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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "nsMathMLFrame.h"
#include "gfxContext.h"
#include "gfxUtils.h"
#include "mozilla/gfx/2D.h"
#include "nsCSSValue.h"
#include "nsLayoutUtils.h"
#include "nsNameSpaceManager.h"
#include "nsMathMLChar.h"
#include "nsCSSPseudoElements.h"
#include "mozilla/dom/MathMLElement.h"
#include "gfxMathTable.h"
#include "nsPresContextInlines.h"
// used to map attributes into CSS rules
#include "mozilla/ServoStyleSet.h"
#include "nsDisplayList.h"
using namespace mozilla;
using namespace mozilla::gfx;
eMathMLFrameType nsMathMLFrame::GetMathMLFrameType() {
// see if it is an embellished operator (mapped to 'Op' in TeX)
if (mEmbellishData.coreFrame) {
return GetMathMLFrameTypeFor(mEmbellishData.coreFrame);
}
// if it has a prescribed base, fetch the type from there
if (mPresentationData.baseFrame) {
return GetMathMLFrameTypeFor(mPresentationData.baseFrame);
}
// everything else is treated as ordinary (mapped to 'Ord' in TeX)
return eMathMLFrameType_Ordinary;
}
NS_IMETHODIMP
nsMathMLFrame::InheritAutomaticData(nsIFrame* aParent) {
mEmbellishData.flags = 0;
mEmbellishData.coreFrame = nullptr;
mEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
mEmbellishData.leadingSpace = 0;
mEmbellishData.trailingSpace = 0;
mPresentationData.flags = 0;
mPresentationData.baseFrame = nullptr;
// by default, just inherit the display of our parent
nsPresentationData parentData;
GetPresentationDataFrom(aParent, parentData);
return NS_OK;
}
NS_IMETHODIMP
nsMathMLFrame::UpdatePresentationData(uint32_t aFlagsValues,
uint32_t aWhichFlags) {
NS_ASSERTION(NS_MATHML_IS_COMPRESSED(aWhichFlags) ||
NS_MATHML_IS_DTLS_SET(aWhichFlags),
"aWhichFlags should only be compression or dtls flag");
if (NS_MATHML_IS_COMPRESSED(aWhichFlags)) {
// updating the compression flag is allowed
if (NS_MATHML_IS_COMPRESSED(aFlagsValues)) {
// 'compressed' means 'prime' style in App. G, TeXbook
mPresentationData.flags |= NS_MATHML_COMPRESSED;
}
// no else. the flag is sticky. it retains its value once it is set
}
// These flags determine whether the dtls font feature settings should
// be applied.
if (NS_MATHML_IS_DTLS_SET(aWhichFlags)) {
if (NS_MATHML_IS_DTLS_SET(aFlagsValues)) {
mPresentationData.flags |= NS_MATHML_DTLS;
} else {
mPresentationData.flags &= ~NS_MATHML_DTLS;
}
}
return NS_OK;
}
/* static */
void nsMathMLFrame::GetEmbellishDataFrom(nsIFrame* aFrame,
nsEmbellishData& aEmbellishData) {
// initialize OUT params
aEmbellishData.flags = 0;
aEmbellishData.coreFrame = nullptr;
aEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
aEmbellishData.leadingSpace = 0;
aEmbellishData.trailingSpace = 0;
if (aFrame && aFrame->IsMathMLFrame()) {
nsIMathMLFrame* mathMLFrame = do_QueryFrame(aFrame);
if (mathMLFrame) {
mathMLFrame->GetEmbellishData(aEmbellishData);
}
}
}
// helper to get the presentation data of a frame, by possibly walking up
// the frame hierarchy if we happen to be surrounded by non-MathML frames.
/* static */
void nsMathMLFrame::GetPresentationDataFrom(
nsIFrame* aFrame, nsPresentationData& aPresentationData, bool aClimbTree) {
// initialize OUT params
aPresentationData.flags = 0;
aPresentationData.baseFrame = nullptr;
nsIFrame* frame = aFrame;
while (frame) {
if (frame->IsMathMLFrame()) {
nsIMathMLFrame* mathMLFrame = do_QueryFrame(frame);
if (mathMLFrame) {
mathMLFrame->GetPresentationData(aPresentationData);
break;
}
}
// stop if the caller doesn't want to lookup beyond the frame
if (!aClimbTree) {
break;
}
// stop if we reach the root <math> tag
nsIContent* content = frame->GetContent();
NS_ASSERTION(content || !frame->GetParent(), // no assert for the root
"dangling frame without a content node");
if (!content) {
break;
}
if (content->IsMathMLElement(nsGkAtoms::math)) {
break;
}
frame = frame->GetParent();
}
NS_WARNING_ASSERTION(
frame && frame->GetContent(),
"bad MathML markup - could not find the top <math> element");
}
/* static */
void nsMathMLFrame::GetRuleThickness(DrawTarget* aDrawTarget,
nsFontMetrics* aFontMetrics,
nscoord& aRuleThickness) {
nscoord xHeight = aFontMetrics->XHeight();
char16_t overBar = 0x00AF;
nsBoundingMetrics bm = nsLayoutUtils::AppUnitBoundsOfString(
&overBar, 1, *aFontMetrics, aDrawTarget);
aRuleThickness = bm.ascent + bm.descent;
if (aRuleThickness <= 0 || aRuleThickness >= xHeight) {
// fall-back to the other version
GetRuleThickness(aFontMetrics, aRuleThickness);
}
}
/* static */
void nsMathMLFrame::GetAxisHeight(DrawTarget* aDrawTarget,
nsFontMetrics* aFontMetrics,
nscoord& aAxisHeight) {
RefPtr<gfxFont> mathFont =
aFontMetrics->GetThebesFontGroup()->GetFirstMathFont();
if (mathFont) {
aAxisHeight = mathFont->MathTable()->Constant(
gfxMathTable::AxisHeight, aFontMetrics->AppUnitsPerDevPixel());
return;
}
nscoord xHeight = aFontMetrics->XHeight();
char16_t minus = 0x2212; // not '-', but official Unicode minus sign
nsBoundingMetrics bm = nsLayoutUtils::AppUnitBoundsOfString(
&minus, 1, *aFontMetrics, aDrawTarget);
aAxisHeight = bm.ascent - (bm.ascent + bm.descent) / 2;
if (aAxisHeight <= 0 || aAxisHeight >= xHeight) {
// fall-back to the other version
GetAxisHeight(aFontMetrics, aAxisHeight);
}
}
/* static */
nscoord nsMathMLFrame::CalcLength(nsPresContext* aPresContext,
ComputedStyle* aComputedStyle,
const nsCSSValue& aCSSValue,
float aFontSizeInflation) {
NS_ASSERTION(aCSSValue.IsLengthUnit(), "not a length unit");
if (aCSSValue.IsPixelLengthUnit()) {
return aCSSValue.GetPixelLength();
}
nsCSSUnit unit = aCSSValue.GetUnit();
if (eCSSUnit_EM == unit) {
const nsStyleFont* font = aComputedStyle->StyleFont();
return font->mFont.size.ScaledBy(aCSSValue.GetFloatValue()).ToAppUnits();
}
if (eCSSUnit_XHeight == unit) {
RefPtr<nsFontMetrics> fm = nsLayoutUtils::GetFontMetricsForComputedStyle(
aComputedStyle, aPresContext, aFontSizeInflation);
nscoord xHeight = fm->XHeight();
return NSToCoordRound(aCSSValue.GetFloatValue() * (float)xHeight);
}
// MathML doesn't specify other CSS units such as rem or ch
NS_ERROR("Unsupported unit");
return 0;
}
/* static */
void nsMathMLFrame::GetSubDropFromChild(nsIFrame* aChild, nscoord& aSubDrop,
float aFontSizeInflation) {
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetFontMetricsForFrame(aChild, aFontSizeInflation);
GetSubDrop(fm, aSubDrop);
}
/* static */
void nsMathMLFrame::GetSupDropFromChild(nsIFrame* aChild, nscoord& aSupDrop,
float aFontSizeInflation) {
RefPtr<nsFontMetrics> fm =
nsLayoutUtils::GetFontMetricsForFrame(aChild, aFontSizeInflation);
GetSupDrop(fm, aSupDrop);
}
/* static */
void nsMathMLFrame::ParseNumericValue(const nsString& aString,
nscoord* aLengthValue, uint32_t aFlags,
nsPresContext* aPresContext,
ComputedStyle* aComputedStyle,
float aFontSizeInflation) {
nsCSSValue cssValue;
if (!dom::MathMLElement::ParseNumericValue(aString, cssValue, aFlags,
aPresContext->Document())) {
// Invalid attribute value. aLengthValue remains unchanged, so the default
// length value is used.
return;
}
nsCSSUnit unit = cssValue.GetUnit();
if (unit == eCSSUnit_Percent) {
// Relative units. A multiple of the default length value is used.
*aLengthValue = NSToCoordRound(
*aLengthValue * (unit == eCSSUnit_Percent ? cssValue.GetPercentValue()
: cssValue.GetFloatValue()));
return;
}
// Absolute units.
*aLengthValue =
CalcLength(aPresContext, aComputedStyle, cssValue, aFontSizeInflation);
}
namespace mozilla {
class nsDisplayMathMLBar final : public nsPaintedDisplayItem {
public:
nsDisplayMathMLBar(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aRect)
: nsPaintedDisplayItem(aBuilder, aFrame), mRect(aRect) {
MOZ_COUNT_CTOR(nsDisplayMathMLBar);
}
MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayMathMLBar)
void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
NS_DISPLAY_DECL_NAME("MathMLBar", TYPE_MATHML_BAR)
private:
nsRect mRect;
};
void nsDisplayMathMLBar::Paint(nsDisplayListBuilder* aBuilder,
gfxContext* aCtx) {
// paint the bar with the current text color
DrawTarget* drawTarget = aCtx->GetDrawTarget();
Rect rect = NSRectToNonEmptySnappedRect(
mRect + ToReferenceFrame(), mFrame->PresContext()->AppUnitsPerDevPixel(),
*drawTarget);
ColorPattern color(ToDeviceColor(
mFrame->GetVisitedDependentColor(&nsStyleText::mWebkitTextFillColor)));
drawTarget->FillRect(rect, color);
}
} // namespace mozilla
void nsMathMLFrame::DisplayBar(nsDisplayListBuilder* aBuilder, nsIFrame* aFrame,
const nsRect& aRect,
const nsDisplayListSet& aLists,
uint32_t aIndex) {
if (!aFrame->StyleVisibility()->IsVisible() || aRect.IsEmpty()) {
return;
}
aLists.Content()->AppendNewToTopWithIndex<nsDisplayMathMLBar>(
aBuilder, aFrame, aIndex, aRect);
}
void nsMathMLFrame::GetRadicalParameters(nsFontMetrics* aFontMetrics,
bool aDisplayStyle,
nscoord& aRadicalRuleThickness,
nscoord& aRadicalExtraAscender,
nscoord& aRadicalVerticalGap) {
nscoord oneDevPixel = aFontMetrics->AppUnitsPerDevPixel();
RefPtr<gfxFont> mathFont =
aFontMetrics->GetThebesFontGroup()->GetFirstMathFont();
// get the radical rulethickness
if (mathFont) {
aRadicalRuleThickness = mathFont->MathTable()->Constant(
gfxMathTable::RadicalRuleThickness, oneDevPixel);
} else {
GetRuleThickness(aFontMetrics, aRadicalRuleThickness);
}
// get the leading to be left at the top of the resulting frame
if (mathFont) {
aRadicalExtraAscender = mathFont->MathTable()->Constant(
gfxMathTable::RadicalExtraAscender, oneDevPixel);
} else {
// This seems more reliable than using aFontMetrics->GetLeading() on
// suspicious fonts.
nscoord em;
GetEmHeight(aFontMetrics, em);
aRadicalExtraAscender = nscoord(0.2f * em);
}
// get the clearance between rule and content
if (mathFont) {
aRadicalVerticalGap = mathFont->MathTable()->Constant(
aDisplayStyle ? gfxMathTable::RadicalDisplayStyleVerticalGap
: gfxMathTable::RadicalVerticalGap,
oneDevPixel);
} else {
// Rule 11, App. G, TeXbook
aRadicalVerticalGap =
aRadicalRuleThickness +
(aDisplayStyle ? aFontMetrics->XHeight() : aRadicalRuleThickness) / 4;
}
}