public bool drag_check_threshold (Widget widget, int start_x, int start_y, int current_x, int current_y)
Checks to see if a mouse drag starting at (
start_y) and ending at (
) has passed the GTK drag threshold, and thus should trigger the beginning of a drag-and-drop operation.
X coordinate of start of drag
Y coordinate of start of drag
current X coordinate
current Y coordinate
true if the drag threshold has been passed.