gtk-window-begin-resize-drag (window edge button x y timestamp)

window -- a gtk-window widget
edge -- a gdk-window-edge position of the resize control
button -- an integer with the mouse button that initiated the drag
x -- an integer with the x position where the user clicked to initiate the drag, in root window coordinates
y -- an integer with the y position where the user clicked to initiate the drag
timestamp -- an unsigned integer with 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 or windowing system. Otherwise, GDK will try to emulate window resizing, potentially not all that well, depending on the windowing system.