[pygtk] Manual drag and drop

[Jeffrey Barish]

I am trying to implement a manual drag of a row in a treeview to another
location in the same treeview.  I need to initiate the drag manually
because there are conditions in which I want to disallow dragging of a
particular row.  I have figured out how to initiate the drag:

1. Grab the position of the initial mouse press event.
2. In a motion_notify_event handler, compare the latest position of the
mouse with the initial mouse press using drag_check_threshold.
3. When drag_check_threshold returns True, execute drag_begin.

My problem is that I am not able to end the drag.  When I release the mouse
button at a dropable location, nothing happens.  I have tried detecting all
the drag-related signals, but I don't get any of them when I release the
mouse button.  I even tried detecting button release, but I don't get it
until I escape out of the drag.  Any idea what I am missing?
-- 
Jeffrey Barish