More or less implement RenderTextHarfBuzz

ui/gfx/render_text_harfbuzz.h

Index: ui/gfx/render_text_harfbuzz.h
diff --git a/ui/gfx/render_text_harfbuzz.h b/ui/gfx/render_text_harfbuzz.h
new file mode 100644
index 0000000000000000000000000000000000000000..05dc732ef03940b322e9ed52b0a7ed667f1c7684
--- /dev/null
+++ b/ui/gfx/render_text_harfbuzz.h
@@ -0,0 +1,99 @@
+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_GFX_RENDER_TEXT_HARFBUZZ_H_
+#define UI_GFX_RENDER_TEXT_HARFBUZZ_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_vector.h"
+#include "third_party/harfbuzz-ng/src/hb.h"
+#include "third_party/icu/source/common/unicode/ubidi.h"
+#include "ui/gfx/render_text.h"
+
+namespace gfx {
+
+namespace internal {
+
+struct TextRunHarfBuzz {
+  TextRunHarfBuzz();
+  ~TextRunHarfBuzz();
+
+  int width;
+  Range range;
+  UBiDiDirection direction;
+  UBiDiLevel level;
+
+  scoped_ptr<uint16[]> glyphs;
+  scoped_ptr<SkPoint[]> positions;
+  scoped_ptr<uint32[]> glyph_to_char;
+  size_t glyph_count;
+
+  skia::RefPtr<SkTypeface> skia_face;
+  int font_size;
+  int font_style;
+  bool strike;
+  bool diagonal_strike;
+  bool underline;
+};
+
+}  // namespace internal
+
+class RenderTextHarfBuzz : public RenderText {
+ public:
+  RenderTextHarfBuzz();
+  virtual ~RenderTextHarfBuzz();
+
+  // Overridden from RenderText.
+  virtual Size GetStringSize() OVERRIDE;
+  virtual SelectionModel FindCursorPosition(const Point& point) OVERRIDE;
+  virtual bool IsCursorablePosition(size_t position) OVERRIDE;
+  virtual std::vector<FontSpan> GetFontSpansForTesting() OVERRIDE;
+
+ protected:
+  // Overridden from RenderText.
+  virtual int GetLayoutTextBaseline() OVERRIDE;
+  virtual SelectionModel AdjacentCharSelectionModel(
+      const SelectionModel& selection,
+      VisualCursorDirection direction) OVERRIDE;
+  virtual SelectionModel AdjacentWordSelectionModel(
+      const SelectionModel& selection,
+      VisualCursorDirection direction) OVERRIDE;
+  virtual Range GetGlyphBounds(size_t index) OVERRIDE;
+  virtual std::vector<Rect> GetSubstringBounds(const Range& range) OVERRIDE;
+  virtual size_t TextIndexToLayoutIndex(size_t index) const OVERRIDE;
+  virtual size_t LayoutIndexToTextIndex(size_t index) const OVERRIDE;
+  virtual void ResetLayout() OVERRIDE;
+  virtual void EnsureLayout() OVERRIDE;
+  virtual void DrawVisualText(Canvas* canvas) OVERRIDE;
+
+  void ShapeRun(internal::TextRunHarfBuzz* run);

[msw, 2014/04/29 06:24:45]

nit: comment like "Shape the glyphs needed for the text |run|."

[ckocagil, 2014/05/01 22:02:01]

Done.

+
+  size_t GetRunContainingCaret(const SelectionModel& caret) const;

[msw, 2014/04/29 06:24:45]

nit: copy/adapt the comments from RenderTextWin for this,
[First|Last]SelectionModelInsideRun, and GetRunContainingXCoord.

[ckocagil, 2014/05/01 22:02:01]

Done.

+
+  // Returns the X coordinate of the leading or |trailing| edge of the glyph
+  // starting at |index|, relative to the left of the text (not the view).
+  int GetGlyphXBoundary(size_t run_index, size_t text_index, bool trailing);
+
+  SelectionModel RenderTextHarfBuzz::FirstSelectionModelInsideRun(
+      const internal::TextRunHarfBuzz* run);
+
+  SelectionModel RenderTextHarfBuzz::LastSelectionModelInsideRun(
+      const internal::TextRunHarfBuzz* run);
+
+  size_t GetRunContainingXCoord(int x, int* offset) const;
+
+ private:
+  // Text runs in logical order.
+  ScopedVector<internal::TextRunHarfBuzz> runs_;
+
+  // Maps visual run indices to logical run indices and vice versa.
+  std::vector<int32_t> visual_to_logical_;
+  std::vector<int32_t> logical_to_visual_;
+
+  bool needs_layout_;
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_RENDER_TEXT_HARFBUZZ_H_