with FLTK.Widgets;
use FLTK.Widgets;
with FLTK.Widgets.Buttons;
use FLTK.Widgets.Buttons;
with FLTK.Widgets.Groups.Windows;
use FLTK.Widgets.Groups.Windows;
with Ada.Text_IO;
with Ada.Strings.Unbounded;
use Ada.Strings.Unbounded;


function Callback_Test return Integer is


    Main_View : Window := Create (0, 0, 300, 300, "Tester");
    Pusher : Button := Create (75, 75, 150, 150, "Push me");


    type My_Callback is new Widget_Callback with
        record
            Msg : Unbounded_String;
        end record;

    SC : aliased My_Callback := (Msg => To_Unbounded_String ("Hello!"));
    OC : aliased My_Callback := (Msg => To_Unbounded_String ("And again!"));

    overriding procedure Call
           (This : in     My_Callback;
            Item : in out Widget'Class) is
    begin
        Ada.Text_IO.Put_Line ("Pushed a button :O");
        Ada.Text_IO.Put_Line (To_String (This.Msg));
        if This.Msg = "Hello!" then
            Item.Set_Callback (OC'Access);
            Item.Set_Label ("Push me again!");
        else
            Item.Set_Callback (SC'Access);
            Item.Set_Label ("Push me");
        end if;
    end Call;


begin


    Main_View.Add (Pusher);
    Pusher.Set_Callback (SC'Access);
    Main_View.Show;

    return FLTK.Run;


end Callback_Test;