This is a helper function for implementing DnD onto a gtk.list_box.ListBox.
The passed in row will be highlighted by setting the
gtk.types.StateFlags.DropActive state and any previously highlighted
row will be unhighlighted.
The row will also be unhighlighted when the widget gets
a drag leave event.
Add a drag highlight to a row.
This is a helper function for implementing DnD onto a gtk.list_box.ListBox. The passed in row will be highlighted by setting the gtk.types.StateFlags.DropActive state and any previously highlighted row will be unhighlighted.
The row will also be unhighlighted when the widget gets a drag leave event.