width by height. You can use this function to
force a widget to be either larger or smaller than it is. The
strange "usize" name dates from the early days of GTK+, and derives
from X Window System terminology. In many cases,
gtkWindowSetDefaultSize is a better choice for toplevel
windows than this function; setting the default size will still
allow users to shrink the window. Setting the usize will force them
to leave the window at least as large as the usize. When dealing
with window sizes, gtkWindowSetGeometryHints can be a useful
function as well.
WARNING: gtk_widget_set_usize has been deprecated since version 2.2 and should not be used in newly-written code. Use gtkWidgetSetSizeRequest instead.
gtkWidgetSetUsize(object, width, height)objectwidthheight