Adding drag auto-scrolling to trees. bug 28226, r=hyatt

widget/src/gtk/nsWidget.cpp

@@ -1847,6 +1847,20 @@ nsWidget::OnDragEnterSignal(GdkDragContext *aGdkDragContext,
 nsWidget::OnDragLeaveSignal(GdkDragContext   *context,
                             guint             aTime)
 {
+  // tell anyone who is interested to stop tracking drags, but only when
+  // we're leaving a window, not a child widget
+  nsCOMPtr<nsIWidget> parent ( dont_AddRef(GetParent()) );
+  if ( !parent ) {
+    printf("stopping\n");
+    nsCOMPtr<nsIDragService> dragServ ( do_GetService("component://netscape/widget/dragservice") );
+    if ( dragServ ) {
+      nsCOMPtr<nsIDragSession> session;
+      dragServ->GetCurrentSession ( getter_AddRefs(session) );
+      if ( session )
+        session->StopTracking();
+    }
+  }
+
   // update our drag context
   UpdateDragContext(NULL, NULL, aTime);
 
@@ -1898,6 +1912,16 @@ nsWidget::OnDragDropSignal(GtkWidget      *aWidget,
                            gint            y,
                            guint           aTime)
 {
+  // tell anyone who is interested to stop tracking drags, but only when
+  // we're leaving a window, not a child widget
+  nsCOMPtr<nsIDragService> dragServ ( do_GetService("component://netscape/widget/dragservice") );
+  if ( dragServ ) {
+    nsCOMPtr<nsIDragSession> session;
+    dragServ->GetCurrentSession ( getter_AddRefs(session) );
+    if ( session )
+      session->StopTracking();
+  }
+
   UpdateDragContext(aWidget, aDragContext, aTime);
 
   nsMouseEvent    event;