Fixing bug 42345 - hook up NS_MOVE events when a toplevel window is moved

on Linux.  Also use get_root_origin instead of get_origin so that we
persist the correct position.  r=blizzard.

widget/src/gtk/nsGtkEventHandler.cpp

@@ -45,6 +45,8 @@
 //#define DEBUG_EVENTS 1
 #endif
 
+//#define DEBUG_MOVE
+
 static void
 dispatch_superwin_event(GdkEvent *event, nsWindow *window);
 
@@ -1007,3 +1009,35 @@ handle_superwin_flush(gpointer aData)
   nsWindow *window = (nsWindow *)aData;
   window->Update();
 }
+
+gboolean
+handle_configure_event(GtkWidget *w, GdkEventConfigure *conf, gpointer p)
+{
+  // This event handler is only installed on toplevel windows, because:
+  //  a) gdk_window_get_root_origin gives bad results for inner windows, and
+  //  b) we don't really need to worry about move events on inner windows
+
+  nsWindow *widget = (nsWindow *)p;
+
+  // Find out if the window position has changed
+  nsRect oldBounds;
+  widget->GetBounds(oldBounds);
+
+  nscoord x,y;
+  gdk_window_get_root_origin(w->window, &x, &y);
+
+  if ((oldBounds.x == x) && (oldBounds.y == y))
+    return PR_FALSE;
+
+#ifdef DEBUG_MOVE
+  printf("Window: Move from (%d,%d) to (%d,%d)\n", oldBounds.x, oldBounds.y,
+         x, y);
+#endif
+
+  nscoord relX, relY;
+  gdk_window_get_origin(w->window, &relX, &relY);
+
+  widget->OnMove(relX, relY);
+  return PR_FALSE;
+}
+

widget/src/gtk/nsGtkEventHandler.h

@@ -29,7 +29,7 @@
 
 class nsIWidget;
 
-gint handle_configure_event(GtkWidget *w, GdkEventConfigure *conf, gpointer p);
+gboolean handle_configure_event(GtkWidget *w, GdkEventConfigure *conf, gpointer p);
 void handle_size_allocate(GtkWidget *w, GtkAllocation *alloc, gpointer p);
 gint handle_expose_event(GtkWidget *w, GdkEventExpose *event, gpointer p);
 

widget/src/gtk/nsWidget.cpp

@@ -586,7 +586,7 @@ NS_IMETHODIMP nsWidget::Move(PRInt32 aX, PRInt32 aY)
 
 NS_IMETHODIMP nsWidget::Resize(PRInt32 aWidth, PRInt32 aHeight, PRBool aRepaint)
 {
-#if 0
+#ifdef DEBUG_MOVE
   printf("nsWidget::Resize %s (%p) to %d %d\n",
          (const char *) debug_GetName(mWidget),
          this,

widget/src/gtk/nsWindow.cpp

@@ -222,7 +222,11 @@ NS_IMETHODIMP nsWindow::WidgetToScreen(const nsRect& aOldRect, nsRect& aNewRect)
   {
     if (mMozArea->window)
     {
-      gdk_window_get_origin(mMozArea->window, &x, &y);
+      if (!GTK_WIDGET_MAPPED(mMozArea) || !GTK_WIDGET_REALIZED(mMozArea)) {
+        // get_root_origin will do Bad Things
+        return NS_ERROR_FAILURE;
+      }
+      gdk_window_get_root_origin(mMozArea->window, &x, &y);
       aNewRect.x = x + aOldRect.x;
       aNewRect.y = y + aOldRect.y;
     }
@@ -1892,6 +1896,10 @@ NS_METHOD nsWindow::CreateNative(GtkObject *parentWidget)
                              "size_allocate",
                              GTK_SIGNAL_FUNC(handle_size_allocate),
                              this);
+    gtk_signal_connect_after(GTK_OBJECT(mShell),
+                             "configure_event",
+                             GTK_SIGNAL_FUNC(handle_configure_event),
+                             this);
     break;
 
   case eWindowType_child: