Let cursors be based on CGImage instead of SkBitmap on the Mac

Review URL: http://codereview.chromium.org/8111

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@3869 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 42 insertions, 11 deletions

diff --git a/webkit/glue/webcursor.h b/webkit/glue/webcursor.h
index a80d39c..55281db 100644
--- a/webkit/glue/webcursor.h
+++ b/webkit/glue/webcursor.h
@@ -5,9 +5,28 @@
 #ifndef WEBCURSOR_H__
 #define WEBCURSOR_H__
 
-#include "skia/include/SkBitmap.h"
 #include "build/build_config.h"
 
+#if defined(OS_MACOSX)
+#include <CoreGraphics/CoreGraphics.h>
+#else
+#include "skia/include/SkBitmap.h"
+#endif
+
+// Use CGImage on the Mac and SkBitmap on other platforms.  WebCursorBitmapPtr
+// is a corresponding pointer type: because CGImageRef is already a pointer
+// type, we can just use that directly in the constructor, but we need an
+// SkBitmap* in the Skia case.
+//
+// TODO(port): We should use a bitmap abstraction container.
+#if defined(OS_MACOSX)
+typedef CGImageRef WebCursorBitmap;
+typedef WebCursorBitmap WebCursorBitmapPtr;
+#else
+typedef SkBitmap WebCursorBitmap;
+typedef SkBitmap* WebCursorBitmapPtr;
+#endif
+
 // This class provides the functionality of a generic cursor type. The intent
 // is to stay away from platform specific code here. We do have win32 specific
 // functionality to retreive a HCURSOR from a cursor type. 
@@ -47,7 +66,7 @@ public:
 
   WebCursor();
   WebCursor(Type cursor_type);
-  WebCursor(const SkBitmap* bitmap, int hotspot_x, int hotspot_y);
+  WebCursor(const WebCursorBitmapPtr bitmap, int hotspot_x, int hotspot_y);
   ~WebCursor();
 
   WebCursor(const WebCursor& other);
@@ -56,47 +75,59 @@ public:
   Type type() const { return type_; };
   int hotspot_x() const { return hotspot_x_; }
   int hotspot_y() const { return hotspot_y_; }
-  const SkBitmap& bitmap() const { return bitmap_; }
+  const WebCursorBitmap& bitmap() const { return bitmap_; }
 
   void set_type(Type cursor_type) {
     type_ = cursor_type;
   }
 
-  void set_bitmap(const SkBitmap& bitmap) {
+  void set_bitmap(const WebCursorBitmap& bitmap) {
+#if defined(OS_MACOSX)
+    WebCursorBitmap old_bitmap = bitmap_;
+    CGImageRetain(bitmap_ = bitmap);
+    CGImageRelease(old_bitmap);
+#else
     bitmap_ = bitmap;
+#endif
   }
 
   void set_hotspot(int hotspot_x, int hotspot_y) {
     hotspot_x_ = hotspot_x;
     hotspot_y_ = hotspot_x;
   }
+
 #if defined(OS_WIN)
   // Returns the cursor handle. If the cursor type is a win32 or safari
   // cursor, we use LoadCursor to load the cursor. 
   // Returns NULL on error. 
   HCURSOR GetCursor(HINSTANCE module_handle) const;
   // If the underlying cursor type is a custom cursor, this function converts
-  // the SkBitmap to a cursor and returns the same. The responsiblity of
+  // the WebCursorBitmap to a cursor and returns the same. The responsiblity of
   // freeing the cursor handle lies with the caller.
   // Returns NULL on error.
   HCURSOR GetCustomCursor() const;
 #endif
-  // Returns true if the passed in SkBitmap is the same as the the 
-  // current SkBitmap. We use memcmp to compare the two bitmaps.
-  bool IsSameBitmap(const SkBitmap& bitmap) const;
+
+// TODO(port): Comparing CGImageRefs can be a heavyweight operation on the
+// Mac.  Don't do it if it's not needed.  Maybe we can avoid this type of
+// comparison on other platforms too.
+#if !defined(OS_MACOSX)
+  // Returns true if the passed in WebCursorBitmap is the same as the the 
+  // current WebCursorBitmap. We use memcmp to compare the two bitmaps.
+  bool IsSameBitmap(const WebCursorBitmap& bitmap) const;
 
   // Returns true if the current cursor object contains the same
   // cursor as the cursor object passed in. If the current cursor
   // is a custom cursor, we also compare the bitmaps to verify
   // whether they are equal.
   bool IsEqual(const WebCursor& other) const;
-  
+#endif
+
 protected:
   Type type_;
   int hotspot_x_;
   int hotspot_y_;
-  SkBitmap bitmap_;
+  WebCursorBitmap bitmap_;
 };
 
 #endif  // WEBCURSOR_H__
-