Bug 666446, Part 4/18 - Implement refresh driver based animations in nsImageLoadingContent to improve efficiency of animated GIF images. [r=roc][sr=mats]

content/base/public/nsIImageLoadingContent.idl

@@ -42,6 +42,7 @@ interface nsIChannel;
 interface nsIStreamListener;
 interface nsIURI;
 interface nsIDocument;
+interface nsIFrame;
 
 /**
  * This interface represents a content node that loads images.  The interface
@@ -65,7 +66,7 @@ interface nsIDocument;
  * sufficient, when combined with the imageBlockingStatus information.)
  */
 
-[scriptable, uuid(95c74255-df9a-4060-b5a0-0d111fcafe08)]
+[scriptable, uuid(f7debb84-2854-4731-a57b-1bd752ad71f8)]
 interface nsIImageLoadingContent : imgIDecoderObserver
 {
   /**
@@ -128,6 +129,18 @@ interface nsIImageLoadingContent : imgIDecoderObserver
    */
   imgIRequest getRequest(in long aRequestType);
 
+  /**
+   * Used to notify the image loading content node that a frame has been
+   * created.
+   */
+  void frameCreated(in nsIFrame aFrame);
+
+  /**
+   * Used to notify the image loading content node that a frame has been
+   * destroyed.
+   */
+  void frameDestroyed(in nsIFrame aFrame);
+
   /**
    * Used to find out what type of request one is dealing with (eg
    * which request got passed through to the imgIDecoderObserver

content/base/src/nsDocument.cpp

@@ -3220,6 +3220,7 @@ nsDocument::DeleteShell()
   if (IsEventHandlingEnabled()) {
     RevokeAnimationFrameNotifications();
   }
+
   mPresShell = nsnull;
 }
 

content/base/src/nsImageLoadingContent.cpp

@@ -72,6 +72,7 @@
 #include "nsIDOMNode.h"
 
 #include "nsContentUtils.h"
+#include "nsLayoutUtils.h"
 #include "nsIContentPolicy.h"
 #include "nsContentPolicyUtils.h"
 #include "nsEventDispatcher.h"
@@ -116,7 +117,9 @@ nsImageLoadingContent::nsImageLoadingContent()
     mNewRequestsWillNeedAnimationReset(PR_FALSE),
     mPendingRequestNeedsResetAnimation(PR_FALSE),
     mCurrentRequestNeedsResetAnimation(PR_FALSE),
-    mStateChangerDepth(0)
+    mStateChangerDepth(0),
+    mCurrentRequestRegistered(false),
+    mPendingRequestRegistered(false)
 {
   if (!nsContentUtils::GetImgLoader()) {
     mLoadingEnabled = PR_FALSE;
@@ -330,6 +333,13 @@ nsImageLoadingContent::OnStopDecode(imgIRequest* aRequest,
   nsIPresShell* shell = doc ? doc->GetShell() : nsnull;
   if (shell) {
 
+    // Make sure that our image requests are deregistered from the refresh
+    // driver if they aren't animated. Note that this must be mCurrentRequest,
+    // or we would have aborted up above.
+    nsLayoutUtils::DeregisterImageRequestIfNotAnimated(GetFramePresContext(),
+                                                       mCurrentRequest,
+                                                       &mCurrentRequestRegistered);
+
     // We need to figure out whether to kick off decoding
     bool doRequestDecode = false;
 
@@ -502,6 +512,48 @@ nsImageLoadingContent::GetRequest(PRInt32 aRequestType,
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsImageLoadingContent::FrameCreated(nsIFrame* aFrame)
+{
+  NS_ASSERTION(aFrame, "aFrame is null");
+
+  // We need to make sure that our image request is registered.
+  nsPresContext* presContext = aFrame->PresContext();
+
+  if (mCurrentRequest) {
+    nsLayoutUtils::RegisterImageRequest(presContext, mCurrentRequest,
+                                        &mCurrentRequestRegistered);
+    nsLayoutUtils::DeregisterImageRequestIfNotAnimated(presContext,
+                                                       mCurrentRequest,
+                                                       &mCurrentRequestRegistered);
+  } else if (mPendingRequest) {
+    // We don't need to do the same check for animation, because this will be
+    // done when decoding is finished.
+    nsLayoutUtils::RegisterImageRequest(presContext, mPendingRequest,
+                                        &mPendingRequestRegistered);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsImageLoadingContent::FrameDestroyed(nsIFrame* aFrame)
+{
+  NS_ASSERTION(aFrame, "aFrame is null");
+
+  // We need to make sure that our image request is deregistered.
+  if (mCurrentRequest) {
+    nsLayoutUtils::DeregisterImageRequest(GetFramePresContext(),
+                                          mCurrentRequest,
+                                          &mCurrentRequestRegistered);
+  } else if (mPendingRequest) {
+    nsLayoutUtils::DeregisterImageRequest(GetFramePresContext(),
+                                          mPendingRequest,
+                                          &mPendingRequestRegistered);
+  }
+
+  return NS_OK;
+}
 
 NS_IMETHODIMP
 nsImageLoadingContent::GetRequestType(imgIRequest* aRequest,
@@ -868,6 +920,23 @@ nsImageLoadingContent::GetOurDocument()
   return thisContent->GetOwnerDoc();
 }
 
+nsIFrame*
+nsImageLoadingContent::GetOurPrimaryFrame()
+{
+  nsCOMPtr<nsIContent> thisContent = do_QueryInterface(this);
+  return thisContent->GetPrimaryFrame();
+}
+
+nsPresContext* nsImageLoadingContent::GetFramePresContext()
+{
+  nsIFrame* frame = GetOurPrimaryFrame();
+  if (!frame) {
+    return nsnull;
+  }
+
+  return frame->PresContext();
+}
+
 nsresult
 nsImageLoadingContent::StringToURI(const nsAString& aSpec,
                                    nsIDocument* aDocument,
@@ -987,6 +1056,11 @@ nsImageLoadingContent::ClearCurrentRequest(nsresult aReason)
   NS_ABORT_IF_FALSE(!mCurrentURI,
                     "Shouldn't have both mCurrentRequest and mCurrentURI!");
 
+  // Deregister this image from the refresh driver so it no longer receives
+  // notifications.
+  nsLayoutUtils::DeregisterImageRequest(GetFramePresContext(), mCurrentRequest,
+                                        &mCurrentRequestRegistered);
+
   // Clean up the request.
   UntrackImage(mCurrentRequest);
   mCurrentRequest->CancelAndForgetObserver(aReason);
@@ -1010,12 +1084,29 @@ nsImageLoadingContent::ClearPendingRequest(nsresult aReason)
   nsCxPusher pusher;
   pusher.PushNull();
 
+  // Deregister this image from the refresh driver so it no longer receives
+  // notifications.
+  nsLayoutUtils::DeregisterImageRequest(GetFramePresContext(), mPendingRequest,
+                                        &mPendingRequestRegistered);
+
   UntrackImage(mPendingRequest);
   mPendingRequest->CancelAndForgetObserver(aReason);
   mPendingRequest = nsnull;
   mPendingRequestNeedsResetAnimation = PR_FALSE;
 }
 
+bool*
+nsImageLoadingContent::GetRegisteredFlagForRequest(imgIRequest* aRequest)
+{
+  if (aRequest == mCurrentRequest) {
+    return &mCurrentRequestRegistered;
+  } else if (aRequest == mPendingRequest) {
+    return &mPendingRequestRegistered;
+  } else {
+    return nsnull;
+  }
+}
+
 bool
 nsImageLoadingContent::HaveSize(imgIRequest *aImage)
 {

content/base/src/nsImageLoadingContent.h

@@ -146,6 +146,24 @@ protected:
    */
   nsIDocument* GetOurDocument();
 
+  /**
+   * Helper function to get the frame associated with this content. Not named
+   * GetPrimaryFrame to prevent ambiguous method names in subclasses.
+   *
+   * @return The frame which we belong to, or nsnull if it doesn't exist.
+   */
+  nsIFrame* GetOurPrimaryFrame();
+
+  /**
+   * Helper function to get the PresContext associated with this content's
+   * frame. Not named GetPresContext to prevent ambiguous method names in
+   * subclasses.
+   *
+   * @return The nsPresContext associated with our frame, or nsnull if either
+   *         the frame doesn't exist, or the frame's prescontext doesn't exist.
+   */
+  nsPresContext* GetFramePresContext();
+
   /**
    * CancelImageRequests is called by subclasses when they want to
    * cancel all image requests (for example when the subclass is
@@ -302,6 +320,16 @@ protected:
   void ClearCurrentRequest(nsresult aReason);
   void ClearPendingRequest(nsresult aReason);
 
+  /**
+   * Retrieve a pointer to the 'registered with the refresh driver' flag for
+   * which a particular image request corresponds.
+   *
+   * @returns A pointer to the boolean flag for a given image request, or
+   *          |nsnull| if the request is not either |mPendingRequest| or
+   *          |mCurrentRequest|.
+   */
+  bool* GetRegisteredFlagForRequest(imgIRequest* aRequest);
+
   /**
    * Static helper method to tell us if we have the size of a request. The
    * image may be null.
@@ -382,6 +410,11 @@ private:
 
   /* The number of nested AutoStateChangers currently tracking our state. */
   PRUint8 mStateChangerDepth;
+
+  // Flags to indicate whether each of the current and pending requests are
+  // registered with the refresh driver.
+  bool mCurrentRequestRegistered;
+  bool mPendingRequestRegistered;
 };
 
 #endif // nsImageLoadingContent_h__

layout/generic/nsIFrame.h

@@ -576,6 +576,10 @@ protected:
   /**
    * Implements Destroy(). Do not call this directly except from within a
    * DestroyFrom() implementation.
+   *
+   * @note This will always be called, so it is not necessary to override
+   *       Destroy() in subclasses of nsFrame, just DestroyFrom().
+   *
    * @param  aDestructRoot is the root of the subtree being destroyed
    */
   virtual void DestroyFrom(nsIFrame* aDestructRoot) = 0;

layout/generic/nsImageFrame.cpp

@@ -223,6 +223,10 @@ nsImageFrame::DestroyFrom(nsIFrame* aDestructRoot)
       nsCxPusher pusher;
       pusher.PushNull();
 
+      // Notify our image loading content that we are going away so it can
+      // deregister with our refresh driver.
+      imageLoader->FrameDestroyed(this);
+
       imageLoader->RemoveObserver(mListener);
     }
     
@@ -268,6 +272,10 @@ nsImageFrame::Init(nsIContent*      aContent,
   if (!gIconLoad)
     LoadIcons(aPresContext);
 
+  // We have a PresContext now, so we need to notify the image content node
+  // that it can register images.
+  imageLoader->FrameCreated(this);
+
   // Give image loads associated with an image frame a small priority boost!
   nsCOMPtr<imgIRequest> currentRequest;
   imageLoader->GetRequest(nsIImageLoadingContent::CURRENT_REQUEST,

layout/svg/base/src/nsSVGImageFrame.cpp

@@ -100,6 +100,7 @@ public:
   NS_IMETHOD Init(nsIContent*      aContent,
                   nsIFrame*        aParent,
                   nsIFrame*        aPrevInFlow);
+  virtual void DestroyFrom(nsIFrame* aDestructRoot);
 
   /**
    * Get the "type" of the frame
@@ -176,6 +177,10 @@ nsSVGImageFrame::Init(nsIContent* aContent,
   nsCOMPtr<nsIImageLoadingContent> imageLoader = do_QueryInterface(mContent);
   NS_ENSURE_TRUE(imageLoader, NS_ERROR_UNEXPECTED);
 
+  // We should have a PresContext now, so let's notify our image loader that
+  // we need to register any image animations with the refresh driver.
+  imageLoader->FrameCreated(this);
+
   // Push a null JSContext on the stack so that code that runs within
   // the below code doesn't think it's being called by JS. See bug
   // 604262.
@@ -187,6 +192,19 @@ nsSVGImageFrame::Init(nsIContent* aContent,
   return NS_OK; 
 }
 
+/* virtual */ void
+nsSVGImageFrame::DestroyFrom(nsIFrame* aDestructRoot)
+{
+  nsCOMPtr<nsIImageLoadingContent> imageLoader =
+    do_QueryInterface(nsFrame::mContent);
+
+  if (imageLoader) {
+    imageLoader->FrameDestroyed(this);
+  }
+
+  nsFrame::DestroyFrom(aDestructRoot);
+}
+
 //----------------------------------------------------------------------
 // nsIFrame methods:
 

layout/svg/base/src/nsSVGLeafFrame.cpp

@@ -36,6 +36,7 @@
 
 #include "nsFrame.h"
 #include "nsSVGEffects.h"
+#include "nsImageLoadingContent.h"
 
 class nsSVGLeafFrame : public nsFrame
 {
@@ -47,6 +48,12 @@ protected:
 public:
   NS_DECL_FRAMEARENA_HELPERS
 
+  NS_IMETHOD Init(nsIContent*      aContent,
+                  nsIFrame*        aParent,
+                  nsIFrame*        asPrevInFlow);
+
+  virtual void DestroyFrom(nsIFrame* aDestructRoot);
+
   virtual bool IsFrameOfType(PRUint32 aFlags) const
   {
     return nsFrame::IsFrameOfType(aFlags & ~(nsIFrame::eSVG));
@@ -70,6 +77,33 @@ NS_NewSVGLeafFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
 
 NS_IMPL_FRAMEARENA_HELPERS(nsSVGLeafFrame)
 
+NS_IMETHODIMP
+nsSVGLeafFrame::Init(nsIContent* aContent, nsIFrame* aParent, nsIFrame* asPrevInFlow)
+{
+  nsFrame::Init(aContent, aParent, asPrevInFlow);
+  nsCOMPtr<nsIImageLoadingContent> imageLoader =
+    do_QueryInterface(nsFrame::mContent);
+
+  if (imageLoader) {
+    imageLoader->FrameCreated(this);
+  }
+
+  return NS_OK;
+}
+
+/* virtual */ void
+nsSVGLeafFrame::DestroyFrom(nsIFrame* aDestructRoot)
+{
+  nsCOMPtr<nsIImageLoadingContent> imageLoader =
+    do_QueryInterface(nsFrame::mContent);
+
+  if (imageLoader) {
+    imageLoader->FrameDestroyed(this);
+  }
+
+  nsFrame::DestroyFrom(aDestructRoot);
+}
+
 /* virtual */ void
 nsSVGLeafFrame::DidSetStyleContext(nsStyleContext* aOldStyleContext)
 {