/* 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
nsMathMLmunderoverFrame::Place(nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
if ( NS_MATHML_EMBELLISH_IS_MOVABLELIMITS(mEmbellishData.flags) &&
!NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) {
// place like sub-superscript pair
return nsMathMLmsubsupFrame::PlaceSubSupScript(GetPresContext(),
aRenderingContext,
aPlaceOrigin,
aDesiredSize,
this);
}
////////////////////////////////////
// Get the children's desired sizes
nsBoundingMetrics bmBase, bmUnder, bmOver;
nsHTMLReflowMetrics baseSize (nsnull);
nsHTMLReflowMetrics underSize (nsnull);
nsHTMLReflowMetrics overSize (nsnull);
nsIFrame* overFrame = nsnull;
nsIFrame* underFrame = nsnull;
nsIFrame* baseFrame = mFrames.FirstChild();
if (baseFrame)
underFrame = baseFrame->GetNextSibling();
if (underFrame)
overFrame = underFrame->GetNextSibling();
if (!baseFrame || !underFrame || !overFrame || overFrame->GetNextSibling()) {
// report an error, encourage people to get their markups in order
NS_WARNING("invalid markup");
return ReflowError(aRenderingContext, aDesiredSize);
}
GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
GetReflowAndBoundingMetricsFor(underFrame, underSize, bmUnder);
GetReflowAndBoundingMetricsFor(overFrame, overSize, bmOver);
nscoord onePixel = GetPresContext()->IntScaledPixelsToTwips(1);
////////////////////
// Place Children
aRenderingContext.SetFont(GetStyleFont()->mFont, nsnull);
nsCOMPtr<nsIFontMetrics> fm;
aRenderingContext.GetFontMetrics(*getter_AddRefs(fm));
nscoord xHeight = 0;
fm->GetXHeight (xHeight);
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);
underDelta1 = PR_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
// Should we use Rule 10 like \underline does?
underDelta1 = ruleThickness + onePixel/2;
underDelta2 = ruleThickness;
}
// empty under?
if (!(bmUnder.ascent + bmUnder.descent)) underDelta1 = 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
nscoord bigOpSpacing1, bigOpSpacing3, bigOpSpacing5, dummy;
GetBigOpSpacings (fm,
bigOpSpacing1, dummy,
bigOpSpacing3, dummy,
bigOpSpacing5);
overDelta1 = PR_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 = PR_MAX(bigOpSpacing1, (bigOpSpacing3 - (bmOver.ascent + bmOver.descent)));
}
else {
// Rule 12, App. G, TeXbook
overDelta1 = ruleThickness + onePixel/2;
if (bmBase.ascent < xHeight) {
overDelta1 += xHeight - bmBase.ascent;
}
overDelta2 = ruleThickness;
}
// empty over?
if (!(bmOver.ascent + bmOver.descent)) overDelta1 = 0;
nscoord dxBase, dxOver = 0, dxUnder = 0;
//////////
// 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;
dxOver += correction + (mBoundingMetrics.width - overWidth)/2;
}
else {
mBoundingMetrics.width = PR_MAX(bmBase.width, overWidth);
dxOver += correction/2 + (mBoundingMetrics.width - overWidth)/2;
}
dxBase = (mBoundingMetrics.width - bmBase.width)/2;
mBoundingMetrics.ascent =
bmBase.ascent + overDelta1 + bmOver.ascent + bmOver.descent;
mBoundingMetrics.descent =
bmBase.descent + underDelta1 + bmUnder.ascent + bmUnder.descent;
mBoundingMetrics.leftBearing =
PR_MIN(dxBase + bmBase.leftBearing, dxOver + bmOver.leftBearing);
mBoundingMetrics.rightBearing =
PR_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 =
PR_MAX(mBoundingMetrics.ascent + overDelta2,
overSize.ascent + bmOver.descent + overDelta1 + bmBase.ascent);
GetItalicCorrection(bmAnonymousBase, correction);
nscoord maxWidth = PR_MAX(bmAnonymousBase.width, bmUnder.width);
if (NS_MATHML_EMBELLISH_IS_ACCENTUNDER(mEmbellishData.flags)) {
dxUnder = (maxWidth - bmUnder.width)/2;;
}
else {
dxUnder = -correction/2 + (maxWidth - bmUnder.width)/2;
}
nscoord dxAnonymousBase = (maxWidth - bmAnonymousBase.width)/2;
// adjust the offsets of the real base and overscript since their
// final offsets should be relative to us...
dxOver += dxAnonymousBase;
dxBase += dxAnonymousBase;
mBoundingMetrics.width =
PR_MAX(dxAnonymousBase + bmAnonymousBase.width, dxUnder + bmUnder.width);
mBoundingMetrics.leftBearing =
PR_MIN(dxAnonymousBase + bmAnonymousBase.leftBearing, dxUnder + bmUnder.leftBearing);
mBoundingMetrics.rightBearing =
PR_MAX(dxAnonymousBase + bmAnonymousBase.rightBearing, dxUnder + bmUnder.rightBearing);
aDesiredSize.ascent = ascentAnonymousBase;
aDesiredSize.descent =
PR_MAX(mBoundingMetrics.descent + underDelta2,
bmAnonymousBase.descent + underDelta1 + bmUnder.ascent + underSize.descent);
aDesiredSize.height = aDesiredSize.ascent + aDesiredSize.descent;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
if (aPlaceOrigin) {
nscoord dy;
// place overscript
dy = aDesiredSize.ascent - mBoundingMetrics.ascent + bmOver.ascent - overSize.ascent;
FinishReflowChild (overFrame, GetPresContext(), nsnull, overSize, dxOver, dy, 0);
// place base
dy = aDesiredSize.ascent - baseSize.ascent;
FinishReflowChild (baseFrame, GetPresContext(), nsnull, baseSize, dxBase, dy, 0);
// place underscript
dy = aDesiredSize.ascent + mBoundingMetrics.descent - bmUnder.descent - underSize.ascent;
FinishReflowChild (underFrame, GetPresContext(), nsnull, underSize, dxUnder, dy, 0);
}
return NS_OK;
}
