Blob creation methods for ImageBitmap.

Source/core/page/ImageBitmapFactories.h

Index: Source/core/page/ImageBitmapFactories.h
diff --git a/Source/core/page/ImageBitmapFactories.h b/Source/core/page/ImageBitmapFactories.h
index 05feca4ffc17d90f247e869bd42b51f43ae72575..23c34d98c66c55a1611f9a2587e4ffadf5aab7d3 100644
--- a/Source/core/page/ImageBitmapFactories.h
+++ b/Source/core/page/ImageBitmapFactories.h
@@ -32,9 +32,16 @@
 #define ImageBitmapFactories_h
 
 #include "bindings/v8/ScriptPromiseResolver.h"
+#include "bindings/v8/ScriptState.h"
+#include "core/fileapi/FileReaderLoader.h"
+#include "core/fileapi/FileReaderLoaderClient.h"
+#include "core/platform/graphics/IntRect.h"
+#include "wtf/Forward.h"
+#include "wtf/HashSet.h"
 
 namespace WebCore {
 
+class Blob;
 class CanvasRenderingContext2D;
 class EventTarget;
 class ExceptionState;
@@ -43,23 +50,64 @@ class HTMLImageElement;
 class HTMLVideoElement;
 class ImageBitmap;
 class ImageData;
+class ScriptExecutionContext;
+
+class ImageBitmapFactories {
+
+class ImageBitmapLoader;
+public:
+    static ScriptObject createImageBitmap(EventTarget*, HTMLImageElement*, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, HTMLImageElement*, int sx, int sy, int sw, int sh, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, HTMLVideoElement*, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, HTMLVideoElement*, int sx, int sy, int sw, int sh, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, CanvasRenderingContext2D*, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, CanvasRenderingContext2D*, int sx, int sy, int sw, int sh, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, HTMLCanvasElement*, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, HTMLCanvasElement*, int sx, int sy, int sw, int sh, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, Blob*, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, Blob*, int sx, int sy, int sw, int sh, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, ImageData*, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, ImageData*, int sx, int sy, int sw, int sh, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, ImageBitmap*, ExceptionState&);
+    static ScriptObject createImageBitmap(EventTarget*, ImageBitmap*, int sx, int sy, int sw, int sh, ExceptionState&);
+
+    void didStartLoading(PassRefPtr<ImageBitmapLoader>);
+    void didFinishLoading(PassRefPtr<ImageBitmapLoader>);
+
+private:
+    class ImageBitmapLoader : public RefCounted<ImageBitmapLoader>, public FileReaderLoaderClient {
+    public:
+        static PassRefPtr<ImageBitmapLoader> create(ImageBitmapFactories* factory, PassRefPtr<ScriptPromiseResolver> resolver, IntRect* cropRect)

[do-not-use, 2013/08/12 15:36:15]

It is confusing to take an IntRect raw pointer in argument and take ownership of
it.

+        {
+            RefPtr<ImageBitmapLoader> imageBitmapLoader = adoptRef(new ImageBitmapLoader(factory, resolver, cropRect));

[do-not-use, 2013/08/12 15:36:15]

nit: We don't really need this local variable.

[arbesfeld, 2013/08/12 15:49:40]

Done.

+            return imageBitmapLoader.release();
+        }
+
+        void loadBlobAsync(ScriptExecutionContext*, Blob*);
+
+        ~ImageBitmapLoader() { }
+
+    private:
+        ImageBitmapLoader(ImageBitmapFactories*, PassRefPtr<ScriptPromiseResolver>, IntRect*);
+
+        void rejectPromise();
+
+        // FileReaderLoaderClient
+        virtual void didStartLoading() { }

[do-not-use, 2013/08/12 15:36:15]

Missing OVERRIDE (below as well)

[arbesfeld, 2013/08/12 15:49:40]

Done.

+        virtual void didReceiveData() { }
+        virtual void didFinishLoading();
+        virtual void didFail(FileError::ErrorCode);
+
+        ScriptState* m_scriptState;
+        FileReaderLoader m_loader;
+        ImageBitmapFactories* m_factory;
+        RefPtr<ScriptPromiseResolver> m_resolver;
+        IntRect* m_cropRect;

[do-not-use, 2013/08/12 15:36:15]

Why does m_cropRect need to be a pointer? Do we need to distinguish NULL and
IntRect() ? Also, it seems to be leaking currently.

[arbesfeld, 2013/08/12 15:49:40]

ImageBitmaps created with no x/y/w/h arguments are not cropped, so I use a NULL
IntRect to represent this case. An alternative would be that we use IntRect()
for the uncropped case. Is that more clear? The reason I avoided this was
because an ImageBitmap created with an IntRect(0, 0, 0, 0) would normally throw
an error, so it might be confusing as to why we are throwing an exception for
one overload and using the IntRect() for the other.

+    };
+
+    HashSet<RefPtr<ImageBitmapLoader> > m_pendingLoaders;
+};
 
-namespace ImageBitmapFactories {
-
-ScriptObject createImageBitmap(EventTarget*, HTMLImageElement*, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, HTMLImageElement*, int sx, int sy, int sw, int sh, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, HTMLVideoElement*, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, HTMLVideoElement*, int sx, int sy, int sw, int sh, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, CanvasRenderingContext2D*, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, CanvasRenderingContext2D*, int sx, int sy, int sw, int sh, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, HTMLCanvasElement*, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, HTMLCanvasElement*, int sx, int sy, int sw, int sh, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, ImageData*, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, ImageData*, int sx, int sy, int sw, int sh, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, ImageBitmap*, ExceptionState&);
-ScriptObject createImageBitmap(EventTarget*, ImageBitmap*, int sx, int sy, int sw, int sh, ExceptionState&);
-
-} // namesapce ImageBitmapFactories
 } // namespace WebCore
 
 #endif // ImageBitmapFactories_h