Bug 695763 (Part 1) - Add imgIContainer::IsDecoded. r=joe sr=bz

image/public/imgIContainer.idl

@@ -57,7 +57,7 @@ native nsSize(nsSize);
  *
  * Internally, imgIContainer also manages animation of images.
  */
-[scriptable, builtinclass, uuid(b56906e9-830c-45f4-b572-8c71e7619dad)]
+[scriptable, builtinclass, uuid(f9029a03-758c-4047-a1f3-4b2e51e47363)]
 interface imgIContainer : nsISupports
 {
   /**
@@ -232,6 +232,14 @@ interface imgIContainer : nsISupports
    */
   [noscript] void startDecoding();
 
+  /*
+   * Returns true if no more decoding can be performed on this image. Images
+   * with errors return true since they cannot be decoded any further. Note that
+   * because decoded images may be discarded, isDecoded() may return false even
+   * if it has returned true in the past.
+   */
+  [noscript, notxpcom, nostdcall] bool isDecoded();
+
   /**
     * Increments the lock count on the image. An image will not be discarded
     * as long as the lock count is nonzero. Note that it is still possible for

image/src/ImageWrapper.cpp

@@ -231,6 +231,12 @@ ImageWrapper::StartDecoding()
   return mInnerImage->StartDecoding();
 }
 
+bool
+ImageWrapper::IsDecoded()
+{
+  return mInnerImage->IsDecoded();
+}
+
 NS_IMETHODIMP
 ImageWrapper::LockImage()
 {

image/src/RasterImage.cpp

@@ -2319,6 +2319,11 @@ RasterImage::StartDecoding()
   return RequestDecodeCore(SYNCHRONOUS_NOTIFY_AND_SOME_DECODE);
 }
 
+bool
+RasterImage::IsDecoded()
+{
+  return mDecoded || mError;
+}
 
 NS_IMETHODIMP
 RasterImage::RequestDecodeCore(RequestDecodeType aDecodeType)

image/src/VectorImage.cpp

@@ -762,6 +762,11 @@ VectorImage::StartDecoding()
   return NS_OK;
 }
 
+bool
+VectorImage::IsDecoded()
+{
+  return mIsFullyLoaded || mError;
+}
 
 //******************************************************************************
 /* void lockImage() */