double click

[Lixin Tang <ltang myxo ugcs caltech edu>]

Hello,

I've been using drawing_area widget and connect button_press_event to
certain callback functions in order to handle user's single click on
objects in the drawing_area. But I have no clue about how to handle double
click event (I need double click to have different functionalities, say,
pop up a window). Is there a built-in event (signal) called
double_click_event(?) in general one can use or I have to write my own
"timer" to handle double click? Thanks in advance for any suggestion! 

- Tony