Fire MozScrolledAreaChanged from nsDocShell::RestoreFromHistory() in case document root scroll frame isn't reflowed by the restore. r=roc

docshell/base/nsDocShell.cpp

@@ -6956,6 +6956,11 @@ nsDocShell::RestoreFromHistory()
                    newBounds.y, newBounds.width, newBounds.height);
 #endif
             mContentViewer->SetBounds(newBounds);
+        } else {
+            nsIScrollableFrame *rootScrollFrame = do_QueryFrame(shell->GetRootScrollFrame());
+            if (rootScrollFrame) {
+                rootScrollFrame->PostScrolledAreaEventForCurrentArea();
+            }
         }
     }
 

layout/generic/nsGfxScrollFrame.cpp

@@ -157,7 +157,6 @@ void
 nsHTMLScrollFrame::Destroy()
 {
   mInner.Destroy();
-  mScrolledAreaEventDispatcher.Revoke();
   nsHTMLContainerFrame::Destroy();
 }
 
@@ -895,7 +894,7 @@ nsHTMLScrollFrame::Reflow(nsPresContext*           aPresContext,
   }
 
   if (mInner.mIsRoot && oldScrolledAreaBounds != newScrolledAreaBounds) {
-    PostScrolledAreaEvent(newScrolledAreaBounds);
+    mInner.PostScrolledAreaEvent(newScrolledAreaBounds);
   }
 
   aStatus = NS_FRAME_COMPLETE;
@@ -905,57 +904,6 @@ nsHTMLScrollFrame::Reflow(nsPresContext*           aPresContext,
 }
 
 
-////////////////////////////////////////////////////////////////////////////////
-// ScrolledArea change event dispatch
-
-NS_IMETHODIMP
-nsHTMLScrollFrame::ScrolledAreaEventDispatcher::Run()
-{
-  if (mScrollFrame)
-    mScrollFrame->FireScrolledAreaEvent(mScrolledArea);
-  return NS_OK;
-}
-
-void
-nsHTMLScrollFrame::FireScrolledAreaEvent(nsRect &aScrolledArea)
-{
-  mScrolledAreaEventDispatcher.Forget();
-
-  nsScrollAreaEvent event(PR_TRUE, NS_SCROLLEDAREACHANGED, nsnull);
-  nsPresContext *prescontext = PresContext();
-  nsIContent* content = GetContent();
-
-  event.mArea = aScrolledArea;
-
-  nsIDocument *doc = content->GetCurrentDoc();
-  if (doc) {
-    nsEventDispatcher::Dispatch(doc, prescontext, &event, nsnull);
-  }
-}
-
-void
-nsHTMLScrollFrame::PostScrolledAreaEvent(nsRect &aScrolledArea)
-{
-  if (mScrolledAreaEventDispatcher.IsPending()) {
-    mScrolledAreaEventDispatcher.get()->mScrolledArea = aScrolledArea;
-    return;
-  }
-
-  nsRefPtr<ScrolledAreaEventDispatcher> dp = new ScrolledAreaEventDispatcher(this);
-  if (!dp) {
-    NS_WARNING("OOM while posting NS_SCROLLEDAREACHANGED");
-    return;
-  }
-
-  dp->mScrolledArea = aScrolledArea;
-
-  if (NS_FAILED(NS_DispatchToCurrentThread(dp))) {
-    NS_WARNING("Failed to dispatch ScrolledAreaEventDispatcher");
-  } else {
-    mScrolledAreaEventDispatcher = dp;
-  }  
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 
 #ifdef NS_DEBUG
@@ -991,6 +939,15 @@ nsHTMLScrollFrame::CurPosAttributeChanged(nsIContent* aChild,
   mInner.CurPosAttributeChanged(aChild);
 }
 
+NS_IMETHODIMP 
+nsHTMLScrollFrame::PostScrolledAreaEventForCurrentArea()
+{
+  nsRect currentScrolledArea = mInner.mScrolledFrame->GetView()->GetBounds();
+  mInner.PostScrolledAreaEvent(currentScrolledArea);
+
+  return NS_OK;
+}
+
 NS_QUERYFRAME_HEAD(nsHTMLScrollFrame)
   NS_QUERYFRAME_ENTRY(nsIAnonymousContentCreator)
   NS_QUERYFRAME_ENTRY(nsIScrollableFrame)
@@ -1333,6 +1290,15 @@ nsXULScrollFrame::DoLayout(nsBoxLayoutState& aState)
   return rv;
 }
 
+NS_IMETHODIMP 
+nsXULScrollFrame::PostScrolledAreaEventForCurrentArea()
+{
+  nsRect currentScrolledArea = mInner.mScrolledFrame->GetView()->GetBounds();
+  mInner.PostScrolledAreaEvent(currentScrolledArea);
+
+  return NS_OK;
+}
+
 NS_QUERYFRAME_HEAD(nsXULScrollFrame)
   NS_QUERYFRAME_ENTRY(nsIAnonymousContentCreator)
   NS_QUERYFRAME_ENTRY(nsIScrollableFrame)
@@ -1777,6 +1743,7 @@ nsGfxScrollFrameInner::Destroy()
     mOuter->PresContext()->PresShell()->CancelReflowCallback(this);
     mPostedReflowCallback = PR_FALSE;
   }
+  mScrolledAreaEventDispatcher.Revoke();
   nsIScrollableView *view = GetScrollableView();
   NS_ASSERTION(view, "unexpected null pointer");
   if (view)
@@ -2880,3 +2847,56 @@ nsGfxScrollFrameInner::RestoreState(nsPresState* aState)
     mLastPos = nsPoint(0, 0);
   }
 }
+
+void
+nsGfxScrollFrameInner::PostScrolledAreaEvent(nsRect &aScrolledArea)
+{
+  if (mScrolledAreaEventDispatcher.IsPending()) {
+    mScrolledAreaEventDispatcher.get()->mScrolledArea = aScrolledArea;
+    return;
+  }
+
+  nsRefPtr<ScrolledAreaEventDispatcher> dp = new ScrolledAreaEventDispatcher(this);
+  if (!dp) {
+    NS_WARNING("OOM while posting NS_SCROLLEDAREACHANGED");
+    return;
+  }
+
+  dp->mScrolledArea = aScrolledArea;
+
+  if (NS_FAILED(NS_DispatchToCurrentThread(dp))) {
+    NS_WARNING("Failed to dispatch ScrolledAreaEventDispatcher");
+  } else {
+    mScrolledAreaEventDispatcher = dp;
+  }  
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// ScrolledArea change event dispatch
+
+NS_IMETHODIMP
+nsGfxScrollFrameInner::ScrolledAreaEventDispatcher::Run()
+{
+  if (mScrollFrameInner)
+    mScrollFrameInner->FireScrolledAreaEvent(mScrolledArea);
+  return NS_OK;
+}
+
+void
+nsGfxScrollFrameInner::FireScrolledAreaEvent(nsRect &aScrolledArea)
+{
+  mScrolledAreaEventDispatcher.Forget();
+
+  nsScrollAreaEvent event(PR_TRUE, NS_SCROLLEDAREACHANGED, nsnull);
+  nsPresContext *prescontext = mOuter->PresContext();
+  nsIContent* content = mOuter->GetContent();
+
+  event.mArea = aScrolledArea;
+
+  nsIDocument *doc = content->GetCurrentDoc();
+  if (doc) {
+    nsEventDispatcher::Dispatch(doc, prescontext, &event, nsnull);
+  }
+}
+
+

layout/generic/nsGfxScrollFrame.h

@@ -51,6 +51,7 @@
 #include "nsIView.h"
 #include "nsIReflowCallback.h"
 #include "nsBoxLayoutState.h"
+#include "nsQueryFrame.h"
 
 class nsPresContext;
 class nsIPresShell;
@@ -105,6 +106,9 @@ public:
   void CurPosAttributeChanged(nsIContent* aChild);
   void PostScrollEvent();
   void FireScrollEvent();
+  void PostScrolledAreaEvent(nsRect &aScrolledArea);
+  void FireScrolledAreaEvent(nsRect &aScrolledArea);
+
 
   class ScrollEvent : public nsRunnable {
   public:
@@ -232,6 +236,25 @@ public:
   // If true, need to actually update our scrollbar attributes in the
   // reflow callback.
   PRPackedBool mUpdateScrollbarAttributes:1;
+private:
+  class ScrolledAreaEventDispatcher : public nsRunnable {
+  public:
+    NS_DECL_NSIRUNNABLE
+
+    ScrolledAreaEventDispatcher(nsGfxScrollFrameInner *aScrollFrameInner)
+      : mScrollFrameInner(aScrollFrameInner),
+        mScrolledArea(0, 0, 0, 0)
+    {
+    }
+
+    void Revoke() { mScrollFrameInner = nsnull; }
+
+    nsGfxScrollFrameInner *mScrollFrameInner;
+    nsRect mScrolledArea;
+  };
+
+  nsRevocableEventPtr<ScrolledAreaEventDispatcher> mScrolledAreaEventDispatcher;
+
 };
 
 /**
@@ -389,24 +412,7 @@ public:
    * scroll frame's scrolled content area.
    */
 
-  void PostScrolledAreaEvent(nsRect &aScrolledArea);
+  NS_IMETHOD PostScrolledAreaEventForCurrentArea();
-  void FireScrolledAreaEvent(nsRect &aScrolledArea);
-
-  class ScrolledAreaEventDispatcher : public nsRunnable {
-  public:
-    NS_DECL_NSIRUNNABLE
-
-    ScrolledAreaEventDispatcher(nsHTMLScrollFrame *aScrollFrame)
-      : mScrollFrame(aScrollFrame),
-        mScrolledArea(0, 0, 0, 0)
-    {
-    }
-
-    void Revoke() { mScrollFrame = nsnull; }
-
-    nsHTMLScrollFrame *mScrollFrame;
-    nsRect mScrolledArea;
-  };
 
 protected:
   nsHTMLScrollFrame(nsIPresShell* aShell, nsStyleContext* aContext, PRBool aIsRoot);
@@ -440,8 +446,6 @@ protected:
 private:
   friend class nsGfxScrollFrameInner;
   nsGfxScrollFrameInner mInner;
-
-  nsRevocableEventPtr<ScrolledAreaEventDispatcher> mScrolledAreaEventDispatcher;
 };
 
 /**
@@ -604,6 +608,10 @@ public:
     return nsBoxFrame::IsFrameOfType(aFlags);
   }
 
+  void PostScrolledAreaEvent(nsRect &aScrolledArea);
+
+  NS_IMETHOD PostScrolledAreaEventForCurrentArea();
+
 #ifdef NS_DEBUG
   NS_IMETHOD GetFrameName(nsAString& aResult) const;
 #endif

layout/generic/nsIScrollableFrame.h

@@ -119,6 +119,13 @@ public:
    * restored after reflows are done...
    */
   virtual void ScrollToRestoredPosition() = 0;
+
+  /**
+   * Allows the docshell to request that the scroll frame post an event
+   * after being restored from history.
+   */
+  NS_IMETHOD PostScrolledAreaEventForCurrentArea() = 0;
+
 };
 
 #endif