1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/mathml/nsMathMLFrame.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,353 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsMathMLFrame.h"
1.10 +#include "nsNameSpaceManager.h"
1.11 +#include "nsMathMLChar.h"
1.12 +#include "nsCSSPseudoElements.h"
1.13 +#include "nsMathMLElement.h"
1.14 +
1.15 +// used to map attributes into CSS rules
1.16 +#include "nsStyleSet.h"
1.17 +#include "nsAutoPtr.h"
1.18 +#include "nsDisplayList.h"
1.19 +#include "nsRenderingContext.h"
1.20 +
1.21 +eMathMLFrameType
1.22 +nsMathMLFrame::GetMathMLFrameType()
1.23 +{
1.24 + // see if it is an embellished operator (mapped to 'Op' in TeX)
1.25 + if (mEmbellishData.coreFrame)
1.26 + return GetMathMLFrameTypeFor(mEmbellishData.coreFrame);
1.27 +
1.28 + // if it has a prescribed base, fetch the type from there
1.29 + if (mPresentationData.baseFrame)
1.30 + return GetMathMLFrameTypeFor(mPresentationData.baseFrame);
1.31 +
1.32 + // everything else is treated as ordinary (mapped to 'Ord' in TeX)
1.33 + return eMathMLFrameType_Ordinary;
1.34 +}
1.35 +
1.36 +NS_IMETHODIMP
1.37 +nsMathMLFrame::InheritAutomaticData(nsIFrame* aParent)
1.38 +{
1.39 + mEmbellishData.flags = 0;
1.40 + mEmbellishData.coreFrame = nullptr;
1.41 + mEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
1.42 + mEmbellishData.leadingSpace = 0;
1.43 + mEmbellishData.trailingSpace = 0;
1.44 +
1.45 + mPresentationData.flags = 0;
1.46 + mPresentationData.baseFrame = nullptr;
1.47 +
1.48 + // by default, just inherit the display of our parent
1.49 + nsPresentationData parentData;
1.50 + GetPresentationDataFrom(aParent, parentData);
1.51 +
1.52 +#if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
1.53 + mPresentationData.flags |= NS_MATHML_SHOW_BOUNDING_METRICS;
1.54 +#endif
1.55 +
1.56 + return NS_OK;
1.57 +}
1.58 +
1.59 +NS_IMETHODIMP
1.60 +nsMathMLFrame::UpdatePresentationData(uint32_t aFlagsValues,
1.61 + uint32_t aWhichFlags)
1.62 +{
1.63 + NS_ASSERTION(NS_MATHML_IS_COMPRESSED(aWhichFlags),
1.64 + "aWhichFlags should only be compression flag");
1.65 +
1.66 + if (NS_MATHML_IS_COMPRESSED(aWhichFlags)) {
1.67 + // updating the compression flag is allowed
1.68 + if (NS_MATHML_IS_COMPRESSED(aFlagsValues)) {
1.69 + // 'compressed' means 'prime' style in App. G, TeXbook
1.70 + mPresentationData.flags |= NS_MATHML_COMPRESSED;
1.71 + }
1.72 + // no else. the flag is sticky. it retains its value once it is set
1.73 + }
1.74 + return NS_OK;
1.75 +}
1.76 +
1.77 +// Helper to give a style context suitable for doing the stretching of
1.78 +// a MathMLChar. Frame classes that use this should ensure that the
1.79 +// extra leaf style contexts given to the MathMLChars are accessible to
1.80 +// the Style System via the Get/Set AdditionalStyleContext() APIs.
1.81 +/* static */ void
1.82 +nsMathMLFrame::ResolveMathMLCharStyle(nsPresContext* aPresContext,
1.83 + nsIContent* aContent,
1.84 + nsStyleContext* aParentStyleContext,
1.85 + nsMathMLChar* aMathMLChar)
1.86 +{
1.87 + nsCSSPseudoElements::Type pseudoType =
1.88 + nsCSSPseudoElements::ePseudo_mozMathAnonymous; // savings
1.89 + nsRefPtr<nsStyleContext> newStyleContext;
1.90 + newStyleContext = aPresContext->StyleSet()->
1.91 + ResolvePseudoElementStyle(aContent->AsElement(), pseudoType,
1.92 + aParentStyleContext, nullptr);
1.93 +
1.94 + aMathMLChar->SetStyleContext(newStyleContext);
1.95 +}
1.96 +
1.97 +/* static */ void
1.98 +nsMathMLFrame::GetEmbellishDataFrom(nsIFrame* aFrame,
1.99 + nsEmbellishData& aEmbellishData)
1.100 +{
1.101 + // initialize OUT params
1.102 + aEmbellishData.flags = 0;
1.103 + aEmbellishData.coreFrame = nullptr;
1.104 + aEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
1.105 + aEmbellishData.leadingSpace = 0;
1.106 + aEmbellishData.trailingSpace = 0;
1.107 +
1.108 + if (aFrame && aFrame->IsFrameOfType(nsIFrame::eMathML)) {
1.109 + nsIMathMLFrame* mathMLFrame = do_QueryFrame(aFrame);
1.110 + if (mathMLFrame) {
1.111 + mathMLFrame->GetEmbellishData(aEmbellishData);
1.112 + }
1.113 + }
1.114 +}
1.115 +
1.116 +// helper to get the presentation data of a frame, by possibly walking up
1.117 +// the frame hierarchy if we happen to be surrounded by non-MathML frames.
1.118 +/* static */ void
1.119 +nsMathMLFrame::GetPresentationDataFrom(nsIFrame* aFrame,
1.120 + nsPresentationData& aPresentationData,
1.121 + bool aClimbTree)
1.122 +{
1.123 + // initialize OUT params
1.124 + aPresentationData.flags = 0;
1.125 + aPresentationData.baseFrame = nullptr;
1.126 +
1.127 + nsIFrame* frame = aFrame;
1.128 + while (frame) {
1.129 + if (frame->IsFrameOfType(nsIFrame::eMathML)) {
1.130 + nsIMathMLFrame* mathMLFrame = do_QueryFrame(frame);
1.131 + if (mathMLFrame) {
1.132 + mathMLFrame->GetPresentationData(aPresentationData);
1.133 + break;
1.134 + }
1.135 + }
1.136 + // stop if the caller doesn't want to lookup beyond the frame
1.137 + if (!aClimbTree) {
1.138 + break;
1.139 + }
1.140 + // stop if we reach the root <math> tag
1.141 + nsIContent* content = frame->GetContent();
1.142 + NS_ASSERTION(content || !frame->GetParent(), // no assert for the root
1.143 + "dangling frame without a content node");
1.144 + if (!content)
1.145 + break;
1.146 +
1.147 + if (content->Tag() == nsGkAtoms::math) {
1.148 + break;
1.149 + }
1.150 + frame = frame->GetParent();
1.151 + }
1.152 + NS_WARN_IF_FALSE(frame && frame->GetContent(),
1.153 + "bad MathML markup - could not find the top <math> element");
1.154 +}
1.155 +
1.156 +/* static */ void
1.157 +nsMathMLFrame::GetRuleThickness(nsRenderingContext& aRenderingContext,
1.158 + nsFontMetrics* aFontMetrics,
1.159 + nscoord& aRuleThickness)
1.160 +{
1.161 + // get the bounding metrics of the overbar char, the rendering context
1.162 + // is assumed to have been set with the font of the current style context
1.163 + NS_ASSERTION(aRenderingContext.FontMetrics()->Font().
1.164 + Equals(aFontMetrics->Font()),
1.165 + "unexpected state");
1.166 +
1.167 + nscoord xHeight = aFontMetrics->XHeight();
1.168 + char16_t overBar = 0x00AF;
1.169 + nsBoundingMetrics bm = aRenderingContext.GetBoundingMetrics(&overBar, 1);
1.170 + aRuleThickness = bm.ascent + bm.descent;
1.171 + if (aRuleThickness <= 0 || aRuleThickness >= xHeight) {
1.172 + // fall-back to the other version
1.173 + GetRuleThickness(aFontMetrics, aRuleThickness);
1.174 + }
1.175 +}
1.176 +
1.177 +/* static */ void
1.178 +nsMathMLFrame::GetAxisHeight(nsRenderingContext& aRenderingContext,
1.179 + nsFontMetrics* aFontMetrics,
1.180 + nscoord& aAxisHeight)
1.181 +{
1.182 + // get the bounding metrics of the minus sign, the rendering context
1.183 + // is assumed to have been set with the font of the current style context
1.184 + NS_ASSERTION(aRenderingContext.FontMetrics()->Font().
1.185 + Equals(aFontMetrics->Font()),
1.186 + "unexpected state");
1.187 +
1.188 + nscoord xHeight = aFontMetrics->XHeight();
1.189 + char16_t minus = 0x2212; // not '-', but official Unicode minus sign
1.190 + nsBoundingMetrics bm = aRenderingContext.GetBoundingMetrics(&minus, 1);
1.191 + aAxisHeight = bm.ascent - (bm.ascent + bm.descent)/2;
1.192 + if (aAxisHeight <= 0 || aAxisHeight >= xHeight) {
1.193 + // fall-back to the other version
1.194 + GetAxisHeight(aFontMetrics, aAxisHeight);
1.195 + }
1.196 +}
1.197 +
1.198 +/* static */ nscoord
1.199 +nsMathMLFrame::CalcLength(nsPresContext* aPresContext,
1.200 + nsStyleContext* aStyleContext,
1.201 + const nsCSSValue& aCSSValue)
1.202 +{
1.203 + NS_ASSERTION(aCSSValue.IsLengthUnit(), "not a length unit");
1.204 +
1.205 + if (aCSSValue.IsFixedLengthUnit()) {
1.206 + return aCSSValue.GetFixedLength(aPresContext);
1.207 + }
1.208 + if (aCSSValue.IsPixelLengthUnit()) {
1.209 + return aCSSValue.GetPixelLength();
1.210 + }
1.211 +
1.212 + nsCSSUnit unit = aCSSValue.GetUnit();
1.213 +
1.214 + if (eCSSUnit_EM == unit) {
1.215 + const nsStyleFont* font = aStyleContext->StyleFont();
1.216 + return NSToCoordRound(aCSSValue.GetFloatValue() * (float)font->mFont.size);
1.217 + }
1.218 + else if (eCSSUnit_XHeight == unit) {
1.219 + nsRefPtr<nsFontMetrics> fm;
1.220 + nsLayoutUtils::GetFontMetricsForStyleContext(aStyleContext,
1.221 + getter_AddRefs(fm));
1.222 + nscoord xHeight = fm->XHeight();
1.223 + return NSToCoordRound(aCSSValue.GetFloatValue() * (float)xHeight);
1.224 + }
1.225 +
1.226 + // MathML doesn't specify other CSS units such as rem or ch
1.227 + NS_ERROR("Unsupported unit");
1.228 + return 0;
1.229 +}
1.230 +
1.231 +/* static */ void
1.232 +nsMathMLFrame::ParseNumericValue(const nsString& aString,
1.233 + nscoord* aLengthValue,
1.234 + uint32_t aFlags,
1.235 + nsPresContext* aPresContext,
1.236 + nsStyleContext* aStyleContext)
1.237 +{
1.238 + nsCSSValue cssValue;
1.239 +
1.240 + if (!nsMathMLElement::ParseNumericValue(aString, cssValue, aFlags,
1.241 + aPresContext->Document())) {
1.242 + // Invalid attribute value. aLengthValue remains unchanged, so the default
1.243 + // length value is used.
1.244 + return;
1.245 + }
1.246 +
1.247 + nsCSSUnit unit = cssValue.GetUnit();
1.248 +
1.249 + if (unit == eCSSUnit_Percent || unit == eCSSUnit_Number) {
1.250 + // Relative units. A multiple of the default length value is used.
1.251 + *aLengthValue = NSToCoordRound(*aLengthValue * (unit == eCSSUnit_Percent ?
1.252 + cssValue.GetPercentValue() :
1.253 + cssValue.GetFloatValue()));
1.254 + return;
1.255 + }
1.256 +
1.257 + // Absolute units.
1.258 + *aLengthValue = CalcLength(aPresContext, aStyleContext, cssValue);
1.259 +}
1.260 +
1.261 +// ================
1.262 +// Utils to map attributes into CSS rules (work-around to bug 69409 which
1.263 +// is not scheduled to be fixed anytime soon)
1.264 +//
1.265 +
1.266 +struct
1.267 +nsCSSMapping {
1.268 + int32_t compatibility;
1.269 + const nsIAtom* attrAtom;
1.270 + const char* cssProperty;
1.271 +};
1.272 +
1.273 +#if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
1.274 +class nsDisplayMathMLBoundingMetrics : public nsDisplayItem {
1.275 +public:
1.276 + nsDisplayMathMLBoundingMetrics(nsDisplayListBuilder* aBuilder,
1.277 + nsIFrame* aFrame, const nsRect& aRect)
1.278 + : nsDisplayItem(aBuilder, aFrame), mRect(aRect) {
1.279 + MOZ_COUNT_CTOR(nsDisplayMathMLBoundingMetrics);
1.280 + }
1.281 +#ifdef NS_BUILD_REFCNT_LOGGING
1.282 + virtual ~nsDisplayMathMLBoundingMetrics() {
1.283 + MOZ_COUNT_DTOR(nsDisplayMathMLBoundingMetrics);
1.284 + }
1.285 +#endif
1.286 +
1.287 + virtual void Paint(nsDisplayListBuilder* aBuilder,
1.288 + nsRenderingContext* aCtx) MOZ_OVERRIDE;
1.289 + NS_DISPLAY_DECL_NAME("MathMLBoundingMetrics", TYPE_MATHML_BOUNDING_METRICS)
1.290 +private:
1.291 + nsRect mRect;
1.292 +};
1.293 +
1.294 +void nsDisplayMathMLBoundingMetrics::Paint(nsDisplayListBuilder* aBuilder,
1.295 + nsRenderingContext* aCtx)
1.296 +{
1.297 + aCtx->SetColor(NS_RGB(0,0,255));
1.298 + aCtx->DrawRect(mRect + ToReferenceFrame());
1.299 +}
1.300 +
1.301 +nsresult
1.302 +nsMathMLFrame::DisplayBoundingMetrics(nsDisplayListBuilder* aBuilder,
1.303 + nsIFrame* aFrame, const nsPoint& aPt,
1.304 + const nsBoundingMetrics& aMetrics,
1.305 + const nsDisplayListSet& aLists) {
1.306 + if (!NS_MATHML_PAINT_BOUNDING_METRICS(mPresentationData.flags))
1.307 + return NS_OK;
1.308 +
1.309 + nscoord x = aPt.x + aMetrics.leftBearing;
1.310 + nscoord y = aPt.y - aMetrics.ascent;
1.311 + nscoord w = aMetrics.rightBearing - aMetrics.leftBearing;
1.312 + nscoord h = aMetrics.ascent + aMetrics.descent;
1.313 +
1.314 + return aLists.Content()->AppendNewToTop(new (aBuilder)
1.315 + nsDisplayMathMLBoundingMetrics(aBuilder, this, nsRect(x,y,w,h)));
1.316 +}
1.317 +#endif
1.318 +
1.319 +class nsDisplayMathMLBar : public nsDisplayItem {
1.320 +public:
1.321 + nsDisplayMathMLBar(nsDisplayListBuilder* aBuilder,
1.322 + nsIFrame* aFrame, const nsRect& aRect)
1.323 + : nsDisplayItem(aBuilder, aFrame), mRect(aRect) {
1.324 + MOZ_COUNT_CTOR(nsDisplayMathMLBar);
1.325 + }
1.326 +#ifdef NS_BUILD_REFCNT_LOGGING
1.327 + virtual ~nsDisplayMathMLBar() {
1.328 + MOZ_COUNT_DTOR(nsDisplayMathMLBar);
1.329 + }
1.330 +#endif
1.331 +
1.332 + virtual void Paint(nsDisplayListBuilder* aBuilder,
1.333 + nsRenderingContext* aCtx) MOZ_OVERRIDE;
1.334 + NS_DISPLAY_DECL_NAME("MathMLBar", TYPE_MATHML_BAR)
1.335 +private:
1.336 + nsRect mRect;
1.337 +};
1.338 +
1.339 +void nsDisplayMathMLBar::Paint(nsDisplayListBuilder* aBuilder,
1.340 + nsRenderingContext* aCtx)
1.341 +{
1.342 + // paint the bar with the current text color
1.343 + aCtx->SetColor(mFrame->GetVisitedDependentColor(eCSSProperty_color));
1.344 + aCtx->FillRect(mRect + ToReferenceFrame());
1.345 +}
1.346 +
1.347 +void
1.348 +nsMathMLFrame::DisplayBar(nsDisplayListBuilder* aBuilder,
1.349 + nsIFrame* aFrame, const nsRect& aRect,
1.350 + const nsDisplayListSet& aLists) {
1.351 + if (!aFrame->StyleVisibility()->IsVisible() || aRect.IsEmpty())
1.352 + return;
1.353 +
1.354 + aLists.Content()->AppendNewToTop(new (aBuilder)
1.355 + nsDisplayMathMLBar(aBuilder, aFrame, aRect));
1.356 +}
