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Diffstat (limited to 'layout/mathml/nsMathMLChar.h')
| -rw-r--r-- | layout/mathml/nsMathMLChar.h | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/layout/mathml/nsMathMLChar.h b/layout/mathml/nsMathMLChar.h new file mode 100644 index 000000000..fc61d1939 --- /dev/null +++ b/layout/mathml/nsMathMLChar.h @@ -0,0 +1,269 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* 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/. */ + +#ifndef nsMathMLChar_h___ +#define nsMathMLChar_h___ + +#include "nsColor.h" +#include "nsMathMLOperators.h" +#include "nsPoint.h" +#include "nsRect.h" +#include "nsString.h" +#include "nsBoundingMetrics.h" +#include "gfxTextRun.h" + +class nsGlyphTable; +class nsIFrame; +class nsDisplayListBuilder; +class nsDisplayListSet; +class nsPresContext; +class nsRenderingContext; +struct nsBoundingMetrics; +class nsStyleContext; +struct nsFont; + +// Hints for Stretch() to indicate criteria for stretching +enum { + // Don't stretch + NS_STRETCH_NONE = 0x00, + // Variable size stretches + NS_STRETCH_VARIABLE_MASK = 0x0F, + NS_STRETCH_NORMAL = 0x01, // try to stretch to requested size + NS_STRETCH_NEARER = 0x02, // stretch very close to requested size + NS_STRETCH_SMALLER = 0x04, // don't stretch more than requested size + NS_STRETCH_LARGER = 0x08, // don't stretch less than requested size + // A largeop in displaystyle + NS_STRETCH_LARGEOP = 0x10, + NS_STRETCH_INTEGRAL = 0x20, + + // Intended for internal use: + // Find the widest metrics that might be returned from a vertical stretch + NS_STRETCH_MAXWIDTH = 0x40 +}; + +// A single glyph in our internal representation is either +// 1) a 'code@font' pair from the mathfontFONTFAMILY.properties table. The +// 'code' is interpreted as a Unicode point. The 'font' is a numeric +// identifier given to the font to which the glyph belongs, which is 0 for the +// FONTFAMILY and > 0 for 'external' fonts. +// 2) a glyph index from the Open Type MATH table. In that case, all the glyphs +// come from the font containing that table and 'font' is just set to -1. +struct nsGlyphCode { + union { + char16_t code[2]; + uint32_t glyphID; + }; + int8_t font; + + bool IsGlyphID() const { return font == -1; } + + int32_t Length() const { + return (IsGlyphID() || code[1] == char16_t('\0') ? 1 : 2); + } + bool Exists() const + { + return IsGlyphID() ? glyphID != 0 : code[0] != 0; + } + bool operator==(const nsGlyphCode& other) const + { + return (other.font == font && + ((IsGlyphID() && other.glyphID == glyphID) || + (!IsGlyphID() && other.code[0] == code[0] && + other.code[1] == code[1]))); + } + bool operator!=(const nsGlyphCode& other) const + { + return ! operator==(other); + } +}; + +// Class used to handle stretchy symbols (accent, delimiter and boundary +// symbols). +class nsMathMLChar +{ +public: + typedef gfxTextRun::Range Range; + typedef mozilla::gfx::DrawTarget DrawTarget; + + // constructor and destructor + nsMathMLChar() { + MOZ_COUNT_CTOR(nsMathMLChar); + mStyleContext = nullptr; + mUnscaledAscent = 0; + mScaleX = mScaleY = 1.0; + mDraw = DRAW_NORMAL; + mMirrored = false; + } + + // not a virtual destructor: this class is not intended to be subclassed + ~nsMathMLChar(); + + void Display(nsDisplayListBuilder* aBuilder, + nsIFrame* aForFrame, + const nsDisplayListSet& aLists, + uint32_t aIndex, + const nsRect* aSelectedRect = nullptr); + + void PaintForeground(nsPresContext* aPresContext, + nsRenderingContext& aRenderingContext, + nsPoint aPt, + bool aIsSelected); + + // This is the method called to ask the char to stretch itself. + // @param aContainerSize - IN - suggested size for the stretched char + // @param aDesiredStretchSize - OUT - the size that the char wants + nsresult + Stretch(nsPresContext* aPresContext, + DrawTarget* aDrawTarget, + float aFontSizeInflation, + nsStretchDirection aStretchDirection, + const nsBoundingMetrics& aContainerSize, + nsBoundingMetrics& aDesiredStretchSize, + uint32_t aStretchHint, + bool aRTL); + + void + SetData(nsString& aData); + + void + GetData(nsString& aData) { + aData = mData; + } + + int32_t + Length() { + return mData.Length(); + } + + nsStretchDirection + GetStretchDirection() { + return mDirection; + } + + // Sometimes we only want to pass the data to another routine, + // this function helps to avoid copying + const char16_t* + get() { + return mData.get(); + } + + void + GetRect(nsRect& aRect) { + aRect = mRect; + } + + void + SetRect(const nsRect& aRect) { + mRect = aRect; + } + + // Get the maximum width that the character might have after a vertical + // Stretch(). + // + // @param aStretchHint can be the value that will be passed to Stretch(). + // It is used to determine whether the operator is stretchy or a largeop. + nscoord + GetMaxWidth(nsPresContext* aPresContext, + DrawTarget* aDrawTarget, + float aFontSizeInflation, + uint32_t aStretchHint = NS_STRETCH_NORMAL); + + // Metrics that _exactly_ enclose the char. The char *must* have *already* + // being stretched before you can call the GetBoundingMetrics() method. + // IMPORTANT: since chars have their own style contexts, and may be rendered + // with glyphs that are not in the parent font, just calling the default + // aRenderingContext.GetBoundingMetrics(aChar) can give incorrect results. + void + GetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) { + aBoundingMetrics = mBoundingMetrics; + } + + void + SetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) { + mBoundingMetrics = aBoundingMetrics; + } + + // Hooks to access the extra leaf style contexts given to the MathMLChars. + // They provide an interface to make them accessible to the Style System via + // the Get/Set AdditionalStyleContext() APIs. Owners of MathMLChars + // should honor these APIs. + nsStyleContext* GetStyleContext() const; + + void SetStyleContext(nsStyleContext* aStyleContext); + +protected: + friend class nsGlyphTable; + friend class nsPropertiesTable; + friend class nsOpenTypeTable; + nsString mData; + +private: + nsRect mRect; + nsStretchDirection mDirection; + nsBoundingMetrics mBoundingMetrics; + nsStyleContext* mStyleContext; + // mGlyphs/mBmData are arrays describing the glyphs used to draw the operator. + // See the drawing methods below. + RefPtr<gfxTextRun> mGlyphs[4]; + nsBoundingMetrics mBmData[4]; + // mUnscaledAscent is the actual ascent of the char. + nscoord mUnscaledAscent; + // mScaleX, mScaleY are the factors by which we scale the char. + float mScaleX, mScaleY; + + // mDraw indicates how we draw the stretchy operator: + // - DRAW_NORMAL: we render the mData string normally. + // - DRAW_VARIANT: we draw a larger size variant given by mGlyphs[0]. + // - DRAW_PARTS: we assemble several parts given by mGlyphs[0], ... mGlyphs[4] + // XXXfredw: the MATH table can have any numbers of parts and extenders. + enum DrawingMethod { + DRAW_NORMAL, DRAW_VARIANT, DRAW_PARTS + }; + DrawingMethod mDraw; + + // mMirrored indicates whether the character is mirrored. + bool mMirrored; + + class StretchEnumContext; + friend class StretchEnumContext; + + // helper methods + bool + SetFontFamily(nsPresContext* aPresContext, + const nsGlyphTable* aGlyphTable, + const nsGlyphCode& aGlyphCode, + const mozilla::FontFamilyList& aDefaultFamily, + nsFont& aFont, + RefPtr<gfxFontGroup>* aFontGroup); + + nsresult + StretchInternal(nsPresContext* aPresContext, + DrawTarget* aDrawTarget, + float aFontSizeInflation, + nsStretchDirection& aStretchDirection, + const nsBoundingMetrics& aContainerSize, + nsBoundingMetrics& aDesiredStretchSize, + uint32_t aStretchHint, + float aMaxSize = NS_MATHML_OPERATOR_SIZE_INFINITY, + bool aMaxSizeIsAbsolute = false); + + nsresult + PaintVertically(nsPresContext* aPresContext, + gfxContext* aThebesContext, + nsRect& aRect, + nscolor aColor); + + nsresult + PaintHorizontally(nsPresContext* aPresContext, + gfxContext* aThebesContext, + nsRect& aRect, + nscolor aColor); + + void + ApplyTransforms(gfxContext* aThebesContext, int32_t aAppUnitsPerGfxUnit, + nsRect &r); +}; + +#endif /* nsMathMLChar_h___ */ |