Canvas refactoring part 2.

- Rename Canvas to CanvasSkia.
- Create a subclass Canvas that inherits from CanvasSkia for compatibility.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/2862025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50664 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 135 insertions, 0 deletions

diff --git a/gfx/canvas_skia.h b/gfx/canvas_skia.h
new file mode 100644
index 0000000..9a976fd
--- /dev/null
+++ b/gfx/canvas_skia.h
@@ -0,0 +1,135 @@
+// Copyright (c) 2010 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 GFX_CANVAS_SKIA_H_
+#define GFX_CANVAS_SKIA_H_
+
+#include "base/basictypes.h"
+#include "gfx/canvas_2.h"
+#include "skia/ext/platform_canvas.h"
+
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+typedef struct _GdkPixbuf GdkPixbuf;
+#endif
+
+namespace gfx {
+
+class Canvas;
+
+// CanvasSkia is a SkCanvas subclass that provides a number of methods for
+// common operations used throughout an application built using base/gfx and
+// app/gfx.
+//
+// All methods that take integer arguments (as is used throughout views)
+// end with Int. If you need to use methods provided by the superclass
+// you'll need to do a conversion. In particular you'll need to use
+// macro SkIntToScalar(xxx), 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 CanvasSkia : public skia::PlatformCanvas,
+                   public Canvas2 {
+ public:
+  // Creates an empty Canvas. Callers must use initialize before using the
+  // canvas.
+  CanvasSkia();
+
+  CanvasSkia(int width, int height, bool is_opaque);
+
+  virtual ~CanvasSkia();
+
+  // Compute the size required to draw some text with the provided font.
+  // Attempts to fit the text with the provided width and height. Increases
+  // height and then width as needed to make the text fit. This method
+  // supports multiple lines.
+  static void SizeStringInt(const std::wstring& text, const gfx::Font& font,
+                            int* width, int* height, int flags);
+
+  // Returns the default text alignment to be used when drawing text on a
+  // gfx::CanvasSkia based on the directionality of the system locale language.
+  // This function is used by gfx::Canvas::DrawStringInt when the text alignment
+  // is not specified.
+  //
+  // This function returns either gfx::Canvas::TEXT_ALIGN_LEFT or
+  // gfx::Canvas::TEXT_ALIGN_RIGHT.
+  static int DefaultCanvasTextAlignment();
+
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  // Draw the pixbuf in its natural size at (x, y).
+  void DrawGdkPixbuf(GdkPixbuf* pixbuf, int x, int y);
+#endif
+
+#ifdef OS_WIN  // Only implemented on Windows for now.
+  // Draws text with a 1-pixel halo around it of the given color. It allows
+  // ClearType to be drawn to an otherwise transparenct bitmap for drag images.
+  // Drag images have only 1-bit of transparency, so we don't do any fancy
+  // blurring.
+  void DrawStringWithHalo(const std::wstring& text,
+                          const gfx::Font& font,
+                          const SkColor& text_color,
+                          const SkColor& halo_color,
+                          int x, int y, int w, int h, int flags);
+#endif
+
+  // Overridden from Canvas2:
+  virtual bool GetClipRect(gfx::Rect* clip_rect);
+  virtual bool ClipRectInt(int x, int y, int w, int h);
+  virtual bool IntersectsClipRectInt(int x, int y, int w, int h);
+  virtual void TranslateInt(int x, int y);
+  virtual void ScaleInt(int x, int y);
+  virtual void FillRectInt(int x, int y, int w, int h,
+                           const SkPaint& paint);
+  virtual void FillRectInt(const SkColor& color, int x, int y, int w,
+                           int h);
+  virtual void DrawRectInt(const SkColor& color, int x, int y, int w,
+                           int h);
+  virtual void DrawRectInt(const SkColor& color, int x, int y, int w, int h,
+                           SkXfermode::Mode mode);
+  virtual void DrawLineInt(const SkColor& color, int x1, int y1, int x2,
+                           int y2);
+  virtual void DrawBitmapInt(const SkBitmap& bitmap, int x, int y);
+  virtual void DrawBitmapInt(const SkBitmap& bitmap, int x, int y,
+                             const SkPaint& paint);
+  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);
+  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);
+  virtual void DrawStringInt(const std::wstring& text, const gfx::Font& font,
+                             const SkColor& color, int x, int y, int w,
+                             int h);
+  virtual void DrawStringInt(const std::wstring& text, const gfx::Font& font,
+                             const SkColor& color,
+                             const gfx::Rect& display_rect);
+  virtual void DrawStringInt(const std::wstring& text, const gfx::Font& font,
+                             const SkColor& color, int x, int y, int w, int h,
+                             int flags);
+  virtual void DrawFocusRect(int x, int y, int width, int height);
+  virtual void TileImageInt(const SkBitmap& bitmap, int x, int y, int w, int h);
+  virtual void TileImageInt(const SkBitmap& bitmap, int src_x, int src_y,
+                            int dest_x, int dest_y, int w, int h);
+  virtual SkBitmap ExtractBitmap() const;
+
+ private:
+#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 std::wstring& text, HFONT font,
+                     const SkColor& color, int x, int y, int w, int h,
+                     int flags);
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(CanvasSkia);
+};
+
+}  // namespace gfx;
+
+#endif  // GFX_CANVAS_SKIA_H_