MultiTerm/MultiTerm.Wpf.CustomControl/ExtendedTabControl/ExtendedTabControl.cs

using System.Windows;
using System.Windows.Controls;

namespace MultiTerm.Wpf.CustomControl;

public class ExtendedTabControl : TabControl
{
    public static readonly RoutedEvent AddButtonClickedEvent;

    #region Dotnet Properties
    /// <summary>
    /// .NET Property for <see cref="AddButtonClickedEvent"/>
    /// </summary>
    public event RoutedEventHandler AddButtonClicked
    {
        add { this.AddHandler(AddButtonClickedEvent, value); }
        remove { this.RemoveHandler(AddButtonClickedEvent, value); }
    }
    #endregion

    static ExtendedTabControl()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(ExtendedTabControl), new FrameworkPropertyMetadata(typeof(ExtendedTabControl)));

        AddButtonClickedEvent = EventManager.RegisterRoutedEvent("AddButtonClicked",
            RoutingStrategy.Bubble, typeof(RoutedEventArgs),
            typeof(ExtendedTabControl));
    }

    public override void OnApplyTemplate()
    {
        base.OnApplyTemplate();

        // get button from template
        if (GetTemplateChild("addButton") is Button button)
        {
            button.Click += OnAddButtonClicked; ;
        }
    }

    private void OnAddButtonClicked(object sender, RoutedEventArgs e)
    {
        RoutedEventArgs args = new(AddButtonClickedEvent);
        RaiseEvent(args);
    }
}