Backing out patch for bug 108817 to test whether it causes the Tp regression.

layout/forms/nsListControlFrame.cpp

@@ -90,6 +90,9 @@
 #include "nsIDOMMouseMotionListener.h"
 #include "nsIDOMKeyListener.h"
 
+// Timer Includes
+#include "nsITimer.h"
+
 // Constants
 const nscoord kMaxDropDownRows          = 20; // This matches the setting for 4.x browsers
 const PRInt32 kDefaultMultiselectHeight = 4; // This is compatible with 4.x browsers
@@ -279,21 +282,169 @@ if (aReflowState.mComputedWidth != NS_UNCONSTRAINEDSIZE) { \
 //-- Done with macros
 //------------------------------------------------------
 
+//---------------------------------------------------
+//-- Update Timer Stuff
+//---------------------------------------------------
+class nsSelectUpdateTimer : public nsITimerCallback
+{
+public:
+
+  NS_DECL_ISUPPORTS
+
+  nsSelectUpdateTimer()
+      : mPresContext(nsnull), mDelay(0), mHasBeenNotified(PR_FALSE), 
+        mItemsAdded(PR_FALSE), mItemsRemoved(PR_FALSE), mItemsInxSet(PR_FALSE)
+  {
+  }
+
+  virtual ~nsSelectUpdateTimer();
+  NS_DECL_NSITIMERCALLBACK
+
+  // Additional Methods
+  nsresult Start(nsPresContext *aPresContext) 
+  {
+    mPresContext = aPresContext;
+
+    nsresult result = NS_OK;
+    if (!mTimer) {
+      mTimer = do_CreateInstance("@mozilla.org/timer;1", &result);
+
+      if (NS_FAILED(result))
+        return result;
+    }
+    result = mTimer->InitWithCallback(this, mDelay, nsITimer::TYPE_ONE_SHOT);
+
+    if (mHasBeenNotified) {
+      mItemsAdded      = PR_FALSE;
+      mItemsRemoved    = PR_FALSE;
+      mItemsInxSet     = PR_FALSE;
+      mHasBeenNotified = PR_FALSE;
+      mInxArray.Clear();
+    }
+
+    return result;
+  }
+
+  void Init(nsListControlFrame *aList, PRUint32 aDelay)  { mListControl = aList; mDelay = aDelay; }
+  void Stop() { if (mTimer) mTimer->Cancel(); }
+
+  void AdjustIndexes(PRBool aInserted, PRInt32 aInx)
+  {
+    // remove the index from the list
+    if (!aInserted) {
+      PRInt32 inx = (PRInt32)mInxArray.IndexOf((void*)aInx);
+      if (inx > -1) {
+        mInxArray.RemoveElementAt(inx);
+      }
+    }
+
+    PRInt32 count = mInxArray.Count();
+    for (PRInt32 i=0;i<count;i++) {
+      PRInt32 inx = NS_PTR_TO_INT32(mInxArray[i]);
+      if (inx > aInx) {
+        mInxArray.ReplaceElementAt((void*)(inx+(aInserted?1:-1)), i);
+      }
+    }
+  }
+
+  void ItemAdded(PRInt32 aInx, PRInt32 aNumItems)
+  { 
+    mItemsAdded = PR_TRUE;
+    if (mInxArray.Count() > 0 && aInx <= aNumItems-1) {
+      AdjustIndexes(PR_TRUE, aInx);
+    }
+  }
+
+  void ItemRemoved(PRInt32 aInx, PRInt32 aNumItems) 
+  { 
+    mItemsRemoved = PR_TRUE;
+    if (mInxArray.Count() > 0 && aInx <= aNumItems) {
+      AdjustIndexes(PR_FALSE, aInx);
+    }
+  }
+
+  void ItemIndexSet(PRInt32 aInx)  
+  { 
+    mItemsInxSet = PR_TRUE;
+    mInxArray.AppendElement((void*)aInx);
+  }
+
+  PRPackedBool HasBeenNotified()      { return mHasBeenNotified; }
+
+private:
+  nsListControlFrame * mListControl;
+  nsCOMPtr<nsITimer>   mTimer;
+  nsPresContext*      mPresContext;
+  PRUint32             mDelay;
+  PRPackedBool         mHasBeenNotified;
+
+  PRPackedBool         mItemsAdded;
+  PRPackedBool         mItemsRemoved;
+  PRPackedBool         mItemsInxSet;
+  nsVoidArray          mInxArray;
+
+};
+
+NS_IMPL_ADDREF(nsSelectUpdateTimer)
+NS_IMPL_RELEASE(nsSelectUpdateTimer)
+NS_IMPL_QUERY_INTERFACE1(nsSelectUpdateTimer, nsITimerCallback)
+
+nsresult NS_NewUpdateTimer(nsSelectUpdateTimer **aResult)
+{
+  if (!aResult)
+    return NS_ERROR_NULL_POINTER;
+
+  *aResult = (nsSelectUpdateTimer*) new nsSelectUpdateTimer;
+
+  if (!aResult)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  NS_ADDREF(*aResult);
+
+  return NS_OK;
+}
+
+// nsITimerCallback
+NS_IMETHODIMP nsSelectUpdateTimer::Notify(nsITimer *timer)
+{
+  if (mPresContext && mListControl && !mHasBeenNotified) {
+    mHasBeenNotified = PR_TRUE;
+    if (mItemsAdded || mItemsInxSet) {
+      mListControl->ResetList(mPresContext, &mInxArray);
+    } else {
+      mListControl->ItemsHaveBeenRemoved(mPresContext);
+    }
+  }
+  return NS_OK;
+}
+
+nsSelectUpdateTimer::~nsSelectUpdateTimer()
+{
+  if (mTimer) {
+    mTimer->Cancel();
+  }
+}
+
+//---------------------------------------------------
+//-- DONE: Update Timer Stuff
+//---------------------------------------------------
+
+
 //---------------------------------------------------------
 nsListControlFrame::nsListControlFrame(nsIPresShell* aShell,
   nsIDocument* aDocument)
   : nsHTMLScrollFrame(aShell, PR_FALSE)
 {
   mComboboxFrame      = nsnull;
-  mChangesSinceDragStart = PR_FALSE;
   mButtonDown         = PR_FALSE;
   mMaxWidth           = 0;
   mMaxHeight          = 0;
+  mPresContext        = nsnull;
 
   mIsAllContentHere   = PR_FALSE;
   mIsAllFramesHere    = PR_FALSE;
   mHasBeenInitialized = PR_FALSE;
-  mNeedToReset        = PR_TRUE;
+  mDoneWithInitialReflow = PR_FALSE;
 
   mCacheSize.width             = -1;
   mCacheSize.height            = -1;
@@ -306,6 +457,7 @@ nsListControlFrame::nsListControlFrame(nsIPresShell* aShell,
   mOverrideReflowOpt           = PR_FALSE;
   mPassId                      = 0;
 
+  mUpdateTimer                 = nsnull;
   mDummyFrame                  = nsnull;
 
   REFLOW_COUNTER_INIT()
@@ -315,8 +467,13 @@ nsListControlFrame::nsListControlFrame(nsIPresShell* aShell,
 nsListControlFrame::~nsListControlFrame()
 {
   REFLOW_COUNTER_DUMP("nsLCF");
+  if (mUpdateTimer != nsnull) {
+    StopUpdateTimer();
+    NS_RELEASE(mUpdateTimer);
+  }
 
   mComboboxFrame = nsnull;
+  NS_IF_RELEASE(mPresContext);
 }
 
 // for Bug 47302 (remove this comment later)
@@ -426,16 +583,15 @@ void nsListControlFrame::PaintFocus(nsIRenderingContext& aRC, nsFramePaintLayer
     focusedIndex = mEndSelectionIndex;
   }
 
-  nsPresContext* presContext = GetPresContext();
   nsIScrollableView * scrollableView;
-  GetScrollableView(presContext, &scrollableView);
+  GetScrollableView(mPresContext, &scrollableView);
   if (!scrollableView) return;
 
-  nsIPresShell *presShell = presContext->GetPresShell();
+  nsIPresShell *presShell = mPresContext->GetPresShell();
   if (!presShell) return;
 
   nsIFrame* containerFrame;
-  GetOptionsContainer(presContext, &containerFrame);
+  GetOptionsContainer(mPresContext, &containerFrame);
   if (!containerFrame) return;
 
   nsIFrame * childframe = nsnull;
@@ -524,12 +680,12 @@ void nsListControlFrame::PaintFocus(nsIRenderingContext& aRC, nsFramePaintLayer
 
   // set up back stop colors and then ask L&F service for the real colors
   nscolor color;
-  presContext->LookAndFeel()->
+  mPresContext->LookAndFeel()->
     GetColor(lastItemIsSelected ?
              nsILookAndFeel::eColor_WidgetSelectForeground :
              nsILookAndFeel::eColor_WidgetSelectBackground, color);
 
-  nscoord onePixelInTwips = presContext->IntScaledPixelsToTwips(1);
+  nscoord onePixelInTwips = mPresContext->IntScaledPixelsToTwips(1);
 
   nsRect dirty;
   nscolor colors[] = {color, color, color, color};
@@ -692,8 +848,7 @@ NS_IMETHODIMP nsListControlFrame::GetAccessible(nsIAccessible** aAccessible)
 
   if (accService) {
     nsCOMPtr<nsIDOMNode> node = do_QueryInterface(mContent);
-    return accService->CreateHTMLListboxAccessible(node, GetPresContext(),
+    return accService->CreateHTMLListboxAccessible(node, mPresContext, aAccessible);
-                                                   aAccessible);
   }
 
   return NS_ERROR_FAILURE;
@@ -1011,7 +1166,7 @@ nsListControlFrame::Reflow(nsPresContext*          aPresContext,
     nsIContent * option = GetOptionContent(0);
     if (option != nsnull) {
       nsIFrame * optFrame;
-      nsresult result = GetPresContext()->PresShell()->
+      nsresult result = mPresContext->PresShell()->
         GetPrimaryFrameFor(option, &optFrame);
       if (NS_SUCCEEDED(result) && optFrame != nsnull) {
         nsStyleContext* optStyle = optFrame->GetStyleContext();
@@ -1633,6 +1788,8 @@ nsListControlFrame::Init(nsPresContext*  aPresContext,
                          nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
+  mPresContext = aPresContext;
+  NS_ADDREF(mPresContext);
   nsresult result = nsHTMLScrollFrame::Init(aPresContext, aContent, aParent, aContext,
                                             aPrevInFlow);
 
@@ -1890,7 +2047,7 @@ nsListControlFrame::MouseClicked(nsPresContext* aPresContext)
 NS_IMETHODIMP
 nsListControlFrame::OnContentReset()
 {
-  ResetList();
+  ResetList(mPresContext);
   return NS_OK;
 }
 
@@ -1899,7 +2056,7 @@ nsListControlFrame::OnContentReset()
 // those values as determined by the original HTML
 //---------------------------------------------------------
 void 
-nsListControlFrame::ResetList()
+nsListControlFrame::ResetList(nsPresContext* aPresContext, nsVoidArray * aInxList)
 {
   REFLOW_DEBUG_MSG("LBX::ResetList\n");
 
@@ -2098,9 +2255,9 @@ nsListControlFrame::DoneAddingChildren(PRBool aIsDone)
     // If so, then we can initialize;
     if (mIsAllFramesHere == PR_FALSE) {
       // if all the frames are now present we can initalize
-      if (CheckIfAllFramesHere()) {
+      if (CheckIfAllFramesHere() && mPresContext) {
         mHasBeenInitialized = PR_TRUE;
-        ResetList();
+        ResetList(mPresContext);
       }
     }
   }
@@ -2111,6 +2268,8 @@ nsListControlFrame::DoneAddingChildren(PRBool aIsDone)
 NS_IMETHODIMP
 nsListControlFrame::AddOption(nsPresContext* aPresContext, PRInt32 aIndex)
 {
+  StopUpdateTimer();
+
 #ifdef DO_REFLOW_DEBUG
   printf("---- Id: %d nsLCF %p Added Option %d\n", mReflowId, this, aIndex);
 #endif
@@ -2132,8 +2291,10 @@ nsListControlFrame::AddOption(nsPresContext* aPresContext, PRInt32 aIndex)
     return NS_OK;
   }
 
-  // Make sure we scroll to the selected option as needed
+  nsresult rv = StartUpdateTimer(aPresContext);
-  mNeedToReset = PR_TRUE;
+  if (NS_SUCCEEDED(rv) && mUpdateTimer) {
+    mUpdateTimer->ItemAdded(aIndex, numOptions);
+  }
   return NS_OK;
 }
 
@@ -2141,9 +2302,12 @@ nsListControlFrame::AddOption(nsPresContext* aPresContext, PRInt32 aIndex)
 NS_IMETHODIMP
 nsListControlFrame::RemoveOption(nsPresContext* aPresContext, PRInt32 aIndex)
 {
-  // Need to reset if we're a dropdown
+  StopUpdateTimer();
-  if (IsInDropDownMode()) {
+  nsresult rv = StartUpdateTimer(aPresContext);
-    mNeedToReset = PR_TRUE;
+  if (NS_SUCCEEDED(rv) && mUpdateTimer) {
+    PRInt32 numOptions;
+    GetNumberOfOptions(&numOptions);
+    mUpdateTimer->ItemRemoved(aIndex, numOptions);
   }
 
   return NS_OK;
@@ -2243,7 +2407,7 @@ nsListControlFrame::ComboboxFinish(PRInt32 aIndex)
       mComboboxFrame->RedisplaySelectedText();
     }
 
-    mComboboxFrame->RollupFromList(GetPresContext());
+    mComboboxFrame->RollupFromList(mPresContext);
   }
 
   return NS_OK;
@@ -2279,7 +2443,7 @@ nsListControlFrame::FireOnChange()
   nsEventStatus status = nsEventStatus_eIgnore;
   nsEvent event(NS_FORM_CHANGE);
 
-  nsIPresShell *presShell = GetPresContext()->GetPresShell();
+  nsIPresShell *presShell = mPresContext->GetPresShell();
   if (presShell) {
     rv = presShell->HandleEventWithTarget(&event, this, nsnull,
                                            NS_EVENT_FLAG_INIT, &status);
@@ -2433,25 +2597,26 @@ nsListControlFrame::DidReflow(nsPresContext*           aPresContext,
                               const nsHTMLReflowState*  aReflowState,
                               nsDidReflowStatus         aStatus)
 {
-  nsresult rv;
-  
   if (PR_TRUE == IsInDropDownMode()) 
   {
     //SyncViewWithFrame();
     mState &= ~NS_FRAME_SYNC_FRAME_AND_VIEW;
-    rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
+    nsresult rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
     mState |= NS_FRAME_SYNC_FRAME_AND_VIEW;
     SyncViewWithFrame(aPresContext);
+    return rv;
   } else {
-    rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
+    nsresult rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
+    PRInt32 selectedIndex = mEndSelectionIndex;
+    if (selectedIndex == kNothingSelected) {
+      GetSelectedIndex(&selectedIndex);
+    }
+    if (!mDoneWithInitialReflow && selectedIndex != kNothingSelected) {
+      ScrollToIndex(selectedIndex);
+      mDoneWithInitialReflow = PR_TRUE;
+    }
+    return rv;
   }
-
-  if (mNeedToReset) {
-    mNeedToReset = PR_FALSE;
-    ResetList();
-  }
-
-  return rv;
 }
 
 nsIAtom*
@@ -2545,13 +2710,13 @@ nsListControlFrame::MouseUp(nsIDOMEvent* aMouseEvent)
           nsevent->PreventBubble();
         }
       } else {
-        CaptureMouseEvents(GetPresContext(), PR_FALSE);
+        CaptureMouseEvents(mPresContext, PR_FALSE);
         return NS_OK;
       }
-      CaptureMouseEvents(GetPresContext(), PR_FALSE);
+      CaptureMouseEvents(mPresContext, PR_FALSE);
       return NS_ERROR_FAILURE; // means consume event
     } else {
-      CaptureMouseEvents(GetPresContext(), PR_FALSE);
+      CaptureMouseEvents(mPresContext, PR_FALSE);
       return NS_OK;
     }
   }
@@ -2595,7 +2760,7 @@ nsListControlFrame::MouseUp(nsIDOMEvent* aMouseEvent)
           nsevent->PreventBubble();
         }
 
-        CaptureMouseEvents(GetPresContext(), PR_FALSE);
+        CaptureMouseEvents(mPresContext, PR_FALSE);
         return NS_ERROR_FAILURE;
       }
 
@@ -2611,7 +2776,7 @@ nsListControlFrame::MouseUp(nsIDOMEvent* aMouseEvent)
     }
   } else {
     REFLOW_DEBUG_MSG(">>>>>> Didn't find");
-    CaptureMouseEvents(GetPresContext(), PR_FALSE);
+    CaptureMouseEvents(mPresContext, PR_FALSE);
     // Notify
     if (mChangesSinceDragStart) {
       // reset this so that future MouseUps without a prior MouseDown
@@ -2662,13 +2827,12 @@ nsListControlFrame::FireMenuItemActiveEvent()
   nsCOMPtr<nsIDOMEvent> event;
   nsCOMPtr<nsIEventListenerManager> manager;
   mContent->GetListenerManager(getter_AddRefs(manager));
-  nsPresContext* presContext = GetPresContext();
   if (manager &&
-      NS_SUCCEEDED(manager->CreateEvent(presContext, nsnull, NS_LITERAL_STRING("Events"), getter_AddRefs(event)))) {
+      NS_SUCCEEDED(manager->CreateEvent(mPresContext, nsnull, NS_LITERAL_STRING("Events"), getter_AddRefs(event)))) {
     event->InitEvent(NS_LITERAL_STRING("DOMMenuItemActive"), PR_TRUE, PR_TRUE);
     PRBool noDefault;
-    presContext->EventStateManager()->DispatchNewEvent(mContent, event,
+    mPresContext->EventStateManager()->DispatchNewEvent(mContent, event,
-                                                       &noDefault);
+                                                        &noDefault);
   }
 }
 #endif
@@ -2692,7 +2856,7 @@ nsListControlFrame::GetIndexFromDOMEvent(nsIDOMEvent* aMouseEvent,
   mouseEvent->GetTarget(getter_AddRefs(node));
   nsCOMPtr<nsIContent> content = do_QueryInterface(node);
   nsIFrame * frame;
-  GetPresContext()->PresShell()->GetPrimaryFrameFor(content, &frame);
+  mPresContext->PresShell()->GetPrimaryFrameFor(content, &frame);
   printf("Target Frame: %p  this: %p\n", frame, this);
   printf("-->\n");
 #endif
@@ -2700,7 +2864,7 @@ nsListControlFrame::GetIndexFromDOMEvent(nsIDOMEvent* aMouseEvent,
   nsresult rv;
   
   nsCOMPtr<nsIContent> content;
-  GetPresContext()->EventStateManager()->
+  mPresContext->EventStateManager()->
     GetEventTargetContent(nsnull, getter_AddRefs(content));
 
   nsCOMPtr<nsIContent> optionContent = GetOptionFromContent(content);
@@ -2756,7 +2920,7 @@ nsListControlFrame::MouseDown(nsIDOMEvent* aMouseEvent)
   if (NS_SUCCEEDED(GetIndexFromDOMEvent(aMouseEvent, selectedIndex))) {
     if (!IsInDropDownMode()) {
       // Handle Like List
-      CaptureMouseEvents(GetPresContext(), PR_TRUE);
+      CaptureMouseEvents(mPresContext, PR_TRUE);
       mChangesSinceDragStart = HandleListSelection(aMouseEvent, selectedIndex);
     }
   } else {
@@ -2771,7 +2935,7 @@ nsListControlFrame::MouseDown(nsIDOMEvent* aMouseEvent)
       mComboboxFrame->ShowDropDown(!isDroppedDown);
 
       if (isDroppedDown) {
-        CaptureMouseEvents(GetPresContext(), PR_FALSE);
+        CaptureMouseEvents(mPresContext, PR_FALSE);
       }
     }
   }
@@ -2861,8 +3025,7 @@ nsresult
 nsListControlFrame::ScrollToFrame(nsIContent* aOptElement)
 {
   nsIScrollableView * scrollableView;
-  nsPresContext* presContext = GetPresContext();
+  GetScrollableView(mPresContext, &scrollableView);
-  GetScrollableView(presContext, &scrollableView);
 
   if (scrollableView) {
     // if null is passed in we scroll to 0,0
@@ -2872,7 +3035,7 @@ nsListControlFrame::ScrollToFrame(nsIContent* aOptElement)
     }
   
     // otherwise we find the content's frame and scroll to it
-    nsIPresShell *presShell = presContext->PresShell();
+    nsIPresShell *presShell = mPresContext->PresShell();
     nsIFrame * childframe;
     nsresult result;
     if (aOptElement) {
@@ -2898,7 +3061,7 @@ nsListControlFrame::ScrollToFrame(nsIContent* aOptElement)
         nsRect fRect = childframe->GetRect();
         nsPoint pnt;
         nsIView * view;
-        childframe->GetOffsetFromView(presContext, pnt, &view);
+        childframe->GetOffsetFromView(mPresContext, pnt, &view);
 
         // This change for 33421 (remove this comment later)
 
@@ -3306,7 +3469,7 @@ nsListControlFrame::KeyPress(nsIDOMEvent* aKeyEvent)
     // because this isn't needed for Gfx
     if (IsInDropDownMode() == PR_TRUE) {
       // Don't flush anything but reflows lest it destroy us
-      GetPresContext()->PresShell()->
+      mPresContext->PresShell()->
         GetDocument()->FlushPendingNotifications(Flush_OnlyReflow);
     }
     REFLOW_DEBUG_MSG2("  After: %d\n", newIndex);
@@ -3376,3 +3539,40 @@ IGNORE_EVENT(DragMove)
 #undef FORWARD_EVENT
 #undef IGNORE_EVENT
 
+/*=============== Timer Related Code ======================*/
+nsresult
+nsListControlFrame::StartUpdateTimer(nsPresContext * aPresContext)
+{
+
+  if (mUpdateTimer == nsnull) {
+    nsresult result = NS_NewUpdateTimer(&mUpdateTimer);
+    if (NS_FAILED(result))
+      return result;
+
+    mUpdateTimer->Init(this, 0); // delay "0"
+  }
+
+  if (mUpdateTimer != nsnull) {
+    return mUpdateTimer->Start(aPresContext);
+  }
+
+  return NS_ERROR_FAILURE;
+}
+
+void
+nsListControlFrame::StopUpdateTimer()
+{
+  if (mUpdateTimer != nsnull) {
+    mUpdateTimer->Stop();
+  }
+}
+
+void
+nsListControlFrame::ItemsHaveBeenRemoved(nsPresContext * aPresContext)
+{
+  // Only adjust things if it is a combobox
+  // removing items on a listbox should effect anything
+  if (IsInDropDownMode()) {
+    ResetList(aPresContext);
+  }
+}

layout/forms/nsListControlFrame.h

@@ -67,6 +67,7 @@ class nsPresContext;
 class nsVoidArray;
 class nsIScrollableView;
 
+class nsSelectUpdateTimer;
 class nsVoidArray;
 class nsListEventListener;
 
@@ -82,6 +83,7 @@ class nsListControlFrame : public nsHTMLScrollFrame,
 {
 public:
   friend nsresult NS_NewListControlFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame);
+  friend class nsSelectUpdateTimer;
 
    // nsISupports
   NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
@@ -231,7 +233,7 @@ protected:
   PRBool     IsClickingInCombobox(nsIDOMEvent* aMouseEvent);
   void       AdjustIndexForDisabledOpt(PRInt32 aStartIndex, PRInt32 &anNewIndex,
                                        PRInt32 aNumOptions, PRInt32 aDoAdjustInc, PRInt32 aDoAdjustIncNext);
-  virtual void ResetList();
+  virtual void ResetList(nsPresContext* aPresContext, nsVoidArray * aInxList = nsnull);
 
   nsListControlFrame(nsIPresShell* aShell, nsIDocument* aDocument);
   virtual ~nsListControlFrame();
@@ -267,6 +269,11 @@ protected:
   PRBool   HandleListSelection(nsIDOMEvent * aDOMEvent, PRInt32 selectedIndex);
   void     InitSelectionRange(PRInt32 aClickedIndex);
 
+  // Timer Methods
+  nsresult StartUpdateTimer(nsPresContext * aPresContext);
+  void     StopUpdateTimer();
+  void     ItemsHaveBeenRemoved(nsPresContext * aPresContext);
+
   // Data Members
   PRInt32      mStartSelectionIndex;
   PRInt32      mEndSelectionIndex;
@@ -281,15 +288,20 @@ protected:
   PRBool       mIsAllContentHere;
   PRPackedBool mIsAllFramesHere;
   PRPackedBool mHasBeenInitialized;
-  PRPackedBool mNeedToReset;
+  PRPackedBool mDoneWithInitialReflow;
 
   PRPackedBool mOverrideReflowOpt;
 
+  nsPresContext* mPresContext;             // XXX: Remove the need to cache the pres context.
+
   nsRefPtr<nsListEventListener> mEventListener;
 
   PRInt16 mPassId;
   nscoord mCachedDesiredMEW;
 
+  // Update timer
+  nsSelectUpdateTimer * mUpdateTimer;
+
   nsIFrame* mDummyFrame;
 
   //Resize Reflow OpitmizationSize;

layout/html/forms/src/nsListControlFrame.cpp

@@ -90,6 +90,9 @@
 #include "nsIDOMMouseMotionListener.h"
 #include "nsIDOMKeyListener.h"
 
+// Timer Includes
+#include "nsITimer.h"
+
 // Constants
 const nscoord kMaxDropDownRows          = 20; // This matches the setting for 4.x browsers
 const PRInt32 kDefaultMultiselectHeight = 4; // This is compatible with 4.x browsers
@@ -279,21 +282,169 @@ if (aReflowState.mComputedWidth != NS_UNCONSTRAINEDSIZE) { \
 //-- Done with macros
 //------------------------------------------------------
 
+//---------------------------------------------------
+//-- Update Timer Stuff
+//---------------------------------------------------
+class nsSelectUpdateTimer : public nsITimerCallback
+{
+public:
+
+  NS_DECL_ISUPPORTS
+
+  nsSelectUpdateTimer()
+      : mPresContext(nsnull), mDelay(0), mHasBeenNotified(PR_FALSE), 
+        mItemsAdded(PR_FALSE), mItemsRemoved(PR_FALSE), mItemsInxSet(PR_FALSE)
+  {
+  }
+
+  virtual ~nsSelectUpdateTimer();
+  NS_DECL_NSITIMERCALLBACK
+
+  // Additional Methods
+  nsresult Start(nsPresContext *aPresContext) 
+  {
+    mPresContext = aPresContext;
+
+    nsresult result = NS_OK;
+    if (!mTimer) {
+      mTimer = do_CreateInstance("@mozilla.org/timer;1", &result);
+
+      if (NS_FAILED(result))
+        return result;
+    }
+    result = mTimer->InitWithCallback(this, mDelay, nsITimer::TYPE_ONE_SHOT);
+
+    if (mHasBeenNotified) {
+      mItemsAdded      = PR_FALSE;
+      mItemsRemoved    = PR_FALSE;
+      mItemsInxSet     = PR_FALSE;
+      mHasBeenNotified = PR_FALSE;
+      mInxArray.Clear();
+    }
+
+    return result;
+  }
+
+  void Init(nsListControlFrame *aList, PRUint32 aDelay)  { mListControl = aList; mDelay = aDelay; }
+  void Stop() { if (mTimer) mTimer->Cancel(); }
+
+  void AdjustIndexes(PRBool aInserted, PRInt32 aInx)
+  {
+    // remove the index from the list
+    if (!aInserted) {
+      PRInt32 inx = (PRInt32)mInxArray.IndexOf((void*)aInx);
+      if (inx > -1) {
+        mInxArray.RemoveElementAt(inx);
+      }
+    }
+
+    PRInt32 count = mInxArray.Count();
+    for (PRInt32 i=0;i<count;i++) {
+      PRInt32 inx = NS_PTR_TO_INT32(mInxArray[i]);
+      if (inx > aInx) {
+        mInxArray.ReplaceElementAt((void*)(inx+(aInserted?1:-1)), i);
+      }
+    }
+  }
+
+  void ItemAdded(PRInt32 aInx, PRInt32 aNumItems)
+  { 
+    mItemsAdded = PR_TRUE;
+    if (mInxArray.Count() > 0 && aInx <= aNumItems-1) {
+      AdjustIndexes(PR_TRUE, aInx);
+    }
+  }
+
+  void ItemRemoved(PRInt32 aInx, PRInt32 aNumItems) 
+  { 
+    mItemsRemoved = PR_TRUE;
+    if (mInxArray.Count() > 0 && aInx <= aNumItems) {
+      AdjustIndexes(PR_FALSE, aInx);
+    }
+  }
+
+  void ItemIndexSet(PRInt32 aInx)  
+  { 
+    mItemsInxSet = PR_TRUE;
+    mInxArray.AppendElement((void*)aInx);
+  }
+
+  PRPackedBool HasBeenNotified()      { return mHasBeenNotified; }
+
+private:
+  nsListControlFrame * mListControl;
+  nsCOMPtr<nsITimer>   mTimer;
+  nsPresContext*      mPresContext;
+  PRUint32             mDelay;
+  PRPackedBool         mHasBeenNotified;
+
+  PRPackedBool         mItemsAdded;
+  PRPackedBool         mItemsRemoved;
+  PRPackedBool         mItemsInxSet;
+  nsVoidArray          mInxArray;
+
+};
+
+NS_IMPL_ADDREF(nsSelectUpdateTimer)
+NS_IMPL_RELEASE(nsSelectUpdateTimer)
+NS_IMPL_QUERY_INTERFACE1(nsSelectUpdateTimer, nsITimerCallback)
+
+nsresult NS_NewUpdateTimer(nsSelectUpdateTimer **aResult)
+{
+  if (!aResult)
+    return NS_ERROR_NULL_POINTER;
+
+  *aResult = (nsSelectUpdateTimer*) new nsSelectUpdateTimer;
+
+  if (!aResult)
+    return NS_ERROR_OUT_OF_MEMORY;
+
+  NS_ADDREF(*aResult);
+
+  return NS_OK;
+}
+
+// nsITimerCallback
+NS_IMETHODIMP nsSelectUpdateTimer::Notify(nsITimer *timer)
+{
+  if (mPresContext && mListControl && !mHasBeenNotified) {
+    mHasBeenNotified = PR_TRUE;
+    if (mItemsAdded || mItemsInxSet) {
+      mListControl->ResetList(mPresContext, &mInxArray);
+    } else {
+      mListControl->ItemsHaveBeenRemoved(mPresContext);
+    }
+  }
+  return NS_OK;
+}
+
+nsSelectUpdateTimer::~nsSelectUpdateTimer()
+{
+  if (mTimer) {
+    mTimer->Cancel();
+  }
+}
+
+//---------------------------------------------------
+//-- DONE: Update Timer Stuff
+//---------------------------------------------------
+
+
 //---------------------------------------------------------
 nsListControlFrame::nsListControlFrame(nsIPresShell* aShell,
   nsIDocument* aDocument)
   : nsHTMLScrollFrame(aShell, PR_FALSE)
 {
   mComboboxFrame      = nsnull;
-  mChangesSinceDragStart = PR_FALSE;
   mButtonDown         = PR_FALSE;
   mMaxWidth           = 0;
   mMaxHeight          = 0;
+  mPresContext        = nsnull;
 
   mIsAllContentHere   = PR_FALSE;
   mIsAllFramesHere    = PR_FALSE;
   mHasBeenInitialized = PR_FALSE;
-  mNeedToReset        = PR_TRUE;
+  mDoneWithInitialReflow = PR_FALSE;
 
   mCacheSize.width             = -1;
   mCacheSize.height            = -1;
@@ -306,6 +457,7 @@ nsListControlFrame::nsListControlFrame(nsIPresShell* aShell,
   mOverrideReflowOpt           = PR_FALSE;
   mPassId                      = 0;
 
+  mUpdateTimer                 = nsnull;
   mDummyFrame                  = nsnull;
 
   REFLOW_COUNTER_INIT()
@@ -315,8 +467,13 @@ nsListControlFrame::nsListControlFrame(nsIPresShell* aShell,
 nsListControlFrame::~nsListControlFrame()
 {
   REFLOW_COUNTER_DUMP("nsLCF");
+  if (mUpdateTimer != nsnull) {
+    StopUpdateTimer();
+    NS_RELEASE(mUpdateTimer);
+  }
 
   mComboboxFrame = nsnull;
+  NS_IF_RELEASE(mPresContext);
 }
 
 // for Bug 47302 (remove this comment later)
@@ -426,16 +583,15 @@ void nsListControlFrame::PaintFocus(nsIRenderingContext& aRC, nsFramePaintLayer
     focusedIndex = mEndSelectionIndex;
   }
 
-  nsPresContext* presContext = GetPresContext();
   nsIScrollableView * scrollableView;
-  GetScrollableView(presContext, &scrollableView);
+  GetScrollableView(mPresContext, &scrollableView);
   if (!scrollableView) return;
 
-  nsIPresShell *presShell = presContext->GetPresShell();
+  nsIPresShell *presShell = mPresContext->GetPresShell();
   if (!presShell) return;
 
   nsIFrame* containerFrame;
-  GetOptionsContainer(presContext, &containerFrame);
+  GetOptionsContainer(mPresContext, &containerFrame);
   if (!containerFrame) return;
 
   nsIFrame * childframe = nsnull;
@@ -524,12 +680,12 @@ void nsListControlFrame::PaintFocus(nsIRenderingContext& aRC, nsFramePaintLayer
 
   // set up back stop colors and then ask L&F service for the real colors
   nscolor color;
-  presContext->LookAndFeel()->
+  mPresContext->LookAndFeel()->
     GetColor(lastItemIsSelected ?
              nsILookAndFeel::eColor_WidgetSelectForeground :
              nsILookAndFeel::eColor_WidgetSelectBackground, color);
 
-  nscoord onePixelInTwips = presContext->IntScaledPixelsToTwips(1);
+  nscoord onePixelInTwips = mPresContext->IntScaledPixelsToTwips(1);
 
   nsRect dirty;
   nscolor colors[] = {color, color, color, color};
@@ -692,8 +848,7 @@ NS_IMETHODIMP nsListControlFrame::GetAccessible(nsIAccessible** aAccessible)
 
   if (accService) {
     nsCOMPtr<nsIDOMNode> node = do_QueryInterface(mContent);
-    return accService->CreateHTMLListboxAccessible(node, GetPresContext(),
+    return accService->CreateHTMLListboxAccessible(node, mPresContext, aAccessible);
-                                                   aAccessible);
   }
 
   return NS_ERROR_FAILURE;
@@ -1011,7 +1166,7 @@ nsListControlFrame::Reflow(nsPresContext*          aPresContext,
     nsIContent * option = GetOptionContent(0);
     if (option != nsnull) {
       nsIFrame * optFrame;
-      nsresult result = GetPresContext()->PresShell()->
+      nsresult result = mPresContext->PresShell()->
         GetPrimaryFrameFor(option, &optFrame);
       if (NS_SUCCEEDED(result) && optFrame != nsnull) {
         nsStyleContext* optStyle = optFrame->GetStyleContext();
@@ -1633,6 +1788,8 @@ nsListControlFrame::Init(nsPresContext*  aPresContext,
                          nsStyleContext*  aContext,
                          nsIFrame*        aPrevInFlow)
 {
+  mPresContext = aPresContext;
+  NS_ADDREF(mPresContext);
   nsresult result = nsHTMLScrollFrame::Init(aPresContext, aContent, aParent, aContext,
                                             aPrevInFlow);
 
@@ -1890,7 +2047,7 @@ nsListControlFrame::MouseClicked(nsPresContext* aPresContext)
 NS_IMETHODIMP
 nsListControlFrame::OnContentReset()
 {
-  ResetList();
+  ResetList(mPresContext);
   return NS_OK;
 }
 
@@ -1899,7 +2056,7 @@ nsListControlFrame::OnContentReset()
 // those values as determined by the original HTML
 //---------------------------------------------------------
 void 
-nsListControlFrame::ResetList()
+nsListControlFrame::ResetList(nsPresContext* aPresContext, nsVoidArray * aInxList)
 {
   REFLOW_DEBUG_MSG("LBX::ResetList\n");
 
@@ -2098,9 +2255,9 @@ nsListControlFrame::DoneAddingChildren(PRBool aIsDone)
     // If so, then we can initialize;
     if (mIsAllFramesHere == PR_FALSE) {
       // if all the frames are now present we can initalize
-      if (CheckIfAllFramesHere()) {
+      if (CheckIfAllFramesHere() && mPresContext) {
         mHasBeenInitialized = PR_TRUE;
-        ResetList();
+        ResetList(mPresContext);
       }
     }
   }
@@ -2111,6 +2268,8 @@ nsListControlFrame::DoneAddingChildren(PRBool aIsDone)
 NS_IMETHODIMP
 nsListControlFrame::AddOption(nsPresContext* aPresContext, PRInt32 aIndex)
 {
+  StopUpdateTimer();
+
 #ifdef DO_REFLOW_DEBUG
   printf("---- Id: %d nsLCF %p Added Option %d\n", mReflowId, this, aIndex);
 #endif
@@ -2132,8 +2291,10 @@ nsListControlFrame::AddOption(nsPresContext* aPresContext, PRInt32 aIndex)
     return NS_OK;
   }
 
-  // Make sure we scroll to the selected option as needed
+  nsresult rv = StartUpdateTimer(aPresContext);
-  mNeedToReset = PR_TRUE;
+  if (NS_SUCCEEDED(rv) && mUpdateTimer) {
+    mUpdateTimer->ItemAdded(aIndex, numOptions);
+  }
   return NS_OK;
 }
 
@@ -2141,9 +2302,12 @@ nsListControlFrame::AddOption(nsPresContext* aPresContext, PRInt32 aIndex)
 NS_IMETHODIMP
 nsListControlFrame::RemoveOption(nsPresContext* aPresContext, PRInt32 aIndex)
 {
-  // Need to reset if we're a dropdown
+  StopUpdateTimer();
-  if (IsInDropDownMode()) {
+  nsresult rv = StartUpdateTimer(aPresContext);
-    mNeedToReset = PR_TRUE;
+  if (NS_SUCCEEDED(rv) && mUpdateTimer) {
+    PRInt32 numOptions;
+    GetNumberOfOptions(&numOptions);
+    mUpdateTimer->ItemRemoved(aIndex, numOptions);
   }
 
   return NS_OK;
@@ -2243,7 +2407,7 @@ nsListControlFrame::ComboboxFinish(PRInt32 aIndex)
       mComboboxFrame->RedisplaySelectedText();
     }
 
-    mComboboxFrame->RollupFromList(GetPresContext());
+    mComboboxFrame->RollupFromList(mPresContext);
   }
 
   return NS_OK;
@@ -2279,7 +2443,7 @@ nsListControlFrame::FireOnChange()
   nsEventStatus status = nsEventStatus_eIgnore;
   nsEvent event(NS_FORM_CHANGE);
 
-  nsIPresShell *presShell = GetPresContext()->GetPresShell();
+  nsIPresShell *presShell = mPresContext->GetPresShell();
   if (presShell) {
     rv = presShell->HandleEventWithTarget(&event, this, nsnull,
                                            NS_EVENT_FLAG_INIT, &status);
@@ -2433,25 +2597,26 @@ nsListControlFrame::DidReflow(nsPresContext*           aPresContext,
                               const nsHTMLReflowState*  aReflowState,
                               nsDidReflowStatus         aStatus)
 {
-  nsresult rv;
-  
   if (PR_TRUE == IsInDropDownMode()) 
   {
     //SyncViewWithFrame();
     mState &= ~NS_FRAME_SYNC_FRAME_AND_VIEW;
-    rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
+    nsresult rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
     mState |= NS_FRAME_SYNC_FRAME_AND_VIEW;
     SyncViewWithFrame(aPresContext);
+    return rv;
   } else {
-    rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
+    nsresult rv = nsHTMLScrollFrame::DidReflow(aPresContext, aReflowState, aStatus);
+    PRInt32 selectedIndex = mEndSelectionIndex;
+    if (selectedIndex == kNothingSelected) {
+      GetSelectedIndex(&selectedIndex);
+    }
+    if (!mDoneWithInitialReflow && selectedIndex != kNothingSelected) {
+      ScrollToIndex(selectedIndex);
+      mDoneWithInitialReflow = PR_TRUE;
+    }
+    return rv;
   }
-
-  if (mNeedToReset) {
-    mNeedToReset = PR_FALSE;
-    ResetList();
-  }
-
-  return rv;
 }
 
 nsIAtom*
@@ -2545,13 +2710,13 @@ nsListControlFrame::MouseUp(nsIDOMEvent* aMouseEvent)
           nsevent->PreventBubble();
         }
       } else {
-        CaptureMouseEvents(GetPresContext(), PR_FALSE);
+        CaptureMouseEvents(mPresContext, PR_FALSE);
         return NS_OK;
       }
-      CaptureMouseEvents(GetPresContext(), PR_FALSE);
+      CaptureMouseEvents(mPresContext, PR_FALSE);
       return NS_ERROR_FAILURE; // means consume event
     } else {
-      CaptureMouseEvents(GetPresContext(), PR_FALSE);
+      CaptureMouseEvents(mPresContext, PR_FALSE);
       return NS_OK;
     }
   }
@@ -2595,7 +2760,7 @@ nsListControlFrame::MouseUp(nsIDOMEvent* aMouseEvent)
           nsevent->PreventBubble();
         }
 
-        CaptureMouseEvents(GetPresContext(), PR_FALSE);
+        CaptureMouseEvents(mPresContext, PR_FALSE);
         return NS_ERROR_FAILURE;
       }
 
@@ -2611,7 +2776,7 @@ nsListControlFrame::MouseUp(nsIDOMEvent* aMouseEvent)
     }
   } else {
     REFLOW_DEBUG_MSG(">>>>>> Didn't find");
-    CaptureMouseEvents(GetPresContext(), PR_FALSE);
+    CaptureMouseEvents(mPresContext, PR_FALSE);
     // Notify
     if (mChangesSinceDragStart) {
       // reset this so that future MouseUps without a prior MouseDown
@@ -2662,13 +2827,12 @@ nsListControlFrame::FireMenuItemActiveEvent()
   nsCOMPtr<nsIDOMEvent> event;
   nsCOMPtr<nsIEventListenerManager> manager;
   mContent->GetListenerManager(getter_AddRefs(manager));
-  nsPresContext* presContext = GetPresContext();
   if (manager &&
-      NS_SUCCEEDED(manager->CreateEvent(presContext, nsnull, NS_LITERAL_STRING("Events"), getter_AddRefs(event)))) {
+      NS_SUCCEEDED(manager->CreateEvent(mPresContext, nsnull, NS_LITERAL_STRING("Events"), getter_AddRefs(event)))) {
     event->InitEvent(NS_LITERAL_STRING("DOMMenuItemActive"), PR_TRUE, PR_TRUE);
     PRBool noDefault;
-    presContext->EventStateManager()->DispatchNewEvent(mContent, event,
+    mPresContext->EventStateManager()->DispatchNewEvent(mContent, event,
-                                                       &noDefault);
+                                                        &noDefault);
   }
 }
 #endif
@@ -2692,7 +2856,7 @@ nsListControlFrame::GetIndexFromDOMEvent(nsIDOMEvent* aMouseEvent,
   mouseEvent->GetTarget(getter_AddRefs(node));
   nsCOMPtr<nsIContent> content = do_QueryInterface(node);
   nsIFrame * frame;
-  GetPresContext()->PresShell()->GetPrimaryFrameFor(content, &frame);
+  mPresContext->PresShell()->GetPrimaryFrameFor(content, &frame);
   printf("Target Frame: %p  this: %p\n", frame, this);
   printf("-->\n");
 #endif
@@ -2700,7 +2864,7 @@ nsListControlFrame::GetIndexFromDOMEvent(nsIDOMEvent* aMouseEvent,
   nsresult rv;
   
   nsCOMPtr<nsIContent> content;
-  GetPresContext()->EventStateManager()->
+  mPresContext->EventStateManager()->
     GetEventTargetContent(nsnull, getter_AddRefs(content));
 
   nsCOMPtr<nsIContent> optionContent = GetOptionFromContent(content);
@@ -2756,7 +2920,7 @@ nsListControlFrame::MouseDown(nsIDOMEvent* aMouseEvent)
   if (NS_SUCCEEDED(GetIndexFromDOMEvent(aMouseEvent, selectedIndex))) {
     if (!IsInDropDownMode()) {
       // Handle Like List
-      CaptureMouseEvents(GetPresContext(), PR_TRUE);
+      CaptureMouseEvents(mPresContext, PR_TRUE);
       mChangesSinceDragStart = HandleListSelection(aMouseEvent, selectedIndex);
     }
   } else {
@@ -2771,7 +2935,7 @@ nsListControlFrame::MouseDown(nsIDOMEvent* aMouseEvent)
       mComboboxFrame->ShowDropDown(!isDroppedDown);
 
       if (isDroppedDown) {
-        CaptureMouseEvents(GetPresContext(), PR_FALSE);
+        CaptureMouseEvents(mPresContext, PR_FALSE);
       }
     }
   }
@@ -2861,8 +3025,7 @@ nsresult
 nsListControlFrame::ScrollToFrame(nsIContent* aOptElement)
 {
   nsIScrollableView * scrollableView;
-  nsPresContext* presContext = GetPresContext();
+  GetScrollableView(mPresContext, &scrollableView);
-  GetScrollableView(presContext, &scrollableView);
 
   if (scrollableView) {
     // if null is passed in we scroll to 0,0
@@ -2872,7 +3035,7 @@ nsListControlFrame::ScrollToFrame(nsIContent* aOptElement)
     }
   
     // otherwise we find the content's frame and scroll to it
-    nsIPresShell *presShell = presContext->PresShell();
+    nsIPresShell *presShell = mPresContext->PresShell();
     nsIFrame * childframe;
     nsresult result;
     if (aOptElement) {
@@ -2898,7 +3061,7 @@ nsListControlFrame::ScrollToFrame(nsIContent* aOptElement)
         nsRect fRect = childframe->GetRect();
         nsPoint pnt;
         nsIView * view;
-        childframe->GetOffsetFromView(presContext, pnt, &view);
+        childframe->GetOffsetFromView(mPresContext, pnt, &view);
 
         // This change for 33421 (remove this comment later)
 
@@ -3306,7 +3469,7 @@ nsListControlFrame::KeyPress(nsIDOMEvent* aKeyEvent)
     // because this isn't needed for Gfx
     if (IsInDropDownMode() == PR_TRUE) {
       // Don't flush anything but reflows lest it destroy us
-      GetPresContext()->PresShell()->
+      mPresContext->PresShell()->
         GetDocument()->FlushPendingNotifications(Flush_OnlyReflow);
     }
     REFLOW_DEBUG_MSG2("  After: %d\n", newIndex);
@@ -3376,3 +3539,40 @@ IGNORE_EVENT(DragMove)
 #undef FORWARD_EVENT
 #undef IGNORE_EVENT
 
+/*=============== Timer Related Code ======================*/
+nsresult
+nsListControlFrame::StartUpdateTimer(nsPresContext * aPresContext)
+{
+
+  if (mUpdateTimer == nsnull) {
+    nsresult result = NS_NewUpdateTimer(&mUpdateTimer);
+    if (NS_FAILED(result))
+      return result;
+
+    mUpdateTimer->Init(this, 0); // delay "0"
+  }
+
+  if (mUpdateTimer != nsnull) {
+    return mUpdateTimer->Start(aPresContext);
+  }
+
+  return NS_ERROR_FAILURE;
+}
+
+void
+nsListControlFrame::StopUpdateTimer()
+{
+  if (mUpdateTimer != nsnull) {
+    mUpdateTimer->Stop();
+  }
+}
+
+void
+nsListControlFrame::ItemsHaveBeenRemoved(nsPresContext * aPresContext)
+{
+  // Only adjust things if it is a combobox
+  // removing items on a listbox should effect anything
+  if (IsInDropDownMode()) {
+    ResetList(aPresContext);
+  }
+}

layout/html/forms/src/nsListControlFrame.h

@@ -67,6 +67,7 @@ class nsPresContext;
 class nsVoidArray;
 class nsIScrollableView;
 
+class nsSelectUpdateTimer;
 class nsVoidArray;
 class nsListEventListener;
 
@@ -82,6 +83,7 @@ class nsListControlFrame : public nsHTMLScrollFrame,
 {
 public:
   friend nsresult NS_NewListControlFrame(nsIPresShell* aPresShell, nsIFrame** aNewFrame);
+  friend class nsSelectUpdateTimer;
 
    // nsISupports
   NS_IMETHOD QueryInterface(const nsIID& aIID, void** aInstancePtr);
@@ -231,7 +233,7 @@ protected:
   PRBool     IsClickingInCombobox(nsIDOMEvent* aMouseEvent);
   void       AdjustIndexForDisabledOpt(PRInt32 aStartIndex, PRInt32 &anNewIndex,
                                        PRInt32 aNumOptions, PRInt32 aDoAdjustInc, PRInt32 aDoAdjustIncNext);
-  virtual void ResetList();
+  virtual void ResetList(nsPresContext* aPresContext, nsVoidArray * aInxList = nsnull);
 
   nsListControlFrame(nsIPresShell* aShell, nsIDocument* aDocument);
   virtual ~nsListControlFrame();
@@ -267,6 +269,11 @@ protected:
   PRBool   HandleListSelection(nsIDOMEvent * aDOMEvent, PRInt32 selectedIndex);
   void     InitSelectionRange(PRInt32 aClickedIndex);
 
+  // Timer Methods
+  nsresult StartUpdateTimer(nsPresContext * aPresContext);
+  void     StopUpdateTimer();
+  void     ItemsHaveBeenRemoved(nsPresContext * aPresContext);
+
   // Data Members
   PRInt32      mStartSelectionIndex;
   PRInt32      mEndSelectionIndex;
@@ -281,15 +288,20 @@ protected:
   PRBool       mIsAllContentHere;
   PRPackedBool mIsAllFramesHere;
   PRPackedBool mHasBeenInitialized;
-  PRPackedBool mNeedToReset;
+  PRPackedBool mDoneWithInitialReflow;
 
   PRPackedBool mOverrideReflowOpt;
 
+  nsPresContext* mPresContext;             // XXX: Remove the need to cache the pres context.
+
   nsRefPtr<nsListEventListener> mEventListener;
 
   PRInt16 mPassId;
   nscoord mCachedDesiredMEW;
 
+  // Update timer
+  nsSelectUpdateTimer * mUpdateTimer;
+
   nsIFrame* mDummyFrame;
 
   //Resize Reflow OpitmizationSize;