Add RenderText DirectionalityMode enum and support; etc.

ui/gfx/render_text.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_H_
 #define UI_GFX_RENDER_TEXT_H_
 
 #include <algorithm>
 #include <cstring>
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/i18n/rtl.h"
 #include "base/string16.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "ui/base/range/range.h"
 #include "ui/gfx/font_list.h"
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/selection_model.h"
 #include "ui/gfx/shadow_value.h"
+#include "ui/gfx/text_constants.h"
 
 class SkCanvas;
 class SkDrawLooper;
 struct SkPoint;
 class SkShader;
 class SkTypeface;
 
 namespace gfx {
 
 class Canvas;
@@ skipping 48 matching lines @@
   // A gfx::Font::FontStyle flag to specify bold and italic styles.
   int font_style;
   bool strike;
   bool diagonal_strike;
   bool underline;
   ui::Range range;
 };
 
 typedef std::vector<StyleRange> StyleRanges;
 
-// TODO(msw): Distinguish between logical character stops and glyph stops?
-// CHARACTER_BREAK cursor movements should stop at neighboring characters.
-// WORD_BREAK cursor movements should stop at the nearest word boundaries.
-// LINE_BREAK cursor movements should stop at the text ends as shown on screen.
-enum BreakType {
-  CHARACTER_BREAK,
-  WORD_BREAK,
-  LINE_BREAK,
-};
-
-// Horizontal text alignment styles.
-enum HorizontalAlignment {
-  ALIGN_LEFT,
-  ALIGN_CENTER,
-  ALIGN_RIGHT,
-};
-
 // RenderText represents an abstract model of styled text and its corresponding
 // visual layout. Support is built in for a cursor, a selection, simple styling,
 // complex scripts, and bi-directional text. Implementations provide mechanisms
 // for rendering and translation between logical and visual data.
 class UI_EXPORT RenderText {
  public:
   virtual ~RenderText();
 
   // Creates a platform-specific RenderText instance.
   static RenderText* CreateInstance();
@@ skipping 119 matching lines @@
 
   const ui::Range& GetCompositionRange() const;
   void SetCompositionRange(const ui::Range& composition_range);
 
   // Apply |style_range| to the internal style model.
   void ApplyStyleRange(const StyleRange& style_range);
 
   // Apply |default_style_| over the entire text range.
   void ApplyDefaultStyle();
 
-  // Returns the dominant direction of the current text.
-  virtual base::i18n::TextDirection GetTextDirection() = 0;
+  // Set the text directionality mode and get the text direction yielded.
+  void SetDirectionalityMode(DirectionalityMode mode);
+  base::i18n::TextDirection GetTextDirection();
 
   // Returns the visual movement direction corresponding to the logical end
   // of the text, considering only the dominant direction returned by
   // |GetTextDirection()|, not the direction of a particular run.
   VisualCursorDirection GetVisualDirectionOfLogicalEnd();
 
   // Returns the size in pixels of the entire string. For the height, this will
   // return the maximum height among the different fonts in the text runs.
   // Note that this returns the raw size of the string, which does not include
   // the margin area of text shadows.
@@ skipping 171 matching lines @@
   // Draw the selection and cursor.
   void DrawSelection(Canvas* canvas);
   void DrawCursor(Canvas* canvas);
 
   // Logical UTF-16 string data to be drawn.
   string16 text_;
 
   // Horizontal alignment of the text with respect to |display_rect_|.
   HorizontalAlignment horizontal_alignment_;
 
+  // The text directionality mode, defaults to DIRECTIONALITY_FROM_TEXT.
+  DirectionalityMode directionality_mode_;
+
+  // The cached text direction, potentially computed from the text or UI locale.

[Alexei Svitkine (slow), 2012/07/31 23:33:29]

Mention that it shouldn't be used directly but through :GetTextDirection().

[msw, 2012/08/01 17:30:10]

Done.

+  base::i18n::TextDirection text_direction_;
+
   // A list of fonts used to render |text_|.
   FontList font_list_;
 
   // Logical selection range and visual cursor position.
   SelectionModel selection_model_;
 
   // The cached cursor bounds; get these bounds with GetUpdatedCursorBounds.
   Rect cursor_bounds_;
 
   // Specifies whether the cursor is enabled. If disabled, no space is reserved
@@ skipping 56 matching lines @@
 
   // Text shadows to be drawn.
   ShadowValues text_shadows_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderText);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_H_