for webrender to handle SVG foreign object
*/
class nsDisplayForeignObject : public nsDisplayWrapList {
public:
nsDisplayForeignObject(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayForeignObject();
#endif
NS_DISPLAY_DECL_NAME("ForeignObject", TYPE_FOREIGN_OBJECT)
virtual bool ShouldFlattenAway(nsDisplayListBuilder* aBuilder) override;
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override {
GetChildren()->Paint(aBuilder, aCtx,
mFrame->PresContext()->AppUnitsPerDevPixel());
}
bool CreateWebRenderCommands(
wr::DisplayListBuilder& aBuilder, wr::IpcResourceUpdateQueue& aResources,
const StackingContextHelper& aSc,
layers::RenderRootStateManager* aManager,
nsDisplayListBuilder* aDisplayListBuilder) override;
};
/**
* A display item to represent a hyperlink.
*/
class nsDisplayLink : public nsPaintedDisplayItem {
public:
nsDisplayLink(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const char* aLinkSpec, const nsRect& aRect)
: nsPaintedDisplayItem(aBuilder, aFrame),
mLinkSpec(aLinkSpec),
mRect(aRect) {}
NS_DISPLAY_DECL_NAME("Link", TYPE_LINK)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
private:
nsCString mLinkSpec;
nsRect mRect;
};
/**
* A display item to represent a destination within the document.
*/
class nsDisplayDestination : public nsPaintedDisplayItem {
public:
nsDisplayDestination(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const char* aDestinationName, const nsPoint& aPosition)
: nsPaintedDisplayItem(aBuilder, aFrame),
mDestinationName(aDestinationName),
mPosition(aPosition) {}
NS_DISPLAY_DECL_NAME("Destination", TYPE_DESTINATION)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
private:
nsCString mDestinationName;
nsPoint mPosition;
};
class FlattenedDisplayListIterator {
public:
FlattenedDisplayListIterator(nsDisplayListBuilder* aBuilder,
nsDisplayList* aList)
: FlattenedDisplayListIterator(aBuilder, aList, true) {}
virtual bool HasNext() const { return mNext || !mStack.IsEmpty(); }
nsDisplayItem* GetNextItem() {
if (!mNext) {
return nullptr;
}
nsDisplayItem* next = mNext;
mNext = next->GetAbove();
if (mNext && next->HasChildren() && mNext->HasChildren()) {
// Since |next| and |mNext| are container items in the same list,
// merging them might be possible.
next = TryMergingFrom(next);
}
ResolveFlattening();
return next;
}
nsDisplayItem* PeekNext() { return mNext; }
protected:
FlattenedDisplayListIterator(nsDisplayListBuilder* aBuilder,
nsDisplayList* aList,
const bool aResolveFlattening)
: mBuilder(aBuilder), mNext(aList->GetBottom()) {
if (aResolveFlattening) {
// This is done conditionally in case subclass overrides
// ShouldFlattenNextItem().
ResolveFlattening();
}
}
virtual void EnterChildList(nsDisplayItem* aContainerItem) {}
virtual void ExitChildList() {}
bool AtEndOfNestedList() const { return !mNext && mStack.Length() > 0; }
virtual bool ShouldFlattenNextItem() {
return mNext && mNext->ShouldFlattenAway(mBuilder);
}
void ResolveFlattening() {
// Handle the case where we reach the end of a nested list, or the current
// item should start a new nested list. Repeat this until we find an actual
// item, or the very end of the outer list.
while (AtEndOfNestedList() || ShouldFlattenNextItem()) {
if (AtEndOfNestedList()) {
ExitChildList();
// We reached the end of the list, pop the next item from the stack.
mNext = mStack.PopLastElement();
} else {
EnterChildList(mNext);
// This item wants to be flattened. Store the next item on the stack,
// and use the first item in the child list instead.
mStack.AppendElement(mNext->GetAbove());
mNext = mNext->GetChildren()->GetBottom();
}
}
}
/**
* Tries to merge display items starting from |aCurrent|.
* Updates the internal pointer to the next display item.
*/
nsDisplayItem* TryMergingFrom(nsDisplayItem* aCurrent) {
MOZ_ASSERT(aCurrent);
MOZ_ASSERT(aCurrent->GetAbove());
nsDisplayWrapList* current = aCurrent->AsDisplayWrapList();
nsDisplayWrapList* next = mNext->AsDisplayWrapList();
if (!current || !next) {
// Either the current or the next item do not support merging.
return aCurrent;
}
// Attempt to merge |next| with |current|.
if (current->CanMerge(next)) {
// Merging is possible, collect all the successive mergeable items.
AutoTArray<nsDisplayWrapList*, 2> willMerge{current};
do {
willMerge.AppendElement(next);
mNext = next->GetAbove();
next = mNext ? mNext->AsDisplayWrapList() : nullptr;
} while (next && current->CanMerge(next));
current = mBuilder->MergeItems(willMerge);
}
// Here |mNext| will be either the first item that could not be merged with
// |current|, or nullptr.
return current;
}
private:
nsDisplayListBuilder* mBuilder;
nsDisplayItem* mNext;
AutoTArray<nsDisplayItem*, 16> mStack;
};
class PaintTelemetry {
public:
class AutoRecordPaint {
public:
AutoRecordPaint();
~AutoRecordPaint();
private:
TimeStamp mStart;
};
private:
static uint32_t sPaintLevel;
};
} // namespace mozilla
#endif /*NSDISPLAYLIST_H_*/