port from perforce

intromat/Intromat/Controls/SourceEditor.cs

@@ -0,0 +1,66 @@
+using System;
+using System.ComponentModel;
+using System.Windows;
+using ICSharpCode.AvalonEdit;
+
+namespace Intromat.Controls
+{
+    public class SourceEditor : TextEditor, INotifyPropertyChanged
+    {
+        /// <summary>
+        ///     The bindable text property dependency property
+        /// </summary>
+        public static readonly DependencyProperty TextProperty = DependencyProperty.Register("Text", typeof(string), typeof(SourceEditor), new FrameworkPropertyMetadata
+        {
+            DefaultValue = default(string),
+            BindsTwoWayByDefault = true,
+            PropertyChangedCallback = OnDependencyPropertyChanged
+        });
+
+        /// <summary>
+        ///     A bindable Text property
+        /// </summary>
+        public new string Text
+        {
+            get => (string)GetValue(TextProperty);
+            set
+            {
+                SetValue(TextProperty, value);
+                RaisePropertyChanged("Text");
+            }
+        }
+
+        public event PropertyChangedEventHandler? PropertyChanged;
+
+        protected static void OnDependencyPropertyChanged(DependencyObject obj, DependencyPropertyChangedEventArgs args)
+        {
+            var target = (SourceEditor)obj;
+            if (target.Document == null)
+                return;
+
+            var caretOffset = target.CaretOffset;
+            var newValue = args.NewValue ?? "";
+
+            target.Document.Text = (string)newValue;
+            target.CaretOffset = Math.Min(caretOffset, target.Document.Text.Length);
+        }
+
+        protected override void OnTextChanged(EventArgs e)
+        {
+            if (Document != null)
+                Text = Document.Text;
+
+            base.OnTextChanged(e);
+        }
+
+        /// <summary>
+        ///     Raises a property changed event
+        /// </summary>
+        /// <param name="property">The name of the property that updates</param>
+        public void RaisePropertyChanged(string property)
+        {
+            if (PropertyChanged != null)
+                PropertyChanged(this, new PropertyChangedEventArgs(property));
+        }
+    }
+}