/* static */ void
nsMathMLFrame::GetRuleThickness(nsIRenderingContext& aRenderingContext,
nsIFontMetrics* aFontMetrics,
nscoord& aRuleThickness)
{
// get the bounding metrics of the overbar char, the rendering context
// is assumed to have been set with the font of the current style context
#ifdef NS_DEBUG
nsCOMPtr<nsIFontMetrics> currFontMetrics;
aRenderingContext.GetFontMetrics(*getter_AddRefs(currFontMetrics));
NS_ASSERTION(currFontMetrics->Font().Equals(aFontMetrics->Font()),
"unexpected state");
#endif
nscoord xHeight;
aFontMetrics->GetXHeight(xHeight);
PRUnichar overBar = 0x00AF;
nsBoundingMetrics bm;
nsresult rv = aRenderingContext.GetBoundingMetrics(&overBar, PRUint32(1), bm);
if (NS_SUCCEEDED(rv)) {
aRuleThickness = bm.ascent + bm.descent;
}
if (NS_FAILED(rv) || aRuleThickness <= 0 || aRuleThickness >= xHeight) {
// fall-back to the other version
GetRuleThickness(aFontMetrics, aRuleThickness);
}
#if 0
nscoord oldRuleThickness;
GetRuleThickness(aFontMetrics, oldRuleThickness);
PRUnichar sqrt = 0xE063; // a sqrt glyph from TeX's CMEX font
rv = aRenderingContext.GetBoundingMetrics(&sqrt, PRUint32(1), bm);
nscoord sqrtrule = bm.ascent; // according to TeX, the ascent should be the rule
printf("xheight:%4d rule:%4d oldrule:%4d sqrtrule:%4d\n",
xHeight, aRuleThickness, oldRuleThickness, sqrtrule);
#endif
}
/* static */ void
nsMathMLFrame::GetRuleThickness(nsRenderingContext& aRenderingContext,
nsFontMetrics* aFontMetrics,
nscoord& aRuleThickness)
{
// get the bounding metrics of the overbar char, the rendering context
// is assumed to have been set with the font of the current style context
NS_ASSERTION(aRenderingContext.FontMetrics()->Font().
Equals(aFontMetrics->Font()),
"unexpected state");
nscoord xHeight = aFontMetrics->XHeight();
PRUnichar overBar = 0x00AF;
nsBoundingMetrics bm = aRenderingContext.GetBoundingMetrics(&overBar, 1);
aRuleThickness = bm.ascent + bm.descent;
if (aRuleThickness <= 0 || aRuleThickness >= xHeight) {
// fall-back to the other version
GetRuleThickness(aFontMetrics, aRuleThickness);
}
}
/* 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
nsMathMLmsqrtFrame::Reflow(nsPresContext* aPresContext,
nsHTMLReflowMetrics& aDesiredSize,
const nsHTMLReflowState& aReflowState,
nsReflowStatus& aStatus)
{
///////////////
// Let the base class format our content like an inferred mrow
nsHTMLReflowMetrics baseSize(aDesiredSize);
nsresult rv = nsMathMLContainerFrame::Reflow(aPresContext, baseSize,
aReflowState, aStatus);
//NS_ASSERTION(NS_FRAME_IS_COMPLETE(aStatus), "bad status");
if (NS_FAILED(rv)) return rv;
nsBoundingMetrics bmSqr, bmBase;
bmBase = baseSize.mBoundingMetrics;
////////////
// Prepare the radical symbol and the overline bar
nsIRenderingContext& renderingContext = *aReflowState.rendContext;
renderingContext.SetFont(GetStyleFont()->mFont, nsnull);
nsCOMPtr<nsIFontMetrics> fm;
renderingContext.GetFontMetrics(*getter_AddRefs(fm));
nscoord ruleThickness, leading, em;
GetRuleThickness(renderingContext, fm, ruleThickness);
nsBoundingMetrics bmOne;
renderingContext.GetBoundingMetrics(NS_LITERAL_STRING("1").get(), 1, bmOne);
// 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 (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags))
fm->GetXHeight(phi);
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;
// Stretch the radical symbol to the appropriate height if it is not big enough.
nsBoundingMetrics contSize = bmBase;
contSize.ascent = ruleThickness;
contSize.descent = bmBase.ascent + bmBase.descent + psi;
// height(radical) should be >= height(base) + psi + ruleThickness
nsBoundingMetrics radicalSize;
mSqrChar.Stretch(aPresContext, renderingContext,
NS_STRETCH_DIRECTION_VERTICAL,
contSize, radicalSize,
NS_STRETCH_LARGER);
// radicalSize have changed at this point, and should match with
// the bounding metrics of the char
mSqrChar.GetBoundingMetrics(bmSqr);
// According to TeX, the ascent of the returned radical should be
// the thickness of the overline
ruleThickness = bmSqr.ascent;
// make sure that the rule appears on the screen
nscoord onePixel = aPresContext->IntScaledPixelsToTwips(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
nscoord dx = 0, dy = 0;
// place the radical symbol and the radical bar
dy = leading; // leave a leading at the top
mSqrChar.SetRect(nsRect(dx, dy, bmSqr.width, bmSqr.ascent + bmSqr.descent));
dx = bmSqr.width;
mBarRect.SetRect(dx, dy, bmBase.width, ruleThickness);
// Update the desired size for the container.
// the baseline will be that of the base.
mBoundingMetrics.ascent = bmBase.ascent + psi + ruleThickness;
mBoundingMetrics.descent =
PR_MAX(bmBase.descent, (bmSqr.descent - (bmBase.ascent + psi)));
mBoundingMetrics.width = bmSqr.width + bmBase.width;
mBoundingMetrics.leftBearing = bmSqr.leftBearing;
mBoundingMetrics.rightBearing = bmSqr.width +
PR_MAX(bmBase.width, bmBase.rightBearing); // take also care of the rule
aDesiredSize.ascent = mBoundingMetrics.ascent + leading;
aDesiredSize.descent =
PR_MAX(baseSize.descent, (mBoundingMetrics.descent + ruleThickness));
aDesiredSize.height = aDesiredSize.ascent + aDesiredSize.descent;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
//////////////////
// Adjust the origins to leave room for the sqrt char and the overline bar
dx = radicalSize.width;
dy = aDesiredSize.ascent - baseSize.ascent;
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
childFrame->SetPosition(childFrame->GetPosition() + nsPoint(dx, dy));
childFrame = childFrame->GetNextSibling();
}
if (aDesiredSize.mComputeMEW) {
aDesiredSize.mMaxElementWidth = aDesiredSize.width;
}
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
// exported routine that both munderover and msubsup share.
// munderover uses this when movablelimits is set.
nsresult
nsMathMLmsubsupFrame::PlaceSubSupScript(nsPresContext* aPresContext,
nsRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize,
nsMathMLContainerFrame* aFrame,
nscoord aUserSubScriptShift,
nscoord aUserSupScriptShift,
nscoord aScriptSpace)
{
// force the scriptSpace to be atleast 1 pixel
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
aScriptSpace = NS_MAX(onePixel, aScriptSpace);
////////////////////////////////////
// Get the children's desired sizes
nsHTMLReflowMetrics baseSize;
nsHTMLReflowMetrics subScriptSize;
nsHTMLReflowMetrics supScriptSize;
nsBoundingMetrics bmBase, bmSubScript, bmSupScript;
nsIFrame* subScriptFrame = nsnull;
nsIFrame* supScriptFrame = nsnull;
nsIFrame* baseFrame = aFrame->GetFirstPrincipalChild();
if (baseFrame)
subScriptFrame = baseFrame->GetNextSibling();
if (subScriptFrame)
supScriptFrame = subScriptFrame->GetNextSibling();
if (!baseFrame || !subScriptFrame || !supScriptFrame ||
supScriptFrame->GetNextSibling()) {
// report an error, encourage people to get their markups in order
return aFrame->ReflowError(aRenderingContext, aDesiredSize);
}
GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, bmSubScript);
GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, bmSupScript);
// get the subdrop from the subscript font
nscoord subDrop;
GetSubDropFromChild(subScriptFrame, subDrop);
// parameter v, Rule 18a, App. G, TeXbook
nscoord minSubScriptShift = bmBase.descent + subDrop;
// get the supdrop from the supscript font
nscoord supDrop;
GetSupDropFromChild(supScriptFrame, supDrop);
// parameter u, Rule 18a, App. G, TeXbook
nscoord minSupScriptShift = bmBase.ascent - supDrop;
//////////////////
// Place Children
//////////////////
//////////////////////////////////////////////////
// Get subscript shift
// slightly different from nsMathMLmsubFrame.cpp
//////////////////////////////////////////////////
// subScriptShift{1,2}
// = minimum amount to shift the subscript down
// = sub{1,2} in TeXbook
// subScriptShift1 = subscriptshift attribute * x-height
nscoord subScriptShift1, subScriptShift2;
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(baseFrame, getter_AddRefs(fm));
aRenderingContext.SetFont(fm);
// get x-height (an ex)
nscoord xHeight = fm->XHeight();
nscoord ruleSize;
GetRuleThickness (aRenderingContext, fm, ruleSize);
// Get subScriptShift{1,2} default from font
GetSubScriptShifts (fm, subScriptShift1, subScriptShift2);
if (0 < aUserSubScriptShift) {
// the user has set the subscriptshift attribute
float scaler = ((float) subScriptShift2) / subScriptShift1;
subScriptShift1 = NS_MAX(subScriptShift1, aUserSubScriptShift);
subScriptShift2 = NSToCoordRound(scaler * subScriptShift1);
}
// get a tentative value for subscriptshift
// Rule 18d, App. G, TeXbook
nscoord subScriptShift =
NS_MAX(minSubScriptShift,NS_MAX(subScriptShift1,subScriptShift2));
//////////////////////////////////////////////////
// Get supscript shift
// same code from nsMathMLmsupFrame.cpp
//////////////////////////////////////////////////
// get min supscript shift limit from x-height
// = d(x) + 1/4 * sigma_5, Rule 18c, App. G, TeXbook
nscoord minShiftFromXHeight = (nscoord)
(bmSupScript.descent + (1.0f/4.0f) * xHeight);
// supScriptShift{1,2,3}
// = minimum amount to shift the supscript up
// = sup{1,2,3} in TeX
// supScriptShift1 = superscriptshift attribute * x-height
// Note that there are THREE values for supscript shifts depending
// on the current style
nscoord supScriptShift1, supScriptShift2, supScriptShift3;
// Set supScriptShift{1,2,3} default from font
GetSupScriptShifts (fm, supScriptShift1, supScriptShift2, supScriptShift3);
if (0 < aUserSupScriptShift) {
// the user has set the superscriptshift attribute
float scaler2 = ((float) supScriptShift2) / supScriptShift1;
float scaler3 = ((float) supScriptShift3) / supScriptShift1;
supScriptShift1 = NS_MAX(supScriptShift1, aUserSupScriptShift);
supScriptShift2 = NSToCoordRound(scaler2 * supScriptShift1);
supScriptShift3 = NSToCoordRound(scaler3 * supScriptShift1);
}
// get sup script shift depending on current script level and display style
// Rule 18c, App. G, TeXbook
nscoord supScriptShift;
nsPresentationData presentationData;
aFrame->GetPresentationData(presentationData);
if ( aFrame->GetStyleFont()->mScriptLevel == 0 &&
NS_MATHML_IS_DISPLAYSTYLE(presentationData.flags) &&
!NS_MATHML_IS_COMPRESSED(presentationData.flags)) {
// Style D in TeXbook
supScriptShift = supScriptShift1;
}
else if (NS_MATHML_IS_COMPRESSED(presentationData.flags)) {
// Style C' in TeXbook = D',T',S',SS'
supScriptShift = supScriptShift3;
}
else {
// everything else = T,S,SS
supScriptShift = supScriptShift2;
}
// get tentative value for superscriptshift
// Rule 18c, App. G, TeXbook
supScriptShift =
NS_MAX(minSupScriptShift,NS_MAX(supScriptShift,minShiftFromXHeight));
//////////////////////////////////////////////////
// Negotiate between supScriptShift and subScriptShift
// so that there will be enough gap between them
// Rule 18e, App. G, TeXbook
//////////////////////////////////////////////////
nscoord gap =
(supScriptShift - bmSupScript.descent) -
(bmSubScript.ascent - subScriptShift);
if (gap < 4.0f * ruleSize) {
// adjust subScriptShift to get a gap of (4.0 * ruleSize)
subScriptShift += NSToCoordRound ((4.0f * ruleSize) - gap);
}
// next we want to ensure that the bottom of the superscript
// will be > (4/5) * x-height above baseline
gap = NSToCoordRound ((4.0f/5.0f) * xHeight -
(supScriptShift - bmSupScript.descent));
if (gap > 0) {
supScriptShift += gap;
subScriptShift -= gap;
}
//////////////////////////////////////////////////
// Do the Placing
//////////////////////////////////////////////////
// get bounding box for base + subscript + superscript
nsBoundingMetrics boundingMetrics;
boundingMetrics.ascent =
NS_MAX(bmBase.ascent, (bmSupScript.ascent + supScriptShift));
boundingMetrics.descent =
NS_MAX(bmBase.descent, (bmSubScript.descent + subScriptShift));
// leave aScriptSpace after both super/subscript
// add italicCorrection between base and superscript
// add "a little to spare" as well (see TeXbook Ch.11, p.64), as we
// estimate the italic creation ourselves and it isn't the same as TeX
nscoord italicCorrection;
GetItalicCorrection(bmBase, italicCorrection);
italicCorrection += onePixel;
boundingMetrics.width = bmBase.width + aScriptSpace +
NS_MAX((italicCorrection + bmSupScript.width), bmSubScript.width);
boundingMetrics.leftBearing = bmBase.leftBearing;
boundingMetrics.rightBearing = bmBase.width +
NS_MAX((italicCorrection + bmSupScript.rightBearing), bmSubScript.rightBearing);
aFrame->SetBoundingMetrics(boundingMetrics);
// reflow metrics
aDesiredSize.ascent =
NS_MAX(baseSize.ascent,
NS_MAX(subScriptSize.ascent - subScriptShift,
supScriptSize.ascent + supScriptShift));
aDesiredSize.height = aDesiredSize.ascent +
NS_MAX(baseSize.height - baseSize.ascent,
NS_MAX(subScriptSize.height - subScriptSize.ascent + subScriptShift,
supScriptSize.height - subScriptSize.ascent - supScriptShift));
aDesiredSize.width = boundingMetrics.width;
aDesiredSize.mBoundingMetrics = boundingMetrics;
aFrame->SetReference(nsPoint(0, aDesiredSize.ascent));
if (aPlaceOrigin) {
nscoord dx, dy;
// now place the base ...
dx = 0; dy = aDesiredSize.ascent - baseSize.ascent;
FinishReflowChild(baseFrame, aPresContext, nsnull,
baseSize, dx, dy, 0);
// ... and subscript
dx = bmBase.width;
dy = aDesiredSize.ascent - (subScriptSize.ascent - subScriptShift);
FinishReflowChild(subScriptFrame, aPresContext, nsnull,
subScriptSize, dx, dy, 0);
// ... and the superscript
dx = bmBase.width + italicCorrection;
dy = aDesiredSize.ascent - (supScriptSize.ascent + supScriptShift);
FinishReflowChild(supScriptFrame, aPresContext, nsnull,
supScriptSize, dx, 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;
}
/* virtual */ nsresult
nsMathMLmoverFrame::Place(nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
if ( NS_MATHML_EMBELLISH_IS_MOVABLELIMITS(mEmbellishData.flags) &&
!NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) {
// place like superscript
return nsMathMLmsupFrame::PlaceSuperScript(PresContext(),
aRenderingContext,
aPlaceOrigin,
aDesiredSize,
this, 0, nsPresContext::CSSPointsToAppUnits(0.5f));
}
////////////////////////////////////
// Get the children's desired sizes
nsBoundingMetrics bmBase, bmOver;
nsHTMLReflowMetrics baseSize;
nsHTMLReflowMetrics overSize;
nsIFrame* overFrame = nsnull;
nsIFrame* baseFrame = mFrames.FirstChild();
if (baseFrame)
overFrame = baseFrame->GetNextSibling();
if (!baseFrame || !overFrame || overFrame->GetNextSibling()) {
// report an error, encourage people to get their markups in order
return ReflowError(aRenderingContext, aDesiredSize);
}
GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
GetReflowAndBoundingMetricsFor(overFrame, overSize, bmOver);
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
////////////////////
// Place Children
aRenderingContext.SetFont(GetStyleFont()->mFont,
PresContext()->GetUserFontSet());
nsCOMPtr<nsIFontMetrics> fm;
aRenderingContext.GetFontMetrics(*getter_AddRefs(fm));
nscoord xHeight = 0;
fm->GetXHeight (xHeight);
nscoord ruleThickness;
GetRuleThickness (aRenderingContext, fm, ruleThickness);
// there are 2 different types of placement depending on
// whether we want an accented overscript or not
nscoord correction = 0;
GetItalicCorrection (bmBase, correction);
nscoord delta1 = 0; // gap between base and overscript
nscoord delta2 = 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);
delta1 = NS_MAX(bigOpSpacing1, (bigOpSpacing3 - bmOver.descent));
delta2 = bigOpSpacing5;
// XXX This is not a TeX rule...
// delta1 (as computed above) 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)
delta1 = NS_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.
delta1 = ruleThickness + onePixel/2; // we have at least the padding
if (bmBase.ascent < xHeight) {
// also ensure at least x-height above the baseline of the base
delta1 += xHeight - bmBase.ascent;
}
delta2 = ruleThickness;
}
// empty over?
if (!(bmOver.ascent + bmOver.descent)) delta1 = 0;
nscoord dxBase, dxOver = 0;
// 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 = NS_MAX(bmBase.width, overWidth);
dxOver += correction/2 + (mBoundingMetrics.width - overWidth)/2;
}
dxBase = (mBoundingMetrics.width - bmBase.width) / 2;
mBoundingMetrics.ascent =
bmOver.ascent + bmOver.descent + delta1 + bmBase.ascent;
mBoundingMetrics.descent = bmBase.descent;
mBoundingMetrics.leftBearing =
NS_MIN(dxBase + bmBase.leftBearing, dxOver + bmOver.leftBearing);
mBoundingMetrics.rightBearing =
NS_MAX(dxBase + bmBase.rightBearing, dxOver + bmOver.rightBearing);
aDesiredSize.ascent =
NS_MAX(mBoundingMetrics.ascent + delta2,
overSize.ascent + bmOver.descent + delta1 + bmBase.ascent);
aDesiredSize.height = aDesiredSize.ascent +
baseSize.height - baseSize.ascent;
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
if (aPlaceOrigin) {
// place base
nscoord dy = aDesiredSize.ascent - baseSize.ascent;
FinishReflowChild (baseFrame, PresContext(), nsnull, baseSize, dxBase, dy, 0);
// place overscript
dy = aDesiredSize.ascent -
mBoundingMetrics.ascent + bmOver.ascent - overSize.ascent;
FinishReflowChild (overFrame, PresContext(), nsnull, overSize, dxOver, 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.ascent = 0;
nsBoundingMetrics bmSqr, bmBase, bmIndex;
nsRenderingContext& renderingContext = *aReflowState.rendContext;
//////////////////
// Reflow Children
PRInt32 count = 0;
nsIFrame* baseFrame = nsnull;
nsIFrame* indexFrame = nsnull;
nsHTMLReflowMetrics baseSize;
nsHTMLReflowMetrics indexSize;
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
// ask our children to compute their bounding metrics
nsHTMLReflowMetrics childDesiredSize(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
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
renderingContext.SetFont(GetStyleFont()->mFont,
aPresContext->GetUserFontSet());
nsFontMetrics* fm = renderingContext.FontMetrics();
// 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);
PRUnichar 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 (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags))
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);
// 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 =
NS_MAX(bmBase.descent,
(bmSqr.ascent + bmSqr.descent - mBoundingMetrics.ascent));
mBoundingMetrics.width = bmSqr.width + bmBase.width;
mBoundingMetrics.leftBearing = bmSqr.leftBearing;
mBoundingMetrics.rightBearing = bmSqr.width +
NS_MAX(bmBase.width, bmBase.rightBearing); // take also care of the rule
aDesiredSize.ascent = mBoundingMetrics.ascent + leading;
aDesiredSize.height = aDesiredSize.ascent +
NS_MAX(baseSize.height - baseSize.ascent,
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.ascent;
aDesiredSize.ascent = mBoundingMetrics.ascent + leading;
aDesiredSize.height = aDesiredSize.ascent + descent;
}
nscoord dxIndex, dxSqr;
GetRadicalXOffsets(bmIndex.width, bmSqr.width, fm, &dxIndex, &dxSqr);
// place the index
nscoord dx = dxIndex;
nscoord dy = aDesiredSize.ascent - (indexRaisedAscent + indexSize.ascent - bmIndex.ascent);
FinishReflowChild(indexFrame, aPresContext, nsnull, indexSize, 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(dx, dy, bmSqr.width, bmSqr.ascent + bmSqr.descent));
dx += bmSqr.width;
mBarRect.SetRect(dx, dy, bmBase.width, ruleThickness);
// place the base
dy = aDesiredSize.ascent - baseSize.ascent;
FinishReflowChild(baseFrame, aPresContext, nsnull, baseSize, dx, dy, 0);
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
mBoundingMetrics.width = dx + bmBase.width;
mBoundingMetrics.leftBearing =
NS_MIN(dxIndex + bmIndex.leftBearing, dxSqr + bmSqr.leftBearing);
mBoundingMetrics.rightBearing = dx +
NS_MAX(bmBase.width, bmBase.rightBearing);
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
GatherAndStoreOverflow(&aDesiredSize);
aStatus = NS_FRAME_COMPLETE;
NS_FRAME_SET_TRUNCATION(aStatus, aReflowState, aDesiredSize);
return NS_OK;
}
/* virtual */ nsresult
nsMathMLmmultiscriptsFrame::Place(nsRenderingContext& aRenderingContext,
bool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
////////////////////////////////////
// Get the children's desired sizes
nscoord minShiftFromXHeight, subDrop, supDrop;
////////////////////////////////////////
// Initialize super/sub shifts that
// depend only on the current font
////////////////////////////////////////
ProcessAttributes();
// get x-height (an ex)
const nsStyleFont* font = GetStyleFont();
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
aRenderingContext.SetFont(fm);
nscoord xHeight = fm->XHeight();
nscoord ruleSize;
GetRuleThickness (aRenderingContext, fm, ruleSize);
// scriptspace from TeX for extra spacing after sup/subscript (0.5pt in plain TeX)
// forced to be at least 1 pixel here
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
nscoord scriptSpace = NS_MAX(nsPresContext::CSSPointsToAppUnits(0.5f), onePixel);
/////////////////////////////////////
// first the shift for the subscript
// subScriptShift{1,2}
// = minimum amount to shift the subscript down
// = sub{1,2} in TeXbook
// subScriptShift1 = subscriptshift attribute * x-height
nscoord subScriptShift1, subScriptShift2;
// Get subScriptShift{1,2} default from font
GetSubScriptShifts (fm, subScriptShift1, subScriptShift2);
if (0 < mSubScriptShift) {
// the user has set the subscriptshift attribute
float scaler = ((float) subScriptShift2) / subScriptShift1;
subScriptShift1 = NS_MAX(subScriptShift1, mSubScriptShift);
subScriptShift2 = NSToCoordRound(scaler * subScriptShift1);
}
// the font dependent shift
nscoord subScriptShift = NS_MAX(subScriptShift1,subScriptShift2);
/////////////////////////////////////
// next the shift for the superscript
// supScriptShift{1,2,3}
// = minimum amount to shift the supscript up
// = sup{1,2,3} in TeX
// supScriptShift1 = superscriptshift attribute * x-height
// Note that there are THREE values for supscript shifts depending
// on the current style
nscoord supScriptShift1, supScriptShift2, supScriptShift3;
// Set supScriptShift{1,2,3} default from font
GetSupScriptShifts (fm, supScriptShift1, supScriptShift2, supScriptShift3);
if (0 < mSupScriptShift) {
// the user has set the superscriptshift attribute
float scaler2 = ((float) supScriptShift2) / supScriptShift1;
float scaler3 = ((float) supScriptShift3) / supScriptShift1;
supScriptShift1 = NS_MAX(supScriptShift1, mSupScriptShift);
supScriptShift2 = NSToCoordRound(scaler2 * supScriptShift1);
supScriptShift3 = NSToCoordRound(scaler3 * supScriptShift1);
}
// get sup script shift depending on current script level and display style
// Rule 18c, App. G, TeXbook
nscoord supScriptShift;
if ( font->mScriptLevel == 0 &&
NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags) &&
!NS_MATHML_IS_COMPRESSED(mPresentationData.flags)) {
// Style D in TeXbook
supScriptShift = supScriptShift1;
}
else if (NS_MATHML_IS_COMPRESSED(mPresentationData.flags)) {
// Style C' in TeXbook = D',T',S',SS'
supScriptShift = supScriptShift3;
}
else {
// everything else = T,S,SS
supScriptShift = supScriptShift2;
}
////////////////////////////////////
// Get the children's sizes
////////////////////////////////////
nscoord width = 0, prescriptsWidth = 0, rightBearing = 0;
nsIFrame* mprescriptsFrame = nsnull; // frame of <mprescripts/>, if there.
bool isSubScript = false;
nscoord minSubScriptShift = 0, minSupScriptShift = 0;
nscoord trySubScriptShift = subScriptShift;
nscoord trySupScriptShift = supScriptShift;
nscoord maxSubScriptShift = subScriptShift;
nscoord maxSupScriptShift = supScriptShift;
PRInt32 count = 0;
nsHTMLReflowMetrics baseSize;
nsHTMLReflowMetrics subScriptSize;
nsHTMLReflowMetrics supScriptSize;
nsIFrame* baseFrame = nsnull;
nsIFrame* subScriptFrame = nsnull;
nsIFrame* supScriptFrame = nsnull;
bool firstPrescriptsPair = false;
nsBoundingMetrics bmBase, bmSubScript, bmSupScript;
nscoord italicCorrection = 0;
mBoundingMetrics.width = 0;
mBoundingMetrics.ascent = mBoundingMetrics.descent = -0x7FFFFFFF;
nscoord ascent = -0x7FFFFFFF, descent = -0x7FFFFFFF;
aDesiredSize.width = aDesiredSize.height = 0;
nsIFrame* childFrame = mFrames.FirstChild();
while (childFrame) {
if (childFrame->GetContent()->Tag() == nsGkAtoms::mprescripts_) {
if (mprescriptsFrame) {
// duplicate <mprescripts/> found
// report an error, encourage people to get their markups in order
return ReflowError(aRenderingContext, aDesiredSize);
}
mprescriptsFrame = childFrame;
firstPrescriptsPair = true;
}
else {
if (0 == count) {
// base
baseFrame = childFrame;
GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
GetItalicCorrection(bmBase, italicCorrection);
// for the superscript, we always add "a little to spare"
italicCorrection += onePixel;
// we update mBoundingMetrics.{ascent,descent} with that
// of the baseFrame only after processing all the sup/sub pairs
// XXX need italic correction only *if* there are postscripts ?
mBoundingMetrics.width = bmBase.width + italicCorrection;
mBoundingMetrics.rightBearing = bmBase.rightBearing;
mBoundingMetrics.leftBearing = bmBase.leftBearing; // until overwritten
}
else {
// super/subscript block
if (isSubScript) {
// subscript
subScriptFrame = childFrame;
GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, bmSubScript);
// get the subdrop from the subscript font
GetSubDropFromChild (subScriptFrame, subDrop);
// parameter v, Rule 18a, App. G, TeXbook
minSubScriptShift = bmBase.descent + subDrop;
trySubScriptShift = NS_MAX(minSubScriptShift,subScriptShift);
mBoundingMetrics.descent =
NS_MAX(mBoundingMetrics.descent,bmSubScript.descent);
descent = NS_MAX(descent,subScriptSize.height - subScriptSize.ascent);
width = bmSubScript.width + scriptSpace;
rightBearing = bmSubScript.rightBearing;
}
else {
// supscript
supScriptFrame = childFrame;
GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, bmSupScript);
// get the supdrop from the supscript font
GetSupDropFromChild (supScriptFrame, supDrop);
// parameter u, Rule 18a, App. G, TeXbook
minSupScriptShift = bmBase.ascent - supDrop;
// get min supscript shift limit from x-height
// = d(x) + 1/4 * sigma_5, Rule 18c, App. G, TeXbook
minShiftFromXHeight = NSToCoordRound
((bmSupScript.descent + (1.0f/4.0f) * xHeight));
trySupScriptShift =
NS_MAX(minSupScriptShift,NS_MAX(minShiftFromXHeight,supScriptShift));
mBoundingMetrics.ascent =
NS_MAX(mBoundingMetrics.ascent,bmSupScript.ascent);
ascent = NS_MAX(ascent,supScriptSize.ascent);
width = NS_MAX(width, bmSupScript.width + scriptSpace);
rightBearing = NS_MAX(rightBearing, bmSupScript.rightBearing);
if (!mprescriptsFrame) { // we are still looping over base & postscripts
mBoundingMetrics.rightBearing = mBoundingMetrics.width + rightBearing;
mBoundingMetrics.width += width;
}
else {
prescriptsWidth += width;
if (firstPrescriptsPair) {
firstPrescriptsPair = false;
mBoundingMetrics.leftBearing =
NS_MIN(bmSubScript.leftBearing, bmSupScript.leftBearing);
}
}
width = rightBearing = 0;
// negotiate between the various shifts so that
// there is enough gap between the sup and subscripts
// Rule 18e, App. G, TeXbook
nscoord gap =
(trySupScriptShift - bmSupScript.descent) -
(bmSubScript.ascent - trySubScriptShift);
if (gap < 4.0f * ruleSize) {
// adjust trySubScriptShift to get a gap of (4.0 * ruleSize)
trySubScriptShift += NSToCoordRound ((4.0f * ruleSize) - gap);
}
// next we want to ensure that the bottom of the superscript
// will be > (4/5) * x-height above baseline
gap = NSToCoordRound ((4.0f/5.0f) * xHeight -
(trySupScriptShift - bmSupScript.descent));
if (gap > 0.0f) {
trySupScriptShift += gap;
trySubScriptShift -= gap;
}
maxSubScriptShift = NS_MAX(maxSubScriptShift, trySubScriptShift);
maxSupScriptShift = NS_MAX(maxSupScriptShift, trySupScriptShift);
trySubScriptShift = subScriptShift;
trySupScriptShift = supScriptShift;
}
}
isSubScript = !isSubScript;
}
count++;
childFrame = childFrame->GetNextSibling();
}
// note: width=0 if all sup-sub pairs match correctly
if ((0 != width) || !baseFrame || !subScriptFrame || !supScriptFrame) {
// report an error, encourage people to get their markups in order
return ReflowError(aRenderingContext, aDesiredSize);
}
// we left out the width of prescripts, so ...
mBoundingMetrics.rightBearing += prescriptsWidth;
mBoundingMetrics.width += prescriptsWidth;
// we left out the base during our bounding box updates, so ...
mBoundingMetrics.ascent =
NS_MAX(mBoundingMetrics.ascent+maxSupScriptShift,bmBase.ascent);
mBoundingMetrics.descent =
NS_MAX(mBoundingMetrics.descent+maxSubScriptShift,bmBase.descent);
// get the reflow metrics ...
aDesiredSize.ascent =
NS_MAX(ascent+maxSupScriptShift,baseSize.ascent);
aDesiredSize.height = aDesiredSize.ascent +
NS_MAX(descent+maxSubScriptShift,baseSize.height - baseSize.ascent);
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
//////////////////
// Place Children
// Place prescripts, followed by base, and then postscripts.
// The list of frames is in the order: {base} {postscripts} {prescripts}
// We go over the list in a circular manner, starting at <prescripts/>
if (aPlaceOrigin) {
nscoord dx = 0, dy = 0;
count = 0;
childFrame = mprescriptsFrame;
do {
if (!childFrame) { // end of prescripts,
// place the base ...
childFrame = baseFrame;
dy = aDesiredSize.ascent - baseSize.ascent;
FinishReflowChild (baseFrame, PresContext(), nsnull, baseSize,
MirrorIfRTL(aDesiredSize.width,
baseSize.width,
dx),
dy, 0);
dx += bmBase.width + italicCorrection;
}
else if (mprescriptsFrame != childFrame) {
// process each sup/sub pair
if (0 == count) {
subScriptFrame = childFrame;
count = 1;
}
else if (1 == count) {
supScriptFrame = childFrame;
count = 0;
// get the ascent/descent of sup/subscripts stored in their rects
// rect.x = descent, rect.y = ascent
GetReflowAndBoundingMetricsFor(subScriptFrame, subScriptSize, bmSubScript);
GetReflowAndBoundingMetricsFor(supScriptFrame, supScriptSize, bmSupScript);
// center w.r.t. largest width
width = NS_MAX(subScriptSize.width, supScriptSize.width);
dy = aDesiredSize.ascent - subScriptSize.ascent +
maxSubScriptShift;
FinishReflowChild (subScriptFrame, PresContext(), nsnull,
subScriptSize,
MirrorIfRTL(aDesiredSize.width,
subScriptSize.width,
dx + (width-subScriptSize.width)/2),
dy, 0);
dy = aDesiredSize.ascent - supScriptSize.ascent -
maxSupScriptShift;
FinishReflowChild (supScriptFrame, PresContext(), nsnull,
supScriptSize,
MirrorIfRTL(aDesiredSize.width,
supScriptSize.width,
dx + (width-supScriptSize.width)/2),
dy, 0);
dx += width + scriptSpace;
}
}
childFrame = childFrame->GetNextSibling();
} while (mprescriptsFrame != childFrame);
}
return NS_OK;
}
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 = nsnull;
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
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 = NS_MAX(onePixel, coreData.leftSpace);
nscoord rightSpace = NS_MAX(onePixel, coreData.rightSpace);
//////////////////
// 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 = NS_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 =
NS_MAX(dxNum + bmNum.rightBearing, dxDen + bmDen.rightBearing);
if (mBoundingMetrics.rightBearing < width - rightSpace)
mBoundingMetrics.rightBearing = width - rightSpace;
mBoundingMetrics.leftBearing =
NS_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, nsnull, sizeNum, dxNum, dy, 0);
// place denominator
dy = aDesiredSize.height - sizeDen.height;
FinishReflowChild(frameDen, presContext, nsnull, 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 *
NS_MIN(2 * mLineThickness, slashMaxWidthConstant);
nscoord leftSpace = NS_MAX(padding, coreData.leftSpace);
nscoord rightSpace = NS_MAX(padding, coreData.rightSpace);
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 = NS_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 = NS_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 +
NS_MIN(slashMaxWidthConstant,
(mBoundingMetrics.ascent + mBoundingMetrics.descent) /
slashRatio);
}
// Set horizontal bounding metrics
mBoundingMetrics.leftBearing = leftSpace + bmNum.leftBearing;
mBoundingMetrics.rightBearing =
leftSpace + bmNum.width + mLineRect.width + bmDen.rightBearing;
mBoundingMetrics.width =
leftSpace + bmNum.width + mLineRect.width + bmDen.width + rightSpace;
// 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) {
FinishReflowChild(frameNum, presContext, nsnull, sizeNum,
leftSpace,
aDesiredSize.ascent - numShift - sizeNum.ascent, 0);
mLineRect.SetRect(leftSpace + bmNum.width,
aDesiredSize.ascent - mBoundingMetrics.ascent,
mLineRect.width,
aDesiredSize.height - 2 * padding);
FinishReflowChild(frameDen, presContext, nsnull, sizeDen,
leftSpace + bmNum.width + mLineRect.width,
aDesiredSize.ascent + denShift - sizeDen.ascent, 0);
}
}
return NS_OK;
}
/* virtual */ nsresult
nsMathMLmencloseFrame::PlaceInternal(nsRenderingContext& aRenderingContext,
bool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize,
bool aWidthOnly)
{
///////////////
// Measure the size of our content using the base class to format like an
// inferred mrow.
nsHTMLReflowMetrics baseSize;
nsresult rv =
nsMathMLContainerFrame::Place(aRenderingContext, false, baseSize);
if (NS_MATHML_HAS_ERROR(mPresentationData.flags) || NS_FAILED(rv)) {
DidReflowChildren(GetFirstPrincipalChild());
return rv;
}
nsBoundingMetrics bmBase = baseSize.mBoundingMetrics;
nscoord dx_left = 0, dx_right = 0;
nsBoundingMetrics bmLongdivChar, bmRadicalChar;
nscoord radicalAscent = 0, radicalDescent = 0;
nscoord longdivAscent = 0, longdivDescent = 0;
nscoord psi = 0;
///////////////
// Thickness of bars and font metrics
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
nscoord mEmHeight;
nsRefPtr<nsFontMetrics> fm;
nsLayoutUtils::GetFontMetricsForFrame(this, getter_AddRefs(fm));
aRenderingContext.SetFont(fm);
GetRuleThickness(aRenderingContext, fm, mRuleThickness);
GetEmHeight(fm, mEmHeight);
PRUnichar one = '1';
nsBoundingMetrics bmOne = aRenderingContext.GetBoundingMetrics(&one, 1);
///////////////
// General rules: the menclose element takes the size of the enclosed content.
// We add a padding when needed.
// determine padding & psi
nscoord padding = 3 * mRuleThickness;
nscoord delta = padding % onePixel;
if (delta)
padding += onePixel - delta; // round up
if (IsToDraw(NOTATION_LONGDIV) || IsToDraw(NOTATION_RADICAL)) {
nscoord phi;
// Rule 11, App. G, TeXbook
// psi = clearance between rule and content
if (NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags))
phi = fm->XHeight();
else
phi = mRuleThickness;
psi = mRuleThickness + phi / 4;
delta = psi % onePixel;
if (delta)
psi += onePixel - delta; // round up
}
if (mRuleThickness < onePixel)
mRuleThickness = onePixel;
// Set horizontal parameters
if (IsToDraw(NOTATION_ROUNDEDBOX) ||
IsToDraw(NOTATION_TOP) ||
IsToDraw(NOTATION_LEFT) ||
IsToDraw(NOTATION_BOTTOM) ||
IsToDraw(NOTATION_CIRCLE))
dx_left = padding;
if (IsToDraw(NOTATION_ROUNDEDBOX) ||
IsToDraw(NOTATION_TOP) ||
IsToDraw(NOTATION_RIGHT) ||
IsToDraw(NOTATION_BOTTOM) ||
IsToDraw(NOTATION_CIRCLE))
dx_right = padding;
// Set vertical parameters
if (IsToDraw(NOTATION_RIGHT) ||
IsToDraw(NOTATION_LEFT) ||
IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
IsToDraw(NOTATION_VERTICALSTRIKE) ||
IsToDraw(NOTATION_CIRCLE) ||
IsToDraw(NOTATION_ROUNDEDBOX) ||
IsToDraw(NOTATION_RADICAL) ||
IsToDraw(NOTATION_LONGDIV)) {
// set a minimal value for the base height
bmBase.ascent = NS_MAX(bmOne.ascent, bmBase.ascent);
bmBase.descent = NS_MAX(0, bmBase.descent);
}
mBoundingMetrics.ascent = bmBase.ascent;
mBoundingMetrics.descent = bmBase.descent;
if (IsToDraw(NOTATION_ROUNDEDBOX) ||
IsToDraw(NOTATION_TOP) ||
IsToDraw(NOTATION_LEFT) ||
IsToDraw(NOTATION_RIGHT) ||
IsToDraw(NOTATION_CIRCLE))
mBoundingMetrics.ascent += padding;
if (IsToDraw(NOTATION_ROUNDEDBOX) ||
IsToDraw(NOTATION_LEFT) ||
IsToDraw(NOTATION_RIGHT) ||
IsToDraw(NOTATION_BOTTOM) ||
IsToDraw(NOTATION_CIRCLE))
mBoundingMetrics.descent += padding;
///////////////
// circle notation: we don't want the ellipse to overlap the enclosed
// content. Hence, we need to increase the size of the bounding box by a
// factor of at least sqrt(2).
if (IsToDraw(NOTATION_CIRCLE)) {
double ratio = (sqrt(2.0) - 1.0) / 2.0;
nscoord padding2;
// Update horizontal parameters
padding2 = ratio * bmBase.width;
dx_left = NS_MAX(dx_left, padding2);
dx_right = NS_MAX(dx_right, padding2);
// Update vertical parameters
padding2 = ratio * (bmBase.ascent + bmBase.descent);
mBoundingMetrics.ascent = NS_MAX(mBoundingMetrics.ascent,
bmBase.ascent + padding2);
mBoundingMetrics.descent = NS_MAX(mBoundingMetrics.descent,
bmBase.descent + padding2);
}
///////////////
// longdiv notation:
if (IsToDraw(NOTATION_LONGDIV)) {
if (aWidthOnly) {
nscoord longdiv_width = mMathMLChar[mLongDivCharIndex].
GetMaxWidth(PresContext(), aRenderingContext);
// Update horizontal parameters
dx_left = NS_MAX(dx_left, longdiv_width);
} else {
// Stretch the parenthesis to the appropriate height if it is not
// big enough.
nsBoundingMetrics contSize = bmBase;
contSize.ascent = mRuleThickness;
contSize.descent = bmBase.ascent + bmBase.descent + psi;
// height(longdiv) should be >= height(base) + psi + mRuleThickness
mMathMLChar[mLongDivCharIndex].Stretch(PresContext(), aRenderingContext,
NS_STRETCH_DIRECTION_VERTICAL,
contSize, bmLongdivChar,
NS_STRETCH_LARGER, false);
mMathMLChar[mLongDivCharIndex].GetBoundingMetrics(bmLongdivChar);
// Update horizontal parameters
dx_left = NS_MAX(dx_left, bmLongdivChar.width);
// Update vertical parameters
longdivAscent = bmBase.ascent + psi + mRuleThickness;
longdivDescent = NS_MAX(bmBase.descent,
(bmLongdivChar.ascent + bmLongdivChar.descent -
longdivAscent));
mBoundingMetrics.ascent = NS_MAX(mBoundingMetrics.ascent,
longdivAscent);
mBoundingMetrics.descent = NS_MAX(mBoundingMetrics.descent,
longdivDescent);
}
}
///////////////
// radical notation:
if (IsToDraw(NOTATION_RADICAL)) {
nscoord *dx_leading =
NS_MATHML_IS_RTL(mPresentationData.flags) ? &dx_right : &dx_left;
if (aWidthOnly) {
nscoord radical_width = mMathMLChar[mRadicalCharIndex].
GetMaxWidth(PresContext(), aRenderingContext);
// Update horizontal parameters
*dx_leading = NS_MAX(*dx_leading, radical_width);
} else {
// Stretch the radical symbol to the appropriate height if it is not
// big enough.
nsBoundingMetrics contSize = bmBase;
contSize.ascent = mRuleThickness;
contSize.descent = bmBase.ascent + bmBase.descent + psi;
// height(radical) should be >= height(base) + psi + mRuleThickness
mMathMLChar[mRadicalCharIndex].Stretch(PresContext(), aRenderingContext,
NS_STRETCH_DIRECTION_VERTICAL,
contSize, bmRadicalChar,
NS_STRETCH_LARGER,
NS_MATHML_IS_RTL(mPresentationData.flags));
mMathMLChar[mRadicalCharIndex].GetBoundingMetrics(bmRadicalChar);
// Update horizontal parameters
*dx_leading = NS_MAX(*dx_leading, bmRadicalChar.width);
// Update vertical parameters
radicalAscent = bmBase.ascent + psi + mRuleThickness;
radicalDescent = NS_MAX(bmBase.descent,
(bmRadicalChar.ascent + bmRadicalChar.descent -
radicalAscent));
mBoundingMetrics.ascent = NS_MAX(mBoundingMetrics.ascent,
radicalAscent);
mBoundingMetrics.descent = NS_MAX(mBoundingMetrics.descent,
radicalDescent);
}
}
///////////////
//
if (IsToDraw(NOTATION_CIRCLE) ||
IsToDraw(NOTATION_ROUNDEDBOX) ||
(IsToDraw(NOTATION_LEFT) && IsToDraw(NOTATION_RIGHT))) {
// center the menclose around the content (horizontally)
dx_left = dx_right = NS_MAX(dx_left, dx_right);
}
///////////////
// The maximum size is now computed: set the remaining parameters
mBoundingMetrics.width = dx_left + bmBase.width + dx_right;
mBoundingMetrics.leftBearing = NS_MIN(0, dx_left + bmBase.leftBearing);
mBoundingMetrics.rightBearing =
NS_MAX(mBoundingMetrics.width, dx_left + bmBase.rightBearing);
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.ascent = NS_MAX(mBoundingMetrics.ascent, baseSize.ascent);
aDesiredSize.height = aDesiredSize.ascent +
NS_MAX(mBoundingMetrics.descent, baseSize.height - baseSize.ascent);
if (IsToDraw(NOTATION_LONGDIV) || IsToDraw(NOTATION_RADICAL)) {
// get the leading to be left at the top of the resulting frame
// this seems more reliable than using fm->GetLeading() on suspicious
// fonts
nscoord leading = nscoord(0.2f * mEmHeight);
nscoord desiredSizeAscent = aDesiredSize.ascent;
nscoord desiredSizeDescent = aDesiredSize.height - aDesiredSize.ascent;
if (IsToDraw(NOTATION_LONGDIV)) {
desiredSizeAscent = NS_MAX(desiredSizeAscent,
longdivAscent + leading);
desiredSizeDescent = NS_MAX(desiredSizeDescent,
longdivDescent + mRuleThickness);
}
if (IsToDraw(NOTATION_RADICAL)) {
desiredSizeAscent = NS_MAX(desiredSizeAscent,
radicalAscent + leading);
desiredSizeDescent = NS_MAX(desiredSizeDescent,
radicalDescent + mRuleThickness);
}
aDesiredSize.ascent = desiredSizeAscent;
aDesiredSize.height = desiredSizeAscent + desiredSizeDescent;
}
if (IsToDraw(NOTATION_CIRCLE) ||
IsToDraw(NOTATION_ROUNDEDBOX) ||
(IsToDraw(NOTATION_TOP) && IsToDraw(NOTATION_BOTTOM))) {
// center the menclose around the content (vertically)
nscoord dy = NS_MAX(aDesiredSize.ascent - bmBase.ascent,
aDesiredSize.height - aDesiredSize.ascent -
bmBase.descent);
aDesiredSize.ascent = bmBase.ascent + dy;
aDesiredSize.height = aDesiredSize.ascent + bmBase.descent + dy;
}
// Update mBoundingMetrics ascent/descent
if (IsToDraw(NOTATION_TOP) ||
IsToDraw(NOTATION_RIGHT) ||
IsToDraw(NOTATION_LEFT) ||
IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
IsToDraw(NOTATION_VERTICALSTRIKE) ||
IsToDraw(NOTATION_CIRCLE) ||
IsToDraw(NOTATION_ROUNDEDBOX))
mBoundingMetrics.ascent = aDesiredSize.ascent;
if (IsToDraw(NOTATION_BOTTOM) ||
IsToDraw(NOTATION_RIGHT) ||
IsToDraw(NOTATION_LEFT) ||
IsToDraw(NOTATION_UPDIAGONALSTRIKE) ||
IsToDraw(NOTATION_DOWNDIAGONALSTRIKE) ||
IsToDraw(NOTATION_VERTICALSTRIKE) ||
IsToDraw(NOTATION_CIRCLE) ||
IsToDraw(NOTATION_ROUNDEDBOX))
mBoundingMetrics.descent = aDesiredSize.height - aDesiredSize.ascent;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
if (aPlaceOrigin) {
//////////////////
// Set position and size of MathMLChars
if (IsToDraw(NOTATION_LONGDIV))
mMathMLChar[mLongDivCharIndex].SetRect(nsRect(dx_left -
bmLongdivChar.width,
aDesiredSize.ascent -
longdivAscent,
bmLongdivChar.width,
bmLongdivChar.ascent +
bmLongdivChar.descent));
if (IsToDraw(NOTATION_RADICAL)) {
nscoord dx = NS_MATHML_IS_RTL(mPresentationData.flags) ?
dx_left + bmBase.width : dx_left - bmRadicalChar.width;
mMathMLChar[mRadicalCharIndex].SetRect(nsRect(dx,
aDesiredSize.ascent -
radicalAscent,
bmRadicalChar.width,
bmRadicalChar.ascent +
bmRadicalChar.descent));
}
mContentWidth = bmBase.width;
//////////////////
// Finish reflowing child frames
PositionRowChildFrames(dx_left, aDesiredSize.ascent);
}
return NS_OK;
}
/* virtual */ nsresult
nsMathMLmfracFrame::Place(nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
////////////////////////////////////
// Get the children's desired sizes
nsBoundingMetrics bmNum, bmDen;
nsHTMLReflowMetrics sizeNum;
nsHTMLReflowMetrics sizeDen;
nsIFrame* frameDen = nsnull;
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
NS_WARNING("invalid markup");
return ReflowError(aRenderingContext, aDesiredSize);
}
GetReflowAndBoundingMetricsFor(frameNum, sizeNum, bmNum);
GetReflowAndBoundingMetricsFor(frameDen, sizeDen, bmDen);
//////////////////
// Get shifts
nsPresContext* presContext = PresContext();
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
aRenderingContext.SetFont(GetStyleFont()->mFont, nsnull);
nsCOMPtr<nsIFontMetrics> fm;
aRenderingContext.GetFontMetrics(*getter_AddRefs(fm));
nscoord defaultRuleThickness, axisHeight;
GetRuleThickness(aRenderingContext, fm, defaultRuleThickness);
GetAxisHeight(aRenderingContext, fm, axisHeight);
// 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)
nsEmbellishData coreData;
GetEmbellishDataFrom(mEmbellishData.coreFrame, coreData);
nscoord leftSpace = PR_MAX(onePixel, coreData.leftSpace);
nscoord rightSpace = PR_MAX(onePixel, coreData.rightSpace);
// see if the linethickness attribute is there
nsAutoString value;
GetAttribute(mContent, mPresentationData.mstyle, nsGkAtoms::linethickness_, value);
mLineRect.height = CalcLineThickness(presContext, mStyleContext, value,
onePixel, defaultRuleThickness);
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 = mLineRect.height;
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 = PR_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 =
PR_MAX(dxNum + bmNum.rightBearing, dxDen + bmDen.rightBearing);
if (mBoundingMetrics.rightBearing < width - rightSpace)
mBoundingMetrics.rightBearing = width - rightSpace;
mBoundingMetrics.leftBearing =
PR_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, nsnull, sizeNum, dxNum, dy, 0);
// place denominator
dy = aDesiredSize.height - sizeDen.height;
FinishReflowChild(frameDen, presContext, nsnull, 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);
}
return NS_OK;
}
/* virtual */ nsresult
nsMathMLmunderFrame::Place(nsIRenderingContext& aRenderingContext,
PRBool aPlaceOrigin,
nsHTMLReflowMetrics& aDesiredSize)
{
if ( NS_MATHML_EMBELLISH_IS_MOVABLELIMITS(mEmbellishData.flags) &&
!NS_MATHML_IS_DISPLAYSTYLE(mPresentationData.flags)) {
// place like subscript
return nsMathMLmsubFrame::PlaceSubScript(PresContext(),
aRenderingContext,
aPlaceOrigin,
aDesiredSize,
this, 0, nsPresContext::CSSPointsToAppUnits(0.5f));
}
////////////////////////////////////
// Get the children's desired sizes
nsBoundingMetrics bmBase, bmUnder;
nsHTMLReflowMetrics baseSize;
nsHTMLReflowMetrics underSize;
nsIFrame* underFrame = nsnull;
nsIFrame* baseFrame = mFrames.FirstChild();
if (baseFrame)
underFrame = baseFrame->GetNextSibling();
if (!baseFrame || !underFrame || underFrame->GetNextSibling()) {
// report an error, encourage people to get their markups in order
return ReflowError(aRenderingContext, aDesiredSize);
}
GetReflowAndBoundingMetricsFor(baseFrame, baseSize, bmBase);
GetReflowAndBoundingMetricsFor(underFrame, underSize, bmUnder);
nscoord onePixel = nsPresContext::CSSPixelsToAppUnits(1);
////////////////////
// Place Children
aRenderingContext.SetFont(GetStyleFont()->mFont,
PresContext()->GetUserFontSet());
nsCOMPtr<nsIFontMetrics> fm;
aRenderingContext.GetFontMetrics(*getter_AddRefs(fm));
nscoord xHeight = 0;
fm->GetXHeight (xHeight);
nscoord ruleThickness;
GetRuleThickness (aRenderingContext, fm, ruleThickness);
// there are 2 different types of placement depending on
// whether we want an accented under or not
nscoord correction = 0;
GetItalicCorrection (bmBase, correction);
nscoord delta1 = 0; // gap between base and underscript
nscoord delta2 = 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);
delta1 = NS_MAX(bigOpSpacing2, (bigOpSpacing4 - bmUnder.ascent));
delta2 = 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?
delta1 = ruleThickness + onePixel/2;
delta2 = ruleThickness;
}
// empty under?
if (!(bmUnder.ascent + bmUnder.descent)) delta1 = 0;
nscoord dxBase, dxUnder = 0;
// 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 = NS_MAX(bmBase.width, underWidth);
if (NS_MATHML_EMBELLISH_IS_ACCENTUNDER(mEmbellishData.flags)) {
dxUnder += (maxWidth - underWidth)/2;
}
else {
dxUnder += -correction/2 + (maxWidth - underWidth)/2;
}
dxBase = (maxWidth - bmBase.width)/2;
mBoundingMetrics.width =
NS_MAX(dxBase + bmBase.width, dxUnder + bmUnder.width);
mBoundingMetrics.ascent = bmBase.ascent;
mBoundingMetrics.descent =
bmBase.descent + delta1 + bmUnder.ascent + bmUnder.descent;
mBoundingMetrics.leftBearing =
NS_MIN(dxBase + bmBase.leftBearing, dxUnder + bmUnder.leftBearing);
mBoundingMetrics.rightBearing =
NS_MAX(dxBase + bmBase.rightBearing, dxUnder + bmUnder.rightBearing);
aDesiredSize.ascent = baseSize.ascent;
aDesiredSize.height = aDesiredSize.ascent +
NS_MAX(mBoundingMetrics.descent + delta2,
bmBase.descent + delta1 + bmUnder.ascent +
underSize.height - underSize.ascent);
aDesiredSize.width = mBoundingMetrics.width;
aDesiredSize.mBoundingMetrics = mBoundingMetrics;
mReference.x = 0;
mReference.y = aDesiredSize.ascent;
if (aPlaceOrigin) {
nscoord dy = 0;
// place base
FinishReflowChild(baseFrame, PresContext(), nsnull, baseSize, dxBase, dy, 0);
// place underscript
dy = aDesiredSize.ascent + mBoundingMetrics.descent - bmUnder.descent - underSize.ascent;
FinishReflowChild(underFrame, PresContext(), nsnull, underSize, dxUnder, dy, 0);
}
return NS_OK;
}