All widgets that receive events (see FAQ 3.3) can attach to button_press_event to 'listen' for button presses. It may be necessary to alter the event mask for certain widgets (gtk.Window, for instance):

 window.add_events(gtk.gdk.BUTTON_PRESS_MASK)

You can easily capture a specific button press pattern by checking event.button and comparing event.type with the constants defined in gtk.gdk for multiple button presses. To do this, connect a handler like this one to "button_press_event" on your widget:

 def button_clicked(widget, event):
     # which button was clicked?
     if event.button == 1:
         print "left click"
     elif event.button == 2:
         print "middle click"
     elif event.button == 3:
         print "right click"

     # was it a multiple click?
     if event.type == gtk.gdk.BUTTON_PRESS:
         print "single click"
     elif event.type == gtk.gdk._2BUTTON_PRESS:
         print "double click"
     elif event.type == gtk.gdk._3BUTTON_PRESS:
         print "triple click. ouch, you hurt your user."

Note that it seems that, at least in PyGTK 0.6.x (confirm for 2.x), spawning a modal dialog when handling a double-click event causes a strange focus bug. I've experienced this personally, but this message confirms the problem: [mail.gnome.org] To work around it, I changed the modality using idle_add(win.set_modal, 1) before calling mainloop, but it's a very ugly fix.