Bug 594771 - Reset animations when .src changes. r=joe,bz a=blocking-final

content/base/src/nsImageLoadingContent.cpp

@@ -114,6 +114,9 @@ nsImageLoadingContent::nsImageLoadingContent()
     mUserDisabled(PR_FALSE),
     mSuppressed(PR_FALSE),
     mBlockingOnload(PR_FALSE),
+    mNewRequestsWillNeedAnimationReset(PR_FALSE),
+    mPendingRequestNeedsResetAnimation(PR_FALSE),
+    mCurrentRequestNeedsResetAnimation(PR_FALSE),
     mStateChangerDepth(0)
 {
   if (!nsContentUtils::GetImgLoader()) {
@@ -281,10 +284,20 @@ nsImageLoadingContent::OnStopDecode(imgIRequest* aRequest,
   if (aRequest == mPendingRequest) {
     PrepareCurrentRequest() = mPendingRequest;
     mPendingRequest = nsnull;
+    mCurrentRequestNeedsResetAnimation = mPendingRequestNeedsResetAnimation;
+    mPendingRequestNeedsResetAnimation = PR_FALSE;
   }
   NS_ABORT_IF_FALSE(aRequest == mCurrentRequest,
                     "One way or another, we should be current by now");
 
+  if (mCurrentRequestNeedsResetAnimation) {
+    nsCOMPtr<imgIContainer> container;
+    mCurrentRequest->GetImage(getter_AddRefs(container));
+    if (container)
+      container->ResetAnimation();
+    mCurrentRequestNeedsResetAnimation = PR_FALSE;
+  }
+
   // We just loaded all the data we're going to get. If we haven't done an
   // initial paint, we want to make sure the image starts decoding for 2
   // reasons:
@@ -914,6 +927,8 @@ nsImageLoadingContent::PrepareCurrentRequest()
   // Get rid of anything that was there previously.
   ClearCurrentRequest(NS_ERROR_IMAGE_SRC_CHANGED);
 
+  mCurrentRequestNeedsResetAnimation = mNewRequestsWillNeedAnimationReset;
+
   // Return a reference.
   return mCurrentRequest;
 }
@@ -924,6 +939,8 @@ nsImageLoadingContent::PreparePendingRequest()
   // Get rid of anything that was there previously.
   ClearPendingRequest(NS_ERROR_IMAGE_SRC_CHANGED);
 
+  mPendingRequestNeedsResetAnimation = mNewRequestsWillNeedAnimationReset;
+
   // Return a reference.
   return mPendingRequest;
 }
@@ -944,6 +961,7 @@ nsImageLoadingContent::ClearCurrentRequest(nsresult aReason)
   UntrackImage(mCurrentRequest);
   mCurrentRequest->CancelAndForgetObserver(aReason);
   mCurrentRequest = nsnull;
+  mCurrentRequestNeedsResetAnimation = PR_FALSE;
 
   // We only block onload during the decoding of "current" images. This one is
   // going away, so we should unblock unconditionally here.
@@ -958,6 +976,7 @@ nsImageLoadingContent::ClearPendingRequest(nsresult aReason)
   UntrackImage(mPendingRequest);
   mPendingRequest->CancelAndForgetObserver(aReason);
   mPendingRequest = nsnull;
+  mPendingRequestNeedsResetAnimation = PR_FALSE;
 }
 
 bool

content/base/src/nsImageLoadingContent.h

@@ -339,6 +339,21 @@ private:
    */
   PRPackedBool mBlockingOnload : 1;
 
+protected:
+  /**
+   * A hack to get animations to reset, see bug 594771. On requests
+   * that originate from setting .src, we mark them for needing their animation
+   * reset when they are ready. mNewRequestsWillNeedAnimationReset is set to
+   * true while preparing such requests (as a hack around needing to change an
+   * interface), and the other two booleans store which of the current
+   * and pending requests are of the sort that need their animation restarted.
+   */
+  PRPackedBool mNewRequestsWillNeedAnimationReset : 1;
+
+private:
+  PRPackedBool mPendingRequestNeedsResetAnimation : 1;
+  PRPackedBool mCurrentRequestNeedsResetAnimation : 1;
+
   /* The number of nested AutoStateChangers currently tracking our state. */
   PRUint8 mStateChangerDepth;
 };

content/html/content/src/nsHTMLImageElement.cpp

@@ -510,7 +510,8 @@ nsHTMLImageElement::SetAttr(PRInt32 aNameSpaceID, nsIAtom* aName,
       return NS_OK;
     }
 
-    nsCOMPtr<imgIRequest> oldCurrentRequest = mCurrentRequest;
+    // A hack to get animations to reset. See bug 594771.
+    mNewRequestsWillNeedAnimationReset = PR_TRUE;
 
     // Force image loading here, so that we'll try to load the image from
     // network if it's set to be not cacheable...  If we change things so that
@@ -519,17 +520,7 @@ nsHTMLImageElement::SetAttr(PRInt32 aNameSpaceID, nsIAtom* aName,
     // here.
     LoadImage(aValue, PR_TRUE, aNotify);
 
-    if (mCurrentRequest && !mPendingRequest &&
-        oldCurrentRequest != mCurrentRequest) {
-      // We have a current request, and it's not the same one as we used
-      // to have, and we have no pending request.  So imglib already had
-      // that image.  Reset the animation on it -- see bug 210001
-      nsCOMPtr<imgIContainer> container;
-      mCurrentRequest->GetImage(getter_AddRefs(container));
-      if (container) {
-        container->ResetAnimation();
-      }
-    }
+    mNewRequestsWillNeedAnimationReset = PR_FALSE;
   }
     
   return nsGenericHTMLElement::SetAttr(aNameSpaceID, aName, aPrefix, aValue,