Gtk.Window.prototype.set_deletable

function set_deletable(setting:Boolean):void {
    // Gjs wrapper for gtk_window_set_deletable()
}

By default, windows have a close button in the window frame. Some <link linkend="gtk-X11-arch">window managers</link> allow GTK+ to disable this button. If you set the deletable property to false using this function, GTK+ will do its best to convince the window manager not to show a close button. Depending on the system, this function may not have any effect when called on a window that is already visible, so you should call it before calling Gtk.Widget.prototype.show.

On Windows, this function always works, since there's no window manager policy involved.

Since 2.10