how to remove an actor from a St.ScrollView and add other, by pressing a button [javascript] [Gjs]

Question

I have the following code: in a St.ScrollView I have added a St.BoxLayout . The St.Scrollview is added in a menu.box.Now I want to create a St.Button, to remove the St.BoxLayout from St.ScrollView and add another St.BoxLayout there.I have tried to make a function "clicked" connected with the button, and do this:

    this.buttonnotifications.connect('clicked', this.displayNotifications);

    displayNotifications: function() {

      this.scrollbox.remove(this.vbox);
      this.menu.box.remove(this.scrollbox);
      this.scrollbox.add_actor(this.vbox1);
      this.menu.box.add(this.scrollbox);

},

but it does not work.A snippet of the code is below:

      this.buttonbox = new St.BoxLayout();
      this.buttontoday = new St.Button({ label: 'Today', width: 140, x_align: 1, style_class: 'selectbutton'});
      this.buttonnotifications = new St.Button({ label: 'Notifications', width: 140,  x_align: 1, style_class: 'selectbutton'});

      this.buttonbox.add_actor(this.buttontoday);
      this.buttonbox.add_actor(this.buttonnotifications);
      this.menu.box.add(this.buttonbox);

      this.scrollbox = new St.ScrollView({
                          height: 700,
                          width: 330,
                          hscrollbar_policy: 2,
                          vscrollbar_policy: 2,
                          enable_mouse_scrolling: true
                        });

      this.vbox = new St.BoxLayout({
                          //height: 1400,
                          //width: 330,
                          vertical: true,
                        //y_expand: true,
                          style_class: "datemenu-displays-box",
                          style: "border:10px;"
                        });

     this.vbox1 = new St.BoxLayout({
                          //height: 1400,
                          //width: 330,
                          vertical: true,
                        //y_expand: true,
                          style_class: "datemenu-displays-box",
                          style: "border:10px;"
                        });

      this.vbox.add_actor(this._date.actor);
      this.vbox.add_actor(this._calendar.actor);
      this.vbox1.add_actor(this._eventsSection.actor, {
                                               //x_fill: true
                                                 });
      this.vbox.add_actor(this._mediaSection.actor);
      this.vbox.add_actor(this._clocksSection.actor);
      this.vbox.add_actor(this._weatherSection.actor, {
                                                  //x_fill: true
                                                 });
      this.vbox1.add_actor(this._messageList.actor);

      this.scrollbox.add_actor(this.vbox);
      this.menu.box.add(this.scrollbox);     

In other words I want to remove the vbox and add vbox1 pressing the buttonnotifications. Any help will be appreciated. Thanks in advance.

Answer 1

I have managed to solve this by adding this code:

this.buttonnotifications.connect('clicked', this.displayNotifications.bind(this));

The difference to the previous code is

 .bind(this)

method.