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pjs/layout/base/nsDisplayList.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=2 sw=2 et tw=78:
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Novell code.
*
* The Initial Developer of the Original Code is Novell Corporation.
* Portions created by the Initial Developer are Copyright (C) 2006
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* robert@ocallahan.org
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK *****
*/
/*
* structures that represent things to be painted (ordered in z-order),
* used during painting and hit testing
*/
#ifndef NSDISPLAYLIST_H_
#define NSDISPLAYLIST_H_
#include "nsCOMPtr.h"
#include "nsIFrame.h"
#include "nsPoint.h"
#include "nsRect.h"
#include "nsISelection.h"
#include "nsCaret.h"
#include "plarena.h"
#include "Layers.h"
#include "nsRegion.h"
#include "FrameLayerBuilder.h"
#include "nsThemeConstants.h"
#include <stdlib.h>
class nsIPresShell;
class nsIContent;
class nsIRenderingContext;
class nsIDeviceContext;
class nsDisplayTableItem;
class nsDisplayItem;
/*
* 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.
*/
// All types are defined in nsDisplayItemTypes.h
#ifdef NS_DEBUG
#define NS_DISPLAY_DECL_NAME(n, e) \
virtual const char* Name() { return n; } \
virtual Type GetType() { return e; }
#else
#define NS_DISPLAY_DECL_NAME(n, e) \
virtual Type GetType() { return e; }
#endif
/**
* 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 a PLArena. 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 {
public:
typedef mozilla::FramePropertyDescriptor FramePropertyDescriptor;
typedef mozilla::FrameLayerBuilder FrameLayerBuilder;
typedef nsIWidget::ThemeGeometry ThemeGeometry;
/**
* @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 aIsForEvents PR_TRUE if we're creating this list in order to
* determine which frame is under the mouse position
* @param aBuildCaret whether or not we should include the caret in any
* display lists that we make.
*/
enum Mode {
PAINTING,
EVENT_DELIVERY,
PLUGIN_GEOMETRY,
OTHER
};
nsDisplayListBuilder(nsIFrame* aReferenceFrame, Mode aMode, PRBool aBuildCaret);
~nsDisplayListBuilder();
/**
* @return PR_TRUE if the display is being built in order to determine which
* frame is under the mouse position.
*/
PRBool IsForEventDelivery() { return mMode == EVENT_DELIVERY; }
/**
* @return PR_TRUE if the display list is being built to compute geometry
* for plugins.
*/
PRBool IsForPluginGeometry() { return mMode == PLUGIN_GEOMETRY; }
/**
* @return PR_TRUE if the display list is being built for painting.
*/
PRBool IsForPainting() { return mMode == PAINTING; }
/**
* @return PR_TRUE if "painting is suppressed" during page load and we
* should paint only the background of the document.
*/
PRBool IsBackgroundOnly() {
NS_ASSERTION(mPresShellStates.Length() > 0,
"don't call this if we're not in a presshell");
return CurrentPresShellState()->mIsBackgroundOnly;
}
/**
* @return PR_TRUE if the currently active BuildDisplayList call is being
* applied to a frame at the root of a pseudo stacking context. A pseudo
* stacking context is either a real stacking context or basically what
* CSS2.1 appendix E refers to with "treat the element as if it created
* a new stacking context
*/
PRBool IsAtRootOfPseudoStackingContext() { return mIsAtRootOfPseudoStackingContext; }
/**
* @return the selection that painting should be restricted to (or nsnull
* in the normal unrestricted case)
*/
nsISelection* GetBoundingSelection() { return mBoundingSelection; }
/**
* @return the root of the display list's frame (sub)tree, whose origin
* establishes the coordinate system for the display list
*/
nsIFrame* ReferenceFrame() { 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. It may be optimized to be faster than
* aFrame->GetOffsetToCrossDoc(ReferenceFrame()) (but currently isn't).
*/
nsPoint ToReferenceFrame(const nsIFrame* aFrame) {
return aFrame->GetOffsetToCrossDoc(ReferenceFrame());
}
/**
* 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; }
/**
* 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 = PR_TRUE; }
PRBool GetIncludeAllOutOfFlows() const { return mIncludeAllOutOfFlows; }
/**
* Calling this setter makes us exclude all leaf frames that does
* not have the NS_FRAME_SELECTED_CONTENT bit.
*/
void SetSelectedFramesOnly() { mSelectedFramesOnly = PR_TRUE; }
PRBool GetSelectedFramesOnly() { return mSelectedFramesOnly; }
/**
* Calling this setter makes us compute accurate visible regions at the cost
* of performance if regions get very complex.
*/
void SetAccurateVisibleRegions() { mAccurateVisibleRegions = PR_TRUE; }
PRBool GetAccurateVisibleRegions() { return mAccurateVisibleRegions; }
/**
* Allows callers to selectively override the regular paint suppression checks,
* so that methods like GetFrameForPoint work when painting is suppressed.
*/
void IgnorePaintSuppression() { mIgnoreSuppression = PR_TRUE; }
/**
* @return Returns if this builder will ignore paint suppression.
*/
PRBool IsIgnoringPaintSuppression() { return mIgnoreSuppression; }
/**
* @return Returns if this builder had to ignore painting suppression on some
* document when building the display list.
*/
PRBool GetHadToIgnorePaintSuppression() { return mHadToIgnoreSuppression; }
/**
* Call this if we're doing normal painting to the window.
*/
void SetPaintingToWindow(PRBool aToWindow) { mIsPaintingToWindow = aToWindow; }
PRBool IsPaintingToWindow() const { return mIsPaintingToWindow; }
/**
* Display the caret if needed.
*/
nsresult DisplayCaret(nsIFrame* aFrame, const nsRect& aDirtyRect,
nsDisplayList* aList) {
nsIFrame* frame = GetCaretFrame();
if (aFrame != frame) {
return NS_OK;
}
return frame->DisplayCaret(this, aDirtyRect, aList);
}
/**
* Get the frame that the caret is supposed to draw in.
* If the caret is currently invisible, this will be null.
*/
nsIFrame* GetCaretFrame() {
return CurrentPresShellState()->mCaretFrame;
}
/**
* Get the caret associated with the current presshell.
*/
nsCaret* GetCaret();
/**
* Notify the display list builder that we're entering a presshell.
* aReferenceFrame should be a frame in the new presshell and aDirtyRect
* should be the current dirty rect in aReferenceFrame's coordinate space.
*/
void EnterPresShell(nsIFrame* aReferenceFrame, const nsRect& aDirtyRect);
/**
* Notify the display list builder that we're leaving a presshell.
*/
void LeavePresShell(nsIFrame* aReferenceFrame, const nsRect& aDirtyRect);
/**
* Returns true if we're currently building a display list that's
* directly or indirectly under an nsDisplayTransform or SVG
* foreignObject.
*/
PRBool IsInTransform() { return mInTransform; }
/**
* Indicate whether or not we're directly or indirectly under and
* nsDisplayTransform or SVG foreignObject.
*/
void SetInTransform(PRBool aInTransform) { mInTransform = aInTransform; }
/**
* Returns true if snapping is enabled for the final drawing context.
* The default is true.
*/
PRBool IsSnappingEnabled() { return mSnappingEnabled; }
/**
* Set if snapping is enabled for the final drawing context.
*/
void SetSnappingEnabled(PRBool aSnappingEnabled) { mSnappingEnabled = aSnappingEnabled; }
/**
* @return PR_TRUE if images have been set to decode synchronously.
*/
PRBool ShouldSyncDecodeImages() { 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(PRBool aSyncDecodeImages) {
mSyncDecodeImages = aSyncDecodeImages;
}
/**
* Helper method to generate background painting flags based on the
* information available in the display list builder. Currently only
* accounts for mSyncDecodeImages.
*/
PRUint32 GetBackgroundPaintFlags();
/**
* Subtracts aRegion from *aVisibleRegion. We avoid letting
* aVisibleRegion become overcomplex by simplifying it if necessary ---
* unless mAccurateVisibleRegions is set, in which case we let it
* get arbitrarily complex.
*/
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,
const nsRect& aDirtyRect);
/**
* Return the FrameLayerBuilder.
*/
FrameLayerBuilder* LayerBuilder() { return &mLayerBuilder; }
/**
* Get the area of the final transparent region.
*/
const nsRegion* GetFinalTransparentRegion() { return mFinalTransparentRegion; }
/**
* Record the area of the final transparent region after all visibility
* calculations were performed.
*/
void SetFinalTransparentRegion(const nsRegion& aFinalTransparentRegion)
{
mFinalTransparentRegion = &aFinalTransparentRegion;
}
const nsTArray<ThemeGeometry>& GetThemeGeometries() { return mThemeGeometries; }
/**
* 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) const {
return
(aFrame->GetStateBits() & NS_FRAME_FORCE_DISPLAY_LIST_DESCEND_INTO) ||
GetIncludeAllOutOfFlows();
}
/**
* 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
* NS_THEME_MOZ_MAC_UNIFIED_TOOLBAR and NS_THEME_TOOLBAR) 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 aRect the device-pixel rect relative to the widget's displayRoot
* for the themed widget
*/
void RegisterThemeGeometry(PRUint8 aWidgetType,
const nsIntRect& aRect) {
if (mIsPaintingToWindow && mPresShellStates.Length() == 1) {
ThemeGeometry geometry(aWidgetType, aRect);
mThemeGeometries.AppendElement(geometry);
}
}
/**
* Allocate memory in our arena. It will only be freed when this display list
* builder is destroyed. This memory holds nsDisplayItems. nsDisplayItem
* destructors are called as soon as the item is no longer used.
*/
void* Allocate(size_t aSize);
/**
* A helper class to temporarily set the value of
* mIsAtRootOfPseudoStackingContext.
*/
class AutoIsRootSetter;
friend class AutoIsRootSetter;
class AutoIsRootSetter {
public:
AutoIsRootSetter(nsDisplayListBuilder* aBuilder, PRBool aIsRoot)
: mBuilder(aBuilder), mOldValue(aBuilder->mIsAtRootOfPseudoStackingContext) {
aBuilder->mIsAtRootOfPseudoStackingContext = aIsRoot;
}
~AutoIsRootSetter() {
mBuilder->mIsAtRootOfPseudoStackingContext = mOldValue;
}
private:
nsDisplayListBuilder* mBuilder;
PRPackedBool mOldValue;
};
/**
* A helper class to temporarily set the value of mInTransform.
*/
class AutoInTransformSetter;
friend class AutoInTransformSetter;
class AutoInTransformSetter {
public:
AutoInTransformSetter(nsDisplayListBuilder* aBuilder, PRBool aInTransform)
: mBuilder(aBuilder), mOldValue(aBuilder->mInTransform) {
aBuilder->mInTransform = aInTransform;
}
~AutoInTransformSetter() {
mBuilder->mInTransform = mOldValue;
}
private:
nsDisplayListBuilder* mBuilder;
PRPackedBool mOldValue;
};
// Helpers for tables
nsDisplayTableItem* GetCurrentTableItem() { return mCurrentTableItem; }
void SetCurrentTableItem(nsDisplayTableItem* aTableItem) { mCurrentTableItem = aTableItem; }
NS_DECLARE_FRAME_PROPERTY(OutOfFlowDirtyRectProperty, nsIFrame::DestroyRect)
nsPresContext* CurrentPresContext() {
return CurrentPresShellState()->mPresShell->GetPresContext();
}
private:
struct PresShellState {
nsIPresShell* mPresShell;
nsIFrame* mCaretFrame;
PRUint32 mFirstFrameMarkedForDisplay;
PRPackedBool mIsBackgroundOnly;
};
PresShellState* CurrentPresShellState() {
NS_ASSERTION(mPresShellStates.Length() > 0,
"Someone forgot to enter a presshell");
return &mPresShellStates[mPresShellStates.Length() - 1];
}
FrameLayerBuilder mLayerBuilder;
nsIFrame* mReferenceFrame;
nsIFrame* mIgnoreScrollFrame;
PLArenaPool mPool;
nsCOMPtr<nsISelection> mBoundingSelection;
nsAutoTArray<PresShellState,8> mPresShellStates;
nsAutoTArray<nsIFrame*,100> mFramesMarkedForDisplay;
nsAutoTArray<ThemeGeometry,2> mThemeGeometries;
nsDisplayTableItem* mCurrentTableItem;
const nsRegion* mFinalTransparentRegion;
Mode mMode;
PRPackedBool mBuildCaret;
PRPackedBool mIgnoreSuppression;
PRPackedBool mHadToIgnoreSuppression;
PRPackedBool mIsAtRootOfPseudoStackingContext;
PRPackedBool mIncludeAllOutOfFlows;
PRPackedBool mSelectedFramesOnly;
PRPackedBool mAccurateVisibleRegions;
// True when we're building a display list that's directly or indirectly
// under an nsDisplayTransform
PRPackedBool mInTransform;
PRPackedBool mSyncDecodeImages;
PRPackedBool mIsPaintingToWindow;
PRPackedBool mSnappingEnabled;
};
class nsDisplayItem;
class nsDisplayList;
/**
* 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(nsnull) {}
nsDisplayItem* mAbove;
friend class nsDisplayList;
};
/**
* This is the unit of rendering and event testing. Each instance of this
* class represents an entity that can be drawn on the screen, e.g., a
* frame's CSS background, or a frame's text string.
*
* nsDisplayListItems can be containers --- i.e., they can perform hit testing
* and painting by recursively traversing a list of child items.
*
* These are arena-allocated during display list construction. A typical
* subclass would just have a frame pointer, so its object would be just three
* pointers (vtable, next-item, frame).
*
* Display items belong to a list at all times (except temporarily as they
* move from one list to another).
*/
class nsDisplayItem : public nsDisplayItemLink {
public:
typedef mozilla::layers::FrameMetrics::ViewID ViewID;
typedef mozilla::layers::Layer Layer;
typedef mozilla::layers::LayerManager LayerManager;
typedef mozilla::LayerState LayerState;
// This is never instantiated directly (it has pure virtual methods), so no
// need to count constructors and destructors.
nsDisplayItem(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) :
mFrame(aFrame) {
if (aFrame) {
mToReferenceFrame = aBuilder->ToReferenceFrame(aFrame);
}
}
virtual ~nsDisplayItem() {}
void* operator new(size_t aSize,
nsDisplayListBuilder* aBuilder) CPP_THROW_NEW {
return aBuilder->Allocate(aSize);
}
// Contains all the type integers for each display list item type
#include "nsDisplayItemTypes.h"
struct HitTestState {
typedef nsTArray<ViewID> ShadowArray;
HitTestState(ShadowArray* aShadows = NULL)
: mShadows(aShadows) {
}
~HitTestState() {
NS_ASSERTION(mItemBuffer.Length() == 0,
"mItemBuffer should have been cleared");
}
nsAutoTArray<nsDisplayItem*, 100> mItemBuffer;
// It is sometimes useful to hit test for frames that are not in this
// process. Display items may append IDs into this array if it is
// non-null.
ShadowArray* mShadows;
};
/**
* 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.
*/
virtual Type GetType() = 0;
/**
* If this returns a non-zero value, then pairing this with the
* GetUnderlyingFrame() pointer gives a key that uniquely identifies
* this display item in the display item tree.
* This will only return a zero value for items which wrap display lists
* and do not create a CSS stacking context, therefore requiring
* display items to be individually wrapped --- currently nsDisplayClip
* and nsDisplayClipRoundedRect only.
*/
virtual PRUint32 GetPerFrameKey() { return PRUint32(GetType()); }
/**
* 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.
*
* @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) {}
/**
* @return the frame that this display item is based on. This is used to sort
* items by z-index and content order and for some other uses. For some items
* that wrap item lists, this could return nsnull because there is no single
* underlying frame; for leaf items it will never return nsnull.
*/
inline nsIFrame* GetUnderlyingFrame() { return mFrame; }
/**
* The default bounds is the frame border rect.
* @return a rectangle relative to aBuilder->ReferenceFrame() that
* contains the area drawn by this display item
*/
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) {
return nsRect(ToReferenceFrame(), GetUnderlyingFrame()->GetSize());
}
/**
* @return a region of the item that is opaque --- every pixel painted
* with an opaque color.
*/
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
PRBool* aForceTransparentSurface = nsnull)
{
if (aForceTransparentSurface) {
*aForceTransparentSurface = PR_FALSE;
}
return nsRegion();
}
/**
* If this returns true, then aColor is set to the uniform color
* @return PR_TRUE if the item is guaranteed to paint every pixel in its
* bounds with the same (possibly translucent) color
*/
virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor) { return PR_FALSE; }
/**
* @return PR_FALSE if the painting performed by the item is invariant
* when the item's underlying frame is moved relative to aFrame.
* In other words, if you render the item at locations P and P', the rendering
* only differs by the translation.
* It return PR_TRUE for all wrapped lists.
*/
virtual PRBool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame)
{ return PR_FALSE; }
/**
* @return PR_TRUE if the contents of this item are rendered fixed relative
* to the nearest viewport *and* they cover the viewport's scrollport.
* Only return true if the contents actually vary when scrolling in the viewport.
*/
virtual PRBool IsFixedAndCoveringViewport(nsDisplayListBuilder* aBuilder)
{ return PR_FALSE; }
/**
* @return LAYER_NONE if BuildLayer will return null. In this case
* there is no layer for the item, and Paint should be called instead
* to paint the content using Thebes.
* Return LAYER_INACTIVE if there is a layer --- BuildLayer will
* not return null (unless there's an error) --- but the layer contents
* are not changing frequently. In this case it makes sense to composite
* the layer into a ThebesLayer with other content, so we don't have to
* recomposite it every time we paint.
* Note: GetLayerState is only allowed to return LAYER_INACTIVE if all
* descendant display items returned LAYER_INACTIVE or LAYER_NONE. Also,
* all descendant display item frames must have an active scrolled root
* that's either the same as this item's frame's active scrolled root, or
* a descendant of this item's frame. This ensures that the entire
* set of display items can be collapsed onto a single ThebesLayer.
* Return LAYER_ACTIVE if the layer is active, that is, its contents are
* changing frequently. In this case it makes sense to keep the layer
* as a separate buffer in VRAM and composite it into the destination
* every time we paint.
*/
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager)
{ return mozilla::LAYER_NONE; }
/**
* Actually paint this item to some rendering context.
* Content outside mVisibleRect need not be painted.
* aCtx must be set up as for nsDisplayList::Paint.
*/
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx) {}
/**
* Get the layer drawn by this display item. Call this only if
* GetLayerState() returns something other than LAYER_NONE.
* If GetLayerState returned LAYER_NONE then Paint will be called
* instead.
* This is called while aManager is in the construction phase.
*
* The caller (nsDisplayList) is responsible for setting the visible
* region of the layer.
*/
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager)
{ return nsnull; }
/**
* On entry, aVisibleRegion contains the region (relative to ReferenceFrame())
* which may be visible. If the display item opaquely covers an area, it
* can remove that area from aVisibleRegion before returning.
* nsDisplayList::ComputeVisibility automatically subtracts the region
* returned by GetOpaqueRegion, and automatically removes items whose bounds
* do not intersect the visible area, so implementations of
* nsDisplayItem::ComputeVisibility do not need to do these things.
* nsDisplayList::ComputeVisibility will already have set mVisibleRect on
* this item to the intersection of *aVisibleRegion and this item's bounds.
* We rely on that, so this should only be called by
* nsDisplayList::ComputeVisibility or nsDisplayItem::RecomputeVisibility.
*
* @return PR_TRUE if the item is visible, PR_FALSE if no part of the item
* is visible
*/
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion)
{ return !mVisibleRect.IsEmpty(); }
/**
* 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).
* @return PR_TRUE if the merge was successful and the other item should be deleted
*/
virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
return PR_FALSE;
}
/**
* If this is a leaf item we return null, otherwise we return the wrapped
* list.
*/
virtual nsDisplayList* GetList() { return nsnull; }
/**
* Returns the visible rect. Should only be called after ComputeVisibility
* has happened.
*/
const nsRect& GetVisibleRect() { return mVisibleRect; }
#ifdef NS_DEBUG
/**
* For debugging and stuff
*/
virtual const char* Name() = 0;
#endif
nsDisplayItem* GetAbove() { return mAbove; }
/**
* Like ComputeVisibility, but does the work that nsDisplayList
* does per-item:
* -- Intersects GetBounds with aVisibleRegion and puts the result
* in mVisibleRect
* -- Subtracts bounds from aVisibleRegion if the item is opaque
*/
PRBool RecomputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
/**
* Returns the result of aBuilder->ToReferenceFrame(GetUnderlyingFrame())
*/
const nsPoint& ToReferenceFrame() {
NS_ASSERTION(mFrame, "No frame?");
return mToReferenceFrame;
}
/**
* 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) { return nsRect(); }
/**
* Disable usage of component alpha. Currently only relevant for items that have text.
*/
virtual void DisableComponentAlpha() {}
protected:
friend class nsDisplayList;
nsDisplayItem() {
mAbove = nsnull;
}
nsIFrame* mFrame;
// Result of ToReferenceFrame(mFrame), if mFrame is non-null
nsPoint mToReferenceFrame;
// This is the rectangle that needs to be painted.
// nsDisplayList::ComputeVisibility sets this to the visible region
// of the item by intersecting the current visible region with the bounds
// of the item. Paint implementations can use this to limit their drawing.
// Guaranteed to be contained in GetBounds().
nsRect mVisibleRect;
};
/**
* 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(), ComputeVisibility()) 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:
typedef mozilla::layers::Layer Layer;
typedef mozilla::layers::LayerManager LayerManager;
typedef mozilla::layers::ThebesLayer ThebesLayer;
/**
* Create an empty list.
*/
nsDisplayList() :
mIsOpaque(PR_FALSE)
{
mTop = &mSentinel;
mSentinel.mAbove = nsnull;
#ifdef DEBUG
mDidComputeVisibility = PR_FALSE;
#endif
}
~nsDisplayList() {
if (mSentinel.mAbove) {
NS_WARNING("Nonempty list left over?");
}
DeleteAll();
}
/**
* 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) {
NS_ASSERTION(aItem, "No item to append!");
NS_ASSERTION(!aItem->mAbove, "Already in a list!");
mTop->mAbove = aItem;
mTop = aItem;
}
/**
* Append a new item to the top of the list. If the item is null we return
* NS_ERROR_OUT_OF_MEMORY. The intended usage is AppendNewToTop(new ...);
*/
nsresult AppendNewToTop(nsDisplayItem* aItem) {
if (!aItem)
return NS_ERROR_OUT_OF_MEMORY;
AppendToTop(aItem);
return NS_OK;
}
/**
* Append a new item to the bottom of the list. If the item is null we return
* NS_ERROR_OUT_OF_MEMORY. The intended usage is AppendNewToBottom(new ...);
*/
nsresult AppendNewToBottom(nsDisplayItem* aItem) {
if (!aItem)
return NS_ERROR_OUT_OF_MEMORY;
AppendToBottom(aItem);
return NS_OK;
}
/**
* 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) {
NS_ASSERTION(aItem, "No item to append!");
NS_ASSERTION(!aItem->mAbove, "Already in a list!");
aItem->mAbove = mSentinel.mAbove;
mSentinel.mAbove = aItem;
if (mTop == &mSentinel) {
mTop = aItem;
}
}
/**
* 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 = nsnull;
}
}
/**
* 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;
mTop = aList->mTop;
mSentinel.mAbove = aList->mSentinel.mAbove;
aList->mTop = &aList->mSentinel;
aList->mSentinel.mAbove = nsnull;
}
}
/**
* Remove an item from the bottom of the list and return it.
*/
nsDisplayItem* RemoveBottom();
/**
* Remove all items from the list and call their destructors.
*/
void DeleteAll();
/**
* @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) : nsnull;
}
/**
* @return the item at the bottom of the list, or null if the list is empty
*/
nsDisplayItem* GetBottom() const { return mSentinel.mAbove; }
PRBool IsEmpty() const { return mTop == &mSentinel; }
/**
* This is *linear time*!
* @return the number of items in the list
*/
PRUint32 Count() const;
/**
* Stable sort the list by the z-order of GetUnderlyingFrame() on
* each item. 'auto' is counted as zero. Content order is used as the
* secondary order.
* @param aCommonAncestor a common ancestor of all the content elements
* associated with the display items, for speeding up tree order
* checks, or nsnull 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 SortByZOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor);
/**
* 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 nsnull 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(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor);
/**
* Generic stable sort. Take care, because some of the items might be nsDisplayLists
* themselves.
* aCmp(item1, item2) should return true if item1 <= item2. We sort the items
* into increasing order.
*/
typedef PRBool (* SortLEQ)(nsDisplayItem* aItem1, nsDisplayItem* aItem2,
void* aClosure);
void Sort(nsDisplayListBuilder* aBuilder, SortLEQ aCmp, void* aClosure);
/**
* Compute visiblity for the items in the list.
* We put this logic here so it can be shared by top-level
* painting and also display items that maintain child lists.
* This is also a good place to put ComputeVisibility-related logic
* that must be applied to every display item. In particular, this
* sets mVisibleRect on each display item.
* This sets mIsOpaque if the entire visible area of this list has
* been removed from aVisibleRegion when we return.
* This does not remove any items from the list, so we can recompute
* visiblity with different regions later (see
* FrameLayerBuilder::DrawThebesLayer).
*
* @param aVisibleRegion the area that is visible, relative to the
* reference frame; on return, this contains the area visible under the list.
* I.e., opaque contents of this list are subtracted from aVisibleRegion.
* @param aListVisibleBounds must be equal to the bounds of the intersection
* of aVisibleRegion and GetBounds() for this list.
* @return true if any item in the list is visible
*/
PRBool ComputeVisibilityForSublist(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion,
const nsRect& aListVisibleBounds);
/**
* As ComputeVisibilityForSublist, but computes visibility for a root
* list (a list that does not belong to an nsDisplayItem).
*
* @param aVisibleRegion the area that is visible
*/
PRBool ComputeVisibilityForRoot(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
/**
* Returns true if the visible region output from ComputeVisiblity was
* empty, i.e. everything visible in this list is opaque.
*/
PRBool IsOpaque() const {
NS_ASSERTION(mDidComputeVisibility, "Need to have called ComputeVisibility");
return mIsOpaque;
}
/**
* Returns true if during ComputeVisibility any display item
* set the surface to be transparent.
*/
PRBool NeedsTransparentSurface() const {
NS_ASSERTION(mDidComputeVisibility, "Need to have called ComputeVisibility");
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_FLUSH_LAYERS is set, we'll force a completely new layer
* tree to be created for this paint *and* the next paint.
*
* ComputeVisibility must be called before Paint.
*
* This must only be called on the root display list of the display list
* tree.
*/
enum {
PAINT_DEFAULT = 0,
PAINT_USE_WIDGET_LAYERS = 0x01,
PAINT_FLUSH_LAYERS = 0x02
};
void PaintRoot(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx,
PRUint32 aFlags) const;
/**
* Like PaintRoot, but used for internal display sublists.
* aForFrame is the frame that the list is associated with.
*/
void PaintForFrame(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx,
nsIFrame* aForFrame, PRUint32 aFlags) const;
/**
* Get the bounds. Takes the union of the bounds of all children.
*/
nsRect GetBounds(nsDisplayListBuilder* aBuilder) const;
/**
* 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;
#ifdef DEBUG
PRBool DidComputeVisibility() const { return mDidComputeVisibility; }
#endif
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) CPP_THROW_NEW;
// Utility function used to massage the list during ComputeVisibility.
void FlattenTo(nsTArray<nsDisplayItem*>* aElements);
// Utility function used to massage the list during sorting, to rewrite
// any wrapper items with null GetUnderlyingFrame
void ExplodeAnonymousChildLists(nsDisplayListBuilder* aBuilder);
nsDisplayItemLink mSentinel;
nsDisplayItemLink* mTop;
// This is set by ComputeVisibility
nsRect mVisibleRect;
// This is set to true by ComputeVisibility if the final visible region
// is empty (i.e. everything that was visible is covered by some
// opaque content in this list).
PRPackedBool mIsOpaque;
// This is set to true by ComputeVisibility if any display item in this
// list needs to force the surface to be transparent (e.g. if the
// item "punch holes" on the surface by clearing part of its area).
PRPackedBool mForceTransparentSurface;
#ifdef DEBUG
PRPackedBool mDidComputeVisibility;
#endif
};
/**
* 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; }
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) CPP_THROW_NEW;
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 {
nsDisplayListCollection() :
nsDisplayListSet(&mLists[0], &mLists[1], &mLists[2], &mLists[3], &mLists[4],
&mLists[5]) {}
nsDisplayListCollection(nsDisplayList* aBorderBackground) :
nsDisplayListSet(aBorderBackground, &mLists[1], &mLists[2], &mLists[3], &mLists[4],
&mLists[5]) {}
/**
* Sort all lists by content order.
*/
void SortAllByContentOrder(nsDisplayListBuilder* aBuilder, nsIContent* aCommonAncestor) {
for (PRInt32 i = 0; i < 6; ++i) {
mLists[i].SortByContentOrder(aBuilder, aCommonAncestor);
}
}
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) CPP_THROW_NEW;
nsDisplayList mLists[6];
};
/**
* 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 nsDisplayItem {
public:
typedef void (* PaintCallback)(nsIFrame* aFrame, nsIRenderingContext* aCtx,
const nsRect& aDirtyRect, nsPoint aFramePt);
nsDisplayGeneric(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
PaintCallback aPaint, const char* aName, Type aType)
: nsDisplayItem(aBuilder, aFrame), mPaint(aPaint)
#ifdef DEBUG
, mName(aName)
#endif
, mType(aType)
{
MOZ_COUNT_CTOR(nsDisplayGeneric);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayGeneric() {
MOZ_COUNT_DTOR(nsDisplayGeneric);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx) {
mPaint(mFrame, aCtx, mVisibleRect, ToReferenceFrame());
}
NS_DISPLAY_DECL_NAME(mName, mType)
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder) {
if (mType == nsDisplayItem::TYPE_HEADER_FOOTER)
return GetBounds(aBuilder);
return nsRect();
}
protected:
PaintCallback mPaint;
#ifdef DEBUG
const char* mName;
#endif
Type mType;
};
#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 nsFrame::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 nsDisplayItem {
public:
nsDisplayReflowCount(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const char* aFrameName,
PRUint32 aColor = 0)
: nsDisplayItem(aBuilder, aFrame),
mFrameName(aFrameName),
mColor(aColor)
{
MOZ_COUNT_CTOR(nsDisplayReflowCount);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayReflowCount() {
MOZ_COUNT_DTOR(nsDisplayReflowCount);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx) {
nsPoint pt = ToReferenceFrame();
nsIRenderingContext::AutoPushTranslation translate(aCtx, pt.x, pt.y);
mFrame->PresContext()->PresShell()->PaintCount(mFrameName, aCtx,
mFrame->PresContext(),
mFrame, mColor);
}
NS_DISPLAY_DECL_NAME("nsDisplayReflowCount", TYPE_REFLOW_COUNT)
protected:
const char* mFrameName;
nscolor mColor;
};
#define DO_GLOBAL_REFLOW_COUNT_DSP(_name) \
PR_BEGIN_MACRO \
if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \
PresContext()->PresShell()->IsPaintingFrameCounts()) { \
nsresult _rv = \
aLists.Outlines()->AppendNewToTop( \
new (aBuilder) nsDisplayReflowCount(aBuilder, this, _name)); \
NS_ENSURE_SUCCESS(_rv, _rv); \
} \
PR_END_MACRO
#define DO_GLOBAL_REFLOW_COUNT_DSP_COLOR(_name, _color) \
PR_BEGIN_MACRO \
if (!aBuilder->IsBackgroundOnly() && !aBuilder->IsForEventDelivery() && \
PresContext()->PresShell()->IsPaintingFrameCounts()) { \
nsresult _rv = \
aLists.Outlines()->AppendNewToTop( \
new (aBuilder) nsDisplayReflowCount(aBuilder, this, _name, _color)); \
NS_ENSURE_SUCCESS(_rv, _rv); \
} \
PR_END_MACRO
/*
Macro to be used for classes that don't actually implement BuildDisplayList
*/
#define DECL_DO_GLOBAL_REFLOW_COUNT_DSP(_class, _super) \
NS_IMETHOD BuildDisplayList(nsDisplayListBuilder* aBuilder, \
const nsRect& aDirtyRect, \
const nsDisplayListSet& aLists) { \
DO_GLOBAL_REFLOW_COUNT_DSP(#_class); \
return _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 nsDisplayItem {
public:
nsDisplayCaret(nsDisplayListBuilder* aBuilder, nsIFrame* aCaretFrame,
nsCaret *aCaret)
: nsDisplayItem(aBuilder, aCaretFrame), mCaret(aCaret) {
MOZ_COUNT_CTOR(nsDisplayCaret);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayCaret() {
MOZ_COUNT_DTOR(nsDisplayCaret);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) {
// The caret returns a rect in the coordinates of mFrame.
return mCaret->GetCaretRect() + ToReferenceFrame();
}
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
NS_DISPLAY_DECL_NAME("Caret", TYPE_CARET)
protected:
nsRefPtr<nsCaret> mCaret;
};
/**
* The standard display item to paint the CSS borders of a frame.
*/
class nsDisplayBorder : public nsDisplayItem {
public:
nsDisplayBorder(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) :
nsDisplayItem(aBuilder, aFrame),
mSnappingEnabled(aBuilder->IsSnappingEnabled() && !aBuilder->IsInTransform()) {
MOZ_COUNT_CTOR(nsDisplayBorder);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayBorder() {
MOZ_COUNT_DTOR(nsDisplayBorder);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
NS_DISPLAY_DECL_NAME("Border", TYPE_BORDER)
protected:
PRPackedBool mSnappingEnabled;
};
/**
* 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 nsDisplaySolidColor : public nsDisplayItem {
public:
nsDisplaySolidColor(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aBounds, nscolor aColor)
: nsDisplayItem(aBuilder, aFrame), mBounds(aBounds), mColor(aColor) {
NS_ASSERTION(NS_GET_A(aColor) > 0, "Don't create invisible nsDisplaySolidColors!");
MOZ_COUNT_CTOR(nsDisplaySolidColor);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplaySolidColor() {
MOZ_COUNT_DTOR(nsDisplaySolidColor);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) { return mBounds; }
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
PRBool* aOutTransparentBackground = nsnull) {
if (aOutTransparentBackground) {
*aOutTransparentBackground = PR_FALSE;
}
nsRegion result;
if (NS_GET_A(mColor) == 255) {
result = GetBounds(aBuilder);
}
return result;
}
virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor)
{
*aColor = mColor;
return PR_TRUE;
}
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
NS_DISPLAY_DECL_NAME("SolidColor", TYPE_SOLID_COLOR)
private:
nsRect mBounds;
nscolor mColor;
PRBool mTransparentBackground;
};
/**
* The standard display item to paint the CSS background of a frame.
*/
class nsDisplayBackground : public nsDisplayItem {
public:
nsDisplayBackground(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayBackground() {
MOZ_COUNT_DTOR(nsDisplayBackground);
}
#endif
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
PRBool* aForceTransparentSurface = nsnull);
virtual PRBool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame);
virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor);
virtual PRBool IsFixedAndCoveringViewport(nsDisplayListBuilder* aBuilder);
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
NS_DISPLAY_DECL_NAME("Background", TYPE_BACKGROUND)
protected:
nsRegion GetInsideClipRegion(nsPresContext* aPresContext, PRUint8 aClip,
const nsRect& aRect);
/* Used to cache mFrame->IsThemed() since it isn't a cheap call */
PRPackedBool mIsThemed;
PRPackedBool mSnappingEnabled;
nsITheme::Transparency mThemeTransparency;
};
/**
* The standard display item to paint the outer CSS box-shadows of a frame.
*/
class nsDisplayBoxShadowOuter : public nsDisplayItem {
public:
nsDisplayBoxShadowOuter(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayBoxShadowOuter);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayBoxShadowOuter() {
MOZ_COUNT_DTOR(nsDisplayBoxShadowOuter);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
NS_DISPLAY_DECL_NAME("BoxShadowOuter", TYPE_BOX_SHADOW_OUTER)
private:
nsRegion mVisibleRegion;
};
/**
* The standard display item to paint the inner CSS box-shadows of a frame.
*/
class nsDisplayBoxShadowInner : public nsDisplayItem {
public:
nsDisplayBoxShadowInner(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayBoxShadowInner);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayBoxShadowInner() {
MOZ_COUNT_DTOR(nsDisplayBoxShadowInner);
}
#endif
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
NS_DISPLAY_DECL_NAME("BoxShadowInner", TYPE_BOX_SHADOW_INNER)
private:
nsRegion mVisibleRegion;
};
/**
* The standard display item to paint the CSS outline of a frame.
*/
class nsDisplayOutline : public nsDisplayItem {
public:
nsDisplayOutline(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame) :
nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayOutline);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayOutline() {
MOZ_COUNT_DTOR(nsDisplayOutline);
}
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
NS_DISPLAY_DECL_NAME("Outline", TYPE_OUTLINE)
};
/**
* A class that lets you receive events within the frame bounds but never paints.
*/
class nsDisplayEventReceiver : public nsDisplayItem {
public:
nsDisplayEventReceiver(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame)
: nsDisplayItem(aBuilder, aFrame) {
MOZ_COUNT_CTOR(nsDisplayEventReceiver);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayEventReceiver() {
MOZ_COUNT_DTOR(nsDisplayEventReceiver);
}
#endif
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames);
NS_DISPLAY_DECL_NAME("EventReceiver", TYPE_EVENT_RECEIVER)
};
/**
* 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 nsnull. Callers to GetUnderlyingFrame must
* detect and handle this case.
*/
class nsDisplayWrapList : public nsDisplayItem {
// This is never instantiated directly, so no need to count constructors and
// destructors.
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);
virtual ~nsDisplayWrapList();
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames);
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
PRBool* aForceTransparentSurface = nsnull);
virtual PRBool IsUniform(nsDisplayListBuilder* aBuilder, nscolor* aColor);
virtual PRBool IsVaryingRelativeToMovingFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame);
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem) {
NS_WARNING("This list should already have been flattened!!!");
return PR_FALSE;
}
NS_DISPLAY_DECL_NAME("WrapList", TYPE_WRAP_LIST)
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder);
virtual nsDisplayList* GetList() { return &mList; }
/**
* This creates a copy of this item, but wrapping aItem instead of
* our existing list. Only gets called if this item returned nsnull
* for GetUnderlyingFrame(). aItem is guaranteed to return non-null from
* GetUnderlyingFrame().
*/
virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem) {
NS_NOTREACHED("We never returned nsnull for GetUnderlyingFrame!");
return nsnull;
}
/**
* Returns true if all descendant display items can be placed in the same
* ThebesLayer --- GetLayerState returns LAYER_INACTIVE or LAYER_NONE,
* and they all have the given aActiveScrolledRoot.
*/
static PRBool ChildrenCanBeInactive(nsDisplayListBuilder* aBuilder,
LayerManager* aManager,
const nsDisplayList& aList,
nsIFrame* aActiveScrolledRoot);
protected:
nsDisplayWrapList() {}
nsDisplayList mList;
};
/**
* 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 nsDisplayWrapper {
public:
// This is never instantiated directly (it has pure virtual methods), so no
// need to count constructors and destructors.
virtual PRBool WrapBorderBackground() { return PR_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:
nsDisplayWrapper() {}
};
/**
* 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);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayOpacity();
#endif
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
PRBool* aForceTransparentSurface = nsnull);
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager);
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem);
NS_DISPLAY_DECL_NAME("Opacity", TYPE_OPACITY)
};
/**
* A display item that has no purpose but to ensure its contents get
* their own layer.
*/
class nsDisplayOwnLayer : public nsDisplayWrapList {
public:
nsDisplayOwnLayer(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayOwnLayer();
#endif
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager);
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager)
{
return mozilla::LAYER_ACTIVE;
}
virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem)
{
// Don't allow merging, each sublist must have its own layer
return PR_FALSE;
}
NS_DISPLAY_DECL_NAME("OwnLayer", TYPE_OWN_LAYER)
};
#ifdef MOZ_IPC
/**
* This creates a layer for the given list of items, whose visibility is
* determined by the displayport for the given frame instead of what is
* passed in to ComputeVisibility.
*
* Here in content, we can use this to render more content than is actually
* visible. Then, the compositing process can manipulate the generated layer
* through transformations so that asynchronous scrolling can be implemented.
*
* Note that setting the displayport will not change any hit testing! The
* content process will know nothing about what the user is actually seeing,
* so it can only do hit testing for what is supposed to be the visible region.
*/
class nsDisplayScrollLayer : public nsDisplayOwnLayer
{
public:
/**
* @param aForFrame This will determine what the displayport is. It should be
* the root content frame of the scrolled area.
* @param aViewportFrame The viewport frame you see this content through.
*/
nsDisplayScrollLayer(nsDisplayListBuilder* aBuilder, nsDisplayList* aList,
nsIFrame* aForFrame, nsIFrame* aViewportFrame);
NS_DISPLAY_DECL_NAME("ScrollLayer", TYPE_SCROLL_LAYER)
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayScrollLayer();
#endif
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
private:
nsIFrame* mViewportFrame;
};
#endif
/**
* nsDisplayClip can clip a list of items, but we take a single item
* initially and then later merge other items into it when we merge
* adjacent matching nsDisplayClips
*/
class nsDisplayClip : public nsDisplayWrapList {
public:
/**
* @param aFrame the frame that should be considered the underlying
* frame for this content, e.g. the frame whose z-index we have. This
* is *not* the frame that is inducing the clipping.
*/
nsDisplayClip(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayItem* aItem, const nsRect& aRect);
nsDisplayClip(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList, const nsRect& aRect);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayClip();
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem);
NS_DISPLAY_DECL_NAME("Clip", TYPE_CLIP)
virtual PRUint32 GetPerFrameKey() { return 0; }
const nsRect& GetClipRect() { return mClip; }
void SetClipRect(const nsRect& aRect) { mClip = aRect; }
virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem);
protected:
nsRect mClip;
};
/**
* A display item to clip a list of items to the border-radius of a
* frame.
*/
class nsDisplayClipRoundedRect : public nsDisplayClip {
public:
/**
* @param aFrame the frame that should be considered the underlying
* frame for this content, e.g. the frame whose z-index we have. This
* is *not* the frame that is inducing the clipping.
*/
nsDisplayClipRoundedRect(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayItem* aItem,
const nsRect& aRect, nscoord aRadii[8]);
nsDisplayClipRoundedRect(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
const nsRect& aRect, nscoord aRadii[8]);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayClipRoundedRect();
#endif
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
PRBool* aForceTransparentSurface = nsnull);
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem);
NS_DISPLAY_DECL_NAME("ClipRoundedRect", TYPE_CLIP_ROUNDED_RECT)
virtual nsDisplayWrapList* WrapWithClone(nsDisplayListBuilder* aBuilder,
nsDisplayItem* aItem);
void GetRadii(nscoord aRadii[8]) {
memcpy(aRadii, mRadii, sizeof(mRadii));
}
private:
nscoord mRadii[8];
};
/**
* nsDisplayZoom is used for subdocuments that have a different full zoom than
* their parent documents. This item creates a container layer.
*/
class nsDisplayZoom : public nsDisplayOwnLayer {
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.
*/
nsDisplayZoom(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList,
PRInt32 aAPD, PRInt32 aParentAPD);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayZoom();
#endif
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder);
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
NS_DISPLAY_DECL_NAME("Zoom", TYPE_ZOOM)
// Get the app units per dev pixel ratio of the child document.
PRInt32 GetChildAppUnitsPerDevPixel() { return mAPD; }
// Get the app units per dev pixel ratio of the parent document.
PRInt32 GetParentAppUnitsPerDevPixel() { return mParentAPD; }
private:
PRInt32 mAPD, mParentAPD;
};
#ifdef MOZ_SVG
/**
* A display item to paint a stacking context with effects
* set by the stacking context root frame's style.
*/
class nsDisplaySVGEffects : public nsDisplayWrapList {
public:
nsDisplaySVGEffects(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
nsDisplayList* aList);
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplaySVGEffects();
#endif
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
PRBool* aForceTransparentSurface = nsnull);
virtual void HitTest(nsDisplayListBuilder* aBuilder, const nsRect& aRect,
HitTestState* aState, nsTArray<nsIFrame*> *aOutFrames);
virtual nsRect GetBounds(nsDisplayListBuilder* aBuilder) {
return mBounds + aBuilder->ToReferenceFrame(mEffectsFrame);
}
virtual void Paint(nsDisplayListBuilder* aBuilder, nsIRenderingContext* aCtx);
virtual PRBool ComputeVisibility(nsDisplayListBuilder* aBuilder,
nsRegion* aVisibleRegion);
virtual PRBool TryMerge(nsDisplayListBuilder* aBuilder, nsDisplayItem* aItem);
NS_DISPLAY_DECL_NAME("SVGEffects", TYPE_SVG_EFFECTS)
nsIFrame* GetEffectsFrame() { return mEffectsFrame; }
private:
nsIFrame* mEffectsFrame;
// relative to mEffectsFrame
nsRect mBounds;
};
#endif
/* A display item that applies a transformation to all of its descendent
* elements. This wrapper should only be used if there is a transform applied
* to the root element.
* INVARIANT: The wrapped frame is transformed.
* INVARIANT: The wrapped frame is non-null.
*/
class nsDisplayTransform: public nsDisplayItem
{
public:
/* 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) :
nsDisplayItem(aBuilder, aFrame), mStoredList(aBuilder, aFrame, aList)
{
MOZ_COUNT_CTOR(nsDisplayTransform);
}
#ifdef NS_BUILD_REFCNT_LOGGING
virtual ~nsDisplayTransform()
{
MOZ_COUNT_DTOR(nsDisplayTransform);
}
#endif
NS_DISPLAY_DECL_NAME("nsDisplayTransform", TYPE_TRANSFORM);
virtual nsRect GetComponentAlphaBounds(nsDisplayListBuilder* aBuilder)
{
if (mStoredList.GetComponentAlphaBounds(aBuilder).IsEmpty())
return nsRect();
return GetBounds(aBuilder);
}
#ifdef NS_DEBUG
nsDisplayWrapList* GetStoredList() { return &mStoredList; }
#endif
virtual void HitTest(nsDisplayListBuilder *aBuilder, const nsRect& aRect,
HitTestState *aState, nsTArray<nsIFrame*> *aOutFrames);
virtual nsRect GetBounds(nsDisplayListBuilder *aBuilder);
virtual nsRegion GetOpaqueRegion(nsDisplayListBuilder *aBuilder,
PRBool* aForceTransparentSurface = nsnull);
virtual PRBool IsUniform(nsDisplayListBuilder *aBuilder, nscolor* aColor);
virtual LayerState GetLayerState(nsDisplayListBuilder* aBuilder,
LayerManager* aManager);
virtual already_AddRefed<Layer> BuildLayer(nsDisplayListBuilder* aBuilder,
LayerManager* aManager);
virtual PRBool ComputeVisibility(nsDisplayListBuilder *aBuilder,
nsRegion *aVisibleRegion);
virtual PRBool TryMerge(nsDisplayListBuilder *aBuilder, nsDisplayItem *aItem);
/**
* 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 aOrigin The origin of the transform relative to aFrame's local
* coordinate space.
* @param aBoundsOverride (optional) Rather than using the frame's computed
* bounding rect as frame bounds, use this rectangle instead. Pass
* nsnull (or nothing at all) to use the default.
*/
static nsRect TransformRect(const nsRect &aUntransformedBounds,
const nsIFrame* aFrame,
const nsPoint &aOrigin,
const nsRect* aBoundsOverride = nsnull);
/* UntransformRect is like TransformRect, except that it inverts the
* transform.
*/
static nsRect UntransformRect(const nsRect &aUntransformedBounds,
const nsIFrame* aFrame,
const nsPoint &aOrigin);
/**
* Returns the bounds of a frame as defined for transforms. If
* UNIFIED_CONTINUATIONS is not defined, this is simply the frame's bounding
* rectangle, translated to the origin. Otherwise, returns the smallest
* rectangle containing a frame and all of its continuations. For example,
* if there is a <span> element with several continuations split over
* several lines, this function will return the rectangle containing all of
* those continuations. This rectangle is relative to the origin of the
* frame's local coordinate space.
*
* @param aFrame The frame to get the bounding rect for.
* @return The frame's bounding rect, as described above.
*/
static nsRect GetFrameBoundsForTransform(const nsIFrame* aFrame);
/**
* Given a frame with the -moz-transform property, 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 aScaleFactor The number of app units per graphics unit.
* @param aBoundsOverride [optional] If this is nsnull (the default), the
* computation will use the value of GetFrameBoundsForTransform(aFrame)
* for the frame's bounding rectangle. 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.
*/
static gfxMatrix GetResultingTransformMatrix(const nsIFrame* aFrame,
const nsPoint& aOrigin,
float aFactor,
const nsRect* aBoundsOverride = nsnull);
private:
nsDisplayWrapList mStoredList;
};
#endif /*NSDISPLAYLIST_H_*/
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