MainWindow.blp

using Gtk 4.0;

template $ExampleWindow: Gtk.ApplicationWindow {
  title: 'Python - PyGObject - GTK';
  default-width: 683;
  default-height: 384;

  [titlebar]
  Gtk.HeaderBar header_bar {
    [end]
    Gtk.MenuButton {
      icon-name: 'open-menu-symbolic';
      menu-model: primary_menu;
    }
  }

  Gtk.Box {
    orientation: vertical;
    homogeneous: true;
    margin-top: 12;
    margin-end: 12;
    margin-bottom: 12;
    margin-start: 12;
    spacing: 12;

    Gtk.ListBox {
      selection-mode: none;

      styles [
        'boxed-list',
      ]

      Gtk.ListBoxRow {
        selectable: false;

        Gtk.Box {
          orientation: horizontal;

          Gtk.Label {
            label: 'Line 01';
            hexpand: true;
            xalign: 0;
            margin-top: 6;
            margin-end: 6;
            margin-bottom: 6;
            margin-start: 6;
          }

          Gtk.Switch {
            margin-top: 6;
            margin-end: 6;
            margin-bottom: 6;
            margin-start: 6;
          }
        }
      }

      Gtk.ListBoxRow {
        selectable: false;

        Gtk.Box {
          orientation: horizontal;

          Gtk.Label {
            label: 'Line 02';
            hexpand: true;
            xalign: 0;
            margin-top: 6;
            margin-end: 6;
            margin-bottom: 6;
            margin-start: 6;
          }

          Gtk.Switch {
            margin-top: 6;
            margin-end: 6;
            margin-bottom: 6;
            margin-start: 6;
          }
        }
      }

      Gtk.ListBoxRow {
        selectable: false;

        Gtk.Box {
          orientation: horizontal;

          Gtk.Label {
            label: 'Line 03';
            hexpand: true;
            xalign: 0;
            margin-top: 6;
            margin-end: 6;
            margin-bottom: 6;
            margin-start: 6;
          }

          Gtk.Switch {
            margin-top: 6;
            margin-end: 6;
            margin-bottom: 6;
            margin-start: 6;
          }
        }
      }
    }

    Gtk.ListBox {
      selection-mode: single;
      show-separators: true;
      vexpand: true;
      row-activated => $on_row_clicked();

      styles [
        'boxed-list',
      ]

      Gtk.ListBoxRow {
        Gtk.Label {
          label: 'Line 01';
        }
      }

      Gtk.ListBoxRow {
        Gtk.Label {
          label: 'Line 02';
        }
      }

      Gtk.ListBoxRow {
        Gtk.Label {
          label: 'Line 03';
        }
      }
    }
  }
}

menu primary_menu {
  section {
    item {
      label: _('Preferences');
      action: 'app.preferences';
    }
  }
}