gecko-dev/layout/generic/nsViewportFrame.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/*
* rendering object that is the root of the frame tree, which contains
* the document's scrollbars and contains fixed-positioned elements
*/
#include "nsViewportFrame.h"
#include "nsGkAtoms.h"
#include "nsIScrollableFrame.h"
#include "nsSubDocumentFrame.h"
#include "nsCanvasFrame.h"
#include "nsAbsoluteContainingBlock.h"
#include "GeckoProfiler.h"
#include "nsIMozBrowserFrame.h"
using namespace mozilla;
typedef nsAbsoluteContainingBlock::AbsPosReflowFlags AbsPosReflowFlags;
ViewportFrame*
NS_NewViewportFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) ViewportFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(ViewportFrame)
NS_QUERYFRAME_HEAD(ViewportFrame)
NS_QUERYFRAME_ENTRY(ViewportFrame)
NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
void
ViewportFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow)
{
nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
nsIFrame* parent = nsLayoutUtils::GetCrossDocParentFrame(this);
if (parent) {
nsFrameState state = parent->GetStateBits();
mState |= state & (NS_FRAME_IN_POPUP);
}
}
void
ViewportFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
PROFILER_LABEL("ViewportFrame", "BuildDisplayList",
js::ProfileEntry::Category::GRAPHICS);
if (nsIFrame* kid = mFrames.FirstChild()) {
// make the kid's BorderBackground our own. This ensures that the canvas
// frame's background becomes our own background and therefore appears
// below negative z-index elements.
BuildDisplayListForChild(aBuilder, kid, aDirtyRect, aLists);
}
nsDisplayList topLayerList;
BuildDisplayListForTopLayer(aBuilder, &topLayerList);
if (!topLayerList.IsEmpty()) {
// Wrap the whole top layer in a single item with maximum z-index,
// and append it at the very end, so that it stays at the topmost.
nsDisplayWrapList* wrapList =
new (aBuilder) nsDisplayWrapList(aBuilder, this, &topLayerList);
wrapList->SetOverrideZIndex(
std::numeric_limits<decltype(wrapList->ZIndex())>::max());
aLists.PositionedDescendants()->AppendNewToTop(wrapList);
}
}
#ifdef DEBUG
/**
* Returns whether we are going to put an element in the top layer for
* fullscreen. This function should matches the CSS rule in ua.css.
*/
static bool
ShouldInTopLayerForFullscreen(Element* aElement)
{
if (!aElement->GetParent()) {
return false;
}
nsCOMPtr<nsIMozBrowserFrame> browserFrame = do_QueryInterface(aElement);
if (browserFrame && browserFrame->GetReallyIsBrowserOrApp()) {
return false;
}
return true;
}
#endif // DEBUG
static void
BuildDisplayListForTopLayerFrame(nsDisplayListBuilder* aBuilder,
nsIFrame* aFrame,
nsDisplayList* aList)
{
nsRect dirty;
DisplayListClipState::AutoClipMultiple clipState(aBuilder);
nsDisplayListBuilder::OutOfFlowDisplayData*
savedOutOfFlowData = nsDisplayListBuilder::GetOutOfFlowData(aFrame);
if (savedOutOfFlowData) {
dirty = savedOutOfFlowData->mDirtyRect;
clipState.SetClipForContainingBlockDescendants(
&savedOutOfFlowData->mContainingBlockClip);
clipState.SetScrollClipForContainingBlockDescendants(
aBuilder, savedOutOfFlowData->mContainingBlockScrollClip);
}
nsDisplayList list;
aFrame->BuildDisplayListForStackingContext(aBuilder, dirty, &list);
aList->AppendToTop(&list);
}
void
ViewportFrame::BuildDisplayListForTopLayer(nsDisplayListBuilder* aBuilder,
nsDisplayList* aList)
{
nsIDocument* doc = PresContext()->Document();
nsTArray<Element*> fullscreenStack = doc->GetFullscreenStack();
for (Element* elem : fullscreenStack) {
if (nsIFrame* frame = elem->GetPrimaryFrame()) {
// There are two cases where an element in fullscreen is not in
// the top layer:
// 1. When building display list for purpose other than painting,
// it is possible that there is inconsistency between the style
// info and the content tree.
// 2. This is an element which we are not going to put in the top
// layer for fullscreen. See ShouldInTopLayerForFullscreen().
// In both cases, we want to skip the frame here and paint it in
// the normal path.
if (frame->StyleDisplay()->mTopLayer == NS_STYLE_TOP_LAYER_NONE) {
MOZ_ASSERT(!aBuilder->IsForPainting() ||
!ShouldInTopLayerForFullscreen(elem));
continue;
}
MOZ_ASSERT(ShouldInTopLayerForFullscreen(elem));
// Inner SVG, MathML elements, as well as children of some XUL
// elements are not allowed to be out-of-flow. They should not
// be handled as top layer element here.
if (!(frame->GetStateBits() & NS_FRAME_OUT_OF_FLOW)) {
MOZ_ASSERT(!elem->GetParent()->IsHTMLElement(), "HTML element "
"should always be out-of-flow if in the top layer");
continue;
}
if (nsIFrame* backdropPh =
frame->GetChildList(kBackdropList).FirstChild()) {
MOZ_ASSERT(backdropPh->GetType() == nsGkAtoms::placeholderFrame);
nsIFrame* backdropFrame =
static_cast<nsPlaceholderFrame*>(backdropPh)->GetOutOfFlowFrame();
MOZ_ASSERT(backdropFrame);
BuildDisplayListForTopLayerFrame(aBuilder, backdropFrame, aList);
}
BuildDisplayListForTopLayerFrame(aBuilder, frame, aList);
}
}
nsIPresShell* shell = PresContext()->PresShell();
if (nsCanvasFrame* canvasFrame = shell->GetCanvasFrame()) {
if (Element* container = canvasFrame->GetCustomContentContainer()) {
if (nsIFrame* frame = container->GetPrimaryFrame()) {
BuildDisplayListForTopLayerFrame(aBuilder, frame, aList);
}
}
}
}
#ifdef DEBUG
void
ViewportFrame::AppendFrames(ChildListID aListID,
nsFrameList& aFrameList)
{
NS_ASSERTION(aListID == kPrincipalList, "unexpected child list");
NS_ASSERTION(GetChildList(aListID).IsEmpty(), "Shouldn't have any kids!");
nsContainerFrame::AppendFrames(aListID, aFrameList);
}
void
ViewportFrame::InsertFrames(ChildListID aListID,
nsIFrame* aPrevFrame,
nsFrameList& aFrameList)
{
NS_ASSERTION(aListID == kPrincipalList, "unexpected child list");
NS_ASSERTION(GetChildList(aListID).IsEmpty(), "Shouldn't have any kids!");
nsContainerFrame::InsertFrames(aListID, aPrevFrame, aFrameList);
}
void
ViewportFrame::RemoveFrame(ChildListID aListID,
nsIFrame* aOldFrame)
{
NS_ASSERTION(aListID == kPrincipalList, "unexpected child list");
nsContainerFrame::RemoveFrame(aListID, aOldFrame);
}
#endif
/* virtual */ nscoord
ViewportFrame::GetMinISize(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_MIN_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetMinISize(aRenderingContext);
return result;
}
/* virtual */ nscoord
ViewportFrame::GetPrefISize(nsRenderingContext *aRenderingContext)
{
nscoord result;
DISPLAY_PREF_WIDTH(this, result);
if (mFrames.IsEmpty())
result = 0;
else
result = mFrames.FirstChild()->GetPrefISize(aRenderingContext);
return result;
}
nsPoint
ViewportFrame::AdjustReflowInputForScrollbars(ReflowInput* aReflowInput) const
{
// Get our prinicpal child frame and see if we're scrollable
nsIFrame* kidFrame = mFrames.FirstChild();
nsIScrollableFrame* scrollingFrame = do_QueryFrame(kidFrame);
if (scrollingFrame) {
WritingMode wm = aReflowInput->GetWritingMode();
LogicalMargin scrollbars(wm, scrollingFrame->GetActualScrollbarSizes());
aReflowInput->SetComputedISize(aReflowInput->ComputedISize() -
scrollbars.IStartEnd(wm));
aReflowInput->AvailableISize() -= scrollbars.IStartEnd(wm);
aReflowInput->SetComputedBSizeWithoutResettingResizeFlags(
aReflowInput->ComputedBSize() - scrollbars.BStartEnd(wm));
return nsPoint(scrollbars.Left(wm), scrollbars.Top(wm));
}
return nsPoint(0, 0);
}
nsRect
ViewportFrame::AdjustReflowInputAsContainingBlock(ReflowInput* aReflowInput) const
{
#ifdef DEBUG
nsPoint offset =
#endif
AdjustReflowInputForScrollbars(aReflowInput);
NS_ASSERTION(GetAbsoluteContainingBlock()->GetChildList().IsEmpty() ||
(offset.x == 0 && offset.y == 0),
"We don't handle correct positioning of fixed frames with "
"scrollbars in odd positions");
// If a scroll position clamping scroll-port size has been set, layout
// fixed position elements to this size instead of the computed size.
nsRect rect(0, 0, aReflowInput->ComputedWidth(), aReflowInput->ComputedHeight());
nsIPresShell* ps = PresContext()->PresShell();
if (ps->IsScrollPositionClampingScrollPortSizeSet()) {
rect.SizeTo(ps->GetScrollPositionClampingScrollPortSize());
}
return rect;
}
void
ViewportFrame::Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus)
{
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT("ViewportFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowInput, aDesiredSize, aStatus);
NS_FRAME_TRACE_REFLOW_IN("ViewportFrame::Reflow");
// Initialize OUT parameters
aStatus = NS_FRAME_COMPLETE;
// Because |Reflow| sets ComputedBSize() on the child to our
// ComputedBSize().
AddStateBits(NS_FRAME_CONTAINS_RELATIVE_BSIZE);
// Set our size up front, since some parts of reflow depend on it
// being already set. Note that the computed height may be
// unconstrained; that's ok. Consumers should watch out for that.
SetSize(nsSize(aReflowInput.ComputedWidth(), aReflowInput.ComputedHeight()));
// Reflow the main content first so that the placeholders of the
// fixed-position frames will be in the right places on an initial
// reflow.
nscoord kidBSize = 0;
WritingMode wm = aReflowInput.GetWritingMode();
if (mFrames.NotEmpty()) {
// Deal with a non-incremental reflow or an incremental reflow
// targeted at our one-and-only principal child frame.
if (aReflowInput.ShouldReflowAllKids() ||
aReflowInput.IsBResize() ||
NS_SUBTREE_DIRTY(mFrames.FirstChild())) {
// Reflow our one-and-only principal child frame
nsIFrame* kidFrame = mFrames.FirstChild();
ReflowOutput kidDesiredSize(aReflowInput);
WritingMode wm = kidFrame->GetWritingMode();
LogicalSize availableSpace = aReflowInput.AvailableSize(wm);
ReflowInput kidReflowInput(aPresContext, aReflowInput,
kidFrame, availableSpace);
// Reflow the frame
kidReflowInput.SetComputedBSize(aReflowInput.ComputedBSize());
ReflowChild(kidFrame, aPresContext, kidDesiredSize, kidReflowInput,
0, 0, 0, aStatus);
kidBSize = kidDesiredSize.BSize(wm);
FinishReflowChild(kidFrame, aPresContext, kidDesiredSize, nullptr, 0, 0, 0);
} else {
kidBSize = LogicalSize(wm, mFrames.FirstChild()->GetSize()).BSize(wm);
}
}
NS_ASSERTION(aReflowInput.AvailableISize() != NS_UNCONSTRAINEDSIZE,
"shouldn't happen anymore");
// Return the max size as our desired size
LogicalSize maxSize(wm, aReflowInput.AvailableISize(),
// Being flowed initially at an unconstrained block size
// means we should return our child's intrinsic size.
aReflowInput.ComputedBSize() != NS_UNCONSTRAINEDSIZE
? aReflowInput.ComputedBSize()
: kidBSize);
aDesiredSize.SetSize(wm, maxSize);
aDesiredSize.SetOverflowAreasToDesiredBounds();
if (HasAbsolutelyPositionedChildren()) {
// Make a copy of the reflow state and change the computed width and height
// to reflect the available space for the fixed items
ReflowInput reflowInput(aReflowInput);
if (reflowInput.AvailableBSize() == NS_UNCONSTRAINEDSIZE) {
// We have an intrinsic-height document with abs-pos/fixed-pos children.
// Set the available height and mComputedHeight to our chosen height.
reflowInput.AvailableBSize() = maxSize.BSize(wm);
// Not having border/padding simplifies things
NS_ASSERTION(reflowInput.ComputedPhysicalBorderPadding() == nsMargin(0,0,0,0),
"Viewports can't have border/padding");
reflowInput.SetComputedBSize(maxSize.BSize(wm));
}
nsRect rect = AdjustReflowInputAsContainingBlock(&reflowInput);
nsOverflowAreas* overflowAreas = &aDesiredSize.mOverflowAreas;
nsIScrollableFrame* rootScrollFrame =
aPresContext->PresShell()->GetRootScrollFrameAsScrollable();
if (rootScrollFrame && !rootScrollFrame->IsIgnoringViewportClipping()) {
overflowAreas = nullptr;
}
AbsPosReflowFlags flags =
AbsPosReflowFlags::eCBWidthAndHeightChanged; // XXX could be optimized
GetAbsoluteContainingBlock()->Reflow(this, aPresContext, reflowInput, aStatus,
rect, flags, overflowAreas);
}
if (mFrames.NotEmpty()) {
ConsiderChildOverflow(aDesiredSize.mOverflowAreas, mFrames.FirstChild());
}
// If we were dirty then do a repaint
if (GetStateBits() & NS_FRAME_IS_DIRTY) {
InvalidateFrame();
}
// Clipping is handled by the document container (e.g., nsSubDocumentFrame),
// so we don't need to change our overflow areas.
bool overflowChanged = FinishAndStoreOverflow(&aDesiredSize);
if (overflowChanged) {
// We may need to alert our container to get it to pick up the
// overflow change.
nsSubDocumentFrame* container = static_cast<nsSubDocumentFrame*>
(nsLayoutUtils::GetCrossDocParentFrame(this));
if (container && !container->ShouldClipSubdocument()) {
container->PresContext()->PresShell()->
FrameNeedsReflow(container, nsIPresShell::eResize, NS_FRAME_IS_DIRTY);
}
}
NS_FRAME_TRACE_REFLOW_OUT("ViewportFrame::Reflow", aStatus);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize);
}
bool
ViewportFrame::ComputeCustomOverflow(nsOverflowAreas& aOverflowAreas)
{
nsIScrollableFrame* rootScrollFrame =
PresContext()->PresShell()->GetRootScrollFrameAsScrollable();
if (rootScrollFrame && !rootScrollFrame->IsIgnoringViewportClipping()) {
return false;
}
return nsContainerFrame::ComputeCustomOverflow(aOverflowAreas);
}
nsIAtom*
ViewportFrame::GetType() const
{
return nsGkAtoms::viewportFrame;
}
#ifdef DEBUG_FRAME_DUMP
nsresult
ViewportFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Viewport"), aResult);
}
#endif