Gtk.Widget.prototype.drag_check_threshold

function drag_check_threshold(start_x:Number, start_y:Number, current_x:Number, current_y:Number):Boolean {
    // Gjs wrapper for gtk_drag_check_threshold()
}

Checks to see if a mouse drag starting at (start_x, start_y) and ending at (current_x, current_y) has passed the GTK+ drag threshold, and thus should trigger the beginning of a drag-and-drop operation.