gecko-dev/layout/mathml/nsMathMLmrootFrame.cpp
Ting-Yu Lin 2e869d8f3d Bug 1341009 - Add nsReflowStatus::IsEmpty() assertions to all nsIFrame::Reflow() methods and some reflow helpers, and remove unneeded Reset(). r=dholbert
nsReflowStatus::IsEmpty() assertions are added after DISPLAY_REFLOW in the
beginning of the Reflow().

A few Reflow() implementations have Reset() calls at the end which are left
in place by this patch (with an explanatory comment added to each). These
ending Reset()s are only needed for cases where a non-splittable frame
passes its own nsReflowStatus to a child's reflow method. Just in case the
child leaves a "not fully complete" value in the nsReflowStatus, the
non-splittable parent frame must clear out the nsReflowStatus before
returning, so that its own parent doesn't then try to split it.

MozReview-Commit-ID: 6Jj3jfMAqj4

--HG--
extra : rebase_source : e1fe6a775ad97e16a6d7cc224634ff962ccb0fbf
2017-09-13 18:00:25 +08:00

418 lines
15 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/. */
#include "nsMathMLmrootFrame.h"
#include "nsPresContext.h"
#include <algorithm>
#include "gfxContext.h"
#include "gfxMathTable.h"
using namespace mozilla;
//
// <mroot> -- form a radical - implementation
//
// additional style context to be used by our MathMLChar.
#define NS_SQR_CHAR_STYLE_CONTEXT_INDEX 0
static const char16_t kSqrChar = char16_t(0x221A);
nsIFrame*
NS_NewMathMLmrootFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
{
return new (aPresShell) nsMathMLmrootFrame(aContext);
}
NS_IMPL_FRAMEARENA_HELPERS(nsMathMLmrootFrame)
nsMathMLmrootFrame::nsMathMLmrootFrame(nsStyleContext* aContext) :
nsMathMLContainerFrame(aContext, kClassID),
mSqrChar(),
mBarRect()
{
}
nsMathMLmrootFrame::~nsMathMLmrootFrame()
{
}
void
nsMathMLmrootFrame::Init(nsIContent* aContent,
nsContainerFrame* aParent,
nsIFrame* aPrevInFlow)
{
nsMathMLContainerFrame::Init(aContent, aParent, aPrevInFlow);
nsPresContext *presContext = PresContext();
// No need to track the style context given to our MathML char.
// The Style System will use Get/SetAdditionalStyleContext() to keep it
// up-to-date if dynamic changes arise.
nsAutoString sqrChar; sqrChar.Assign(kSqrChar);
mSqrChar.SetData(sqrChar);
ResolveMathMLCharStyle(presContext, mContent, mStyleContext, &mSqrChar);
}
NS_IMETHODIMP
nsMathMLmrootFrame::TransmitAutomaticData()
{
// 1. The REC says:
// The <mroot> element increments scriptlevel by 2, and sets displaystyle to
// "false", within index, but leaves both attributes unchanged within base.
// 2. The TeXbook (Ch 17. p.141) says \sqrt is compressed
UpdatePresentationDataFromChildAt(1, 1,
NS_MATHML_COMPRESSED,
NS_MATHML_COMPRESSED);
UpdatePresentationDataFromChildAt(0, 0,
NS_MATHML_COMPRESSED, NS_MATHML_COMPRESSED);
PropagateFrameFlagFor(mFrames.LastChild(),
NS_FRAME_MATHML_SCRIPT_DESCENDANT);
return NS_OK;
}
void
nsMathMLmrootFrame::BuildDisplayList(nsDisplayListBuilder* aBuilder,
const nsDisplayListSet& aLists)
{
/////////////
// paint the content we are square-rooting
nsMathMLContainerFrame::BuildDisplayList(aBuilder, aLists);
/////////////
// paint the sqrt symbol
if (!NS_MATHML_HAS_ERROR(mPresentationData.flags)) {
mSqrChar.Display(aBuilder, this, aLists, 0);
DisplayBar(aBuilder, this, mBarRect, aLists);
#if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
// for visual debug
nsRect rect;
mSqrChar.GetRect(rect);
nsBoundingMetrics bm;
mSqrChar.GetBoundingMetrics(bm);
DisplayBoundingMetrics(aBuilder, this, rect.TopLeft(), bm, aLists);
#endif
}
}
void
nsMathMLmrootFrame::GetRadicalXOffsets(nscoord aIndexWidth, nscoord aSqrWidth,
nsFontMetrics* aFontMetrics,
nscoord* aIndexOffset,
nscoord* aSqrOffset)
{
// The index is tucked in closer to the radical while making sure
// that the kern does not make the index and radical collide
nscoord dxIndex, dxSqr;
nscoord xHeight = aFontMetrics->XHeight();
nscoord indexRadicalKern = NSToCoordRound(1.35f * xHeight);
nscoord oneDevPixel = aFontMetrics->AppUnitsPerDevPixel();
gfxFont* mathFont = aFontMetrics->GetThebesFontGroup()->GetFirstMathFont();
if (mathFont) {
indexRadicalKern =
mathFont->MathTable()->Constant(gfxMathTable::RadicalKernAfterDegree,
oneDevPixel);
indexRadicalKern = -indexRadicalKern;
}
if (indexRadicalKern > aIndexWidth) {
dxIndex = indexRadicalKern - aIndexWidth;
dxSqr = 0;
}
else {
dxIndex = 0;
dxSqr = aIndexWidth - indexRadicalKern;
}
if (mathFont) {
// add some kern before the radical index
nscoord indexRadicalKernBefore = 0;
indexRadicalKernBefore =
mathFont->MathTable()->Constant(gfxMathTable::RadicalKernBeforeDegree,
oneDevPixel);
dxIndex += indexRadicalKernBefore;
dxSqr += indexRadicalKernBefore;
} else {
// avoid collision by leaving a minimum space between index and radical
nscoord minimumClearance = aSqrWidth / 2;
if (dxIndex + aIndexWidth + minimumClearance > dxSqr + aSqrWidth) {
if (aIndexWidth + minimumClearance < aSqrWidth) {
dxIndex = aSqrWidth - (aIndexWidth + minimumClearance);
dxSqr = 0;
}
else {
dxIndex = 0;
dxSqr = (aIndexWidth + minimumClearance) - aSqrWidth;
}
}
}
if (aIndexOffset)
*aIndexOffset = dxIndex;
if (aSqrOffset)
*aSqrOffset = dxSqr;
}
void
nsMathMLmrootFrame::Reflow(nsPresContext* aPresContext,
ReflowOutput& aDesiredSize,
const ReflowInput& aReflowInput,
nsReflowStatus& aStatus)
{
MarkInReflow();
MOZ_ASSERT(aStatus.IsEmpty(), "Caller should pass a fresh reflow status!");
nsReflowStatus childStatus;
mPresentationData.flags &= ~NS_MATHML_ERROR;
aDesiredSize.ClearSize();
aDesiredSize.SetBlockStartAscent(0);
nsBoundingMetrics bmSqr, bmBase, bmIndex;
DrawTarget* drawTarget = aReflowInput.mRenderingContext->GetDrawTarget();
//////////////////
// Reflow Children
int32_t count = 0;
nsIFrame* baseFrame = nullptr;
nsIFrame* indexFrame = nullptr;
ReflowOutput baseSize(aReflowInput);
ReflowOutput indexSize(aReflowInput);
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
// ask our children to compute their bounding metrics
ReflowOutput childDesiredSize(aReflowInput,
aDesiredSize.mFlags
| NS_REFLOW_CALC_BOUNDING_METRICS);
WritingMode wm = childFrame->GetWritingMode();
LogicalSize availSize = aReflowInput.ComputedSize(wm);
availSize.BSize(wm) = NS_UNCONSTRAINEDSIZE;
ReflowInput childReflowInput(aPresContext, aReflowInput,
childFrame, availSize);
ReflowChild(childFrame, aPresContext,
childDesiredSize, childReflowInput, childStatus);
//NS_ASSERTION(childStatus.IsComplete(), "bad status");
if (0 == count) {
// base
baseFrame = childFrame;
baseSize = childDesiredSize;
bmBase = childDesiredSize.mBoundingMetrics;
}
else if (1 == count) {
// index
indexFrame = childFrame;
indexSize = childDesiredSize;
bmIndex = childDesiredSize.mBoundingMetrics;
}
count++;
childFrame = childFrame->GetNextSibling();
}
if (2 != count) {
// report an error, encourage people to get their markups in order
ReportChildCountError();
ReflowError(drawTarget, aDesiredSize);
NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize);
// Call DidReflow() for the child frames we successfully did reflow.
DidReflowChildren(mFrames.FirstChild(), childFrame);
return;
}
////////////
// Prepare the radical symbol and the overline bar
float fontSizeInflation = nsLayoutUtils::FontSizeInflationFor(this);
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetFontMetricsForFrame(this, fontSizeInflation);
nscoord ruleThickness, leading, psi;
GetRadicalParameters(fm, StyleFont()->mMathDisplay ==
NS_MATHML_DISPLAYSTYLE_BLOCK,
ruleThickness, leading, psi);
// built-in: adjust clearance psi to emulate \mathstrut using '1' (TexBook, p.131)
char16_t one = '1';
nsBoundingMetrics bmOne =
nsLayoutUtils::AppUnitBoundsOfString(&one, 1, *fm, drawTarget);
if (bmOne.ascent > bmBase.ascent)
psi += bmOne.ascent - bmBase.ascent;
// make sure that the rule appears on on screen
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
if (ruleThickness < onePixel) {
ruleThickness = onePixel;
}
// adjust clearance psi to get an exact number of pixels -- this
// gives a nicer & uniform look on stacked radicals (bug 130282)
nscoord delta = psi % onePixel;
if (delta)
psi += onePixel - delta; // round up
// Stretch the radical symbol to the appropriate height if it is not big enough.
nsBoundingMetrics contSize = bmBase;
contSize.descent = bmBase.ascent + bmBase.descent + psi;
contSize.ascent = ruleThickness;
// height(radical) should be >= height(base) + psi + ruleThickness
nsBoundingMetrics radicalSize;
mSqrChar.Stretch(this, drawTarget,
fontSizeInflation,
NS_STRETCH_DIRECTION_VERTICAL,
contSize, radicalSize,
NS_STRETCH_LARGER,
StyleVisibility()->mDirection);
// radicalSize have changed at this point, and should match with
// the bounding metrics of the char
mSqrChar.GetBoundingMetrics(bmSqr);
// Update the desired size for the container (like msqrt, index is not yet included)
// the baseline will be that of the base.
mBoundingMetrics.ascent = bmBase.ascent + psi + ruleThickness;
mBoundingMetrics.descent =
std::max(bmBase.descent,
(bmSqr.ascent + bmSqr.descent - mBoundingMetrics.ascent));
mBoundingMetrics.width = bmSqr.width + bmBase.width;
mBoundingMetrics.leftBearing = bmSqr.leftBearing;
mBoundingMetrics.rightBearing = bmSqr.width +
std::max(bmBase.width, bmBase.rightBearing); // take also care of the rule
aDesiredSize.SetBlockStartAscent(mBoundingMetrics.ascent + leading);
aDesiredSize.Height() = aDesiredSize.BlockStartAscent() +
std::max(baseSize.Height() - baseSize.BlockStartAscent(),
mBoundingMetrics.descent + ruleThickness);
aDesiredSize.Width() = mBoundingMetrics.width;
/////////////
// Re-adjust the desired size to include the index.
// the index is raised by some fraction of the height
// of the radical, see \mroot macro in App. B, TexBook
float raiseIndexPercent = 0.6f;
gfxFont* mathFont = fm->GetThebesFontGroup()->GetFirstMathFont();
if (mathFont) {
raiseIndexPercent = mathFont->MathTable()->
Constant(gfxMathTable::RadicalDegreeBottomRaisePercent);
}
nscoord raiseIndexDelta = NSToCoordRound(raiseIndexPercent *
(bmSqr.ascent + bmSqr.descent));
nscoord indexRaisedAscent = mBoundingMetrics.ascent // top of radical
- (bmSqr.ascent + bmSqr.descent) // to bottom of radical
+ raiseIndexDelta + bmIndex.ascent + bmIndex.descent; // to top of raised index
nscoord indexClearance = 0;
if (mBoundingMetrics.ascent < indexRaisedAscent) {
indexClearance =
indexRaisedAscent - mBoundingMetrics.ascent; // excess gap introduced by a tall index
mBoundingMetrics.ascent = indexRaisedAscent;
nscoord descent = aDesiredSize.Height() - aDesiredSize.BlockStartAscent();
aDesiredSize.SetBlockStartAscent(mBoundingMetrics.ascent + leading);
aDesiredSize.Height() = aDesiredSize.BlockStartAscent() + descent;
}
nscoord dxIndex, dxSqr;
GetRadicalXOffsets(bmIndex.width, bmSqr.width, fm, &dxIndex, &dxSqr);
mBoundingMetrics.width = dxSqr + bmSqr.width + bmBase.width;
mBoundingMetrics.leftBearing =
std::min(dxIndex + bmIndex.leftBearing, dxSqr + bmSqr.leftBearing);
mBoundingMetrics.rightBearing = dxSqr + bmSqr.width +
std::max(bmBase.width, bmBase.rightBearing);
aDesiredSize.Width() = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
GatherAndStoreOverflow(&aDesiredSize);
// place the index
nscoord dx = dxIndex;
nscoord dy = aDesiredSize.BlockStartAscent() -
(indexRaisedAscent + indexSize.BlockStartAscent() - bmIndex.ascent);
FinishReflowChild(indexFrame, aPresContext, indexSize, nullptr,
MirrorIfRTL(aDesiredSize.Width(), indexSize.Width(), dx),
dy, 0);
// place the radical symbol and the radical bar
dx = dxSqr;
dy = indexClearance + leading; // leave a leading at the top
mSqrChar.SetRect(nsRect(MirrorIfRTL(aDesiredSize.Width(), bmSqr.width, dx),
dy, bmSqr.width, bmSqr.ascent + bmSqr.descent));
dx += bmSqr.width;
mBarRect.SetRect(MirrorIfRTL(aDesiredSize.Width(), bmBase.width, dx),
dy, bmBase.width, ruleThickness);
// place the base
dy = aDesiredSize.BlockStartAscent() - baseSize.BlockStartAscent();
FinishReflowChild(baseFrame, aPresContext, baseSize, nullptr,
MirrorIfRTL(aDesiredSize.Width(), baseSize.Width(), dx),
dy, 0);
mReference.x = 0;
mReference.y = aDesiredSize.BlockStartAscent();
NS_FRAME_SET_TRUNCATION(aStatus, aReflowInput, aDesiredSize);
}
/* virtual */ void
nsMathMLmrootFrame::GetIntrinsicISizeMetrics(gfxContext* aRenderingContext, ReflowOutput& aDesiredSize)
{
nsIFrame* baseFrame = mFrames.FirstChild();
nsIFrame* indexFrame = nullptr;
if (baseFrame)
indexFrame = baseFrame->GetNextSibling();
if (!indexFrame || indexFrame->GetNextSibling()) {
ReflowError(aRenderingContext->GetDrawTarget(), aDesiredSize);
return;
}
float fontSizeInflation = nsLayoutUtils::FontSizeInflationFor(this);
nscoord baseWidth =
nsLayoutUtils::IntrinsicForContainer(aRenderingContext, baseFrame,
nsLayoutUtils::PREF_ISIZE);
nscoord indexWidth =
nsLayoutUtils::IntrinsicForContainer(aRenderingContext, indexFrame,
nsLayoutUtils::PREF_ISIZE);
nscoord sqrWidth = mSqrChar.GetMaxWidth(this,
aRenderingContext->GetDrawTarget(),
fontSizeInflation);
nscoord dxSqr;
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetFontMetricsForFrame(this, fontSizeInflation);
GetRadicalXOffsets(indexWidth, sqrWidth, fm, nullptr, &dxSqr);
nscoord width = dxSqr + sqrWidth + baseWidth;
aDesiredSize.Width() = width;
aDesiredSize.mBoundingMetrics.width = width;
aDesiredSize.mBoundingMetrics.leftBearing = 0;
aDesiredSize.mBoundingMetrics.rightBearing = width;
}
// ----------------------
// the Style System will use these to pass the proper style context to our MathMLChar
nsStyleContext*
nsMathMLmrootFrame::GetAdditionalStyleContext(int32_t aIndex) const
{
switch (aIndex) {
case NS_SQR_CHAR_STYLE_CONTEXT_INDEX:
return mSqrChar.GetStyleContext();
default:
return nullptr;
}
}
void
nsMathMLmrootFrame::SetAdditionalStyleContext(int32_t aIndex,
nsStyleContext* aStyleContext)
{
switch (aIndex) {
case NS_SQR_CHAR_STYLE_CONTEXT_INDEX:
mSqrChar.SetStyleContext(aStyleContext);
break;
}
}