gecko-dev/layout/generic/nsBRFrame.cpp
Xidorn Quan 60bcaa5c0b Bug 1257121 part 4 - Use return value rather than out param to return font metrics. r=jfkthame
MozReview-Commit-ID: 6xrHYbgHGVd

--HG--
extra : rebase_source : 4d0cea24689588d8a1daa1869502e31ac7c3dc56
2016-03-17 13:55:48 +08:00

280 lines
9.3 KiB
C++

/* -*- 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 HTML <br> elements */
#include "nsCOMPtr.h"
#include "nsFontMetrics.h"
#include "nsFrame.h"
#include "nsPresContext.h"
#include "nsLineLayout.h"
#include "nsStyleConsts.h"
#include "nsGkAtoms.h"
#include "nsRenderingContext.h"
#include "nsLayoutUtils.h"
//FOR SELECTION
#include "nsIContent.h"
//END INCLUDES FOR SELECTION
using namespace mozilla;
class BRFrame : public nsFrame {
public:
NS_DECL_FRAMEARENA_HELPERS
friend nsIFrame* NS_NewBRFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
virtual ContentOffsets CalcContentOffsetsFromFramePoint(nsPoint aPoint) override;
virtual FrameSearchResult PeekOffsetNoAmount(bool aForward, int32_t* aOffset) override;
virtual FrameSearchResult PeekOffsetCharacter(bool aForward, int32_t* aOffset,
bool aRespectClusters = true) override;
virtual FrameSearchResult PeekOffsetWord(bool aForward, bool aWordSelectEatSpace,
bool aIsKeyboardSelect, int32_t* aOffset,
PeekWordState* aState) override;
virtual void Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus) override;
virtual void AddInlineMinISize(nsRenderingContext *aRenderingContext,
InlineMinISizeData *aData) override;
virtual void AddInlinePrefISize(nsRenderingContext *aRenderingContext,
InlinePrefISizeData *aData) override;
virtual nscoord GetMinISize(nsRenderingContext *aRenderingContext) override;
virtual nscoord GetPrefISize(nsRenderingContext *aRenderingContext) override;
virtual nsIAtom* GetType() const override;
virtual nscoord GetLogicalBaseline(mozilla::WritingMode aWritingMode) const override;
virtual bool IsFrameOfType(uint32_t aFlags) const override
{
return nsFrame::IsFrameOfType(aFlags & ~(nsIFrame::eReplaced |
nsIFrame::eLineParticipant));
}
#ifdef ACCESSIBILITY
virtual mozilla::a11y::AccType AccessibleType() override;
#endif
protected:
explicit BRFrame(nsStyleContext* aContext) : nsFrame(aContext) {}
virtual ~BRFrame();
nscoord mAscent;
};
nsIFrame*
NS_NewBRFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) BRFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(BRFrame)
BRFrame::~BRFrame()
{
}
void
BRFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aMetrics,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
MarkInReflow();
DO_GLOBAL_REFLOW_COUNT("BRFrame");
DISPLAY_REFLOW(aPresContext, this, aReflowState, aMetrics, aStatus);
WritingMode wm = aReflowState.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 = aReflowState.mLineLayout;
if (ll && !GetParent()->StyleContext()->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 = aReflowState.CalcLineHeight();
finalSize.BSize(wm) = logicalHeight;
aMetrics.SetBlockStartAscent(nsLayoutUtils::GetCenteredFontBaseline(
fm, logicalHeight, wm.IsLineInverted()));
}
else {
aMetrics.SetBlockStartAscent(aMetrics.BSize(wm) = 0);
}
// XXX temporary until I figure out a better solution; see the
// code in nsLineLayout::VerticalAlignFrames that zaps minY/maxY
// if the width is zero.
// XXX This also fixes bug 10036!
// Warning: nsTextControlFrame::CalculateSizeStandard depends on
// the following line, see bug 228752.
finalSize.ISize(wm) = 1;
}
// Return our reflow status
uint32_t breakType = aReflowState.mStyleDisplay->PhysicalBreakType(wm);
if (NS_STYLE_CLEAR_NONE == breakType) {
breakType = NS_STYLE_CLEAR_LINE;
}
aStatus = NS_INLINE_BREAK | NS_INLINE_BREAK_AFTER |
NS_INLINE_MAKE_BREAK_TYPE(breakType);
ll->SetLineEndsInBR(true);
}
else {
aStatus = NS_FRAME_COMPLETE;
}
aMetrics.SetSize(wm, finalSize);
aMetrics.SetOverflowAreasToDesiredBounds();
mAscent = aMetrics.BlockStartAscent();
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aMetrics);
}
/* virtual */ void
BRFrame::AddInlineMinISize(nsRenderingContext *aRenderingContext,
nsIFrame::InlineMinISizeData *aData)
{
if (!GetParent()->StyleContext()->ShouldSuppressLineBreak()) {
aData->ForceBreak();
}
}
/* virtual */ void
BRFrame::AddInlinePrefISize(nsRenderingContext *aRenderingContext,
nsIFrame::InlinePrefISizeData *aData)
{
if (!GetParent()->StyleContext()->ShouldSuppressLineBreak()) {
aData->ForceBreak();
}
}
/* virtual */ nscoord
BRFrame::GetMinISize(nsRenderingContext *aRenderingContext)
{
nscoord result = 0;
DISPLAY_MIN_WIDTH(this, result);
return result;
}
/* virtual */ nscoord
BRFrame::GetPrefISize(nsRenderingContext *aRenderingContext)
{
nscoord result = 0;
DISPLAY_PREF_WIDTH(this, result);
return result;
}
nsIAtom*
BRFrame::GetType() const
{
return nsGkAtoms::brFrame;
}
nscoord
BRFrame::GetLogicalBaseline(mozilla::WritingMode aWritingMode) const
{
return mAscent;
}
nsIFrame::ContentOffsets BRFrame::CalcContentOffsetsFromFramePoint(nsPoint aPoint)
{
ContentOffsets offsets;
offsets.content = mContent->GetParent();
if (offsets.content) {
offsets.offset = offsets.content->IndexOf(mContent);
offsets.secondaryOffset = offsets.offset;
offsets.associate = CARET_ASSOCIATE_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,
bool aRespectClusters)
{
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)
{
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()
{
nsIContent *parent = mContent->GetParent();
if (parent && parent->IsRootOfNativeAnonymousSubtree() &&
parent->GetChildCount() == 1) {
// This <br> is the only node in a text control, therefore it is the hacky
// "bogus node" used when there is no text in the control
return a11y::eNoType;
}
// Trailing HTML br element don't play any difference. We don't need to expose
// it to AT (see bug https://bugzilla.mozilla.org/show_bug.cgi?id=899433#c16
// for details).
if (!mContent->GetNextSibling() && !GetNextSibling()) {
return a11y::eNoType;
}
return a11y::eHTMLBRType;
}
#endif