Simplify handling of BiDi cursor movement

ui/gfx/render_text_linux.h

 // 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_LINUX_H_
 #define UI_GFX_RENDER_TEXT_LINUX_H_
 #pragma once
 
 #include <pango/pango.h>
 #include <vector>
 
 #include "ui/gfx/render_text.h"
 
 namespace gfx {
 
 // RenderTextLinux is the Linux implementation of RenderText using Pango.
 class RenderTextLinux : public RenderText {
  public:
   RenderTextLinux();
   virtual ~RenderTextLinux();
 
   // Overridden from RenderText:
   virtual base::i18n::TextDirection GetTextDirection() OVERRIDE;
-  virtual int GetStringWidth() OVERRIDE;
+  virtual Size GetStringSize() OVERRIDE;
   virtual SelectionModel FindCursorPosition(const Point& point) OVERRIDE;
-  virtual Rect GetCursorBounds(const SelectionModel& position,
-                               bool insert_mode) OVERRIDE;
 
  protected:
   // Overridden from RenderText:
   virtual SelectionModel AdjacentCharSelectionModel(
       const SelectionModel& selection,
       VisualCursorDirection direction) OVERRIDE;
   virtual SelectionModel AdjacentWordSelectionModel(
       const SelectionModel& selection,
       VisualCursorDirection direction) OVERRIDE;
-  virtual SelectionModel EdgeSelectionModel(
-      VisualCursorDirection direction) OVERRIDE;
-  virtual std::vector<Rect> GetSubstringBounds(size_t from, size_t to) OVERRIDE;
+  virtual void GetGlyphBounds(size_t index,
+                              ui::Range* xspan,
+                              int* height) OVERRIDE;
+  virtual std::vector<Rect> GetSubstringBounds(ui::Range range) OVERRIDE;
   virtual void SetSelectionModel(const SelectionModel& model) OVERRIDE;
   virtual bool IsCursorablePosition(size_t position) OVERRIDE;
   virtual void UpdateLayout() OVERRIDE;
   virtual void EnsureLayout() OVERRIDE;
   virtual void DrawVisualText(Canvas* canvas) OVERRIDE;
 
  private:
   virtual size_t IndexOfAdjacentGrapheme(
       size_t index,
       LogicalCursorDirection direction) OVERRIDE;
 
-  // Returns the run that contains |position|. Return NULL if not found.
-  GSList* GetRunContainingPosition(size_t position) const;
+  // Returns the run that contains the character attached to the caret in the
+  // given selection model. Return NULL if not found.
+  GSList* GetRunContainingCaret(const SelectionModel& caret) const;
 
   // Given |layout_index_of_current_grapheme|, returns the layout (UTF-8) index
   // of the |next| or previous grapheme in logical order. Returns 0 if there is
   // no previous grapheme, or the |text_| length if there is no next grapheme.
   size_t LayoutIndexOfAdjacentGrapheme(size_t layout_index_of_current_grapheme,
                                        LogicalCursorDirection direction) const;
 
   // Given a |run|, returns the SelectionModel that contains the logical first
   // or last caret position inside (not at a boundary of) the run.
   // The returned value represents a cursor/caret position without a selection.
   SelectionModel FirstSelectionModelInsideRun(const PangoItem* run) const;
   SelectionModel LastSelectionModelInsideRun(const PangoItem* run) const;
 
   // Unref |layout_| and |pango_line_|. Set them to NULL.
   void ResetLayout();
 
   // Setup pango attribute: foreground, background, font, strike.
   void SetupPangoAttributes(PangoLayout* layout);
 
   // Append one pango attribute |pango_attr| into pango attribute list |attrs|.
   void AppendPangoAttribute(size_t start,
                             size_t end,
                             PangoAttribute* pango_attr,
                             PangoAttrList* attrs);
 
   // Convert between indices into text() and indices into |layout_text_|.
   size_t TextIndexToLayoutIndex(size_t index) const;
   size_t LayoutIndexToTextIndex(size_t index) const;
 
-  // Calculate the visual bounds containing the logical substring within |from|
-  // to |to|.
-  std::vector<Rect> CalculateSubstringBounds(size_t from, size_t to);
+  // Calculate the visual bounds containing the logical substring within the
+  // given range.
+  std::vector<Rect> CalculateSubstringBounds(ui::Range range);
 
   // Get the visual bounds of the logical selection.
   std::vector<Rect> GetSelectionBounds();
 
   // Pango Layout.
   PangoLayout* layout_;
   // A single line layout resulting from laying out via |layout_|.
   PangoLayoutLine* current_line_;
 
   // Information about character attributes.
   PangoLogAttr* log_attrs_;
   // Number of attributes in |log_attrs_|.
   int num_log_attrs_;
 
   // Vector of the visual bounds containing the logical substring of selection.
   std::vector<Rect> selection_visual_bounds_;
 
   // The text in the |layout_|.
   const char* layout_text_;
   // The text length.
   size_t layout_text_len_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderTextLinux);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_LINUX_H_