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-rw-r--r--layout/mathml/nsMathMLFrame.cpp383
1 files changed, 383 insertions, 0 deletions
diff --git a/layout/mathml/nsMathMLFrame.cpp b/layout/mathml/nsMathMLFrame.cpp
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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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#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);
+
+#if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
+ mPresentationData.flags |= NS_MATHML_SHOW_BOUNDING_METRICS;
+#endif
+
+ 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->IsFrameOfType(nsIFrame::eMathML)) {
+ 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->IsFrameOfType(nsIFrame::eMathML)) {
+ 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 || unit == eCSSUnit_Number) {
+ // 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 {
+#if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
+class nsDisplayMathMLBoundingMetrics final : public nsDisplayItem {
+ public:
+ nsDisplayMathMLBoundingMetrics(nsDisplayListBuilder* aBuilder,
+ nsIFrame* aFrame, const nsRect& aRect)
+ : nsDisplayItem(aBuilder, aFrame), mRect(aRect) {
+ MOZ_COUNT_CTOR(nsDisplayMathMLBoundingMetrics);
+ }
+ MOZ_COUNTED_DTOR_OVERRIDE(nsDisplayMathMLBoundingMetrics)
+
+ virtual void Paint(nsDisplayListBuilder* aBuilder, gfxContext* aCtx) override;
+ NS_DISPLAY_DECL_NAME("MathMLBoundingMetrics", TYPE_MATHML_BOUNDING_METRICS)
+ private:
+ nsRect mRect;
+};
+
+void nsDisplayMathMLBoundingMetrics::Paint(nsDisplayListBuilder* aBuilder,
+ gfxContext* aCtx) {
+ DrawTarget* drawTarget = aCtx->GetDrawTarget();
+ Rect r = NSRectToRect(mRect + ToReferenceFrame(),
+ mFrame->PresContext()->AppUnitsPerDevPixel());
+ ColorPattern blue(ToDeviceColor(Color(0.f, 0.f, 1.f, 1.f)));
+ drawTarget->StrokeRect(r, blue);
+}
+
+void nsMathMLFrame::DisplayBoundingMetrics(nsDisplayListBuilder* aBuilder,
+ nsIFrame* aFrame, const nsPoint& aPt,
+ const nsBoundingMetrics& aMetrics,
+ const nsDisplayListSet& aLists) {
+ if (!NS_MATHML_PAINT_BOUNDING_METRICS(mPresentationData.flags)) return;
+
+ nscoord x = aPt.x + aMetrics.leftBearing;
+ nscoord y = aPt.y - aMetrics.ascent;
+ nscoord w = aMetrics.rightBearing - aMetrics.leftBearing;
+ nscoord h = aMetrics.ascent + aMetrics.descent;
+
+ aLists.Content()->AppendNewToTop<nsDisplayMathMLBoundingMetrics>(
+ aBuilder, aFrame, nsRect(x, y, w, h));
+}
+#endif
+
+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)
+
+ virtual 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;
+ }
+}