Expose array of bitmaps contained by gfx::Image similar to NSImage

ui/gfx/image/image_skia.h

Index: ui/gfx/image/image_skia.h
diff --git a/ui/gfx/image/image_skia.h b/ui/gfx/image/image_skia.h
new file mode 100644
index 0000000000000000000000000000000000000000..0606f49c6c77de10fd1609b569961007392e651b
--- /dev/null
+++ b/ui/gfx/image/image_skia.h
@@ -0,0 +1,57 @@
+// 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_IMAGE_IMAGE_SKIA_H_
+#define UI_GFX_IMAGE_IMAGE_SKIA_H_
+#pragma once
+
+#include <vector>
+
+#include "base/basictypes.h"
+#include "third_party/skia/include/core/SkBitmap.h"
+#include "ui/gfx/size.h"
+
+// Container for images at various densities.

[Robert Sesek, 2012/04/16 16:06:01]

This should be filled out more (use cases, should this be created directly, if
so, when?). Also, move this to be at the class-level, not at the namespace.

+// Smallest image is assumed to represent 1x density.
+namespace gfx {
+
+class UI_EXPORT ImageSkia {
+ public:
+  ImageSkia(const SkBitmap* bitmap);

[Robert Sesek, 2012/04/16 16:06:01]

explicit?

+  ImageSkia(const std::vector<const SkBitmap*>& bitmaps);
+  virtual ~ImageSkia();
+
+  // Returns the bitmap whose density best matches |device_scale_factor|.
+  const SkBitmap* GetBitmapForScaleFactor(float device_scale_factor) const;
+
+  // Gets the number of bitmaps in this image.
+  size_t GetNumberOfBitmaps() const { return bitmaps_.size(); }

[Robert Sesek, 2012/04/16 16:06:01]

Out-of-line.

+
+  // Gets the bitmap at the given index.
+  const SkBitmap* GetBitmapAtIndex(size_t index) const {
+      return bitmaps_[index];

[Robert Sesek, 2012/04/16 16:06:01]

Out-of-line.

+  }
+
+  // Returns true if the smallest bitmap is empty.
+  bool empty() const { return size_.IsEmpty(); }

[Robert Sesek, 2012/04/16 16:06:01]

This is unclear and confounds IsEmpty() in image.h. Also, out-of-line this.
Naming: IsZeroSized().

+
+  // Returns true if the object contains no bitmaps.
+  bool isNull() const { return bitmaps_.empty(); };

[Robert Sesek, 2012/04/16 16:06:01]

Naming: IsEmpty() to be consistent with image.h. Out-of-line.

+
+  // Width and height of image in DIP coordinate system.
+  int width() const { return size_.width(); }
+  int height() const { return size_.height(); }
+
+  const SkBitmap* bitmap() { return bitmaps_[0]; }

[Robert Sesek, 2012/04/16 16:06:01]

Needs a comment.

+
+private:
+  std::vector<const SkBitmap*> bitmaps_;
+  gfx::Size size_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImageSkia);
+};
+
+}  // namespace gfx
+
+#endif  // UI_GFX_IMAGE_IMAGE_SKIA_H_