let create_gui () =
let window = GWindow.window ~title:"ViewGraph"
~allow_shrink:true ~allow_grow:true () in
let vbox = GPack.vbox ~border_width:4 ~spacing:4 ~packing:window#add () in
let ui_m = create_menu () in
window#add_accel_group ui_m#get_accel_group ;
vbox#pack ~expand:false (ui_m#get_widget "/MenuBar") ;
let frame = GBin.frame ~label:"How to use this :" ~packing:vbox#pack () in
let _ = GMisc.label ~text:"\n Open the Help window to know more...\n"
~packing:frame#add () in
let pack = vbox#pack ~expand:true ~fill:true in
let canvas = ViewGraph_utils.create_scrolled_canvas pack in
let hbox = GPack.hbox ~spacing:4 ~packing:vbox#pack () in
let select_init_env =
ViewGraph_select.init ViewGraph_select.default_options
canvas (hbox#pack ~expand:true ~fill:true) in
let actions = match ui_m#get_action_groups with
| a::[] -> a | _ -> assert false
in
let open_action = actions#get_action "Open" in
let _ = open_action#connect#activate ~callback:(open_cb select_init_env) in
let _ = window#connect#destroy ~callback:quit_cb in
let _ = window#show () in
(canvas, select_init_env)