michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsMathMLFrame.h"
michael@0: #include "nsNameSpaceManager.h"
michael@0: #include "nsMathMLChar.h"
michael@0: #include "nsCSSPseudoElements.h"
michael@0: #include "nsMathMLElement.h"
michael@0: 
michael@0: // used to map attributes into CSS rules
michael@0: #include "nsStyleSet.h"
michael@0: #include "nsAutoPtr.h"
michael@0: #include "nsDisplayList.h"
michael@0: #include "nsRenderingContext.h"
michael@0: 
michael@0: eMathMLFrameType
michael@0: nsMathMLFrame::GetMathMLFrameType()
michael@0: {
michael@0:   // see if it is an embellished operator (mapped to 'Op' in TeX)
michael@0:   if (mEmbellishData.coreFrame)
michael@0:     return GetMathMLFrameTypeFor(mEmbellishData.coreFrame);
michael@0: 
michael@0:   // if it has a prescribed base, fetch the type from there
michael@0:   if (mPresentationData.baseFrame)
michael@0:     return GetMathMLFrameTypeFor(mPresentationData.baseFrame);
michael@0: 
michael@0:   // everything else is treated as ordinary (mapped to 'Ord' in TeX)
michael@0:   return eMathMLFrameType_Ordinary;  
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsMathMLFrame::InheritAutomaticData(nsIFrame* aParent) 
michael@0: {
michael@0:   mEmbellishData.flags = 0;
michael@0:   mEmbellishData.coreFrame = nullptr;
michael@0:   mEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
michael@0:   mEmbellishData.leadingSpace = 0;
michael@0:   mEmbellishData.trailingSpace = 0;
michael@0: 
michael@0:   mPresentationData.flags = 0;
michael@0:   mPresentationData.baseFrame = nullptr;
michael@0: 
michael@0:   // by default, just inherit the display of our parent
michael@0:   nsPresentationData parentData;
michael@0:   GetPresentationDataFrom(aParent, parentData);
michael@0: 
michael@0: #if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
michael@0:   mPresentationData.flags |= NS_MATHML_SHOW_BOUNDING_METRICS;
michael@0: #endif
michael@0: 
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: NS_IMETHODIMP
michael@0: nsMathMLFrame::UpdatePresentationData(uint32_t        aFlagsValues,
michael@0:                                       uint32_t        aWhichFlags)
michael@0: {
michael@0:   NS_ASSERTION(NS_MATHML_IS_COMPRESSED(aWhichFlags),
michael@0:                "aWhichFlags should only be compression flag"); 
michael@0: 
michael@0:   if (NS_MATHML_IS_COMPRESSED(aWhichFlags)) {
michael@0:     // updating the compression flag is allowed
michael@0:     if (NS_MATHML_IS_COMPRESSED(aFlagsValues)) {
michael@0:       // 'compressed' means 'prime' style in App. G, TeXbook
michael@0:       mPresentationData.flags |= NS_MATHML_COMPRESSED;
michael@0:     }
michael@0:     // no else. the flag is sticky. it retains its value once it is set
michael@0:   }
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: // Helper to give a style context suitable for doing the stretching of
michael@0: // a MathMLChar. Frame classes that use this should ensure that the 
michael@0: // extra leaf style contexts given to the MathMLChars are accessible to
michael@0: // the Style System via the Get/Set AdditionalStyleContext() APIs.
michael@0: /* static */ void
michael@0: nsMathMLFrame::ResolveMathMLCharStyle(nsPresContext*  aPresContext,
michael@0:                                       nsIContent*      aContent,
michael@0:                                       nsStyleContext*  aParentStyleContext,
michael@0:                                       nsMathMLChar*    aMathMLChar)
michael@0: {
michael@0:   nsCSSPseudoElements::Type pseudoType =
michael@0:     nsCSSPseudoElements::ePseudo_mozMathAnonymous; // savings
michael@0:   nsRefPtr<nsStyleContext> newStyleContext;
michael@0:   newStyleContext = aPresContext->StyleSet()->
michael@0:     ResolvePseudoElementStyle(aContent->AsElement(), pseudoType,
michael@0:                               aParentStyleContext, nullptr);
michael@0: 
michael@0:   aMathMLChar->SetStyleContext(newStyleContext);
michael@0: }
michael@0: 
michael@0: /* static */ void
michael@0: nsMathMLFrame::GetEmbellishDataFrom(nsIFrame*        aFrame,
michael@0:                                     nsEmbellishData& aEmbellishData)
michael@0: {
michael@0:   // initialize OUT params
michael@0:   aEmbellishData.flags = 0;
michael@0:   aEmbellishData.coreFrame = nullptr;
michael@0:   aEmbellishData.direction = NS_STRETCH_DIRECTION_UNSUPPORTED;
michael@0:   aEmbellishData.leadingSpace = 0;
michael@0:   aEmbellishData.trailingSpace = 0;
michael@0: 
michael@0:   if (aFrame && aFrame->IsFrameOfType(nsIFrame::eMathML)) {
michael@0:     nsIMathMLFrame* mathMLFrame = do_QueryFrame(aFrame);
michael@0:     if (mathMLFrame) {
michael@0:       mathMLFrame->GetEmbellishData(aEmbellishData);
michael@0:     }
michael@0:   }
michael@0: }
michael@0: 
michael@0: // helper to get the presentation data of a frame, by possibly walking up
michael@0: // the frame hierarchy if we happen to be surrounded by non-MathML frames.
michael@0: /* static */ void
michael@0: nsMathMLFrame::GetPresentationDataFrom(nsIFrame*           aFrame,
michael@0:                                        nsPresentationData& aPresentationData,
michael@0:                                        bool                aClimbTree)
michael@0: {
michael@0:   // initialize OUT params
michael@0:   aPresentationData.flags = 0;
michael@0:   aPresentationData.baseFrame = nullptr;
michael@0: 
michael@0:   nsIFrame* frame = aFrame;
michael@0:   while (frame) {
michael@0:     if (frame->IsFrameOfType(nsIFrame::eMathML)) {
michael@0:       nsIMathMLFrame* mathMLFrame = do_QueryFrame(frame);
michael@0:       if (mathMLFrame) {
michael@0:         mathMLFrame->GetPresentationData(aPresentationData);
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0:     // stop if the caller doesn't want to lookup beyond the frame
michael@0:     if (!aClimbTree) {
michael@0:       break;
michael@0:     }
michael@0:     // stop if we reach the root <math> tag
michael@0:     nsIContent* content = frame->GetContent();
michael@0:     NS_ASSERTION(content || !frame->GetParent(), // no assert for the root
michael@0:                  "dangling frame without a content node"); 
michael@0:     if (!content)
michael@0:       break;
michael@0: 
michael@0:     if (content->Tag() == nsGkAtoms::math) {
michael@0:       break;
michael@0:     }
michael@0:     frame = frame->GetParent();
michael@0:   }
michael@0:   NS_WARN_IF_FALSE(frame && frame->GetContent(),
michael@0:                    "bad MathML markup - could not find the top <math> element");
michael@0: }
michael@0: 
michael@0: /* static */ void
michael@0: nsMathMLFrame::GetRuleThickness(nsRenderingContext& aRenderingContext,
michael@0:                                 nsFontMetrics*      aFontMetrics,
michael@0:                                 nscoord&             aRuleThickness)
michael@0: {
michael@0:   // get the bounding metrics of the overbar char, the rendering context
michael@0:   // is assumed to have been set with the font of the current style context
michael@0:   NS_ASSERTION(aRenderingContext.FontMetrics()->Font().
michael@0:                Equals(aFontMetrics->Font()),
michael@0:                "unexpected state");
michael@0: 
michael@0:   nscoord xHeight = aFontMetrics->XHeight();
michael@0:   char16_t overBar = 0x00AF;
michael@0:   nsBoundingMetrics bm = aRenderingContext.GetBoundingMetrics(&overBar, 1);
michael@0:   aRuleThickness = bm.ascent + bm.descent;
michael@0:   if (aRuleThickness <= 0 || aRuleThickness >= xHeight) {
michael@0:     // fall-back to the other version
michael@0:     GetRuleThickness(aFontMetrics, aRuleThickness);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /* static */ void
michael@0: nsMathMLFrame::GetAxisHeight(nsRenderingContext& aRenderingContext,
michael@0:                              nsFontMetrics*      aFontMetrics,
michael@0:                              nscoord&             aAxisHeight)
michael@0: {
michael@0:   // get the bounding metrics of the minus sign, the rendering context
michael@0:   // is assumed to have been set with the font of the current style context
michael@0:   NS_ASSERTION(aRenderingContext.FontMetrics()->Font().
michael@0:                Equals(aFontMetrics->Font()),
michael@0:                "unexpected state");
michael@0: 
michael@0:   nscoord xHeight = aFontMetrics->XHeight();
michael@0:   char16_t minus = 0x2212; // not '-', but official Unicode minus sign
michael@0:   nsBoundingMetrics bm = aRenderingContext.GetBoundingMetrics(&minus, 1);
michael@0:   aAxisHeight = bm.ascent - (bm.ascent + bm.descent)/2;
michael@0:   if (aAxisHeight <= 0 || aAxisHeight >= xHeight) {
michael@0:     // fall-back to the other version
michael@0:     GetAxisHeight(aFontMetrics, aAxisHeight);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /* static */ nscoord
michael@0: nsMathMLFrame::CalcLength(nsPresContext*   aPresContext,
michael@0:                           nsStyleContext*   aStyleContext,
michael@0:                           const nsCSSValue& aCSSValue)
michael@0: {
michael@0:   NS_ASSERTION(aCSSValue.IsLengthUnit(), "not a length unit");
michael@0: 
michael@0:   if (aCSSValue.IsFixedLengthUnit()) {
michael@0:     return aCSSValue.GetFixedLength(aPresContext);
michael@0:   }
michael@0:   if (aCSSValue.IsPixelLengthUnit()) {
michael@0:     return aCSSValue.GetPixelLength();
michael@0:   }
michael@0: 
michael@0:   nsCSSUnit unit = aCSSValue.GetUnit();
michael@0: 
michael@0:   if (eCSSUnit_EM == unit) {
michael@0:     const nsStyleFont* font = aStyleContext->StyleFont();
michael@0:     return NSToCoordRound(aCSSValue.GetFloatValue() * (float)font->mFont.size);
michael@0:   }
michael@0:   else if (eCSSUnit_XHeight == unit) {
michael@0:     nsRefPtr<nsFontMetrics> fm;
michael@0:     nsLayoutUtils::GetFontMetricsForStyleContext(aStyleContext,
michael@0:                                                  getter_AddRefs(fm));
michael@0:     nscoord xHeight = fm->XHeight();
michael@0:     return NSToCoordRound(aCSSValue.GetFloatValue() * (float)xHeight);
michael@0:   }
michael@0: 
michael@0:   // MathML doesn't specify other CSS units such as rem or ch
michael@0:   NS_ERROR("Unsupported unit");
michael@0:   return 0;
michael@0: }
michael@0: 
michael@0: /* static */ void
michael@0: nsMathMLFrame::ParseNumericValue(const nsString&   aString,
michael@0:                                  nscoord*          aLengthValue,
michael@0:                                  uint32_t          aFlags,
michael@0:                                  nsPresContext*    aPresContext,
michael@0:                                  nsStyleContext*   aStyleContext)
michael@0: {
michael@0:   nsCSSValue cssValue;
michael@0: 
michael@0:   if (!nsMathMLElement::ParseNumericValue(aString, cssValue, aFlags,
michael@0:                                           aPresContext->Document())) {
michael@0:     // Invalid attribute value. aLengthValue remains unchanged, so the default
michael@0:     // length value is used.
michael@0:     return;
michael@0:   }
michael@0: 
michael@0:   nsCSSUnit unit = cssValue.GetUnit();
michael@0: 
michael@0:   if (unit == eCSSUnit_Percent || unit == eCSSUnit_Number) {
michael@0:     // Relative units. A multiple of the default length value is used.
michael@0:     *aLengthValue = NSToCoordRound(*aLengthValue * (unit == eCSSUnit_Percent ?
michael@0:                                                     cssValue.GetPercentValue() :
michael@0:                                                     cssValue.GetFloatValue()));
michael@0:     return;
michael@0:   }
michael@0:   
michael@0:   // Absolute units.
michael@0:   *aLengthValue = CalcLength(aPresContext, aStyleContext, cssValue);
michael@0: }
michael@0: 
michael@0: // ================
michael@0: // Utils to map attributes into CSS rules (work-around to bug 69409 which
michael@0: // is not scheduled to be fixed anytime soon)
michael@0: //
michael@0: 
michael@0: struct
michael@0: nsCSSMapping {
michael@0:   int32_t        compatibility;
michael@0:   const nsIAtom* attrAtom;
michael@0:   const char*    cssProperty;
michael@0: };
michael@0: 
michael@0: #if defined(DEBUG) && defined(SHOW_BOUNDING_BOX)
michael@0: class nsDisplayMathMLBoundingMetrics : public nsDisplayItem {
michael@0: public:
michael@0:   nsDisplayMathMLBoundingMetrics(nsDisplayListBuilder* aBuilder,
michael@0:                                  nsIFrame* aFrame, const nsRect& aRect)
michael@0:     : nsDisplayItem(aBuilder, aFrame), mRect(aRect) {
michael@0:     MOZ_COUNT_CTOR(nsDisplayMathMLBoundingMetrics);
michael@0:   }
michael@0: #ifdef NS_BUILD_REFCNT_LOGGING
michael@0:   virtual ~nsDisplayMathMLBoundingMetrics() {
michael@0:     MOZ_COUNT_DTOR(nsDisplayMathMLBoundingMetrics);
michael@0:   }
michael@0: #endif
michael@0: 
michael@0:   virtual void Paint(nsDisplayListBuilder* aBuilder,
michael@0:                      nsRenderingContext* aCtx) MOZ_OVERRIDE;
michael@0:   NS_DISPLAY_DECL_NAME("MathMLBoundingMetrics", TYPE_MATHML_BOUNDING_METRICS)
michael@0: private:
michael@0:   nsRect    mRect;
michael@0: };
michael@0: 
michael@0: void nsDisplayMathMLBoundingMetrics::Paint(nsDisplayListBuilder* aBuilder,
michael@0:                                            nsRenderingContext* aCtx)
michael@0: {
michael@0:   aCtx->SetColor(NS_RGB(0,0,255));
michael@0:   aCtx->DrawRect(mRect + ToReferenceFrame());
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: nsMathMLFrame::DisplayBoundingMetrics(nsDisplayListBuilder* aBuilder,
michael@0:                                       nsIFrame* aFrame, const nsPoint& aPt,
michael@0:                                       const nsBoundingMetrics& aMetrics,
michael@0:                                       const nsDisplayListSet& aLists) {
michael@0:   if (!NS_MATHML_PAINT_BOUNDING_METRICS(mPresentationData.flags))
michael@0:     return NS_OK;
michael@0:     
michael@0:   nscoord x = aPt.x + aMetrics.leftBearing;
michael@0:   nscoord y = aPt.y - aMetrics.ascent;
michael@0:   nscoord w = aMetrics.rightBearing - aMetrics.leftBearing;
michael@0:   nscoord h = aMetrics.ascent + aMetrics.descent;
michael@0: 
michael@0:   return aLists.Content()->AppendNewToTop(new (aBuilder)
michael@0:       nsDisplayMathMLBoundingMetrics(aBuilder, this, nsRect(x,y,w,h)));
michael@0: }
michael@0: #endif
michael@0: 
michael@0: class nsDisplayMathMLBar : public nsDisplayItem {
michael@0: public:
michael@0:   nsDisplayMathMLBar(nsDisplayListBuilder* aBuilder,
michael@0:                      nsIFrame* aFrame, const nsRect& aRect)
michael@0:     : nsDisplayItem(aBuilder, aFrame), mRect(aRect) {
michael@0:     MOZ_COUNT_CTOR(nsDisplayMathMLBar);
michael@0:   }
michael@0: #ifdef NS_BUILD_REFCNT_LOGGING
michael@0:   virtual ~nsDisplayMathMLBar() {
michael@0:     MOZ_COUNT_DTOR(nsDisplayMathMLBar);
michael@0:   }
michael@0: #endif
michael@0: 
michael@0:   virtual void Paint(nsDisplayListBuilder* aBuilder,
michael@0:                      nsRenderingContext* aCtx) MOZ_OVERRIDE;
michael@0:   NS_DISPLAY_DECL_NAME("MathMLBar", TYPE_MATHML_BAR)
michael@0: private:
michael@0:   nsRect    mRect;
michael@0: };
michael@0: 
michael@0: void nsDisplayMathMLBar::Paint(nsDisplayListBuilder* aBuilder,
michael@0:                                nsRenderingContext* aCtx)
michael@0: {
michael@0:   // paint the bar with the current text color
michael@0:   aCtx->SetColor(mFrame->GetVisitedDependentColor(eCSSProperty_color));
michael@0:   aCtx->FillRect(mRect + ToReferenceFrame());
michael@0: }
michael@0: 
michael@0: void
michael@0: nsMathMLFrame::DisplayBar(nsDisplayListBuilder* aBuilder,
michael@0:                           nsIFrame* aFrame, const nsRect& aRect,
michael@0:                           const nsDisplayListSet& aLists) {
michael@0:   if (!aFrame->StyleVisibility()->IsVisible() || aRect.IsEmpty())
michael@0:     return;
michael@0: 
michael@0:   aLists.Content()->AppendNewToTop(new (aBuilder)
michael@0:     nsDisplayMathMLBar(aBuilder, aFrame, aRect));
michael@0: }