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firefox/layout/generic/BRFrame.cpp
Daniel Baumann 5e9a113729
Adding upstream version 140.0.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-25 09:37:52 +02:00

294 lines
11 KiB
C++

/* -*- 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 HTML <br> elements */
#include "mozilla/CaretAssociationHint.h"
#include "mozilla/PresShell.h"
#include "mozilla/TextControlElement.h"
#include "mozilla/dom/HTMLBRElement.h"
#include "gfxContext.h"
#include "nsBlockFrame.h"
#include "nsCOMPtr.h"
#include "nsComputedDOMStyle.h"
#include "nsContainerFrame.h"
#include "nsFontMetrics.h"
#include "nsGkAtoms.h"
#include "nsHTMLParts.h"
#include "nsIFrame.h"
#include "nsLayoutUtils.h"
#include "nsLineLayout.h"
#include "nsPresContext.h"
#include "nsStyleConsts.h"
#include "nsTextFrame.h"
// FOR SELECTION
#include "nsIContent.h"
// END INCLUDES FOR SELECTION
using namespace mozilla;
namespace mozilla {
class BRFrame final : public nsIFrame {
public:
NS_DECL_FRAMEARENA_HELPERS(BRFrame)
friend nsIFrame* ::NS_NewBRFrame(mozilla::PresShell* aPresShell,
ComputedStyle* aStyle);
ContentOffsets CalcContentOffsetsFromFramePoint(
const nsPoint& aPoint) override;
FrameSearchResult PeekOffsetNoAmount(bool aForward,
int32_t* aOffset) override;
FrameSearchResult PeekOffsetCharacter(
bool aForward, int32_t* aOffset,
PeekOffsetCharacterOptions aOptions =
PeekOffsetCharacterOptions()) override;
FrameSearchResult PeekOffsetWord(bool aForward, bool aWordSelectEatSpace,
bool aIsKeyboardSelect, int32_t* aOffset,
PeekWordState* aState,
bool aTrimSpaces) override;
void Reflow(nsPresContext* aPresContext, ReflowOutput& aMetrics,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus) override;
void AddInlineMinISize(const IntrinsicSizeInput& aInput,
InlineMinISizeData* aData) override;
void AddInlinePrefISize(const IntrinsicSizeInput& aInput,
InlinePrefISizeData* aData) override;
Maybe<nscoord> GetNaturalBaselineBOffset(
WritingMode aWM, BaselineSharingGroup aBaselineGroup,
BaselineExportContext) const override;
#ifdef ACCESSIBILITY
mozilla::a11y::AccType AccessibleType() override;
#endif
#ifdef DEBUG_FRAME_DUMP
nsresult GetFrameName(nsAString& aResult) const override {
return MakeFrameName(u"BR"_ns, aResult);
}
#endif
protected:
BRFrame(ComputedStyle* aStyle, nsPresContext* aPresContext)
: nsIFrame(aStyle, aPresContext, kClassID),
mAscent(NS_INTRINSIC_ISIZE_UNKNOWN) {}
virtual ~BRFrame();
nscoord mAscent;
};
} // namespace mozilla
nsIFrame* NS_NewBRFrame(mozilla::PresShell* aPresShell, ComputedStyle* aStyle) {
return new (aPresShell) BRFrame(aStyle, aPresShell->GetPresContext());
}
NS_IMPL_FRAMEARENA_HELPERS(BRFrame)
BRFrame::~BRFrame() = default;
void BRFrame::Reflow(nsPresContext* aPresContext, ReflowOutput& aMetrics,
const ReflowInput& aReflowInput, nsReflowStatus& aStatus) {
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT("BRFrame");
MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
WritingMode wm = aReflowInput.GetWritingMode();
LogicalSize finalSize(wm);
finalSize.BSize(wm) = 0; // BR frames with block size 0 are ignored in quirks
// mode by nsLineLayout::VerticalAlignFrames .
// However, it's not always 0. See below.
finalSize.ISize(wm) = 0;
aMetrics.SetBlockStartAscent(0);
// Only when the BR is operating in a line-layout situation will it
// behave like a BR. Additionally, we suppress breaks from BR inside
// of ruby frames. To determine if we're inside ruby, we have to rely
// on the *parent's* ShouldSuppressLineBreak() method, instead of our
// own, because we may have custom "display" value that makes our
// ShouldSuppressLineBreak() return false.
nsLineLayout* ll = aReflowInput.mLineLayout;
if (ll && !GetParent()->Style()->ShouldSuppressLineBreak()) {
// Note that the compatibility mode check excludes AlmostStandards
// mode, since this is the inline box model. See bug 161691.
if (ll->LineIsEmpty() ||
aPresContext->CompatibilityMode() == eCompatibility_FullStandards) {
// The line is logically empty; any whitespace is trimmed away.
//
// If this frame is going to terminate the line we know
// that nothing else will go on the line. Therefore, in this
// case, we provide some height for the BR frame so that it
// creates some vertical whitespace. It's necessary to use the
// line-height rather than the font size because the
// quirks-mode fix that doesn't apply the block's min
// line-height makes this necessary to make BR cause a line
// of the full line-height
// We also do this in strict mode because BR should act like a
// normal inline frame. That line-height is used is important
// here for cases where the line-height is less than 1.
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetInflatedFontMetricsForFrame(this);
if (fm) {
nscoord logicalHeight = aReflowInput.GetLineHeight();
finalSize.BSize(wm) = logicalHeight;
aMetrics.SetBlockStartAscent(nsLayoutUtils::GetCenteredFontBaseline(
fm, logicalHeight, wm.IsLineInverted()));
} else {
aMetrics.SetBlockStartAscent(aMetrics.BSize(wm) = 0);
}
}
// Return our reflow status
aStatus.SetInlineLineBreakAfter(
aReflowInput.mStyleDisplay->UsedClear(aReflowInput.GetCBWritingMode()));
ll->SetLineEndsInBR(true);
}
aMetrics.SetSize(wm, finalSize);
aMetrics.SetOverflowAreasToDesiredBounds();
mAscent = aMetrics.BlockStartAscent();
}
/* virtual */
void BRFrame::AddInlineMinISize(const IntrinsicSizeInput& aInput,
InlineMinISizeData* aData) {
if (!GetParent()->Style()->ShouldSuppressLineBreak()) {
aData->ForceBreak();
}
}
/* virtual */
void BRFrame::AddInlinePrefISize(const IntrinsicSizeInput& aInput,
InlinePrefISizeData* aData) {
if (!GetParent()->Style()->ShouldSuppressLineBreak()) {
aData->ForceBreak();
}
}
Maybe<nscoord> BRFrame::GetNaturalBaselineBOffset(
WritingMode aWM, BaselineSharingGroup aBaselineGroup,
BaselineExportContext) const {
if (aBaselineGroup == BaselineSharingGroup::Last) {
return Nothing{};
}
return Some(mAscent);
}
nsIFrame::ContentOffsets BRFrame::CalcContentOffsetsFromFramePoint(
const nsPoint& aPoint) {
ContentOffsets offsets;
offsets.content = mContent->GetParent();
if (offsets.content) {
offsets.offset = offsets.content->ComputeIndexOf_Deprecated(mContent);
offsets.secondaryOffset = offsets.offset;
offsets.associate = CaretAssociationHint::After;
}
return offsets;
}
nsIFrame::FrameSearchResult BRFrame::PeekOffsetNoAmount(bool aForward,
int32_t* aOffset) {
NS_ASSERTION(aOffset && *aOffset <= 1, "aOffset out of range");
int32_t startOffset = *aOffset;
// If we hit the end of a BR going backwards, go to its beginning and stay
// there.
if (!aForward && startOffset != 0) {
*aOffset = 0;
return FOUND;
}
// Otherwise, stop if we hit the beginning, continue (forward) if we hit the
// end.
return (startOffset == 0) ? FOUND : CONTINUE;
}
nsIFrame::FrameSearchResult BRFrame::PeekOffsetCharacter(
bool aForward, int32_t* aOffset, PeekOffsetCharacterOptions aOptions) {
NS_ASSERTION(aOffset && *aOffset <= 1, "aOffset out of range");
// Keep going. The actual line jumping will stop us.
return CONTINUE;
}
nsIFrame::FrameSearchResult BRFrame::PeekOffsetWord(
bool aForward, bool aWordSelectEatSpace, bool aIsKeyboardSelect,
int32_t* aOffset, PeekWordState* aState, bool aTrimSpaces) {
NS_ASSERTION(aOffset && *aOffset <= 1, "aOffset out of range");
// Keep going. The actual line jumping will stop us.
return CONTINUE;
}
#ifdef ACCESSIBILITY
a11y::AccType BRFrame::AccessibleType() {
dom::HTMLBRElement* brElement = dom::HTMLBRElement::FromNode(mContent);
if (!brElement->IsPaddingForEmptyLastLine()) {
// Even if this <br> is a "padding <br> element" used when there is no text
// in an editor, it may be surrounded by before/after pseudo element
// content. Therefore, we need to treat it as a normal <br>.
return a11y::eHTMLBRType;
}
// If it's a padding <br> element used in the anonymous subtree of <textarea>,
// we don't need to expose it as a line break because of in an replaced
// content.
if (brElement->IsInNativeAnonymousSubtree()) {
const auto* textControlElement = TextControlElement::FromNodeOrNull(
brElement->GetClosestNativeAnonymousSubtreeRootParentOrHost());
if (textControlElement &&
textControlElement->IsSingleLineTextControlOrTextArea()) {
return a11y::eNoType;
}
}
// If this <br> is a "padding <br> element" used when there is an empty last
// line before a block boundary in an HTML editor, this is required only for
// the empty last line visible in the CSS layout world. Therefore, this is
// meaningless so that this should not appear in the flattened text. On the
// other hand, if this is a padding <br> element used when there is no
// visible things in the parent block in an editor, this is required to give
// one-line height to the block. So, basically, this is meaningless, but
// this may be surrounded by before/after pseudo content. Then, they appear
// in different lines because of this line break. So, this is not meaningless
// in such case. For now, we should treat this is meaningless only in the
// former case. We can assume that if this is a padding <br>, it directly
// follows a block boundary because our editor does not keep empty nodes at
// least intentionally.
// XXX This does not treat complicated layout cases. However, our editor
// must not work well with such layout. So, this should be okay for the
// web apps in the wild.
nsIFrame* const parentFrame = GetParent();
if (HasAnyStateBits(NS_FRAME_OUT_OF_FLOW) || !parentFrame) {
return a11y::eHTMLBRType;
}
nsIFrame* const currentBlock =
nsBlockFrame::GetNearestAncestorBlock(parentFrame);
nsIContent* const currentBlockContent =
currentBlock ? currentBlock->GetContent() : nullptr;
for (nsIContent* previousContent =
brElement->GetPrevNode(currentBlockContent);
previousContent;
previousContent = previousContent->GetPrevNode(currentBlockContent)) {
nsIFrame* const precedingContentFrame = previousContent->GetPrimaryFrame();
if (!precedingContentFrame || precedingContentFrame->IsEmpty()) {
continue;
}
if (precedingContentFrame->IsBlockFrameOrSubclass()) {
break; // Reached a child block.
}
// FIXME: Oh, this should be a11y::eNoType because it's a meaningless <br>.
return a11y::eHTMLBRType;
}
return a11y::eHTMLBRType;
}
#endif