Ext.Net.TabPanel.OnPreRender C# (CSharp) Method

        protected override void OnPreRender(EventArgs e)
        {
            if (this.AutoPostBack && this.DeferredRender)
            {
                for (int i = 0; i < this.Items.Count; i++)
                {
                    if (this.Items[i] is IContent)
                    {
                        if (!this.Items[i].HasLayout() || (this.Items[i].HasLayout() && this.ActiveTabIndex == i))
                        {
                            ((IContent)this.Items[i]).ContentContainer.Visible = (this.ActiveTabIndex == i);
                        }
                    }

                    foreach (Control control in this.Items[i].Controls)
                    {
                        control.Visible = this.ActiveTabIndex == i;
                    }
                }
            }
            
            bool registerTabMenu = this.DefaultTabMenu.Count > 0;

            if (!registerTabMenu)
            {
                foreach (BoxComponentBase tab in this.Items)
                {
                    if (tab.TabMenu.Count > 0)
                    {
                        registerTabMenu = true;
                        break;
                    }
                }
            }

            if (registerTabMenu)
            {
                bool tabMenuPluginExists = false;

                foreach (Plugin plugin in this.Plugins)
                {
                    if (plugin is TabMenu)
                    {
                        tabMenuPluginExists = true;
                        break;
                    }
                }

                if (!tabMenuPluginExists)
                {
                    this.Plugins.Add(new TabMenu());
                }
            }

            base.OnPreRender(e);
        }
    }