1 files changed, 223 insertions, 0 deletions
diff --git a/layout/mathml/nsMathMLChar.h b/layout/mathml/nsMathMLChar.h
new file mode 100644
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+++ b/layout/mathml/nsMathMLChar.h
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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/. */
+
+#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 gfxContext;
+class nsGlyphTable;
+class nsIFrame;
+class nsDisplayListBuilder;
+class nsDisplayListSet;
+class nsPresContext;
+struct nsBoundingMetrics;
+struct nsFont;
+
+namespace mozilla {
+class ComputedStyle;
+}
+
+// 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() : mDirection(NS_STRETCH_DIRECTION_DEFAULT) {
+    MOZ_COUNT_CTOR(nsMathMLChar);
+    mComputedStyle = 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(nsIFrame* aForFrame, gfxContext& 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(nsIFrame* aForFrame, 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(nsIFrame* aForFrame, 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 ComputedStyles, 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 ComputedStyles given to the MathMLChars.
+  // They provide an interface to make them accessible to the Style System via
+  // the Get/Set AdditionalComputedStyle() APIs. Owners of MathMLChars
+  // should honor these APIs.
+  mozilla::ComputedStyle* GetComputedStyle() const;
+
+  void SetComputedStyle(mozilla::ComputedStyle* aComputedStyle);
+
+ protected:
+  friend class nsGlyphTable;
+  friend class nsPropertiesTable;
+  friend class nsOpenTypeTable;
+  nsString mData;
+
+ private:
+  nsRect mRect;
+  nsStretchDirection mDirection;
+  nsBoundingMetrics mBoundingMetrics;
+  RefPtr<mozilla::ComputedStyle> mComputedStyle;
+  // 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(nsIFrame* aForFrame, 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___ */