reparent the view's descendant widgets when a view is re-inserted into a new view hierarchy position by paginated reflow. b=129034 r=roc+moz sr=kin

view/src/nsViewManager.cpp

@@ -2164,6 +2164,64 @@ NS_IMETHODIMP nsViewManager::GetKeyEventGrabber(nsIView *&aView)
   return NS_OK;
 }
 
+
+// Recursively reparent widgets if necessary 
+
+void nsViewManager::ReparentChildWidgets(nsIView* aView, nsIWidget *aNewWidget)
+{
+  PRBool hasWidget;
+  aView->HasWidget(&hasWidget);
+  if (hasWidget) {
+    // Check to see if the parent widget is the
+    // same as the new parent. If not then reparent
+    // the widget, otherwise there is nothing more
+    // to do for the view and its descendants
+    nsCOMPtr<nsIWidget> widget;
+    aView->GetWidget(*getter_AddRefs(widget));
+    nsCOMPtr<nsIWidget> parentWidget;
+    parentWidget = widget->GetParent();
+    if (parentWidget.get() != aNewWidget) {
+      widget->SetParent(aNewWidget);
+    }
+    return;
+  }
+
+  // Need to check each of the views children to see
+  // if they have a widget and reparent it.
+
+  nsView* view = NS_STATIC_CAST(nsView*, aView);
+  nsView *kid = view->GetFirstChild();
+  while (kid) {
+    ReparentChildWidgets(kid, aNewWidget);
+    kid = kid->GetNextSibling();
+  }
+}
+
+// Reparent a view and its descendant views widgets if necessary
+
+void nsViewManager::ReparentWidgets(nsIView* aView, nsIView *aParent)
+{
+  // Quickly determine whether the view has pre-existing children or a
+  // widget. In most cases the view will not have any pre-existing 
+  // children when this is called.  Only in the case
+  // where a view has been reparented by removing it from
+  // a reinserting it into a new location in the view hierarchy do we
+  // have to consider reparenting the existing widgets for the view and
+  // it's descendants.
+  nsView* view = NS_STATIC_CAST(nsView*, aView);
+  PRBool hasWidget;
+  aView->HasWidget(&hasWidget);
+  if (hasWidget || view->GetFirstChild()) {
+    nsCOMPtr<nsIWidget> parentWidget;
+    GetWidgetForView(aParent, getter_AddRefs(parentWidget));
+    if (parentWidget) {
+      ReparentChildWidgets(aView, parentWidget);
+      return;
+    }
+    NS_WARNING("Can not find a widget for the parent view");
+  }
+}
+
 NS_IMETHODIMP nsViewManager::InsertChild(nsIView *aParent, nsIView *aChild, nsIView *aSibling,
                                          PRBool aAfter)
 {
@@ -2188,6 +2246,7 @@ NS_IMETHODIMP nsViewManager::InsertChild(nsIView *aParent, nsIView *aChild, nsIV
           // insert at end of document order, i.e., before first view
           // this is the common case, by far
           parent->InsertChild(child, nsnull);
+          ReparentWidgets(child, parent);
         } else {
           // insert at beginning of document order, i.e., after last view
           nsView *kid = parent->GetFirstChild();
@@ -2198,6 +2257,7 @@ NS_IMETHODIMP nsViewManager::InsertChild(nsIView *aParent, nsIView *aChild, nsIV
           }
           // prev is last view or null if there are no children
           parent->InsertChild(child, prev);
+          ReparentWidgets(child, parent);
         }
       } else {
         nsView *kid = parent->GetFirstChild();
@@ -2212,9 +2272,11 @@ NS_IMETHODIMP nsViewManager::InsertChild(nsIView *aParent, nsIView *aChild, nsIV
         if (aAfter) {
           // insert after 'kid' in document order, i.e. before in view order
           parent->InsertChild(child, prev);
+          ReparentWidgets(child, parent);
         } else {
           // insert before 'kid' in document order, i.e. after in view order
           parent->InsertChild(child, kid);
+          ReparentWidgets(child, parent);
         }
       }
 #else // don't keep consistent document order, but order things by z-index instead
@@ -2233,6 +2295,7 @@ NS_IMETHODIMP nsViewManager::InsertChild(nsIView *aParent, nsIView *aChild, nsIV
         }
 
       parent->InsertChild(child, prev);
+      ReparentWidgets(child, parent);
 #endif
 
       UpdateTransCnt(nsnull, child);

view/src/nsViewManager.h

@@ -244,6 +244,8 @@ protected:
   void ProcessPendingUpdates(nsView *aView);
 
 private:
+  void ReparentChildWidgets(nsIView* aView, nsIWidget *aNewWidget);
+  void ReparentWidgets(nsIView* aView, nsIView *aParent);
   nsIRenderingContext *CreateRenderingContext(nsView &aView);
   void AddRectToDirtyRegion(nsView* aView, const nsRect &aRect) const;
   void UpdateTransCnt(nsView *oldview, nsView *newview);

widget/public/nsIWidget.h

@@ -320,6 +320,17 @@ class nsIWidget : public nsISupports {
 
     NS_IMETHOD Destroy(void) = 0;
 
+
+    /**
+     * Reparent a widget
+     *
+     * Change the widgets parent
+     *
+     * @param     aNewParent   new parent 
+     */
+    NS_IMETHOD SetParent(nsIWidget* aNewParent) = 0;
+
+
     /**
      * Return the parent Widget of this Widget or nsnull if this is a 
      * top level window

widget/src/windows/nsWindow.cpp

@@ -1622,6 +1622,18 @@ NS_METHOD nsWindow::Destroy()
   return NS_OK;
 }
 
+NS_IMETHODIMP nsWindow::SetParent(nsIWidget *aNewParent)
+{
+  if (aNewParent) {
+    HWND newParent = (HWND)aNewParent->GetNativeData(NS_NATIVE_WINDOW);
+    NS_ASSERTION(newParent, "Parent widget has a null native window handle");
+    ::SetParent(mWnd, newParent);
+    return NS_OK;
+  }
+  NS_WARNING("Null aNewParent passed to SetParent");
+  return NS_ERROR_FAILURE;
+}
+
 
 //-------------------------------------------------------------------------
 //

widget/src/windows/nsWindow.h

@@ -295,6 +295,7 @@ public:
                             nsNativeWidget aNativeParent = nsnull);
 
     NS_IMETHOD              Destroy();
+    NS_IMETHOD              SetParent(nsIWidget *aNewParent);
     virtual nsIWidget*      GetParent(void);
     NS_IMETHOD              Show(PRBool bState);
     NS_IMETHOD              IsVisible(PRBool & aState);

widget/src/xpwidgets/nsBaseWidget.cpp

@@ -252,6 +252,17 @@ NS_METHOD nsBaseWidget::Destroy()
 }
 
 
+//-------------------------------------------------------------------------
+//
+// Set this nsBaseWidget's parent
+//
+//-------------------------------------------------------------------------
+NS_IMETHODIMP nsBaseWidget::SetParent(nsIWidget* aNewParent)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+
 //-------------------------------------------------------------------------
 //
 // Get this nsBaseWidget parent

widget/src/xpwidgets/nsBaseWidget.h

@@ -78,6 +78,7 @@ public:
   NS_IMETHOD              GetClientData(void*& aClientData);
   NS_IMETHOD              SetClientData(void* aClientData);
   NS_IMETHOD              Destroy();
+  NS_IMETHOD              SetParent(nsIWidget* aNewParent);
   virtual nsIWidget*      GetParent(void);
   virtual nsIEnumerator*  GetChildren();
   virtual void            AddChild(nsIWidget* aChild);