MODULE headerbar ;

(*
   m2-GTK4 example - a header bar with window controls.

   A GtkApplicationWindow whose titlebar is a GtkHeaderBar:
     title widget      - a label
     packed start      - a "New" button (connected with GtkClosures.Connect2)
     packed end        - a GtkMenuButton with an application menu
                         (Bold toggle, Quit)
   plus the Ctrl+N / Ctrl+B / Ctrl+Q accelerators.

   Build:  make examples
   Run:    ./build/examples/headerbar
*)

FROM Gio IMPORT g_application_run, g_application_quit;
FROM GtkApplication IMPORT gtk_application_new;
FROM GtkApplicationWindow IMPORT gtk_application_window_new;
FROM GtkWindow IMPORT gtk_window_set_title, gtk_window_set_default_size,
   gtk_window_set_titlebar, gtk_window_set_child, gtk_window_present;
FROM GtkHeaderBar IMPORT gtk_header_bar_new, gtk_header_bar_set_title_widget,
   gtk_header_bar_pack_start, gtk_header_bar_pack_end;
FROM GtkMenuButton IMPORT gtk_menu_button_new,
   gtk_menu_button_set_menu_model, gtk_menu_button_set_icon_name;
FROM GtkLabel IMPORT gtk_label_new, gtk_label_set_text;
FROM GtkButton IMPORT gtk_button_new_with_label;
FROM GSimpleAction IMPORT g_simple_action_new, g_simple_action_new_stateful;
FROM GActionMap IMPORT g_action_map_add_action;
FROM GMenu IMPORT g_menu_new, g_menu_append;
FROM GVariant IMPORT g_variant_new_boolean, g_variant_get_boolean;
FROM GtkUtils IMPORT Connect, SetAccel;
FROM GtkClosures IMPORT Connect2;
FROM SYSTEM IMPORT ADDRESS, ADR;
FROM libc IMPORT printf;

CONST
   AppId = "org.example.m2gtk4.HeaderBar";

VAR
   app, status: ADDRESS;

PROCEDURE OnQuit (action: ADDRESS; param: ADDRESS; data: ADDRESS);
BEGIN
   g_application_quit(app)
END OnQuit;

(* GtkClosures.Handler2: void handler(instance, user_data) *)
PROCEDURE OnNew (instance: ADDRESS; user: ADDRESS);
BEGIN
   gtk_label_set_text(status, "New selected")
END OnNew;

PROCEDURE OnBold (action: ADDRESS; param: ADDRESS; data: ADDRESS);
BEGIN
   IF g_variant_get_boolean(param) # 0 THEN
      gtk_label_set_text(status, "Bold on")
   ELSE
      gtk_label_set_text(status, "Bold off")
   END
END OnBold;

PROCEDURE OnActivate (application: ADDRESS; data: ADDRESS);
VAR
   window, header, newButton, menuButton, menu, action, title: ADDRESS;
BEGIN
   (* app-scoped action: quit *)
   action := g_simple_action_new("quit", NIL);
   Connect(action, "activate", ADR(OnQuit), NIL);
   g_action_map_add_action(application, action);

   window := gtk_application_window_new(application);

   (* window-scoped stateful action: bold *)
   action := g_simple_action_new_stateful("bold", NIL,
                                          g_variant_new_boolean(0));
   Connect(action, "change-state", ADR(OnBold), NIL);
   g_action_map_add_action(window, action);

   (* header bar: title, start button, end-packed menu button *)
   title := gtk_label_new("m2-GTK4 Header Bar");
   header := gtk_header_bar_new();
   gtk_header_bar_set_title_widget(header, title);

   newButton := gtk_button_new_with_label("New");
   Connect2(newButton, "clicked", OnNew, NIL);
   gtk_header_bar_pack_start(header, newButton);

   menu := g_menu_new();
   g_menu_append(menu, "Bold", "win.bold");
   g_menu_append(menu, "Quit", "app.quit");
   menuButton := gtk_menu_button_new();
   gtk_menu_button_set_icon_name(menuButton, "open-menu-symbolic");
   gtk_menu_button_set_menu_model(menuButton, menu);
   gtk_header_bar_pack_end(header, menuButton);

   status := gtk_label_new("Ready");

   SetAccel(application, "app.quit", "<primary>q");
   SetAccel(application, "win.bold", "<primary>b");

   gtk_window_set_title(window, "m2-GTK4 Header Bar");
   gtk_window_set_default_size(window, 420, 220);
   gtk_window_set_titlebar(window, header);
   gtk_window_set_child(window, status);
   gtk_window_present(window)
END OnActivate;

VAR
   rc: INTEGER;
BEGIN
   app := gtk_application_new(AppId, 0);
   IF app = NIL THEN
      printf("gtk_application_new failed\n");
      HALT(1)
   END;
   Connect(app, "activate", ADR(OnActivate), NIL);
   rc := g_application_run(app, 0, NIL)
END headerbar.