Add support for multi resolution icons

ui/gfx/image.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.
 
 // An Image wraps an image any flavor, be it platform-native GdkBitmap/NSImage,
 // or a SkBitmap. This also provides easy conversion to other image types
 // through operator overloading. It will cache the converted representations
 // internally to prevent double-conversion.
 //
 // The lifetime of both the initial representation and any converted ones are
 // tied to the lifetime of the Image object itself.
 
 #ifndef UI_GFX_IMAGE_H_
 #define UI_GFX_IMAGE_H_
 #pragma once
 
 #include <map>
+#include <vector>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "build/build_config.h"
 #include "ui/gfx/native_widget_types.h"  // Forward-declares GdkPixbuf and NSImage.
 
 class SkBitmap;
 
 namespace {
 class ImageTest;
 }
 
 namespace gfx {
 
 namespace internal {
 class ImageRep;
 }
 
 class Image {
  public:
   enum RepresentationType {
     kGdkPixbufRep,
     kNSImageRep,
     kSkBitmapRep,
   };
 
   // Creates a new image with the default representation. The object will take
   // ownership of the image.
   explicit Image(const SkBitmap* bitmap);
+  // To create an Image that supports multiple resolutions pass a vector
+  // of bitmaps, one for each resolution.
+  explicit Image(const std::vector<const SkBitmap*>& bitmaps);
+
 #if defined(OS_LINUX)
   // Does not increase |pixbuf|'s reference count; expects to take ownership.
+  // TODO  Add support for multiple resolutions when necessary.
   explicit Image(GdkPixbuf* pixbuf);
 #elif defined(OS_MACOSX)
   // Does not retain |image|; expects to take ownership.
+  // A single NSImage object can contain multiple bitmaps so there's no reason
+  // to pass a vector of these.
   explicit Image(NSImage* image);
 #endif
 
   // Deletes the image and all of its cached representations.
   ~Image();
 
   // Conversion handlers.
   operator const SkBitmap*();
   operator const SkBitmap&();
 #if defined(OS_LINUX)
   operator GdkPixbuf*();
 #elif defined(OS_MACOSX)
   operator NSImage*();
 #endif
 
+  size_t GetNumberOfSkBitmaps();

[Robert Sesek, 2011/04/15 20:27:20]

I'm not in love with this interface. It's not really intuitive as to what
happens with the extra versions during conversion between formats.

I think I'd prefer something along the lines of:
  gfx::Image* GetVersionBestMatchingSize(gfx::Size);

But that itself can make things tricky...

[sail, 2011/04/16 01:25:00]

I agree the name sucks. It'll be supper easy to change in the future though. My
goal is that no one outside chrome/browser/theme and ui/base/resource will have
to use this API.

+  const SkBitmap* GetSkBitmapAtIndex(size_t index);
+
   // Inspects the representations map to see if the given type exists.
   bool HasRepresentation(RepresentationType type);
 
   // Swaps this image's internal representations with |other|.
   void SwapRepresentations(gfx::Image* other);
 
  private:
   typedef std::map<RepresentationType, internal::ImageRep*> RepresentationMap;
 
   // Returns the ImageRep for the default representation.
@@ skipping 14 matching lines @@
   // more for any converted representations.
   RepresentationMap representations_;
 
   friend class ::ImageTest;
   DISALLOW_COPY_AND_ASSIGN(Image);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_IMAGE_H_