AvalonEditのTextプロパティをbindableへ

BindableEditor.cs

using ICSharpCode.AvalonEdit;
using System;
using System.Windows;

namespace AvalonEditSample
{
    public class BindableEditor : TextEditor
    {
        public BindableEditor()
        {
        }
        public new string Text
        {
            get { return (string)GetValue(TextProperty); }
            set { SetValue(TextProperty, value); }
        }

        public string BaseText
        {
            get { return base.Text; }
            set { base.Text = value; }
        }

        public static DependencyProperty TextProperty =
        DependencyProperty.Register(nameof(Text), typeof(string), typeof(BindableEditor),
            new PropertyMetadata(string.Empty, (obj, args) =>
             {
                 var target = (BindableEditor)obj;
                 if (target.BaseText != (string)args.NewValue)
                     target.BaseText = (string)args.NewValue;
             })
        );

        protected override void OnTextChanged(EventArgs e)
        {
            if (Text != BaseText)
            {
                SetValue(TextProperty, BaseText);
            }
            base.OnTextChanged(e);
        }
    }
}