position of the resize control
mouse button that initiated the drag
X position where the user clicked to initiate the drag, in root window coordinates
Y position where the user clicked to initiate the drag
timestamp from the click event that initiated the drag
Starts resizing a window. This function is used if an application has window resizing controls. When GDK can support it, the resize will be done using the standard mechanism for the [window manager][gtk-X11-arch] or windowing system. Otherwise, GDK will try to emulate window resizing, potentially not all that well, depending on the windowing system.