GdkDragContext drag_begin(array targets, GdkDragAction actions, int button, GdkEvent event);

Initiates a drag on the source side. The function only needs to be used when the application is starting drags itself, and is not needed when drag_source_set() is used.

Table 3. Method parameters

targets The targets (data formats) in which the source can provide the data.
actions A bitmask of the allowed drag actions for this drag.
button The button the user clicked to start the drag.
event The event that triggered the start of the drag.