gfx/thebes/gfxGraphiteShaper.h

   1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef GFX_GRAPHITESHAPER_H
   7 #define GFX_GRAPHITESHAPER_H
   8
   9 #include "gfxFont.h"
  10
  11 #include "mozilla/gfx/2D.h"
  12 #include "nsTHashSet.h"
  13
  14 #include "ThebesRLBoxTypes.h"
  15
  16 struct gr_face;
  17 struct gr_font;
  18 struct gr_segment;
  19
  20 class gfxGraphiteShaper : public gfxFontShaper {
  21  public:
  22   explicit gfxGraphiteShaper(gfxFont* aFont);
  23   virtual ~gfxGraphiteShaper();
  24
  25   bool ShapeText(DrawTarget* aDrawTarget, const char16_t* aText,
  26                  uint32_t aOffset, uint32_t aLength, Script aScript,
  27                  nsAtom* aLanguage, bool aVertical, RoundingFlags aRounding,
  28                  gfxShapedText* aShapedText) override;
  29
  30   static void Shutdown();
  31
  32  protected:
  33   nsresult SetGlyphsFromSegment(gfxShapedText* aShapedText, uint32_t aOffset,
  34                                 uint32_t aLength, const char16_t* aText,
  35                                 tainted_opaque_gr<char16_t*> t_aText,
  36                                 tainted_opaque_gr<gr_segment*> aSegment,
  37                                 RoundingFlags aRounding);
  38
  39   // Graphite is run in a rlbox sandbox. Callback GrGetAdvance must be
  40   // explicitly permitted. Since the sandbox is owned in gfxFontEntry class,
  41   // gfxFontEntry needs access to the protected callback.
  42   friend class gfxFontEntryCallbacks;
  43   static tainted_opaque_gr<float> GrGetAdvance(
  44       rlbox_sandbox_gr& sandbox, tainted_opaque_gr<const void*> appFontHandle,
  45       tainted_opaque_gr<uint16_t> glyphid);
  46
  47   tainted_opaque_gr<gr_face*>
  48       mGrFace;  // owned by the font entry; shaper must call
  49                 // gfxFontEntry::ReleaseGrFace when finished with it
  50   tainted_opaque_gr<gr_font*> mGrFont;  // owned by the shaper itself
  51
  52   // All libGraphite functionality is sandboxed. This is the sandbox instance.
  53   rlbox_sandbox_gr* mSandbox;
  54
  55   // Holds the handle to the permitted callback into Firefox for the sandboxed
  56   // libGraphite
  57   sandbox_callback_gr<float (*)(const void*, uint16_t)>* mCallback;
  58
  59   struct CallbackData {
  60     // mFont is a pointer to the font that owns this shaper, so it will
  61     // remain valid throughout our lifetime
  62     gfxFont* MOZ_NON_OWNING_REF mFont;
  63   };
  64
  65   CallbackData mCallbackData;
  66   static thread_local CallbackData* tl_GrGetAdvanceData;
  67
  68   bool mFallbackToSmallCaps;  // special fallback for the petite-caps case
  69
  70   // Convert HTML 'lang' (BCP47) to Graphite language code
  71   static uint32_t GetGraphiteTagForLang(const nsCString& aLang);
  72   static nsTHashSet<uint32_t>* sLanguageTags;
  73 };
  74
  75 #endif /* GFX_GRAPHITESHAPER_H */