gecko-dev/layout/generic/nsPlaceholderFrame.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 for the point that anchors out-of-flow rendering
* objects such as floats and absolutely positioned elements
*/
#include "nsPlaceholderFrame.h"
#include "nsDisplayList.h"
#include "nsFrameManager.h"
#include "nsLayoutUtils.h"
#include "nsPresContext.h"
#include "nsRenderingContext.h"
nsIFrame*
NS_NewPlaceholderFrame(nsIPresShell* aPresShell, nsStyleContext* aContext,
nsFrameState aTypeBit)
{
return new (aPresShell) nsPlaceholderFrame(aContext, aTypeBit);
}
NS_IMPL_FRAMEARENA_HELPERS(nsPlaceholderFrame)
/* virtual */ nsSize
nsPlaceholderFrame::GetMinSize(nsBoxLayoutState& aBoxLayoutState)
{
nsSize size(0, 0);
DISPLAY_MIN_SIZE(this, size);
return size;
}
/* virtual */ nsSize
nsPlaceholderFrame::GetPrefSize(nsBoxLayoutState& aBoxLayoutState)
{
nsSize size(0, 0);
DISPLAY_PREF_SIZE(this, size);
return size;
}
/* virtual */ nsSize
nsPlaceholderFrame::GetMaxSize(nsBoxLayoutState& aBoxLayoutState)
{
nsSize size(NS_INTRINSICSIZE, NS_INTRINSICSIZE);
DISPLAY_MAX_SIZE(this, size);
return size;
}
/* virtual */ void
nsPlaceholderFrame::AddInlineMinWidth(nsRenderingContext* aRenderingContext,
nsIFrame::InlineMinWidthData* aData)
{
// Override AddInlineMinWith so that *nothing* happens. In
// particular, we don't want to zero out |aData->trailingWhitespace|,
// since nsLineLayout skips placeholders when trimming trailing
// whitespace, and we don't want to set aData->skipWhitespace to
// false.
// ...but push floats onto the list
if (mOutOfFlowFrame->IsFloating()) {
nscoord floatWidth =
nsLayoutUtils::IntrinsicForContainer(aRenderingContext,
mOutOfFlowFrame,
nsLayoutUtils::MIN_WIDTH);
aData->floats.AppendElement(
InlineIntrinsicWidthData::FloatInfo(mOutOfFlowFrame, floatWidth));
}
}
/* virtual */ void
nsPlaceholderFrame::AddInlinePrefWidth(nsRenderingContext* aRenderingContext,
nsIFrame::InlinePrefWidthData* aData)
{
// Override AddInlinePrefWith so that *nothing* happens. In
// particular, we don't want to zero out |aData->trailingWhitespace|,
// since nsLineLayout skips placeholders when trimming trailing
// whitespace, and we don't want to set aData->skipWhitespace to
// false.
// ...but push floats onto the list
if (mOutOfFlowFrame->IsFloating()) {
nscoord floatWidth =
nsLayoutUtils::IntrinsicForContainer(aRenderingContext,
mOutOfFlowFrame,
nsLayoutUtils::PREF_WIDTH);
aData->floats.AppendElement(
InlineIntrinsicWidthData::FloatInfo(mOutOfFlowFrame, floatWidth));
}
}
NS_IMETHODIMP
nsPlaceholderFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
#ifdef DEBUG
// We should be getting reflowed before our out-of-flow.
// If this is our first reflow, and our out-of-flow has already received its
// first reflow (before us), complain.
// XXXdholbert This "look for a previous continuation or IB-split sibling"
// code could use nsLayoutUtils::GetPrevContinuationOrSpecialSibling(), if
// we ever add a function like that. (We currently have a "Next" version.)
if ((GetStateBits() & NS_FRAME_FIRST_REFLOW) &&
!(mOutOfFlowFrame->GetStateBits() & NS_FRAME_FIRST_REFLOW)) {
// Unfortunately, this can currently happen when the placeholder is in a
// later continuation or later IB-split sibling than its out-of-flow (as
// is the case in some of our existing unit tests). So for now, in that
// case, we'll warn instead of asserting.
bool isInContinuationOrIBSplit = false;
nsIFrame* ancestor = this;
while ((ancestor = ancestor->GetParent())) {
if (ancestor->GetPrevContinuation() ||
ancestor->Properties().Get(IBSplitSpecialPrevSibling())) {
isInContinuationOrIBSplit = true;
break;
}
}
if (isInContinuationOrIBSplit) {
NS_WARNING("Out-of-flow frame got reflowed before its placeholder");
} else {
NS_ERROR("Out-of-flow frame got reflowed before its placeholder");
}
}
#endif
DO_GLOBAL_REFLOW_COUNT("nsPlaceholderFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aDesiredSize, aStatus);
aDesiredSize.width = 0;
aDesiredSize.height = 0;
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
void
nsPlaceholderFrame::DestroyFrom(nsIFrame* aDestructRoot)
{
nsIFrame* oof = mOutOfFlowFrame;
if (oof) {
// Unregister out-of-flow frame
nsFrameManager* fm = PresContext()->GetPresShell()->FrameManager();
fm->UnregisterPlaceholderFrame(this);
mOutOfFlowFrame = nullptr;
// If aDestructRoot is not an ancestor of the out-of-flow frame,
// then call RemoveFrame on it here.
// Also destroy it here if it's a popup frame. (Bug 96291)
if ((GetStateBits() & PLACEHOLDER_FOR_POPUP) ||
!nsLayoutUtils::IsProperAncestorFrame(aDestructRoot, oof)) {
ChildListID listId = nsLayoutUtils::GetChildListNameFor(oof);
fm->RemoveFrame(listId, oof);
}
// else oof will be destroyed by its parent
}
nsFrame::DestroyFrom(aDestructRoot);
}
nsIAtom*
nsPlaceholderFrame::GetType() const
{
return nsGkAtoms::placeholderFrame;
}
/* virtual */ bool
nsPlaceholderFrame::CanContinueTextRun() const
{
if (!mOutOfFlowFrame) {
return false;
}
// first-letter frames can continue text runs, and placeholders for floated
// first-letter frames can too
return mOutOfFlowFrame->CanContinueTextRun();
}
nsIFrame*
nsPlaceholderFrame::GetParentStyleContextFrame() const
{
NS_PRECONDITION(GetParent(), "How can we not have a parent here?");
// Lie about our pseudo so we can step out of all anon boxes and
// pseudo-elements. The other option would be to reimplement the
// {ib} split gunk here.
return CorrectStyleParentFrame(GetParent(), nsGkAtoms::placeholderFrame);
}
#ifdef DEBUG
static void
PaintDebugPlaceholder(nsIFrame* aFrame, nsRenderingContext* aCtx,
const nsRect& aDirtyRect, nsPoint aPt)
{
aCtx->SetColor(NS_RGB(0, 255, 255));
nscoord x = nsPresContext::CSSPixelsToAppUnits(-5);
aCtx->FillRect(aPt.x + x, aPt.y,
nsPresContext::CSSPixelsToAppUnits(13),
nsPresContext::CSSPixelsToAppUnits(3));
nscoord y = nsPresContext::CSSPixelsToAppUnits(-10);
aCtx->FillRect(aPt.x, aPt.y + y,
nsPresContext::CSSPixelsToAppUnits(3),
nsPresContext::CSSPixelsToAppUnits(10));
}
#endif // DEBUG
#if defined(DEBUG) || (defined(MOZ_REFLOW_PERF_DSP) && defined(MOZ_REFLOW_PERF))
void
nsPlaceholderFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsRect& aDirtyRect,
const nsDisplayListSet& aLists)
{
DO_GLOBAL_REFLOW_COUNT_DSP("nsPlaceholderFrame");
#ifdef DEBUG
if (GetShowFrameBorders()) {
aLists.Outlines()->AppendNewToTop(
new (aBuilder) nsDisplayGeneric(aBuilder, this, PaintDebugPlaceholder,
"DebugPlaceholder",
nsDisplayItem::TYPE_DEBUG_PLACEHOLDER));
}
#endif
}
#endif // DEBUG || (MOZ_REFLOW_PERF_DSP && MOZ_REFLOW_PERF)
#ifdef DEBUG
NS_IMETHODIMP
nsPlaceholderFrame::GetFrameName(nsAString& aResult) const
{
return MakeFrameName(NS_LITERAL_STRING("Placeholder"), aResult);
}
void
nsPlaceholderFrame::List(FILE* out, int32_t aIndent, uint32_t aFlags) const
{
ListGeneric(out, aIndent, aFlags);
if (mOutOfFlowFrame) {
fprintf(out, " outOfFlowFrame=");
nsFrame::ListTag(out, mOutOfFlowFrame);
}
fputs("\n", out);
}
#endif // DEBUG