From a5615e40a21f647e9a0737b0b4af6e12198081de Mon Sep 17 00:00:00 2001
From: Josh Aas <joshmoz@gmail.com>
Date: Mon, 21 Nov 2011 15:15:38 -0500
Subject: [PATCH] Bug 90268: Part 1, improve support for re-parenting native
 widgets. r=roc r=karlt

---
 widget/public/nsIWidget.h             | 14 +++++++++++---
 widget/src/cocoa/nsChildView.mm       | 28 +++++++++++++++------------
 widget/src/gtk2/nsWindow.cpp          | 12 +++++++++---
 widget/src/xpwidgets/nsBaseWidget.cpp | 15 ++++++++++++++
 widget/src/xpwidgets/nsBaseWidget.h   |  1 +
 5 files changed, 52 insertions(+), 18 deletions(-)

diff --git a/widget/public/nsIWidget.h b/widget/public/nsIWidget.h
index 93aaa4281e5..833d78de298 100644
--- a/widget/public/nsIWidget.h
+++ b/widget/public/nsIWidget.h
@@ -118,8 +118,8 @@ typedef nsEventStatus (* EVENT_CALLBACK)(nsGUIEvent *event);
 #endif
 
 #define NS_IWIDGET_IID \
-  { 0x32966f95, 0x89e0, 0x447a, \
-    { 0x91, 0x8d, 0x58, 0x53, 0xd6, 0x99, 0x4a, 0x72 } }
+  { 0xEAAF1019, 0x0CD8, 0x4DD8, \
+    { 0xBE, 0xB9, 0x8D, 0x8D, 0xEB, 0x52, 0xFC, 0xF6 } }
 
 /*
  * Window shadow styles
@@ -356,6 +356,14 @@ class nsIWidget : public nsISupports {
                 nsWidgetInitData *aInitData = nsnull,
                 bool             aForceUseIWidgetParent = false) = 0;
 
+    /**
+     * Set the event callback for a widget. If a device context is not
+     * provided then the existing device context will remain, it will
+     * not be nulled out.
+     */
+    NS_IMETHOD SetEventCallback(EVENT_CALLBACK aEventFunction,
+                                nsDeviceContext *aContext) = 0;
+
     /**
      * Attach to a top level widget. 
      *
@@ -398,7 +406,7 @@ class nsIWidget : public nsISupports {
     /**
      * Reparent a widget
      *
-     * Change the widgets parent
+     * Change the widget's parent. Null parents are allowed.
      *
      * @param     aNewParent   new parent 
      */
diff --git a/widget/src/cocoa/nsChildView.mm b/widget/src/cocoa/nsChildView.mm
index f8cdcfbc395..fdf16af495b 100644
--- a/widget/src/cocoa/nsChildView.mm
+++ b/widget/src/cocoa/nsChildView.mm
@@ -705,26 +705,30 @@ nsChildView::SetParent(nsIWidget* aNewParent)
 {
   NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;
 
-  NS_ENSURE_ARG(aNewParent);
-
   if (mOnDestroyCalled)
     return NS_OK;
 
-  // make sure we stay alive
   nsCOMPtr<nsIWidget> kungFuDeathGrip(this);
   
-  // remove us from our existing parent
-  if (mParentWidget)
+  if (mParentWidget) {
     mParentWidget->RemoveChild(this);
+  }
 
-  nsresult rv = ReparentNativeWidget(aNewParent);
-  if (NS_SUCCEEDED(rv))
-    mParentWidget = aNewParent;
+  if (aNewParent) {
+    ReparentNativeWidget(aNewParent);
+  } else {
+    [mView removeFromSuperview];
+    mParentView = nil;
+  }
+
+  mParentWidget = aNewParent;
+
+  if (mParentWidget) {
+    mParentWidget->AddChild(this);
+  }
 
-  // add us to the new parent
-  mParentWidget->AddChild(this);
   return NS_OK;
-  
+
   NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
 }
 
@@ -744,7 +748,7 @@ nsChildView::ReparentNativeWidget(nsIWidget* aNewParent)
 
   // we hold a ref to mView, so this is safe
   [mView removeFromSuperview];
-  mParentView   = newParentView;
+  mParentView = newParentView;
   [mParentView addSubview:mView];
   return NS_OK;
 
diff --git a/widget/src/gtk2/nsWindow.cpp b/widget/src/gtk2/nsWindow.cpp
index 612345b2f25..f3d2d4fe1e2 100644
--- a/widget/src/gtk2/nsWindow.cpp
+++ b/widget/src/gtk2/nsWindow.cpp
@@ -897,15 +897,17 @@ nsWindow::GetDPI()
 NS_IMETHODIMP
 nsWindow::SetParent(nsIWidget *aNewParent)
 {
-    if (mContainer || !mGdkWindow || !mParent) {
-        NS_NOTREACHED("nsWindow::SetParent - reparenting a non-child window");
+    if (mContainer || !mGdkWindow) {
+        NS_NOTREACHED("nsWindow::SetParent called illegally");
         return NS_ERROR_NOT_IMPLEMENTED;
     }
 
     NS_ASSERTION(!mTransientParent, "child widget with transient parent");
 
     nsCOMPtr<nsIWidget> kungFuDeathGrip = this;
-    mParent->RemoveChild(this);
+    if (mParent) {
+        mParent->RemoveChild(this);
+    }
 
     mParent = aNewParent;
 
@@ -1002,6 +1004,10 @@ nsWindow::ReparentNativeWidgetInternal(nsIWidget* aNewParent,
             NS_ABORT_IF_FALSE(!gdk_window_is_destroyed(aNewParentWindow),
                               "destroyed GdkWindow with widget");
             SetWidgetForHierarchy(mGdkWindow, aOldContainer, aNewContainer);
+
+            if (aOldContainer == gInvisibleContainer) {
+                CheckDestroyInvisibleContainer();
+            }
         }
 
         if (!mIsTopLevel) {
diff --git a/widget/src/xpwidgets/nsBaseWidget.cpp b/widget/src/xpwidgets/nsBaseWidget.cpp
index a0639ea3887..f76f3c52188 100644
--- a/widget/src/xpwidgets/nsBaseWidget.cpp
+++ b/widget/src/xpwidgets/nsBaseWidget.cpp
@@ -250,6 +250,21 @@ nsBaseWidget::CreateChild(const nsIntRect  &aRect,
   return nsnull;
 }
 
+NS_IMETHODIMP
+nsBaseWidget::SetEventCallback(EVENT_CALLBACK aEventFunction,
+                               nsDeviceContext *aContext)
+{
+  mEventCallback = aEventFunction;
+
+  if (aContext) {
+    NS_IF_RELEASE(mContext);
+    mContext = aContext;
+    NS_ADDREF(mContext);
+  }
+
+  return NS_OK;
+}
+
 // Attach a view to our widget which we'll send events to. 
 NS_IMETHODIMP
 nsBaseWidget::AttachViewToTopLevel(EVENT_CALLBACK aViewEventFunction,
diff --git a/widget/src/xpwidgets/nsBaseWidget.h b/widget/src/xpwidgets/nsBaseWidget.h
index 8d685fec885..bfa0c62777a 100644
--- a/widget/src/xpwidgets/nsBaseWidget.h
+++ b/widget/src/xpwidgets/nsBaseWidget.h
@@ -165,6 +165,7 @@ public:
               nsDeviceContext *aContext,
               nsWidgetInitData *aInitData = nsnull,
               bool             aForceUseIWidgetParent = false);
+  NS_IMETHOD              SetEventCallback(EVENT_CALLBACK aEventFunction, nsDeviceContext *aContext);
   NS_IMETHOD              AttachViewToTopLevel(EVENT_CALLBACK aViewEventFunction, nsDeviceContext *aContext);
   virtual ViewWrapper*    GetAttachedViewPtr();
   NS_IMETHOD              SetAttachedViewPtr(ViewWrapper* aViewWrapper);