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-rw-r--r--layout/generic/nsFirstLetterFrame.cpp448
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diff --git a/layout/generic/nsFirstLetterFrame.cpp b/layout/generic/nsFirstLetterFrame.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* rendering object for CSS :first-letter pseudo-element */
+
+#include "nsFirstLetterFrame.h"
+#include "nsPresContext.h"
+#include "nsPresContextInlines.h"
+#include "mozilla/ComputedStyle.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/PresShellInlines.h"
+#include "mozilla/RestyleManager.h"
+#include "mozilla/ServoStyleSet.h"
+#include "mozilla/StaticPrefs_layout.h"
+#include "nsIContent.h"
+#include "nsLayoutUtils.h"
+#include "nsLineLayout.h"
+#include "nsGkAtoms.h"
+#include "nsFrameManager.h"
+#include "nsPlaceholderFrame.h"
+#include "nsTextFrame.h"
+#include "nsCSSFrameConstructor.h"
+
+using namespace mozilla;
+using namespace mozilla::layout;
+
+nsFirstLetterFrame* NS_NewFirstLetterFrame(PresShell* aPresShell,
+ ComputedStyle* aStyle) {
+ return new (aPresShell)
+ nsFirstLetterFrame(aStyle, aPresShell->GetPresContext());
+}
+
+NS_IMPL_FRAMEARENA_HELPERS(nsFirstLetterFrame)
+
+NS_QUERYFRAME_HEAD(nsFirstLetterFrame)
+ NS_QUERYFRAME_ENTRY(nsFirstLetterFrame)
+NS_QUERYFRAME_TAIL_INHERITING(nsContainerFrame)
+
+#ifdef DEBUG_FRAME_DUMP
+nsresult nsFirstLetterFrame::GetFrameName(nsAString& aResult) const {
+ return MakeFrameName(u"Letter"_ns, aResult);
+}
+#endif
+
+void nsFirstLetterFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
+ const nsDisplayListSet& aLists) {
+ BuildDisplayListForInline(aBuilder, aLists);
+}
+
+void nsFirstLetterFrame::Init(nsIContent* aContent, nsContainerFrame* aParent,
+ nsIFrame* aPrevInFlow) {
+ RefPtr<ComputedStyle> newSC;
+ if (aPrevInFlow) {
+ // Get proper ComputedStyle for ourselves. We're creating the frame
+ // that represents everything *except* the first letter, so just create
+ // a ComputedStyle that inherits from our style parent, with no extra rules.
+ nsIFrame* styleParent =
+ CorrectStyleParentFrame(aParent, PseudoStyleType::firstLetter);
+ ComputedStyle* parentComputedStyle = styleParent->Style();
+ newSC = PresContext()->StyleSet()->ResolveStyleForFirstLetterContinuation(
+ parentComputedStyle);
+ SetComputedStyleWithoutNotification(newSC);
+ }
+
+ nsContainerFrame::Init(aContent, aParent, aPrevInFlow);
+}
+
+void nsFirstLetterFrame::SetInitialChildList(ChildListID aListID,
+ nsFrameList&& aChildList) {
+ MOZ_ASSERT(aListID == FrameChildListID::Principal,
+ "Principal child list is the only "
+ "list that nsFirstLetterFrame should set via this function");
+ for (nsIFrame* f : aChildList) {
+ MOZ_ASSERT(f->GetParent() == this, "Unexpected parent");
+ MOZ_ASSERT(f->IsTextFrame(),
+ "We should not have kids that are containers!");
+ nsLayoutUtils::MarkDescendantsDirty(f); // Drops cached textruns
+ }
+
+ mFrames = std::move(aChildList);
+}
+
+nsresult nsFirstLetterFrame::GetChildFrameContainingOffset(
+ int32_t inContentOffset, bool inHint, int32_t* outFrameContentOffset,
+ nsIFrame** outChildFrame) {
+ nsIFrame* kid = mFrames.FirstChild();
+ if (kid) {
+ return kid->GetChildFrameContainingOffset(
+ inContentOffset, inHint, outFrameContentOffset, outChildFrame);
+ }
+ return nsIFrame::GetChildFrameContainingOffset(
+ inContentOffset, inHint, outFrameContentOffset, outChildFrame);
+}
+
+// Needed for non-floating first-letter frames and for the continuations
+// following the first-letter that we also use nsFirstLetterFrame for.
+/* virtual */
+void nsFirstLetterFrame::AddInlineMinISize(
+ gfxContext* aRenderingContext, nsIFrame::InlineMinISizeData* aData) {
+ DoInlineMinISize(aRenderingContext, aData);
+}
+
+// Needed for non-floating first-letter frames and for the continuations
+// following the first-letter that we also use nsFirstLetterFrame for.
+/* virtual */
+void nsFirstLetterFrame::AddInlinePrefISize(
+ gfxContext* aRenderingContext, nsIFrame::InlinePrefISizeData* aData) {
+ DoInlinePrefISize(aRenderingContext, aData);
+}
+
+// Needed for floating first-letter frames.
+/* virtual */
+nscoord nsFirstLetterFrame::GetMinISize(gfxContext* aRenderingContext) {
+ return nsLayoutUtils::MinISizeFromInline(this, aRenderingContext);
+}
+
+// Needed for floating first-letter frames.
+/* virtual */
+nscoord nsFirstLetterFrame::GetPrefISize(gfxContext* aRenderingContext) {
+ return nsLayoutUtils::PrefISizeFromInline(this, aRenderingContext);
+}
+
+/* virtual */
+nsIFrame::SizeComputationResult nsFirstLetterFrame::ComputeSize(
+ gfxContext* aRenderingContext, WritingMode aWM, const LogicalSize& aCBSize,
+ nscoord aAvailableISize, const LogicalSize& aMargin,
+ const LogicalSize& aBorderPadding, const StyleSizeOverrides& aSizeOverrides,
+ ComputeSizeFlags aFlags) {
+ if (GetPrevInFlow()) {
+ // We're wrapping the text *after* the first letter, so behave like an
+ // inline frame.
+ return {LogicalSize(aWM, NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE),
+ AspectRatioUsage::None};
+ }
+ return nsContainerFrame::ComputeSize(aRenderingContext, aWM, aCBSize,
+ aAvailableISize, aMargin, aBorderPadding,
+ aSizeOverrides, aFlags);
+}
+
+bool nsFirstLetterFrame::UseTightBounds() const {
+ int v = StaticPrefs::layout_css_floating_first_letter_tight_glyph_bounds();
+
+ // Check for the simple cases:
+ // pref value > 0: use legacy gecko behavior
+ // pref value = 0: use webkit/blink-like behavior
+ if (v > 0) {
+ return true;
+ }
+ if (v == 0) {
+ return false;
+ }
+
+ // Pref value < 0: use heuristics to determine whether the page is assuming
+ // webkit/blink-style behavior:
+ // If line-height is less than font-size, or there is a negative block-start
+ // or -end margin, use webkit/blink behavior.
+ if (nsTextFrame* textFrame = do_QueryFrame(mFrames.FirstChild())) {
+ RefPtr<nsFontMetrics> fm = textFrame->InflatedFontMetrics();
+ if (textFrame->ComputeLineHeight() < fm->EmHeight()) {
+ return false;
+ }
+ }
+
+ const auto wm = GetWritingMode();
+ const auto& margin = StyleMargin()->mMargin;
+ const auto& bStart = margin.GetBStart(wm);
+ // Currently, we only check for margins with negative *length* values;
+ // negative percentages seem unlikely to be used/useful in this context.
+ if (bStart.ConvertsToLength() && bStart.ToLength() < 0) {
+ return false;
+ }
+ const auto& bEnd = margin.GetBEnd(wm);
+ if (bEnd.ConvertsToLength() && bEnd.ToLength() < 0) {
+ return false;
+ }
+
+ return true;
+}
+
+void nsFirstLetterFrame::Reflow(nsPresContext* aPresContext,
+ ReflowOutput& aMetrics,
+ const ReflowInput& aReflowInput,
+ nsReflowStatus& aReflowStatus) {
+ MarkInReflow();
+ DO_GLOBAL_REFLOW_COUNT("nsFirstLetterFrame");
+ DISPLAY_REFLOW(aPresContext, this, aReflowInput, aMetrics, aReflowStatus);
+ MOZ_ASSERT(aReflowStatus.IsEmpty(),
+ "Caller should pass a fresh reflow status!");
+
+ // Grab overflow list
+ DrainOverflowFrames(aPresContext);
+
+ nsIFrame* kid = mFrames.FirstChild();
+
+ // Setup reflow input for our child
+ WritingMode wm = aReflowInput.GetWritingMode();
+ LogicalSize availSize = aReflowInput.AvailableSize();
+ const auto bp = aReflowInput.ComputedLogicalBorderPadding(wm);
+ NS_ASSERTION(availSize.ISize(wm) != NS_UNCONSTRAINEDSIZE,
+ "should no longer use unconstrained inline size");
+ availSize.ISize(wm) -= bp.IStartEnd(wm);
+ if (NS_UNCONSTRAINEDSIZE != availSize.BSize(wm)) {
+ availSize.BSize(wm) -= bp.BStartEnd(wm);
+ }
+
+ WritingMode lineWM = aMetrics.GetWritingMode();
+ ReflowOutput kidMetrics(lineWM);
+
+ // Reflow the child
+ if (!aReflowInput.mLineLayout) {
+ // When there is no lineLayout provided, we provide our own. The
+ // only time that the first-letter-frame is not reflowing in a
+ // line context is when its floating.
+ WritingMode kidWritingMode = WritingModeForLine(wm, kid);
+ LogicalSize kidAvailSize = availSize.ConvertTo(kidWritingMode, wm);
+ ReflowInput rs(aPresContext, aReflowInput, kid, kidAvailSize);
+ nsLineLayout ll(aPresContext, nullptr, aReflowInput, nullptr, nullptr);
+
+ ll.BeginLineReflow(
+ bp.IStart(wm), bp.BStart(wm), availSize.ISize(wm), NS_UNCONSTRAINEDSIZE,
+ false, true, kidWritingMode,
+ nsSize(aReflowInput.AvailableWidth(), aReflowInput.AvailableHeight()));
+ rs.mLineLayout = &ll;
+ ll.SetInFirstLetter(true);
+ ll.SetFirstLetterStyleOK(true);
+
+ kid->Reflow(aPresContext, kidMetrics, rs, aReflowStatus);
+
+ ll.EndLineReflow();
+ ll.SetInFirstLetter(false);
+
+ // In the floating first-letter case, we need to set this ourselves;
+ // nsLineLayout::BeginSpan will set it in the other case
+ mBaseline = kidMetrics.BlockStartAscent();
+
+ // Place and size the child and update the output metrics
+ LogicalSize convertedSize = kidMetrics.Size(wm);
+
+ const bool tightBounds = UseTightBounds();
+ const nscoord shift =
+ tightBounds ? 0
+ // Shift by half of the difference between the line-height
+ // we're going to use and current height of the kid frame.
+ : (rs.GetLineHeight() - convertedSize.BSize(wm)) / 2;
+
+ kid->SetRect(nsRect(bp.IStart(wm), bp.BStart(wm) + shift,
+ convertedSize.ISize(wm), convertedSize.BSize(wm)));
+ kid->FinishAndStoreOverflow(&kidMetrics, rs.mStyleDisplay);
+ kid->DidReflow(aPresContext, nullptr);
+
+ if (!tightBounds) {
+ // Adjust size to account for line-height.
+ convertedSize.BSize(wm) = rs.GetLineHeight();
+ }
+
+ convertedSize.ISize(wm) += bp.IStartEnd(wm);
+ convertedSize.BSize(wm) += bp.BStartEnd(wm);
+ aMetrics.SetSize(wm, convertedSize);
+ aMetrics.SetBlockStartAscent(kidMetrics.BlockStartAscent() + bp.BStart(wm));
+
+ // Ensure that the overflow rect contains the child textframe's
+ // overflow rect.
+ // Note that if this is floating, the overline/underline drawable
+ // area is in the overflow rect of the child textframe.
+ aMetrics.UnionOverflowAreasWithDesiredBounds();
+ ConsiderChildOverflow(aMetrics.mOverflowAreas, kid);
+
+ FinishAndStoreOverflow(&aMetrics, aReflowInput.mStyleDisplay);
+ } else {
+ // Pretend we are a span and reflow the child frame
+ nsLineLayout* ll = aReflowInput.mLineLayout;
+ bool pushedFrame;
+
+ ll->SetInFirstLetter(Style()->GetPseudoType() ==
+ PseudoStyleType::firstLetter);
+ ll->BeginSpan(this, &aReflowInput, bp.IStart(wm), availSize.ISize(wm),
+ &mBaseline);
+ ll->ReflowFrame(kid, aReflowStatus, &kidMetrics, pushedFrame);
+ NS_ASSERTION(lineWM.IsVertical() == wm.IsVertical(),
+ "we're assuming we can mix sizes between lineWM and wm "
+ "since we shouldn't have orthogonal writing modes within "
+ "a line.");
+ aMetrics.ISize(lineWM) = ll->EndSpan(this) + bp.IStartEnd(wm);
+ ll->SetInFirstLetter(false);
+
+ if (mComputedStyle->StyleTextReset()->mInitialLetterSize != 0.0f) {
+ aMetrics.SetBlockStartAscent(kidMetrics.BlockStartAscent() +
+ bp.BStart(wm));
+ aMetrics.BSize(lineWM) = kidMetrics.BSize(lineWM) + bp.BStartEnd(wm);
+ } else {
+ nsLayoutUtils::SetBSizeFromFontMetrics(this, aMetrics, bp, lineWM, wm);
+ }
+ }
+
+ if (!aReflowStatus.IsInlineBreakBefore()) {
+ // Create a continuation or remove existing continuations based on
+ // the reflow completion status.
+ if (aReflowStatus.IsComplete()) {
+ if (aReflowInput.mLineLayout) {
+ aReflowInput.mLineLayout->SetFirstLetterStyleOK(false);
+ }
+ if (nsIFrame* kidNextInFlow = kid->GetNextInFlow()) {
+ DestroyContext context(PresShell());
+ // Remove all of the childs next-in-flows
+ kidNextInFlow->GetParent()->DeleteNextInFlowChild(context,
+ kidNextInFlow, true);
+ }
+ } else {
+ // Create a continuation for the child frame if it doesn't already
+ // have one.
+ if (!IsFloating()) {
+ CreateNextInFlow(kid);
+ // And then push it to our overflow list
+ nsFrameList overflow = mFrames.TakeFramesAfter(kid);
+ if (overflow.NotEmpty()) {
+ SetOverflowFrames(std::move(overflow));
+ }
+ } else if (!kid->GetNextInFlow()) {
+ // For floating first letter frames (if a continuation wasn't already
+ // created for us) we need to put the continuation with the rest of the
+ // text that the first letter frame was made out of.
+ nsIFrame* continuation;
+ CreateContinuationForFloatingParent(kid, &continuation, true);
+ }
+ }
+ }
+}
+
+/* virtual */
+bool nsFirstLetterFrame::CanContinueTextRun() const {
+ // We can continue a text run through a first-letter frame.
+ return true;
+}
+
+void nsFirstLetterFrame::CreateContinuationForFloatingParent(
+ nsIFrame* aChild, nsIFrame** aContinuation, bool aIsFluid) {
+ NS_ASSERTION(IsFloating(),
+ "can only call this on floating first letter frames");
+ MOZ_ASSERT(aContinuation, "bad args");
+
+ *aContinuation = nullptr;
+
+ mozilla::PresShell* presShell = PresShell();
+ nsPlaceholderFrame* placeholderFrame = GetPlaceholderFrame();
+ nsContainerFrame* parent = placeholderFrame->GetParent();
+
+ nsIFrame* continuation = presShell->FrameConstructor()->CreateContinuingFrame(
+ aChild, parent, aIsFluid);
+
+ // The continuation will have gotten the first letter style from its
+ // prev continuation, so we need to repair the ComputedStyle so it
+ // doesn't have the first letter styling.
+ //
+ // Note that getting parent frame's ComputedStyle is different from getting
+ // this frame's ComputedStyle's parent in the presence of ::first-line,
+ // which we do want the continuation to inherit from.
+ ComputedStyle* parentSC = parent->Style();
+ if (parentSC) {
+ RefPtr<ComputedStyle> newSC;
+ newSC =
+ presShell->StyleSet()->ResolveStyleForFirstLetterContinuation(parentSC);
+ continuation->SetComputedStyle(newSC);
+ nsLayoutUtils::MarkDescendantsDirty(continuation);
+ }
+
+ // XXX Bidi may not be involved but we have to use the list name
+ // FrameChildListID::NoReflowPrincipal because this is just like creating a
+ // continuation except we have to insert it in a different place and we don't
+ // want a reflow command to try to be issued.
+ parent->InsertFrames(FrameChildListID::NoReflowPrincipal, placeholderFrame,
+ nullptr, nsFrameList(continuation, continuation));
+
+ *aContinuation = continuation;
+}
+
+void nsFirstLetterFrame::DrainOverflowFrames(nsPresContext* aPresContext) {
+ // Check for an overflow list with our prev-in-flow
+ nsFirstLetterFrame* prevInFlow = (nsFirstLetterFrame*)GetPrevInFlow();
+ if (prevInFlow) {
+ AutoFrameListPtr overflowFrames(aPresContext,
+ prevInFlow->StealOverflowFrames());
+ if (overflowFrames) {
+ NS_ASSERTION(mFrames.IsEmpty(), "bad overflow list");
+
+ // When pushing and pulling frames we need to check for whether any
+ // views need to be reparented.
+ nsContainerFrame::ReparentFrameViewList(*overflowFrames, prevInFlow,
+ this);
+ mFrames.InsertFrames(this, nullptr, std::move(*overflowFrames));
+ }
+ }
+
+ // It's also possible that we have an overflow list for ourselves
+ AutoFrameListPtr overflowFrames(aPresContext, StealOverflowFrames());
+ if (overflowFrames) {
+ NS_ASSERTION(mFrames.NotEmpty(), "overflow list w/o frames");
+ mFrames.AppendFrames(nullptr, std::move(*overflowFrames));
+ }
+
+ // Now repair our first frames ComputedStyle (since we only reflow
+ // one frame there is no point in doing any other ones until they
+ // are reflowed)
+ nsIFrame* kid = mFrames.FirstChild();
+ if (kid) {
+ nsIContent* kidContent = kid->GetContent();
+ if (kidContent) {
+ NS_ASSERTION(kidContent->IsText(), "should contain only text nodes");
+ ComputedStyle* parentSC;
+ if (prevInFlow) {
+ // This is for the rest of the content not in the first-letter.
+ nsIFrame* styleParent =
+ CorrectStyleParentFrame(GetParent(), PseudoStyleType::firstLetter);
+ parentSC = styleParent->Style();
+ } else {
+ // And this for the first-letter style.
+ parentSC = mComputedStyle;
+ }
+ RefPtr<ComputedStyle> sc =
+ aPresContext->StyleSet()->ResolveStyleForText(kidContent, parentSC);
+ kid->SetComputedStyle(sc);
+ nsLayoutUtils::MarkDescendantsDirty(kid);
+ }
+ }
+}
+
+Maybe<nscoord> nsFirstLetterFrame::GetNaturalBaselineBOffset(
+ WritingMode aWM, BaselineSharingGroup aBaselineGroup,
+ BaselineExportContext) const {
+ if (aBaselineGroup == BaselineSharingGroup::Last) {
+ return Nothing{};
+ }
+ return Some(mBaseline);
+}
+
+LogicalSides nsFirstLetterFrame::GetLogicalSkipSides() const {
+ if (GetPrevContinuation()) {
+ // We shouldn't get calls to GetSkipSides for later continuations since
+ // they have separate ComputedStyles with initial values for all the
+ // properties that could trigger a call to GetSkipSides. Then again,
+ // it's not really an error to call GetSkipSides on any frame, so
+ // that's why we handle it properly.
+ return LogicalSides(mWritingMode, eLogicalSideBitsAll);
+ }
+ return LogicalSides(mWritingMode); // first continuation displays all sides
+}