void
FetchStreamReader::RejectedCallback(JSContext* aCx,
JS::Handle<JS::Value> aValue)
{
ReportErrorToConsole(aCx, aValue);
CloseAndRelease(aCx, NS_ERROR_FAILURE);
}
/* 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 = StyleFont();
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 = std::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 = std::max(subScriptShift1, mSubScriptShift);
subScriptShift2 = NSToCoordRound(scaler * subScriptShift1);
}
// the font dependent shift
nscoord subScriptShift = std::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 = std::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 = nullptr; // 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;
int32_t count = 0;
nsHTMLReflowMetrics baseSize;
nsHTMLReflowMetrics subScriptSize;
nsHTMLReflowMetrics supScriptSize;
nsIFrame* baseFrame = nullptr;
nsIFrame* subScriptFrame = nullptr;
nsIFrame* supScriptFrame = nullptr;
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
if (aPlaceOrigin) {
ReportErrorToConsole("DuplicateMprescripts");
}
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 = std::max(minSubScriptShift,subScriptShift);
mBoundingMetrics.descent =
std::max(mBoundingMetrics.descent,bmSubScript.descent);
descent = std::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 =
std::max(minSupScriptShift,std::max(minShiftFromXHeight,supScriptShift));
mBoundingMetrics.ascent =
std::max(mBoundingMetrics.ascent,bmSupScript.ascent);
ascent = std::max(ascent,supScriptSize.ascent);
width = std::max(width, bmSupScript.width + scriptSpace);
rightBearing = std::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 =
std::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 = std::max(maxSubScriptShift, trySubScriptShift);
maxSupScriptShift = std::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) {
// report an error, encourage people to get their markups in order
if (aPlaceOrigin) {
if (!baseFrame) {
ReportErrorToConsole("NoBase");
} else {
ReportErrorToConsole("SubSupMismatch");
}
}
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 =
std::max(mBoundingMetrics.ascent+maxSupScriptShift,bmBase.ascent);
mBoundingMetrics.descent =
std::max(mBoundingMetrics.descent+maxSubScriptShift,bmBase.descent);
// get the reflow metrics ...
aDesiredSize.ascent =
std::max(ascent+maxSupScriptShift,baseSize.ascent);
aDesiredSize.height = aDesiredSize.ascent +
std::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(), nullptr, 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 = std::max(subScriptSize.width, supScriptSize.width);
dy = aDesiredSize.ascent - subScriptSize.ascent +
maxSubScriptShift;
FinishReflowChild (subScriptFrame, PresContext(), nullptr,
subScriptSize,
MirrorIfRTL(aDesiredSize.width,
subScriptSize.width,
dx + (width-subScriptSize.width)/2),
dy, 0);
dy = aDesiredSize.ascent - supScriptSize.ascent -
maxSupScriptShift;
FinishReflowChild (supScriptFrame, PresContext(), nullptr,
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;
}
