\ Listing 2: GTK+-Beispiel "Hello World" in Forth

needs GtkWindow
needs GtkButton

oop definitions  gtk api  decimal

:: ( wid data -- ) ." Hello World" cr ;  2 20 cb cb.hello

:: ( wid data -- ) gtk quit ;  2 20 cb cb.destroy

GtkWindow new window
GtkButton new button

: main ( -- )
    GTK_WINDOW_TOPLEVEL window init
    " destroy" cb.destroy 0 window signal connect drop   
    10 window border-width !
    "  Hello World " button init  window add
    " clicked" cb.hello 0 button signal connect drop
    window show all
    term? 0if  gtk main  bye  then
;

main  oop ??