ui/gfx: Make gfx::Canvas inherit from gfx::CanvasSkia.

ui/gfx/canvas_skia.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_CANVAS_SKIA_H_
 #define UI_GFX_CANVAS_SKIA_H_
 #pragma once
 
 #include "base/basictypes.h"
-#include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/string16.h"
 #include "skia/ext/platform_canvas.h"
-#include "ui/gfx/canvas.h"
+#include "ui/gfx/native_widget_types.h"
 
 class SkBitmap;
 
+namespace ui {
+class Transform;
+}
+
 namespace gfx {
 
+class Brush;
+class Rect;
+class Font;
+class Point;
+class Size;
+
 // CanvasSkia is a SkCanvas wrapper that provides a number of methods for
-// common operations used throughout an application built using base/gfx.
+// common operations used throughout an application built using ui/gfx.
 //
 // All methods that take integer arguments (as is used throughout views)
 // end with Int. If you need to use methods provided by SkCanvas, you'll
 // need to do a conversion. In particular you'll need to use |SkIntToScalar()|,
 // or if converting from a scalar to an integer |SkScalarRound()|.
 //
 // A handful of methods in this class are overloaded providing an additional
 // argument of type SkXfermode::Mode. SkXfermode::Mode specifies how the
 // source and destination colors are combined. Unless otherwise specified,
 // the variant that does not take a SkXfermode::Mode uses a transfer mode
 // of kSrcOver_Mode.
-class UI_EXPORT CanvasSkia : public Canvas {
+class UI_EXPORT CanvasSkia {
  public:
   enum TruncateFadeMode {
     TruncateFadeTail,
     TruncateFadeHead,
     TruncateFadeHeadAndTail,
   };
 
+  // Specifies the alignment for text rendered with the DrawStringInt method.
+  enum {
+    TEXT_ALIGN_LEFT = 1,
+    TEXT_ALIGN_CENTER = 2,
+    TEXT_ALIGN_RIGHT = 4,
+    TEXT_VALIGN_TOP = 8,
+    TEXT_VALIGN_MIDDLE = 16,
+    TEXT_VALIGN_BOTTOM = 32,
+
+    // Specifies the text consists of multiple lines.
+    MULTI_LINE = 64,
+
+    // By default DrawStringInt does not process the prefix ('&') character
+    // specially. That is, the string "&foo" is rendered as "&foo". When
+    // rendering text from a resource that uses the prefix character for
+    // mnemonics, the prefix should be processed and can be rendered as an
+    // underline (SHOW_PREFIX), or not rendered at all (HIDE_PREFIX).
+    SHOW_PREFIX = 128,
+    HIDE_PREFIX = 256,
+
+    // Prevent ellipsizing
+    NO_ELLIPSIS = 512,
+
+    // Specifies if words can be split by new lines.
+    // This only works with MULTI_LINE.
+    CHARACTER_BREAK = 1024,
+
+    // Instructs DrawStringInt() to render the text using RTL directionality.
+    // In most cases, passing this flag is not necessary because information
+    // about the text directionality is going to be embedded within the string
+    // in the form of special Unicode characters. However, we don't insert
+    // directionality characters into strings if the locale is LTR because some
+    // platforms (for example, an English Windows XP with no RTL fonts
+    // installed) don't support these characters. Thus, this flag should be
+    // used to render text using RTL directionality when the locale is LTR.
+    FORCE_RTL_DIRECTIONALITY = 2048,
+
+    // Similar to FORCE_RTL_DIRECTIONALITY, but left-to-right.
+    // See FORCE_RTL_DIRECTIONALITY for details.
+    FORCE_LTR_DIRECTIONALITY = 4096,
+  };
+
   // Creates an empty canvas.
   CanvasSkia();
 
   // If this canvas is not opaque, it's explicitly cleared to transparent before
   // being returned.
   CanvasSkia(const gfx::Size& size, bool is_opaque);
 
   // Constructs a canvas the size of the provided |bitmap|, and draws the
   // bitmap into it.
   CanvasSkia(const SkBitmap& bitmap, bool is_opaque);
@@ skipping 36 matching lines @@
   void DrawStringWithHalo(const string16& text,
                           const gfx::Font& font,
                           const SkColor& text_color,
                           const SkColor& halo_color,
                           int x, int y, int w, int h,
                           int flags);
 
   // Extracts a bitmap from the contents of this canvas.
   SkBitmap ExtractBitmap() const;
 
-  // Overridden from Canvas:
-  virtual void Save() OVERRIDE;
-  virtual void SaveLayerAlpha(uint8 alpha) OVERRIDE;
-  virtual void SaveLayerAlpha(uint8 alpha,
-                              const gfx::Rect& layer_bounds) OVERRIDE;
-  virtual void Restore() OVERRIDE;
-  virtual bool ClipRect(const gfx::Rect& rect) OVERRIDE;
-  virtual void Translate(const gfx::Point& point) OVERRIDE;
-  virtual void Scale(int x_scale, int y_scale) OVERRIDE;
-  virtual void FillRect(const gfx::Rect& rect, const SkColor& color) OVERRIDE;
-  virtual void FillRect(const gfx::Rect& rect,
-                        const SkColor& color,
-                        SkXfermode::Mode mode) OVERRIDE;
-  virtual void FillRect(const gfx::Rect& rect,
-                        const gfx::Brush* brush) OVERRIDE;
-  virtual void DrawRect(const gfx::Rect& rect, const SkColor& color) OVERRIDE;
-  virtual void DrawRect(const gfx::Rect& rect,
-                        const SkColor& color,
-                        SkXfermode::Mode mode) OVERRIDE;
-  virtual void DrawRect(const gfx::Rect& rect, const SkPaint& paint) OVERRIDE;
-  virtual void DrawLine(const gfx::Point& p1,
-                        const gfx::Point& p2,
-                        const SkColor& color) OVERRIDE;
-  virtual void DrawBitmapInt(const SkBitmap& bitmap, int x, int y) OVERRIDE;
-  virtual void DrawBitmapInt(const SkBitmap& bitmap,
-                             int x, int y,
-                             const SkPaint& paint) OVERRIDE;
-  virtual void DrawBitmapInt(const SkBitmap& bitmap,
-                             int src_x, int src_y, int src_w, int src_h,
-                             int dest_x, int dest_y, int dest_w, int dest_h,
-                             bool filter) OVERRIDE;
-  virtual void DrawBitmapInt(const SkBitmap& bitmap,
-                             int src_x, int src_y, int src_w, int src_h,
-                             int dest_x, int dest_y, int dest_w, int dest_h,
-                             bool filter,
-                             const SkPaint& paint) OVERRIDE;
-  virtual void DrawStringInt(const string16& text,
-                             const gfx::Font& font,
-                             const SkColor& color,
-                             int x, int y, int w, int h) OVERRIDE;
-  virtual void DrawStringInt(const string16& text,
-                             const gfx::Font& font,
-                             const SkColor& color,
-                             const gfx::Rect& display_rect) OVERRIDE;
-  virtual void DrawStringInt(const string16& text,
-                             const gfx::Font& font,
-                             const SkColor& color,
-                             int x, int y, int w, int h,
-                             int flags) OVERRIDE;
+  // Saves a copy of the drawing state onto a stack, operating on this copy
+  // until a balanced call to Restore() is made.
+  void Save();
+
+  // As with Save(), except draws to a layer that is blended with the canvas
+  // at the specified alpha once Restore() is called.
+  // |layer_bounds| are the bounds of the layer relative to the current
+  // transform.
+  void SaveLayerAlpha(uint8 alpha);
+  void SaveLayerAlpha(uint8 alpha, const gfx::Rect& layer_bounds);
+
+  // Restores the drawing state after a call to Save*(). It is an error to
+  // call Restore() more times than Save*().
+  void Restore() ;
+
+  // Returns true if the clip is non-empty.
+  bool ClipRect(const gfx::Rect& rect);
+
+  void Translate(const gfx::Point& point);
+
+  void Scale(int x_scale, int y_scale);
+
+  // Fills |rect| with |color| using a transfer mode of
+  // SkXfermode::kSrcOver_Mode.
+  void FillRect(const gfx::Rect& rect, const SkColor& color);
+
+  // Fills |rect| with the specified |color| and |mode|.
+  void FillRect(const gfx::Rect& rect,
+                const SkColor& color,
+                SkXfermode::Mode mode);
+
+  // Fills |rect| with the specified |brush|.
+  void FillRect(const gfx::Rect& rect, const gfx::Brush* brush);
+
+  // Draws a single pixel rect in the specified region with the specified
+  // color, using a transfer mode of SkXfermode::kSrcOver_Mode.
+  //
+  // NOTE: if you need a single pixel line, use DrawLine.
+  void DrawRect(const gfx::Rect& rect, const SkColor& color);
+
+  // Draws a single pixel rect in the specified region with the specified
+  // color and transfer mode.
+  //
+  // NOTE: if you need a single pixel line, use DrawLine.
+  void DrawRect(const gfx::Rect& rect,
+                const SkColor& color,
+                SkXfermode::Mode mode);
+
+  // Draws the given rectangle with the given paint's parameters.
+  void DrawRect(const gfx::Rect& rect, const SkPaint& paint);
+
+  // Draws a single pixel line with the specified color.
+  void DrawLine(const gfx::Point& p1,
+                const gfx::Point& p2,
+                const SkColor& color);
+
+  // Draws a bitmap with the origin at the specified location. The upper left
+  // corner of the bitmap is rendered at the specified location.
+  void DrawBitmapInt(const SkBitmap& bitmap, int x, int y);
+
+  // Draws a bitmap with the origin at the specified location, using the
+  // specified paint. The upper left corner of the bitmap is rendered at the
+  // specified location.
+  void DrawBitmapInt(const SkBitmap& bitmap,
+                     int x, int y,
+                     const SkPaint& paint);
+
+  // Draws a portion of a bitmap in the specified location. The src parameters
+  // correspond to the region of the bitmap to draw in the region defined
+  // by the dest coordinates.
+  //
+  // If the width or height of the source differs from that of the destination,
+  // the bitmap will be scaled. When scaling down, it is highly recommended
+  // that you call buildMipMap(false) on your bitmap to ensure that it has
+  // a mipmap, which will result in much higher-quality output. Set |filter|
+  // to use filtering for bitmaps, otherwise the nearest-neighbor algorithm
+  // is used for resampling.
+  //
+  // An optional custom SkPaint can be provided.
+  void DrawBitmapInt(const SkBitmap& bitmap,
+                     int src_x, int src_y, int src_w, int src_h,
+                     int dest_x, int dest_y, int dest_w, int dest_h,
+                     bool filter);
+  void DrawBitmapInt(const SkBitmap& bitmap,
+                     int src_x, int src_y, int src_w, int src_h,
+                     int dest_x, int dest_y, int dest_w, int dest_h,
+                     bool filter,
+                     const SkPaint& paint);
+
+  // Draws text with the specified color, font and location. The text is
+  // aligned to the left, vertically centered, clipped to the region. If the
+  // text is too big, it is truncated and '...' is added to the end.
+  void DrawStringInt(const string16& text,
+                     const gfx::Font& font,
+                     const SkColor& color,
+                     int x, int y, int w, int h);
+  void DrawStringInt(const string16& text,
+                     const gfx::Font& font,
+                     const SkColor& color,
+                     const gfx::Rect& display_rect);
+
+  // Draws text with the specified color, font and location. The last argument
+  // specifies flags for how the text should be rendered. It can be one of
+  // TEXT_ALIGN_CENTER, TEXT_ALIGN_RIGHT or TEXT_ALIGN_LEFT.
+  void DrawStringInt(const string16& text,
+                     const gfx::Font& font,
+                     const SkColor& color,
+                     int x, int y, int w, int h,
+                     int flags);
+
+  // Draws a dotted gray rectangle used for focus purposes.
+  void DrawFocusRect(const gfx::Rect& rect);
+
+  // Tiles the image in the specified region.
+  void TileImageInt(const SkBitmap& bitmap,
+                    int x, int y, int w, int h);
+  void TileImageInt(const SkBitmap& bitmap,
+                    int src_x, int src_y,
+                    int dest_x, int dest_y, int w, int h);
+
+  // Returns a native drawing context for platform specific drawing routines to
+  // use. Must be balanced by a call to EndPlatformPaint().
+  NativeDrawingContext BeginPlatformPaint();
+
+  // Signifies the end of platform drawing using the native drawing context
+  // returned by BeginPlatformPaint().
+  void EndPlatformPaint();
+
+  // Apply transformation on the canvas.
+  void Transform(const ui::Transform& transform);
+
 #if defined(OS_WIN)
   // Draws the given string with the beginning and/or the end using a fade
   // gradient. When truncating the head
   // |desired_characters_to_truncate_from_head| specifies the maximum number of
   // characters that can be truncated.
-  virtual void DrawFadeTruncatingString(
+  void DrawFadeTruncatingString(
       const string16& text,
       TruncateFadeMode truncate_mode,
       size_t desired_characters_to_truncate_from_head,
       const gfx::Font& font,
       const SkColor& color,
       const gfx::Rect& display_rect);
 #endif
-  virtual void DrawFocusRect(const gfx::Rect& rect) OVERRIDE;
-  virtual void TileImageInt(const SkBitmap& bitmap,
-                            int x, int y, int w, int h) OVERRIDE;
-  virtual void TileImageInt(const SkBitmap& bitmap,
-                            int src_x, int src_y,
-                            int dest_x, int dest_y, int w, int h) OVERRIDE;
-  virtual gfx::NativeDrawingContext BeginPlatformPaint() OVERRIDE;
-  virtual void EndPlatformPaint() OVERRIDE;
-  virtual void Transform(const ui::Transform& transform) OVERRIDE;
-  virtual CanvasSkia* AsCanvasSkia() OVERRIDE;
-  virtual const CanvasSkia* AsCanvasSkia() const OVERRIDE;
-  virtual SkCanvas* GetSkCanvas() OVERRIDE;
-  virtual const SkCanvas* GetSkCanvas() const OVERRIDE;
 
+  // TODO(tfarina): Remove these. And stick with sk_canvas() only.
+  CanvasSkia* AsCanvasSkia();
+  const CanvasSkia* AsCanvasSkia() const;
+  SkCanvas* GetSkCanvas();
+  const SkCanvas* GetSkCanvas() const;
   SkCanvas* sk_canvas() const { return canvas_; }
+
   skia::PlatformCanvas* platform_canvas() const { return owned_canvas_.get(); }
 
  private:
   // Test whether the provided rectangle intersects the current clip rect.
   bool IntersectsClipRectInt(int x, int y, int w, int h);
 
 #if defined(OS_WIN)
   // Draws text with the specified color, font and location. The text is
   // aligned to the left, vertically centered, clipped to the region. If the
   // text is too big, it is truncated and '...' is added to the end.
   void DrawStringInt(const string16& text,
                      HFONT font,
                      const SkColor& color,
                      int x, int y, int w, int h,
                      int flags);
 #endif
 
   scoped_ptr<skia::PlatformCanvas> owned_canvas_;
   SkCanvas* canvas_;
 
   DISALLOW_COPY_AND_ASSIGN(CanvasSkia);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_CANVAS_SKIA_H_