the edge or corner from which the drag is started
the button being used to drag, or 0 for a keyboard-initiated drag
root window X coordinate of mouse click that began the drag
root window Y coordinate of mouse click that began the drag
timestamp of mouse click that began the drag (use gdk_event_get_time())
Begins a window resize operation (for a toplevel window).
This function assumes that the drag is controlled by the client pointer device, use gdk_window_begin_resize_drag_for_device() to begin a drag with a different device.