gecko-dev/layout/generic/nsBackdropFrame.cpp

105 строки
3.6 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
// vim:cindent:ts=2:et:sw=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 for CSS "::backdrop" */
#include "nsBackdropFrame.h"
using namespace mozilla;
NS_IMPL_FRAMEARENA_HELPERS(nsBackdropFrame)
/* virtual */ nsIAtom*
nsBackdropFrame::GetType() const
{
return nsGkAtoms::backdropFrame;
}
#ifdef DEBUG_FRAME_DUMP
nsresult
nsBackdropFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Backdrop"), aResult);
}
#endif
/* virtual */ nsStyleContext*
nsBackdropFrame::GetParentStyleContext(nsIFrame** aProviderFrame) const
{
// Style context of backdrop pseudo-element does not inherit from
// any element, per the Fullscreen API spec.
*aProviderFrame = nullptr;
return nullptr;
}
/* virtual */ void
nsBackdropFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
DO_GLOBAL_REFLOW_COUNT_DSP("nsBackdropFrame");
// We want this frame to always be there even if its display value is
// none or contents so that we can respond to style change on it. To
// support those values, we skip painting ourselves in those cases.
auto display = StyleDisplay()->mDisplay;
if (display == NS_STYLE_DISPLAY_NONE ||
display == NS_STYLE_DISPLAY_CONTENTS) {
return;
}
// The WebVR specific render path in nsContainerLayerComposite
// results in an alternating frame strobing effect when an nsBackdropFrame is
// rendered.
// Currently, VR content is composed of a fullscreen canvas element that
// is expected to cover the entire viewport so a backdrop should not
// be necessary.
if (GetStateBits() & NS_FRAME_HAS_VR_CONTENT) {
return;
}
DisplayBorderBackgroundOutline(aBuilder, aLists);
}
/* virtual */ LogicalSize
nsBackdropFrame::ComputeAutoSize(nsRenderingContext *aRenderingContext,
WritingMode aWM,
const LogicalSize& aCBSize,
nscoord aAvailableISize,
const LogicalSize& aMargin,
const LogicalSize& aBorder,
const LogicalSize& aPadding,
bool aShrinkWrap)
{
// Note that this frame is a child of the viewport frame.
LogicalSize result(aWM, 0xdeadbeef, NS_UNCONSTRAINEDSIZE);
if (aShrinkWrap) {
result.ISize(aWM) = 0;
} else {
result.ISize(aWM) = aAvailableISize - aMargin.ISize(aWM) -
aBorder.ISize(aWM) - aPadding.ISize(aWM);
}
return result;
}
/* virtual */ void
nsBackdropFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT("nsBackdropFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
// Note that this frame is a child of the viewport frame.
WritingMode wm = aReflowState.GetWritingMode();
LogicalMargin borderPadding = aReflowState.ComputedLogicalBorderPadding();
nscoord isize = aReflowState.ComputedISize() + borderPadding.IStartEnd(wm);
nscoord bsize = aReflowState.ComputedBSize() + borderPadding.BStartEnd(wm);
aDesiredSize.SetSize(wm, LogicalSize(wm, isize, bsize));
aStatus = NS_FRAME_COMPLETE;
}