ui/gfx/render_text_win.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_GFX_RENDER_TEXT_WIN_H_
   6 #define UI_GFX_RENDER_TEXT_WIN_H_
   7
   8 #include <usp10.h>
   9
  10 #include <map>
  11 #include <string>
  12 #include <vector>
  13
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/scoped_vector.h"
  16 #include "ui/gfx/render_text.h"
  17
  18 namespace gfx {
  19
  20 namespace internal {
  21
  22 struct TextRun {
  23   TextRun();
  24   ~TextRun();
  25
  26   ui::Range range;
  27   Font font;
  28   // A gfx::Font::FontStyle flag to specify bold and italic styles.
  29   // Supersedes |font.GetFontStyle()|. Stored separately to avoid calling
  30   // |font.DeriveFont()|, which is expensive on Windows.
  31   int font_style;
  32
  33   // TODO(msw): Disambiguate color/style from TextRuns for proper glyph shaping.
  34   //            See an example: http://www.catch22.net/tuts/uniscribe-mysteries
  35   SkColor foreground;
  36   bool strike;
  37   bool diagonal_strike;
  38   bool underline;
  39
  40   int width;
  41   // The cumulative widths of preceding runs.
  42   int preceding_run_widths;
  43
  44   SCRIPT_ANALYSIS script_analysis;
  45
  46   scoped_ptr<WORD[]> glyphs;
  47   scoped_ptr<WORD[]> logical_clusters;
  48   scoped_ptr<SCRIPT_VISATTR[]> visible_attributes;
  49   int glyph_count;
  50
  51   scoped_ptr<int[]> advance_widths;
  52   scoped_ptr<GOFFSET[]> offsets;
  53   ABC abc_widths;
  54   SCRIPT_CACHE script_cache;
  55
  56  private:
  57   DISALLOW_COPY_AND_ASSIGN(TextRun);
  58 };
  59
  60 }  // namespace internal
  61
  62 // RenderTextWin is the Windows implementation of RenderText using Uniscribe.
  63 class RenderTextWin : public RenderText {
  64  public:
  65   RenderTextWin();
  66   virtual ~RenderTextWin();
  67
  68   // Overridden from RenderText:
  69   virtual Size GetStringSize() OVERRIDE;
  70   virtual int GetBaseline() OVERRIDE;
  71   virtual SelectionModel FindCursorPosition(const Point& point) OVERRIDE;
  72   virtual std::vector<FontSpan> GetFontSpansForTesting() OVERRIDE;
  73
  74  protected:
  75   // Overridden from RenderText:
  76   virtual SelectionModel AdjacentCharSelectionModel(
  77       const SelectionModel& selection,
  78       VisualCursorDirection direction) OVERRIDE;
  79   virtual SelectionModel AdjacentWordSelectionModel(
  80       const SelectionModel& selection,
  81       VisualCursorDirection direction) OVERRIDE;
  82   virtual void SetSelectionModel(const SelectionModel& model) OVERRIDE;
  83   virtual void GetGlyphBounds(size_t index,
  84                               ui::Range* xspan,
  85                               int* height) OVERRIDE;
  86   virtual std::vector<Rect> GetSubstringBounds(const ui::Range& range) OVERRIDE;
  87   virtual size_t TextIndexToLayoutIndex(size_t index) const OVERRIDE;
  88   virtual size_t LayoutIndexToTextIndex(size_t index) const OVERRIDE;
  89   virtual bool IsCursorablePosition(size_t position) OVERRIDE;
  90   virtual void ResetLayout() OVERRIDE;
  91   virtual void EnsureLayout() OVERRIDE;
  92   virtual void DrawVisualText(Canvas* canvas) OVERRIDE;
  93
  94  private:
  95   void ItemizeLogicalText();
  96   void LayoutVisualText();
  97   void LayoutTextRun(internal::TextRun* run);
  98
  99   // Helper function that calls |ScriptShape()| on the run, which has logic to
 100   // handle E_OUTOFMEMORY return codes.
 101   HRESULT ShapeTextRunWithFont(internal::TextRun* run, const Font& font);
 102
 103   // Returns the number of characters in |run| that have missing glyphs.
 104   int CountCharsWithMissingGlyphs(internal::TextRun* run) const;
 105
 106   // Return the run index that contains the argument; or the length of the
 107   // |runs_| vector if argument exceeds the text length or width.
 108   size_t GetRunContainingCaret(const SelectionModel& caret) const;
 109   size_t GetRunContainingPoint(const Point& point) const;
 110
 111   // Given a |run|, returns the SelectionModel that contains the logical first
 112   // or last caret position inside (not at a boundary of) the run.
 113   // The returned value represents a cursor/caret position without a selection.
 114   SelectionModel FirstSelectionModelInsideRun(const internal::TextRun* run);
 115   SelectionModel LastSelectionModelInsideRun(const internal::TextRun* run);
 116
 117   // Cached HDC for performing Uniscribe API calls.
 118   static HDC cached_hdc_;
 119
 120   // Cached map from font name to the last successful substitute font used.
 121   // TODO(asvitkine): Move the caching logic to font_fallback_win.cc.
 122   static std::map<std::string, Font> successful_substitute_fonts_;
 123
 124   SCRIPT_CONTROL script_control_;
 125   SCRIPT_STATE script_state_;
 126
 127   ScopedVector<internal::TextRun> runs_;
 128   Size string_size_;
 129
 130   // A common vertical baseline for all the text runs. This is computed as the
 131   // largest baseline over all the runs' fonts.
 132   int common_baseline_;
 133
 134   scoped_ptr<int[]> visual_to_logical_;
 135   scoped_ptr<int[]> logical_to_visual_;
 136
 137   bool needs_layout_;
 138
 139   DISALLOW_COPY_AND_ASSIGN(RenderTextWin);
 140 };
 141
 142 }  // namespace gfx
 143
 144 #endif  // UI_GFX_RENDER_TEXT_WIN_H_