def on_mouse_drag_enter(self, x, y):
children_under_mouse = self.__find_children_under_mouse(x, y)<EOL>if self.propagate_mouse_events:<EOL><INDENT>for child in children_under_mouse.entered:<EOL><INDENT>child.dispatch_event('<STR_LIT>', x, y)<EOL><DEDENT><DEDENT>
React to the mouse being dragged into this widget.

The ``on_mouse_drag_enter`` event is propagated to any children under 
the mouse.