I have a simple Gtk.TreeView with a Gtk.ListStore with four columns as the model. I want to be able to drag and drop rows within the TreeView and track row insertions, changes and deletions as they happen so I can implement undo/redo to drag and drop operations. I'm using PyGObject 3 and Python 3.2.
I thought that using methods under the Gtk.TreeDragSource and Gtk.TreeDragDest interfaces would suit my needs perfectly, with Gtk.TreeDragSource.drag_data_get() in my drag_data_get handler and Gtk.TreeDragDest.drag_data_received() or Gtk.tree_get_row_drag_data() in my drag_data_received handler. Basically, what I've tried looks something like this:
def drag_data_received(self, treeview, context, x, y, selection, info, time):
treeselection = tv.get_selection()
model, my_iter = treeselection.get_selected()
path = model.get_path(my_iter)
result = Gtk.TreeDragSource.drag_data_get(path, selection)
def drag_data_received(self, tv, context, x, y, selection, info, time):
result, model, row = Gtk.tree_get_row_drag_data(selection)
my_iter = model.get_iter(row)
data = [model.get_value(my_iter, i) for i in range(model.get_n_columns())]
drop_info = tv.get_dest_row_at_pos(x, y)
if drop_info:
path, position = drop_info
my_iter = model.get_iter(path)
if (position == Gtk.TreeViewDropPosition.BEFORE
or position == Gtk.TreeViewDropPosition.INTO_OR_BEFORE):
model.insert_before(my_iter, [data])
else:
model.insert_after(my_iter, [data])
else:
model.append([data])
if context.get_actions() == Gdk.DragAction.MOVE|Gdk.DragAction.DEFAULT:
context.finish(True, True, time)
return
This fails spectacularly - when Python hits the call to Gtk.TreeDragSource.drag_data_get(), Python crashes and my program window swiftly disappears. I don't even get to the drag_data_received handler. Can anyone point me to some example code showing how these methods using the TreeDragSource and TreeDragDest interfaces work? Any help much appreciated!
