nsresult
nsMathMLmfracFrame::PlaceInternal(nsRenderingContext& aRenderingContext,
bool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize,
bool aWidthOnly)
{
////////////////////////////////////
// Get the children's desired sizes
nsBoundingMetrics bmNum, bmDen;
nsHTMLReflowMetrics sizeNum;
nsHTMLReflowMetrics sizeDen;
nsIFrame* frameDen = nullptr;
nsIFrame* frameNum = mFrames.FirstChild();
if (frameNum)
frameDen = frameNum->GetNextSibling();
if (!frameNum || !frameDen || frameDen->GetNextSibling()) {
// report an error, encourage people to get their markups in order
if (aPlaceOrigin) {
ReportChildCountError();
}
return ReflowError(aRenderingContext, aDesiredSize);
}
GetReflowAndBoundingMetricsFor(frameNum, sizeNum, bmNum);
GetReflowAndBoundingMetricsFor(frameDen, sizeDen, bmDen);
nsPresContext* presContext = PresContext();
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
aRenderingContext.SetFont(fm);
nscoord defaultRuleThickness, axisHeight;
GetRuleThickness(aRenderingContext, fm, defaultRuleThickness);
GetAxisHeight(aRenderingContext, fm, axisHeight);
nsEmbellishData coreData;
GetEmbellishDataFrom(mEmbellishData.coreFrame, coreData);
// see if the linethickness attribute is there
nsAutoString value;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::linethickness_,
value);
mLineThickness = CalcLineThickness(presContext, mStyleContext, value,
onePixel, defaultRuleThickness);
// bevelled attribute
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::bevelled_,
value);
mIsBevelled = value.EqualsLiteral("true");
if (!mIsBevelled) {
mLineRect.height = mLineThickness;
// by default, leave at least one-pixel padding at either end, or use
// lspace & rspace that may come from <mo> if we are an embellished
// container (we fetch values from the core since they may use units that
// depend on style data, and style changes could have occurred in the
// core since our last visit there)
nscoord leftSpace = std::max(onePixel,
NS_MATHML_IS_RTL(mPresentationData.flags) ?
coreData.trailingSpace : coreData.leadingSpace);
nscoord rightSpace = std::max(onePixel,
NS_MATHML_IS_RTL(mPresentationData.flags) ?
coreData.leadingSpace : coreData.trailingSpace);
//////////////////
// Get shifts
nscoord numShift = 0;
nscoord denShift = 0;
// Rule 15b, App. G, TeXbook
nscoord numShift1, numShift2, numShift3;
nscoord denShift1, denShift2;
GetNumeratorShifts(fm, numShift1, numShift2, numShift3);
GetDenominatorShifts(fm, denShift1, denShift2);
if (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) {
// C > T
numShift = numShift1;
denShift = denShift1;
}
else {
numShift = (0 < mLineRect.height) ? numShift2 : numShift3;
denShift = denShift2;
}
nscoord minClearance = 0;
nscoord actualClearance = 0;
nscoord actualRuleThickness = mLineThickness;
if (0 == actualRuleThickness) {
// Rule 15c, App. G, TeXbook
// min clearance between numerator and denominator
minClearance = (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) ?
7 * defaultRuleThickness : 3 * defaultRuleThickness;
actualClearance =
(numShift - bmNum.descent) - (bmDen.ascent - denShift);
// actualClearance should be >= minClearance
if (actualClearance < minClearance) {
nscoord halfGap = (minClearance - actualClearance)/2;
numShift += halfGap;
denShift += halfGap;
}
}
else {
// Rule 15d, App. G, TeXbook
// min clearance between numerator or denominator and middle of bar
// TeX has a different interpretation of the thickness.
// Try $a \above10pt b$ to see. Here is what TeX does:
// minClearance = (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) ?
// 3 * actualRuleThickness : actualRuleThickness;
// we slightly depart from TeX here. We use the defaultRuleThickness instead
// of the value coming from the linethickness attribute, i.e., we recover what
// TeX does if the user hasn't set linethickness. But when the linethickness
// is set, we avoid the wide gap problem.
minClearance = (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) ?
3 * defaultRuleThickness : defaultRuleThickness + onePixel;
// adjust numShift to maintain minClearance if needed
actualClearance =
(numShift - bmNum.descent) - (axisHeight + actualRuleThickness/2);
if (actualClearance < minClearance) {
numShift += (minClearance - actualClearance);
}
// adjust denShift to maintain minClearance if needed
actualClearance =
(axisHeight - actualRuleThickness/2) - (bmDen.ascent - denShift);
if (actualClearance < minClearance) {
denShift += (minClearance - actualClearance);
}
}
//////////////////
// Place Children
// XXX Need revisiting the width. TeX uses the exact width
// e.g. in $$\huge\frac{\displaystyle\int}{i}$$
nscoord width = std::max(bmNum.width, bmDen.width);
nscoord dxNum = leftSpace + (width - sizeNum.width)/2;
nscoord dxDen = leftSpace + (width - sizeDen.width)/2;
width += leftSpace + rightSpace;
// see if the numalign attribute is there
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::numalign_,
value);
if (value.EqualsLiteral("left"))
dxNum = leftSpace;
else if (value.EqualsLiteral("right"))
dxNum = width - rightSpace - sizeNum.width;
// see if the denomalign attribute is there
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::denomalign_,
value);
if (value.EqualsLiteral("left"))
dxDen = leftSpace;
else if (value.EqualsLiteral("right"))
dxDen = width - rightSpace - sizeDen.width;
mBoundingMetrics.rightBearing =
std::max(dxNum + bmNum.rightBearing, dxDen + bmDen.rightBearing);
if (mBoundingMetrics.rightBearing < width - rightSpace)
mBoundingMetrics.rightBearing = width - rightSpace;
mBoundingMetrics.leftBearing =
std::min(dxNum + bmNum.leftBearing, dxDen + bmDen.leftBearing);
if (mBoundingMetrics.leftBearing > leftSpace)
mBoundingMetrics.leftBearing = leftSpace;
mBoundingMetrics.ascent = bmNum.ascent + numShift;
mBoundingMetrics.descent = bmDen.descent + denShift;
mBoundingMetrics.width = width;
aDesiredSize.ascent = sizeNum.ascent + numShift;
aDesiredSize.height = aDesiredSize.ascent +
sizeDen.height - sizeDen.ascent + denShift;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
if (aPlaceOrigin) {
nscoord dy;
// place numerator
dy = 0;
FinishReflowChild(frameNum, presContext, nullptr, sizeNum, dxNum, dy, 0);
// place denominator
dy = aDesiredSize.height - sizeDen.height;
FinishReflowChild(frameDen, presContext, nullptr, sizeDen, dxDen, dy, 0);
// place the fraction bar - dy is top of bar
dy = aDesiredSize.ascent - (axisHeight + actualRuleThickness/2);
mLineRect.SetRect(leftSpace, dy, width - (leftSpace + rightSpace),
actualRuleThickness);
}
} else {
nscoord numShift = 0.0;
nscoord denShift = 0.0;
nscoord padding = 3 * defaultRuleThickness;
nscoord slashRatio = 3;
// Define the constant used in the expression of the maximum width
nscoord em = fm->EmHeight();
nscoord slashMaxWidthConstant = 2 * em;
// For large line thicknesses the minimum slash height is limited to the
// largest expected height of a fraction
nscoord slashMinHeight = slashRatio *
std::min(2 * mLineThickness, slashMaxWidthConstant);
nscoord leadingSpace = std::max(padding, coreData.leadingSpace);
nscoord trailingSpace = std::max(padding, coreData.trailingSpace);
nscoord delta;
// ___________
// | | /
// {|-NUMERATOR-| /
// {|___________| S
// { L
// numShift{ A
// ------------------------------------------------------- baseline
// S _____________ } denShift
// H | |}
// / |-DENOMINATOR-|}
// / |_____________|
//
// first, ensure that the top of the numerator is at least as high as the
// top of the denominator (and the reverse for the bottoms)
delta = std::max(bmDen.ascent - bmNum.ascent,
bmNum.descent - bmDen.descent) / 2;
if (delta > 0) {
numShift += delta;
denShift += delta;
}
if (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) {
delta = std::min(bmDen.ascent + bmDen.descent,
bmNum.ascent + bmNum.descent) / 2;
numShift += delta;
denShift += delta;
} else {
nscoord xHeight = fm->XHeight();
numShift += xHeight / 2;
denShift += xHeight / 4;
}
// Set the ascent/descent of our BoundingMetrics.
mBoundingMetrics.ascent = bmNum.ascent + numShift;
mBoundingMetrics.descent = bmDen.descent + denShift;
// At this point the height of the slash is
// mBoundingMetrics.ascent + mBoundingMetrics.descent
// Ensure that it is greater than slashMinHeight
delta = (slashMinHeight -
(mBoundingMetrics.ascent + mBoundingMetrics.descent)) / 2;
if (delta > 0) {
mBoundingMetrics.ascent += delta;
mBoundingMetrics.descent += delta;
}
// Set the width of the slash
if (aWidthOnly) {
mLineRect.width = mLineThickness + slashMaxWidthConstant;
} else {
mLineRect.width = mLineThickness +
std::min(slashMaxWidthConstant,
(mBoundingMetrics.ascent + mBoundingMetrics.descent) /
slashRatio);
}
// Set horizontal bounding metrics
if (NS_MATHML_IS_RTL(mPresentationData.flags)) {
mBoundingMetrics.leftBearing = trailingSpace + bmDen.leftBearing;
mBoundingMetrics.rightBearing = trailingSpace + bmDen.width + mLineRect.width + bmNum.rightBearing;
} else {
mBoundingMetrics.leftBearing = leadingSpace + bmNum.leftBearing;
mBoundingMetrics.rightBearing = leadingSpace + bmNum.width + mLineRect.width + bmDen.rightBearing;
}
mBoundingMetrics.width =
leadingSpace + bmNum.width + mLineRect.width + bmDen.width +
trailingSpace;
// Set aDesiredSize
aDesiredSize.ascent = mBoundingMetrics.ascent + padding;
aDesiredSize.height =
mBoundingMetrics.ascent + mBoundingMetrics.descent + 2 * padding;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
if (aPlaceOrigin) {
nscoord dx, dy;
// place numerator
dx = MirrorIfRTL(aDesiredSize.width, sizeNum.width,
leadingSpace);
dy = aDesiredSize.ascent - numShift - sizeNum.ascent;
FinishReflowChild(frameNum, presContext, nullptr, sizeNum, dx, dy, 0);
// place the fraction bar
dx = MirrorIfRTL(aDesiredSize.width, mLineRect.width,
leadingSpace + bmNum.width);
dy = aDesiredSize.ascent - mBoundingMetrics.ascent;
mLineRect.SetRect(dx, dy,
mLineRect.width, aDesiredSize.height - 2 * padding);
// place denominator
dx = MirrorIfRTL(aDesiredSize.width, sizeDen.width,
leadingSpace + bmNum.width + mLineRect.width);
dy = aDesiredSize.ascent + denShift - sizeDen.ascent;
FinishReflowChild(frameDen, presContext, nullptr, sizeDen, dx, dy, 0);
}
}
return NS_OK;
}
/* virtual */ nsresult
nsMathMLmunderoverFrame::Place(nsRenderingContext& aRenderingContext,
bool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
nsIAtom* tag = mContent->Tag();
if (NS_MATHML_EMBELLISH_IS_MOVABLELIMITS(mEmbellishData.flags) &&
StyleFont()->mMathDisplay == NS_MATHML_DISPLAYSTYLE_INLINE) {
//place like sub sup or subsup
if (tag == nsGkAtoms::munderover_) {
return nsMathMLmmultiscriptsFrame::PlaceMultiScript(PresContext(),
aRenderingContext,
aPlaceOrigin,
aDesiredSize,
this, 0, 0);
} else if (tag == nsGkAtoms::munder_) {
return nsMathMLmmultiscriptsFrame::PlaceMultiScript(PresContext(),
aRenderingContext,
aPlaceOrigin,
aDesiredSize,
this, 0, 0);
} else {
NS_ASSERTION(tag == nsGkAtoms::mover_, "mContent->Tag() not recognized");
return nsMathMLmmultiscriptsFrame::PlaceMultiScript(PresContext(),
aRenderingContext,
aPlaceOrigin,
aDesiredSize,
this, 0, 0);
}
}
////////////////////////////////////
// Get the children's desired sizes
nsBoundingMetrics bmBase, bmUnder, bmOver;
nsHTMLReflowMetrics baseSize(aDesiredSize.GetWritingMode());
nsHTMLReflowMetrics underSize(aDesiredSize.GetWritingMode());
nsHTMLReflowMetrics overSize(aDesiredSize.GetWritingMode());
nsIFrame* overFrame = nullptr;
nsIFrame* underFrame = nullptr;
nsIFrame* baseFrame = mFrames.FirstChild();
underSize.SetBlockStartAscent(0);
overSize.SetBlockStartAscent(0);
bool haveError = false;
if (baseFrame) {
if (tag == nsGkAtoms::munder_ ||
tag == nsGkAtoms::munderover_) {
underFrame = baseFrame->GetNextSibling();
} else if (tag == nsGkAtoms::mover_) {
overFrame = baseFrame->GetNextSibling();
}
}
if (underFrame && tag == nsGkAtoms::munderover_) {
overFrame = underFrame->GetNextSibling();
}
if (tag == nsGkAtoms::munder_) {
if (!baseFrame || !underFrame || underFrame->GetNextSibling()) {
// report an error, encourage people to get their markups in order
haveError = true;
}
}
if (tag == nsGkAtoms::mover_) {
if (!baseFrame || !overFrame || overFrame->GetNextSibling()) {
// report an error, encourage people to get their markups in order
haveError = true;
}
}
if (tag == nsGkAtoms::munderover_) {
if (!baseFrame || !underFrame || !overFrame || overFrame->GetNextSibling()) {
// report an error, encourage people to get their markups in order
haveError = true;
}
}
if (haveError) {
if (aPlaceOrigin) {
ReportChildCountError();
}
return ReflowError(aRenderingContext, aDesiredSize);
}
GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
if (underFrame) {
GetReflowAndBoundingMetricsFor(underFrame, underSize, bmUnder);
}
if (overFrame) {
GetReflowAndBoundingMetricsFor(overFrame, overSize, bmOver);
}
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
////////////////////
// Place Children
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
nscoord xHeight = fm->XHeight();
nscoord oneDevPixel = fm->AppUnitsPerDevPixel();
gfxFont* mathFont = fm->GetThebesFontGroup()->GetFirstMathFont();
nscoord ruleThickness;
GetRuleThickness (aRenderingContext, fm, ruleThickness);
nscoord correction = 0;
GetItalicCorrection (bmBase, correction);
// there are 2 different types of placement depending on
// whether we want an accented under or not
nscoord underDelta1 = 0; // gap between base and underscript
nscoord underDelta2 = 0; // extra space beneath underscript
if (!NS_MATHML_EMBELLISH_IS_ACCENTUNDER(mEmbellishData.flags)) {
// Rule 13a, App. G, TeXbook
nscoord bigOpSpacing2, bigOpSpacing4, bigOpSpacing5, dummy;
GetBigOpSpacings (fm,
dummy, bigOpSpacing2,
dummy, bigOpSpacing4,
bigOpSpacing5);
if (mathFont) {
// XXXfredw The Open Type MATH table has some StretchStack* parameters
// that we may use when the base is a stretchy horizontal operator. See
// bug 963131.
bigOpSpacing2 =
mathFont->GetMathConstant(gfxFontEntry::LowerLimitGapMin,
oneDevPixel);
bigOpSpacing4 =
mathFont->GetMathConstant(gfxFontEntry::LowerLimitBaselineDropMin,
oneDevPixel);
bigOpSpacing5 = 0;
}
underDelta1 = std::max(bigOpSpacing2, (bigOpSpacing4 - bmUnder.ascent));
underDelta2 = bigOpSpacing5;
}
else {
// No corresponding rule in TeXbook - we are on our own here
// XXX tune the gap delta between base and underscript
// XXX Should we use Rule 10 like \underline does?
// XXXfredw Perhaps use the Underbar* parameters of the MATH table. See
// bug 963125.
underDelta1 = ruleThickness + onePixel/2;
underDelta2 = ruleThickness;
}
// empty under?
if (!(bmUnder.ascent + bmUnder.descent)) {
underDelta1 = 0;
underDelta2 = 0;
}
nscoord overDelta1 = 0; // gap between base and overscript
nscoord overDelta2 = 0; // extra space above overscript
if (!NS_MATHML_EMBELLISH_IS_ACCENTOVER(mEmbellishData.flags)) {
// Rule 13a, App. G, TeXbook
// XXXfredw The Open Type MATH table has some StretchStack* parameters
// that we may use when the base is a stretchy horizontal operator. See
// bug 963131.
nscoord bigOpSpacing1, bigOpSpacing3, bigOpSpacing5, dummy;
GetBigOpSpacings (fm,
bigOpSpacing1, dummy,
bigOpSpacing3, dummy,
bigOpSpacing5);
if (mathFont) {
// XXXfredw The Open Type MATH table has some StretchStack* parameters
// that we may use when the base is a stretchy horizontal operator. See
// bug 963131.
bigOpSpacing1 =
mathFont->GetMathConstant(gfxFontEntry::UpperLimitGapMin,
oneDevPixel);
bigOpSpacing3 =
mathFont->GetMathConstant(gfxFontEntry::UpperLimitBaselineRiseMin,
oneDevPixel);
bigOpSpacing5 = 0;
}
overDelta1 = std::max(bigOpSpacing1, (bigOpSpacing3 - bmOver.descent));
overDelta2 = bigOpSpacing5;
// XXX This is not a TeX rule...
// delta1 (as computed abvove) can become really big when bmOver.descent is
// negative, e.g., if the content is &OverBar. In such case, we use the height
if (bmOver.descent < 0)
overDelta1 = std::max(bigOpSpacing1, (bigOpSpacing3 - (bmOver.ascent + bmOver.descent)));
}
else {
// Rule 12, App. G, TeXbook
// We are going to modify this rule to make it more general.
// The idea behind Rule 12 in the TeXBook is to keep the accent
// as close to the base as possible, while ensuring that the
// distance between the *baseline* of the accent char and
// the *baseline* of the base is atleast x-height.
// The idea is that for normal use, we would like all the accents
// on a line to line up atleast x-height above the baseline
// if possible.
// When the ascent of the base is >= x-height,
// the baseline of the accent char is placed just above the base
// (specifically, the baseline of the accent char is placed
// above the baseline of the base by the ascent of the base).
// For ease of implementation,
// this assumes that the font-designer designs accents
// in such a way that the bottom of the accent is atleast x-height
// above its baseline, otherwise there will be collisions
// with the base. Also there should be proper padding between
// the bottom of the accent char and its baseline.
// The above rule may not be obvious from a first
// reading of rule 12 in the TeXBook !!!
// The mathml <mover> tag can use accent chars that
// do not follow this convention. So we modify TeX's rule
// so that TeX's rule gets subsumed for accents that follow
// TeX's convention,
// while also allowing accents that do not follow the convention :
// we try to keep the *bottom* of the accent char atleast x-height
// from the baseline of the base char. we also slap on an extra
// padding between the accent and base chars.
overDelta1 = ruleThickness + onePixel/2;
nscoord accentBaseHeight = xHeight;
if (mathFont) {
accentBaseHeight =
mathFont->GetMathConstant(gfxFontEntry::AccentBaseHeight,
oneDevPixel);
}
if (bmBase.ascent < accentBaseHeight) {
// also ensure at least accentBaseHeight above the baseline of the base
overDelta1 += accentBaseHeight - bmBase.ascent;
}
overDelta2 = ruleThickness;
}
// empty over?
if (!(bmOver.ascent + bmOver.descent)) {
overDelta1 = 0;
overDelta2 = 0;
}
nscoord dxBase = 0, dxOver = 0, dxUnder = 0;
nsAutoString valueAlign;
enum {
center,
left,
right
} alignPosition = center;
if (mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::align, valueAlign)) {
if (valueAlign.EqualsLiteral("left")) {
alignPosition = left;
} else if (valueAlign.EqualsLiteral("right")) {
alignPosition = right;
}
}
//////////
// pass 1, do what <mover> does: attach the overscript on the base
// Ad-hoc - This is to override fonts which have ready-made _accent_
// glyphs with negative lbearing and rbearing. We want to position
// the overscript ourselves
nscoord overWidth = bmOver.width;
if (!overWidth && (bmOver.rightBearing - bmOver.leftBearing > 0)) {
overWidth = bmOver.rightBearing - bmOver.leftBearing;
dxOver = -bmOver.leftBearing;
}
if (NS_MATHML_EMBELLISH_IS_ACCENTOVER(mEmbellishData.flags)) {
mBoundingMetrics.width = bmBase.width;
if (alignPosition == center) {
dxOver += correction;
}
}
else {
mBoundingMetrics.width = std::max(bmBase.width, overWidth);
if (alignPosition == center) {
dxOver += correction/2;
}
}
if (alignPosition == center) {
dxOver += (mBoundingMetrics.width - overWidth)/2;
dxBase = (mBoundingMetrics.width - bmBase.width)/2;
} else if (alignPosition == right) {
dxOver += mBoundingMetrics.width - overWidth;
dxBase = mBoundingMetrics.width - bmBase.width;
}
mBoundingMetrics.ascent =
bmBase.ascent + overDelta1 + bmOver.ascent + bmOver.descent;
mBoundingMetrics.descent = bmBase.descent;
mBoundingMetrics.leftBearing =
std::min(dxBase + bmBase.leftBearing, dxOver + bmOver.leftBearing);
mBoundingMetrics.rightBearing =
std::max(dxBase + bmBase.rightBearing, dxOver + bmOver.rightBearing);
//////////
// pass 2, do what <munder> does: attach the underscript on the previous
// result. We conceptually view the previous result as an "anynomous base"
// from where to attach the underscript. Hence if the underscript is empty,
// we should end up like <mover>. If the overscript is empty, we should
// end up like <munder>.
nsBoundingMetrics bmAnonymousBase = mBoundingMetrics;
nscoord ascentAnonymousBase =
std::max(mBoundingMetrics.ascent + overDelta2,
overSize.BlockStartAscent() + bmOver.descent +
overDelta1 + bmBase.ascent);
ascentAnonymousBase = std::max(ascentAnonymousBase,
baseSize.BlockStartAscent());
// Width of non-spacing marks is zero so use left and right bearing.
nscoord underWidth = bmUnder.width;
if (!underWidth) {
underWidth = bmUnder.rightBearing - bmUnder.leftBearing;
dxUnder = -bmUnder.leftBearing;
}
nscoord maxWidth = std::max(bmAnonymousBase.width, underWidth);
if (alignPosition == center &&
!NS_MATHML_EMBELLISH_IS_ACCENTUNDER(mEmbellishData.flags)) {
GetItalicCorrection(bmAnonymousBase, correction);
dxUnder += -correction/2;
}
nscoord dxAnonymousBase = 0;
if (alignPosition == center) {
dxUnder += (maxWidth - underWidth)/2;
dxAnonymousBase = (maxWidth - bmAnonymousBase.width)/2;
} else if (alignPosition == right) {
dxUnder += maxWidth - underWidth;
dxAnonymousBase = maxWidth - bmAnonymousBase.width;
}
// adjust the offsets of the real base and overscript since their
// final offsets should be relative to us...
dxOver += dxAnonymousBase;
dxBase += dxAnonymousBase;
mBoundingMetrics.width =
std::max(dxAnonymousBase + bmAnonymousBase.width, dxUnder + bmUnder.width);
// At this point, mBoundingMetrics.ascent = bmAnonymousBase.ascent
mBoundingMetrics.descent =
bmAnonymousBase.descent + underDelta1 + bmUnder.ascent + bmUnder.descent;
mBoundingMetrics.leftBearing =
std::min(dxAnonymousBase + bmAnonymousBase.leftBearing, dxUnder + bmUnder.leftBearing);
mBoundingMetrics.rightBearing =
std::max(dxAnonymousBase + bmAnonymousBase.rightBearing, dxUnder + bmUnder.rightBearing);
aDesiredSize.SetBlockStartAscent(ascentAnonymousBase);
aDesiredSize.Height() = aDesiredSize.BlockStartAscent() +
std::max(mBoundingMetrics.descent + underDelta2,
bmAnonymousBase.descent + underDelta1 + bmUnder.ascent +
underSize.Height() - underSize.BlockStartAscent());
aDesiredSize.Height() = std::max(aDesiredSize.Height(),
aDesiredSize.BlockStartAscent() +
baseSize.Height() - baseSize.BlockStartAscent());
aDesiredSize.Width() = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.BlockStartAscent();
if (aPlaceOrigin) {
nscoord dy;
// place overscript
if (overFrame) {
dy = aDesiredSize.BlockStartAscent() -
mBoundingMetrics.ascent + bmOver.ascent -
overSize.BlockStartAscent();
FinishReflowChild (overFrame, PresContext(), overSize, nullptr, dxOver, dy, 0);
}
// place base
dy = aDesiredSize.BlockStartAscent() - baseSize.BlockStartAscent();
FinishReflowChild (baseFrame, PresContext(), baseSize, nullptr, dxBase, dy, 0);
// place underscript
if (underFrame) {
dy = aDesiredSize.BlockStartAscent() +
mBoundingMetrics.descent - bmUnder.descent -
underSize.BlockStartAscent();
FinishReflowChild (underFrame, PresContext(), underSize, nullptr,
dxUnder, dy, 0);
}
}
return NS_OK;
}
NS_IMETHODIMP
nsMathMLmrootFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
nsresult rv = NS_OK;
nsSize availSize(aReflowState.ComputedWidth(), NS_UNCONSTRAINEDSIZE);
nsReflowStatus childStatus;
aDesiredSize.Width() = aDesiredSize.Height() = 0;
aDesiredSize.SetTopAscent(0);
nsBoundingMetrics bmSqr, bmBase, bmIndex;
nsRenderingContext& renderingContext = *aReflowState.rendContext;
//////////////////
// Reflow Children
int32_t count = 0;
nsIFrame* baseFrame = nullptr;
nsIFrame* indexFrame = nullptr;
nsHTMLReflowMetrics baseSize(aReflowState.GetWritingMode());
nsHTMLReflowMetrics indexSize(aReflowState.GetWritingMode());
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
// ask our children to compute their bounding metrics
nsHTMLReflowMetrics childDesiredSize(aReflowState.GetWritingMode(),
aDesiredSize.mFlags
| NS_REFLOW_CALC_BOUNDING_METRICS);
nsHTMLReflowState childReflowState(aPresContext, aReflowState,
childFrame, availSize);
rv = ReflowChild(childFrame, aPresContext,
childDesiredSize, childReflowState, childStatus);
//NS_ASSERTION(NS_FRAME_IS_COMPLETE(childStatus), "bad status");
if (NS_FAILED(rv)) {
// Call DidReflow() for the child frames we successfully did reflow.
DidReflowChildren(mFrames.FirstChild(), childFrame);
return rv;
}
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();
rv = ReflowError(renderingContext, aDesiredSize);
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
// Call DidReflow() for the child frames we successfully did reflow.
DidReflowChildren(mFrames.FirstChild(), childFrame);
return rv;
}
////////////
// Prepare the radical symbol and the overline bar
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
renderingContext.SetFont(fm);
// For radical glyphs from TeX fonts and some of the radical glyphs from
// Mathematica fonts, the thickness of the overline can be obtained from the
// ascent of the glyph. Most fonts however have radical glyphs above the
// baseline so no assumption can be made about the meaning of the ascent.
nscoord ruleThickness, leading, em;
GetRuleThickness(renderingContext, fm, ruleThickness);
char16_t one = '1';
nsBoundingMetrics bmOne = renderingContext.GetBoundingMetrics(&one, 1);
// get the leading to be left at the top of the resulting frame
// this seems more reliable than using fm->GetLeading() on suspicious fonts
GetEmHeight(fm, em);
leading = nscoord(0.2f * em);
// Rule 11, App. G, TeXbook
// psi = clearance between rule and content
nscoord phi = 0, psi = 0;
if (StyleFont()->mMathDisplay == NS_MATHML_DISPLAYSTYLE_BLOCK)
phi = fm->XHeight();
else
phi = ruleThickness;
psi = ruleThickness + phi/4;
// built-in: adjust clearance psi to emulate \mathstrut using '1' (TexBook, p.131)
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(aPresContext, renderingContext,
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.SetTopAscent(mBoundingMetrics.ascent + leading);
aDesiredSize.Height() = aDesiredSize.TopAscent() +
std::max(baseSize.Height() - baseSize.TopAscent(),
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
nscoord raiseIndexDelta = NSToCoordRound(0.6f * (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.TopAscent();
aDesiredSize.SetTopAscent(mBoundingMetrics.ascent + leading);
aDesiredSize.Height() = aDesiredSize.TopAscent() + 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.TopAscent() - (indexRaisedAscent + indexSize.TopAscent() - 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.TopAscent() - baseSize.TopAscent();
FinishReflowChild(baseFrame, aPresContext, baseSize, nullptr,
MirrorIfRTL(aDesiredSize.Width(), baseSize.Width(), dx),
dy, 0);
mReference.x = 0;
mReference.y = aDesiredSize.TopAscent();
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
