Bug 612190. Make MozAfterPaint actually fire after paint. r=dbaron,a=me (blocks a blocker)

layout/base/nsPresContext.cpp

@@ -1103,24 +1103,33 @@ nsPresContext::Observe(nsISupports* aSubject,
   return NS_ERROR_FAILURE;
 }
 
+static nsPresContext*
+GetParentPresContext(nsPresContext* aPresContext)
+{
+  nsIPresShell* shell = aPresContext->GetPresShell();
+  if (shell) {
+    nsIFrame* rootFrame = shell->FrameManager()->GetRootFrame();
+    if (rootFrame) {
+      nsIFrame* f = nsLayoutUtils::GetCrossDocParentFrame(rootFrame);
+      if (f)
+        return f->PresContext();
+    }
+  }
+  return nsnull;
+}
+
 // We may want to replace this with something faster, maybe caching the root prescontext
 nsRootPresContext*
 nsPresContext::GetRootPresContext()
 {
   nsPresContext* pc = this;
   for (;;) {
-    if (pc->mShell) {
-      nsIFrame* rootFrame = pc->mShell->FrameManager()->GetRootFrame();
-      if (rootFrame) {
-        nsIFrame* f = nsLayoutUtils::GetCrossDocParentFrame(rootFrame);
-        if (f) {
-          pc = f->PresContext();
-          continue;
-        }
-      }
-    }
-    return pc->IsRoot() ? static_cast<nsRootPresContext*>(pc) : nsnull;
+    nsPresContext* parent = GetParentPresContext(pc);
+    if (!parent)
+      break;
+    pc = parent;
   }
+  return pc->IsRoot() ? static_cast<nsRootPresContext*>(pc) : nsnull;
 }
 
 void
@@ -2178,11 +2187,17 @@ nsPresContext::NotifyInvalidation(const nsRect& aRect, PRUint32 aFlags)
   if (aRect.IsEmpty() || !MayHavePaintEventListener())
     return;
 
-  if (!IsDOMPaintEventPending()) {
-    // No event is pending. Dispatch one now.
-    nsCOMPtr<nsIRunnable> ev =
-      NS_NewRunnableMethod(this, &nsPresContext::FireDOMPaintEvent);
-    NS_DispatchToCurrentThread(ev);
+  nsPresContext* pc;
+  for (pc = this; pc; pc = GetParentPresContext(pc)) {
+    if (pc->mFireAfterPaintEvents)
+      break;
+    pc->mFireAfterPaintEvents = PR_TRUE;
+  }
+  if (!pc) {
+    nsRootPresContext* rpc = GetRootPresContext();
+    if (rpc) {
+      rpc->EnsureEventualDidPaintEvent();
+    }
   }
 
   nsInvalidateRequestList::Request* request =
@@ -2194,6 +2209,39 @@ nsPresContext::NotifyInvalidation(const nsRect& aRect, PRUint32 aFlags)
   request->mFlags = aFlags;
 }
 
+static PRBool
+NotifyDidPaintSubdocumentCallback(nsIDocument* aDocument, void* aData)
+{
+  nsIPresShell* shell = aDocument->GetShell();
+  if (shell) {
+    nsPresContext* pc = shell->GetPresContext();
+    if (pc) {
+      pc->NotifyDidPaintForSubtree();
+    }
+  }
+  return PR_TRUE;
+}
+
+void
+nsPresContext::NotifyDidPaintForSubtree()
+{
+  if (!mFireAfterPaintEvents)
+    return;
+  mFireAfterPaintEvents = PR_FALSE;
+
+  if (IsRoot()) {
+    static_cast<nsRootPresContext*>(this)->CancelDidPaintTimer();
+  }
+
+  if (!mInvalidateRequests.mRequests.IsEmpty()) {
+    nsCOMPtr<nsIRunnable> ev =
+      NS_NewRunnableMethod(this, &nsPresContext::FireDOMPaintEvent);
+    nsContentUtils::AddScriptRunner(ev);
+  }
+
+  mDocument->EnumerateSubDocuments(NotifyDidPaintSubdocumentCallback, nsnull);
+}
+
 PRBool
 nsPresContext::HasCachedStyleData()
 {
@@ -2400,6 +2448,7 @@ nsRootPresContext::~nsRootPresContext()
 {
   NS_ASSERTION(mRegisteredPlugins.Count() == 0,
                "All plugins should have been unregistered");
+  CancelDidPaintTimer();
 }
 
 void
@@ -2734,3 +2783,23 @@ nsRootPresContext::RootForgetUpdatePluginGeometryFrame(nsIFrame* aFrame)
     mUpdatePluginGeometryForFrame = nsnull;
   }
 }
+
+static void
+NotifyDidPaintForSubtreeCallback(nsITimer *aTimer, void *aClosure)
+{
+  nsPresContext* presContext = (nsPresContext*)aClosure;
+  nsAutoScriptBlocker blockScripts;
+  presContext->NotifyDidPaintForSubtree();
+}
+
+void
+nsRootPresContext::EnsureEventualDidPaintEvent()
+{
+  if (mNotifyDidPaintTimer)
+    return;
+  mNotifyDidPaintTimer = do_CreateInstance("@mozilla.org/timer;1");
+  if (!mNotifyDidPaintTimer)
+    return;
+  mNotifyDidPaintTimer->InitWithFuncCallback(NotifyDidPaintForSubtreeCallback,
+                                             (void*)this, 100, nsITimer::TYPE_ONE_SHOT);
+}

layout/base/nsPresContext.h

@@ -862,11 +862,12 @@ public:
   PRBool EnsureSafeToHandOutCSSRules();
 
   void NotifyInvalidation(const nsRect& aRect, PRUint32 aFlags);
+  void NotifyDidPaintForSubtree();
   void FireDOMPaintEvent();
+
   PRBool IsDOMPaintEventPending() {
     return !mInvalidateRequests.mRequests.IsEmpty();
   }
-
   void ClearMozAfterPaintEvents() {
     mInvalidateRequests.mRequests.Clear();
   }
@@ -1157,6 +1158,7 @@ protected:
   unsigned              mProcessingAnimationStyleChange : 1;
 
   unsigned              mContainsUpdatePluginGeometryFrame : 1;
+  unsigned              mFireAfterPaintEvents : 1;
 
   // Cache whether we are chrome or not because it is expensive.  
   // mIsChromeIsCached tells us if mIsChrome is valid or we need to get the
@@ -1202,6 +1204,20 @@ public:
   nsRootPresContext(nsIDocument* aDocument, nsPresContextType aType) NS_HIDDEN;
   virtual ~nsRootPresContext();
 
+  /**
+   * Ensure that NotifyDidPaintForSubtree is eventually called on this
+   * object after a timeout.
+   */
+  void EnsureEventualDidPaintEvent();
+
+  void CancelDidPaintTimer()
+  {
+    if (mNotifyDidPaintTimer) {
+      mNotifyDidPaintTimer->Cancel();
+      mNotifyDidPaintTimer = nsnull;
+    }
+  }
+
   /**
    * Registers a plugin to receive geometry updates (position and clip
    * region) so it can update its widget.
@@ -1276,6 +1292,7 @@ public:
   PRUint32 GetDOMGeneration() { return mDOMGeneration; }
 
 private:
+  nsCOMPtr<nsITimer> mNotifyDidPaintTimer;
   nsTHashtable<nsPtrHashKey<nsObjectFrame> > mRegisteredPlugins;
   // if mNeedsToUpdatePluginGeometry is set, then this is the frame to
   // use as the root of the subtree to search for plugin updates, or

layout/base/nsPresShell.cpp

@@ -6093,13 +6093,14 @@ PresShell::Paint(nsIView*           aDisplayRoot,
                            NSCoordToFloat(bounds__.YMost()));
 #endif
 
-  AUTO_LAYOUT_PHASE_ENTRY_POINT(GetPresContext(), Paint);
-
   NS_ASSERTION(!mIsDestroying, "painting a destroyed PresShell");
   NS_ASSERTION(aDisplayRoot, "null view");
   NS_ASSERTION(aViewToPaint, "null view");
   NS_ASSERTION(aWidgetToPaint, "Can't paint without a widget");
 
+  nsPresContext* presContext = GetPresContext();
+  AUTO_LAYOUT_PHASE_ENTRY_POINT(presContext, Paint);
+
   nsIFrame* frame = aPaintDefaultBackground
       ? nsnull : static_cast<nsIFrame*>(aDisplayRoot->GetClientData());
 
@@ -6131,6 +6132,7 @@ PresShell::Paint(nsIView*           aDisplayRoot,
                               nsLayoutUtils::PAINT_WIDGET_LAYERS);
 
     frame->EndDeferringInvalidatesForDisplayRoot();
+    presContext->NotifyDidPaintForSubtree();
     return NS_OK;
   }
 
@@ -6159,6 +6161,7 @@ PresShell::Paint(nsIView*           aDisplayRoot,
   if (frame) {
     frame->EndDeferringInvalidatesForDisplayRoot();
   }
+  presContext->NotifyDidPaintForSubtree();
   return NS_OK;
 }
 

layout/base/tests/test_bug450930.xhtml

@@ -174,24 +174,24 @@ function runTest3() {
       gotScrolledOutInMainDoc = true;
   }
 
-  function IFRAMEListener(event) {
-    if (doesRectContainListElement(
-          iframe.contentDocument.getElementById("d2").getBoundingClientRect(), event.clientRects))
-      gotScrolledOutInSubdoc = true;
-  }
-
   function check() {
     ok(!gotScrolledOutInMainDoc, "scrolled-out invalidation should not propagate to main doc");
-    ok(gotScrolledOutInSubdoc, "scrolled-out invalidation should notify in subdoc");
     window.removeEventListener("MozAfterPaint", listener, false);
     iframe.contentWindow.removeEventListener("MozAfterPaint", IFRAMEListener, false);
     runNext();
   }
 
+  function IFRAMEListener(event) {
+    if (doesRectContainListElement(
+          iframe.contentDocument.getElementById("d2").getBoundingClientRect(), event.clientRects)) {
+      ok(true, "scrolled-out invalidation should notify in subdoc");
+      setTimeout(check, 0);
+    }
+  }
+
   function triggerPaint() {
     window.addEventListener("MozAfterPaint", listener, false);
     iframe.contentWindow.addEventListener("MozAfterPaint", IFRAMEListener, false);
-    setTimeout(check, 100);
     flash(iframe.contentDocument, 'd2');
   }
   triggerPaint();