Initial RenderTextMac implementation using CoreText.

ui/gfx/render_text_mac.h

Index: ui/gfx/render_text_mac.h
===================================================================
--- ui/gfx/render_text_mac.h	(revision 0)
+++ ui/gfx/render_text_mac.h	(revision 0)
@@ -0,0 +1,96 @@
+// Copyright (c) 2012 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_MAC_H_
+#define UI_GFX_RENDER_TEXT_MAC_H_
+
+#include <ApplicationServices/ApplicationServices.h>
+
+#include <string>
+#include <vector>
+
+#include "base/mac/scoped_cftyperef.h"
+#include "ui/gfx/render_text.h"
+
+namespace gfx {
+
+// RenderTextMac is the Mac implementation of RenderText that uses CoreText for
+// layout and Skia for drawing.
+//
+// Note: The current implementation only supports drawing and sizing the text,
+//       but not text selection or cursor movement.
+class RenderTextMac : public RenderText {
+ public:
+  RenderTextMac();
+  virtual ~RenderTextMac();
+
+  // Overridden from RenderText:
+  virtual base::i18n::TextDirection GetTextDirection() OVERRIDE;
+  virtual Size GetStringSize() OVERRIDE;
+  virtual int GetBaseline() OVERRIDE;
+  virtual SelectionModel FindCursorPosition(const Point& point) OVERRIDE;
+  virtual std::vector<FontSpan> GetFontSpansForTesting() OVERRIDE;
+
+ protected:
+  // Overridden from RenderText:
+  virtual SelectionModel AdjacentCharSelectionModel(
+      const SelectionModel& selection,
+      VisualCursorDirection direction) OVERRIDE;
+  virtual SelectionModel AdjacentWordSelectionModel(
+      const SelectionModel& selection,
+      VisualCursorDirection direction) OVERRIDE;
+  virtual void GetGlyphBounds(size_t index,
+                              ui::Range* xspan,
+                              int* height) OVERRIDE;
+  virtual std::vector<Rect> GetSubstringBounds(ui::Range range) OVERRIDE;
+  virtual bool IsCursorablePosition(size_t position) OVERRIDE;
+  virtual void ResetLayout() OVERRIDE;
+  virtual void EnsureLayout() OVERRIDE;
+  virtual void DrawVisualText(Canvas* canvas) OVERRIDE;
+
+ private:
+  struct TextRun {
+    CTRunRef ct_run;
+    SkPoint origin;
+    std::vector<uint16> glyphs;
+    std::vector<SkPoint> glyph_positions;
+    SkScalar width;
+    std::string font_name;
+    int font_style;
+    SkScalar text_size;
+    SkColor foreground;
+    StyleRange style;
+
+    TextRun();
+    ~TextRun();
+  };
+
+  // Applies RenderText styles to |attr_string| with the given |ct_font|.
+  void ApplyStyles(CFMutableAttributedStringRef attr_string, CTFontRef ct_font);
+
+  // Updates |runs_| based on |line_| and sets |runs_valid_| to true.
+  void ComputeRuns();
+
+  // The Core Text line of text. Created by |EnsureLayout()|.
+  base::mac::ScopedCFTypeRef<CTLineRef> line_;
+
+  // Visual dimensions of the text. Computed by |EnsureLayout()|.
+  Size string_size_;
+
+  // Common baseline for this line of text. Computed by |EnsureLayout()|.
+  SkScalar common_baseline_;
+
+  // Visual text runs. Only valid if |runs_valid_| is true. Computed by
+  // |ComputeRuns()|.
+  std::vector<TextRun> runs_;
+
+  // Indicates that |runs_| are valid, set by |ComputeRuns()|.
+  bool runs_valid_;
+
+  DISALLOW_COPY_AND_ASSIGN(RenderTextMac);
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_RENDER_TEXT_MAC_H_