method set_active b =
if b or (active <> b) then
begin
view#set_editable b;
view#set_cursor_visible b;
active <- b;
if b then
view#misc#grab_focus ()
else
(
self#clear;
for i = 1 to nb_waits do GMain.quit () done;
nb_waits <- 0
);
on_active_change b
end