Add resize-window and relayout-window

basis/ui/backend/gtk/gtk.factor

@@ -479,6 +479,8 @@ M: gtk-ui-backend (close-window) ( handle -- )
     window>> [ gtk_widget_destroy ] [ unregister-window ] bi
     event-loop? [ gtk_main_quit ] unless ;
 
+M: gtk-ui-backend resize-window [ handle>> window>> ] [ first2 ] bi* gtk_window_resize ;
+
 M: gtk-ui-backend set-title
     swap [ handle>> window>> ] [ utf8 string>alien ] bi*
     gtk_window_set_title ;

basis/ui/ui.factor

@@ -214,6 +214,13 @@ M: object close-window
     <flag> ui-notify-flag set-global
 ] "ui" add-startup-hook
 
+HOOK: resize-window ui-backend ( world dim -- )
+M: object resize-window 2drop ;
+
+: relayout-window ( gadget -- )
+  [ relayout ]
+  [ find-world [ dup pref-dim resize-window ] when* ] bi ;
+
 : with-ui ( quot: ( -- ) -- )
     ui-running? [ call( -- ) ] [ '[ init-ui @ ] (with-ui) ] if ;