Implement Uniscribe RenderText for Windows.

ui/gfx/render_text.h

 // Copyright (c) 2011 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_
 #pragma once
 
 #include <algorithm>
 #include <vector>
@@ skipping 136 matching lines @@
  public:
   virtual ~RenderText();
 
   // Creates a platform-specific RenderText instance.
   static RenderText* CreateRenderText();
 
   const string16& text() const { return text_; }
   virtual void SetText(const string16& text);
 
   const SelectionModel& selection_model() const { return selection_model_; }
-  void SetSelectionModel(const SelectionModel& sel);
 
   bool cursor_visible() const { return cursor_visible_; }
   void set_cursor_visible(bool visible) { cursor_visible_ = visible; }
 
   bool insert_mode() const { return insert_mode_; }
-  void toggle_insert_mode() { insert_mode_ = !insert_mode_; }
+  void ToggleInsertMode();
 
   bool focused() const { return focused_; }
   void set_focused(bool focused) { focused_ = focused; }
 
   const StyleRange& default_style() const { return default_style_; }
   void set_default_style(StyleRange style) { default_style_ = style; }
 
   const Rect& display_rect() const { return display_rect_; }
   virtual void SetDisplayRect(const Rect& r);
 
   // This cursor position corresponds to SelectionModel::selection_end. In
   // addition to representing the selection end, it's also where logical text
   // edits take place, and doesn't necessarily correspond to
   // SelectionModel::caret_pos.
   size_t GetCursorPosition() const;
-  void SetCursorPosition(const size_t position);
+  void SetCursorPosition(size_t position);
 
   void SetCaretPlacement(SelectionModel::CaretPlacement placement) {
       selection_model_.set_caret_placement(placement);
   }
 
   // Moves the cursor left or right. Cursor movement is visual, meaning that
   // left and right are relative to screen, not the directionality of the text.
-  // If |select| is false, the selection range is emptied at the new position.
+  // If |select| is false, the selection start is moved to the same position.
   void MoveCursorLeft(BreakType break_type, bool select);
   void MoveCursorRight(BreakType break_type, bool select);
 
   // Set the selection_model_ to the value of |selection|.
+  // The selection model components are modified if invalid.
   // Returns true if the cursor position or selection range changed.
-  bool MoveCursorTo(const SelectionModel& selection);
+  bool MoveCursorTo(const SelectionModel& selection_model);
 
   // Move the cursor to the position associated with the clicked point.
-  // If |select| is false, the selection range is emptied at the new position.
+  // If |select| is false, the selection start is moved to the same position.
+  // Returns true if the cursor position or selection range changed.
   bool MoveCursorTo(const Point& point, bool select);
 
   size_t GetSelectionStart() const {
       return selection_model_.selection_start();
   }
   size_t MinOfSelection() const {
       return std::min(GetSelectionStart(), GetCursorPosition());
   }
   size_t MaxOfSelection() const {
       return std::max(GetSelectionStart(), GetCursorPosition());
@@ skipping 22 matching lines @@
   base::i18n::TextDirection GetTextDirection() const;
 
   // Get the width of the entire string.
   virtual int GetStringWidth();
 
   virtual void Draw(Canvas* canvas);
 
   // Gets the SelectionModel from a visual point in local coordinates.
   virtual SelectionModel FindCursorPosition(const Point& point);
 
-  // Get the visual bounds containing the logical substring within |from| to
-  // |to|. These bounds could be visually discontinuous if the substring is
-  // split by a LTR/RTL level change. These bounds are in local coordinates, but
-  // may be outside the visible region if the text is longer than the textfield.
-  // Subsequent text, cursor, or bounds changes may invalidate returned values.
-  virtual std::vector<Rect> GetSubstringBounds(size_t from, size_t to);
-
   // Get the visual bounds of a cursor at |selection|. These bounds typically
   // represent a vertical line, but if |insert_mode| is true they contain the
   // bounds of the associated glyph. These bounds are in local coordinates, but
   // may be outside the visible region if the text is longer than the textfield.
   // Subsequent text, cursor, or bounds changes may invalidate returned values.
   virtual Rect GetCursorBounds(const SelectionModel& selection,
                                bool insert_mode);
 
   // Compute the current cursor bounds, panning the text to show the cursor in
   // the display rect if necessary. These bounds are in local coordinates.
@@ skipping 11 matching lines @@
 
   const StyleRanges& style_ranges() const { return style_ranges_; }
 
   // Get the selection model that visually neighbors |position| by |break_type|.
   // The returned value represents a cursor/caret position without a selection.
   virtual SelectionModel GetLeftSelectionModel(const SelectionModel& current,
                                                BreakType break_type);
   virtual SelectionModel GetRightSelectionModel(const SelectionModel& current,
                                                 BreakType break_type);
 
+  // Get the SelectionModels corresponding to visual text ends.
+  // The returned value represents a cursor/caret position without a selection.
+  virtual SelectionModel LeftEndSelectionModel();
+  virtual SelectionModel RightEndSelectionModel();
+
   // Get the logical index of the grapheme preceeding the argument |position|.
   virtual size_t GetIndexOfPreviousGrapheme(size_t position);
 
+  // Get the visual bounds containing the logical substring within |from| to
+  // |to|. These bounds could be visually discontinuous if the substring is
+  // split by a LTR/RTL level change. These bounds are in local coordinates, but
+  // may be outside the visible region if the text is longer than the textfield.
+  // Subsequent text, cursor, or bounds changes may invalidate returned values.
+  // TODO(msw) Re-evaluate this function's necessity and signature.
+  virtual std::vector<Rect> GetSubstringBounds(size_t from, size_t to);
+
   // Apply composition style (underline) to composition range and selection
   // style (foreground) to selection range.
   void ApplyCompositionAndSelectionStyles(StyleRanges* style_ranges) const;
 
+  // Convert points from the text space to the view space and back.
+  // Handles the display area, display offset, and the application LTR/RTL mode.
+  Point ToTextPoint(const Point& point);
+  Point ToViewPoint(const Point& point);
+
  private:
   friend class RenderTextTest;
 
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, DefaultStyle);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, CustomDefaultStyle);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, ApplyStyleRange);
   FRIEND_TEST_ALL_PREFIXES(RenderTextTest, StyleRangesAdjust);
 
-  // Clear out |style_ranges_|.
-  void ClearStyleRanges();
+  // Sets the selection model, the argument is assumed to be valid.
+  void SetSelectionModel(const SelectionModel& selection_model);
+
+  // Set the cursor to |position|, with the caret trailing the previous
+  // grapheme, or if there is no previous grapheme, leading the cursor position.
+  // If |select| is false, the selection start is moved to the same position.
+  void MoveCursorTo(size_t position, bool select);
 
   bool IsPositionAtWordSelectionBoundary(size_t pos);
 
   // Update the cached bounds and display offset to ensure that the current
   // cursor is within the visible display area.
   void UpdateCachedBoundsAndOffset();
 
   // Logical UTF-16 string data to be drawn.
   string16 text_;
 
@@ skipping 17 matching lines @@
   StyleRanges style_ranges_;
   // The default text style.
   StyleRange default_style_;
 
   // The local display area for rendering the text.
   Rect display_rect_;
   // The offset for the text to be drawn, relative to the display area.
   // Get this point with GetUpdatedDisplayOffset (or risk using a stale value).
   Point display_offset_;
 
-  // The cached bounds and offset are invalidated by operations such as
-  // SetCursorPosition, SetSelectionModel, Font related style change, and other
-  // operations that adjust the visible text bounds.
+  // The cached bounds and offset are invalidated by changes to the cursor,
+  // selection, font, and other operations that adjust the visible text bounds.
   bool cached_bounds_and_offset_valid_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderText);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_H_