enable_model_drag_source

Description:

public void enable_model_drag_source (ModifierType start_button_mask, TargetEntry targets, int n_targets, DragAction actions)

Turns this into a drag source for automatic DND.

this	a `GtkIconTreeView`
start_button_mask	Mask of allowed buttons to start drag
targets	the table of targets that the drag will support
n_targets	the number of items in `targets`
actions	the bitmask of possible actions for a drag from this widget