Downward drag after mouse-down is now causing bookmark bar folders to open, r...

views/view.h

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef VIEWS_VIEW_H_
 #define VIEWS_VIEW_H_
 
 #include "build/build_config.h"
 
 #include <algorithm>
@@ skipping 67 matching lines @@
  public:
   // Writes the data for the drag.
   virtual void WriteDragData(View* sender,
                              int press_x,
                              int press_y,
                              OSExchangeData* data) = 0;
 
   // Returns the supported drag operations (see DragDropTypes for possible
   // values). A drag is only started if this returns a non-zero value.
   virtual int GetDragOperations(View* sender, int x, int y) = 0;
+
+  // Returns true if a drag operation can be started.
+  // |press_x| and |press_y| represent coordinates where mouse was initially
+  // pressed down. |x| and |y| are the current mouse coordinates.
+  virtual bool CanStartDrag(View* sender,
+                            int press_x,
+                            int press_y,
+                            int x,
+                            int y) = 0;
 };
 
-
 /////////////////////////////////////////////////////////////////////////////
 //
 // View class
 //
 //   A View is a rectangle within the views View hierarchy. It is the base
 //   class for all Views.
 //
 //   A View is a container of other Views (there is no such thing as a Leaf
 //   View - makes code simpler, reduces type conversion headaches, design
 //   mistakes etc)
@@ skipping 1138 matching lines @@
   // is going to be flipped horizontally (using the appropriate transform) on
   // right-to-left locales for this View.
   bool flip_canvas_on_paint_for_rtl_ui_;
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // VIEWS_VIEW_H_