XenAdmin.Wizards.PatchingWizard.PatchingWizard_SelectServers.PageLeave C# (CSharp) Method

        public override void PageLeave(PageLoadedDirection direction, ref bool cancel)
        {
            try
            {
                if (direction == PageLoadedDirection.Forward)
                {
                    if (!AllSelectedHostsConnected())
                    {
                        foreach (PatchingHostsDataGridViewRow row in dataGridViewHosts.Rows)
                            row.UpdateIcon();
                        dataGridViewHosts.Invalidate();
                        cancel = true;
                        return;
                    }

                    //Upload the patches to the masters if it is necessary
                    List<Host> masters = SelectedMasters;

                    //Do RBAC check
                    foreach (Host master in masters)
                    {
                        if (!(Role.CanPerform(new RbacMethodList("pool_patch.apply"), master.Connection)))
                        {
                            string nameLabel = master.Name;
                            Pool pool = Helpers.GetPoolOfOne(master.Connection);
                            if (pool != null)
                                nameLabel = pool.Name;

                            using (var dlg = new ThreeButtonDialog(new ThreeButtonDialog.Details(SystemIcons.Warning, string.Format(Messages.RBAC_UPDATES_WIZARD, master.Connection.Username, nameLabel), Messages.UPDATES_WIZARD)))
                            {
                                dlg.ShowDialog(this);
                            }

                            cancel = true;
                            base.PageLeave(direction, ref cancel);
                            return;
                        }
                    }
                }
                base.PageLeave(direction, ref cancel);
            }
            catch (Exception e)
            {
                log.Debug(e);
                throw;//better throw an exception rather than closing the wizard suddenly and silently
            }
        }