MODULE layouts ;

(*
   m2-GTK4 example - the second container batch.

   A GtkPaned splits the window:
     start - a GtkFrame containing a GtkExpander
     end   - a GtkOverlay whose main child is a GtkListBox, with a
             corner label on top
   Activating a list row updates the status label underneath.

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

FROM Gio IMPORT g_application_run;
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_child, gtk_window_present;
FROM GtkBox IMPORT gtk_box_new, gtk_box_append;
FROM GtkEnums IMPORT GtkVertical, GtkHorizontal, GtkAlignEnd, GtkAlignStart,
   GtkSelectionSingle;
FROM GtkLabel IMPORT gtk_label_new, gtk_label_set_text;
FROM GtkWidget IMPORT gtk_widget_set_vexpand, gtk_widget_set_halign,
   gtk_widget_set_valign, gtk_widget_set_margin_top,
   gtk_widget_set_margin_end;
FROM GtkFrame IMPORT gtk_frame_new, gtk_frame_set_child;
FROM GtkExpander IMPORT gtk_expander_new, gtk_expander_set_child,
   gtk_expander_set_expanded;
FROM GtkPaned IMPORT gtk_paned_new, gtk_paned_set_start_child,
   gtk_paned_set_end_child, gtk_paned_set_position;
FROM GtkOverlay IMPORT gtk_overlay_new, gtk_overlay_set_child,
   gtk_overlay_add_overlay;
FROM GtkListBox IMPORT gtk_list_box_new, gtk_list_box_append,
   gtk_list_box_row_new, gtk_list_box_row_set_child,
   gtk_list_box_row_get_index, gtk_list_box_set_selection_mode;
FROM GtkClosures IMPORT Connect2, Connect3;
FROM GtkUtils IMPORT IntToStr, StrAppend;
FROM SYSTEM IMPORT ADDRESS;
FROM libc IMPORT printf;

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

VAR
   status: ADDRESS;

(* 3-argument: "row-activated" carries the GtkListBoxRow *)
PROCEDURE OnRowActivated (listbox: ADDRESS; row: ADDRESS; user: ADDRESS);
VAR
   buf: ARRAY [0..15] OF CHAR;
   line: ARRAY [0..63] OF CHAR;
BEGIN
   line[0] := 0C;
   StrAppend(line, "activated row ");
   IntToStr(gtk_list_box_row_get_index(row), buf);
   StrAppend(line, buf);
   gtk_label_set_text(status, line)
END OnRowActivated;

PROCEDURE OnActivate (application: ADDRESS; data: ADDRESS);
VAR
   window, box, paned, frame, expander, overlay, overlayLabel,
   listbox, row: ADDRESS;
   i: INTEGER;
   text: ARRAY [0..15] OF CHAR;
BEGIN
   status := gtk_label_new("Select a row");

   (* start pane: frame > expander > label *)
   expander := gtk_expander_new("Details");
   gtk_expander_set_child(expander, gtk_label_new("Collapsible content"));
   gtk_expander_set_expanded(expander, 1);
   frame := gtk_frame_new("Left pane");
   gtk_frame_set_child(frame, expander);

   (* end pane: overlay > list box, plus a top-right corner label *)
   listbox := gtk_list_box_new();
   gtk_list_box_set_selection_mode(listbox, GtkSelectionSingle);
   FOR i := 0 TO 4 DO
      IntToStr(i, text);
      row := gtk_list_box_row_new();
      gtk_list_box_row_set_child(row, gtk_label_new(text));
      gtk_list_box_append(listbox, row)
   END;

   overlayLabel := gtk_label_new("overlay");
   overlay := gtk_overlay_new();
   gtk_overlay_set_child(overlay, listbox);
   gtk_overlay_add_overlay(overlay, overlayLabel);
   gtk_widget_set_halign(overlayLabel, GtkAlignEnd);
   gtk_widget_set_valign(overlayLabel, GtkAlignStart);
   gtk_widget_set_margin_top(overlayLabel, 8);
   gtk_widget_set_margin_end(overlayLabel, 8);

   paned := gtk_paned_new(GtkHorizontal);
   gtk_paned_set_start_child(paned, frame);
   gtk_paned_set_end_child(paned, overlay);
   gtk_paned_set_position(paned, 180);
   gtk_widget_set_vexpand(paned, 1);

   Connect3(listbox, "row-activated", OnRowActivated, NIL);

   box := gtk_box_new(GtkVertical, 8);
   gtk_box_append(box, paned);
   gtk_box_append(box, status);

   window := gtk_application_window_new(application);
   gtk_window_set_title(window, "m2-GTK4 Layouts");
   gtk_window_set_default_size(window, 520, 340);
   gtk_window_set_child(window, box);
   gtk_window_present(window)
END OnActivate;

VAR
   app: ADDRESS;
BEGIN
   app := gtk_application_new(AppId, 0);
   IF app = NIL THEN
      printf("gtk_application_new failed\n");
      HALT(1)
   END;
   Connect2(app, "activate", OnActivate, NIL);
   g_application_run(app, 0, NIL)
END layouts.