Added drag/drop

src/AvaloniaEdit.Demo/MainWindow.xaml.cs

@@ -55,6 +55,7 @@ public MainWindow()
             _textEditor.TextArea.TextEntered += textEditor_TextArea_TextEntered;
             _textEditor.TextArea.TextEntering += textEditor_TextArea_TextEntering;
             _textEditor.Options.AllowToggleOverstrikeMode = true;
+            _textEditor.Options.EnableTextDragDrop = true;
             _textEditor.Options.ShowBoxForControlCharacters = true;
             _textEditor.Options.ColumnRulerPositions = new List<int>() { 80, 100 };
             _textEditor.TextArea.IndentationStrategy = new Indentation.CSharp.CSharpIndentationStrategy(_textEditor.Options);

src/AvaloniaEdit.Demo/Program.cs

@@ -1,4 +1,5 @@
-using Avalonia;
+using System;
+using Avalonia;
 
 namespace AvaloniaEdit.Demo
 {
@@ -9,6 +10,7 @@ public static AppBuilder BuildAvaloniaApp()
           => AppBuilder.Configure<App>().UsePlatformDetect();
 
         // The entry point. Things aren't ready yet
+        [STAThread]
         public static int Main(string[] args)
           => BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
     }

src/AvaloniaEdit/Document/DataObjectCopyingEventArgs.cs

@@ -0,0 +1,14 @@
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using AvaloniaEdit.Utils;
+
+namespace AvaloniaEdit.Document;
+
+public class DataObjectCopyingEventArgs(IDataObject dataObject, bool isDragDrop) :
+    RoutedEventArgs(DataObjectEx.DataObjectCopyingEvent)
+{
+    public bool CommandCancelled { get; private set; }
+    public IDataObject DataObject { get; } = dataObject;
+    public bool IsDragDrop { get; } = isDragDrop;
+    public void CancelCommand() => CommandCancelled = true;
+}

src/AvaloniaEdit/Editing/EditingCommandHandler.cs

@@ -25,6 +25,7 @@
 using Avalonia.Input;
 using AvaloniaEdit.Utils;
 using Avalonia.Controls;
+using static System.Net.Mime.MediaTypeNames;
 
 namespace AvaloniaEdit.Editing
 {
@@ -422,6 +423,14 @@ private static bool CopySelectedText(TextArea textArea)
             return true;
         }
 
+        public static bool ConfirmDataFormat(TextArea textArea, DataObject dataObject, string format)
+        {
+            return true;
+            ////var e = new DataObjectSettingDataEventArgs(dataObject, format);
+            ////textArea.RaiseEvent(e);
+            ////return !e.CommandCancelled;
+        }
+
         private static void SetClipboardText(string text, Visual visual)
         {
             try
@@ -526,6 +535,16 @@ private static async void OnPaste(object target, ExecutedRoutedEventArgs args)
             }
         }
 
+        internal static string GetTextToPaste(IDataObject dataObject, TextArea textArea)
+        {
+            if (dataObject.Contains(DataFormats.Text))
+            {
+                return GetTextToPaste((string)dataObject.Get(DataFormats.Text), textArea);
+            }
+
+            return null;
+        }
+
         internal static string GetTextToPaste(string text, TextArea textArea)
         {
             try

src/AvaloniaEdit/Editing/RectangleSelection.cs

@@ -18,6 +18,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
 using System.Text;
 using Avalonia;
@@ -383,24 +384,23 @@ public static bool PerformRectangularPaste(TextArea textArea, TextViewPosition s
             return false;
         }
 
-        // TODO: clipboard
-
-        ///// <summary>
-        ///// Gets the name of the entry in the DataObject that signals rectangle selections.
-        ///// </summary>
-        //public const string RectangularSelectionDataType = "AvalonEditRectangularSelection";
+        /// <summary>
+        /// Gets the name of the entry in the DataObject that signals rectangle selections.
+        /// </summary>
+        public const string RectangularSelectionDataType = "AvalonEditRectangularSelection";
 
-        //public override System.Windows.DataObject CreateDataObject(TextArea textArea)
-        //{
-        //	var data = base.CreateDataObject(textArea);
+        public override Avalonia.Input.DataObject CreateDataObject(TextArea textArea)
+        {
+            var data = base.CreateDataObject(textArea);
 
-        //	if (EditingCommandHandler.ConfirmDataFormat(textArea, data, RectangularSelectionDataType)) {
-        //		MemoryStream isRectangle = new MemoryStream(1);
-        //		isRectangle.WriteByte(1);
-        //		data.SetData(RectangularSelectionDataType, isRectangle, false);
-        //	}
-        //	return data;
-        //}
+            if (EditingCommandHandler.ConfirmDataFormat(textArea, data, RectangularSelectionDataType))
+            {
+                MemoryStream isRectangle = new MemoryStream(1);
+                isRectangle.WriteByte(1);
+                data.Set(RectangularSelectionDataType, isRectangle);
+            }
+            return data;
+        }
 
         /// <inheritdoc/>
         public override string ToString()

src/AvaloniaEdit/Editing/Selection.cs

@@ -20,6 +20,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
+using Avalonia.Input;
 using AvaloniaEdit.Document;
 using AvaloniaEdit.Utils;
 
@@ -262,37 +263,39 @@ public virtual bool Contains(int offset)
                    Segments.Any(s => s.Contains(offset, 0));
         }
 
-        // TODO: clipboard
-        ///// <summary>
-        ///// Creates a data object containing the selection's text.
-        ///// </summary>
-        //public virtual DataObject CreateDataObject(TextArea textArea)
-        //{
-        //	DataObject data = new DataObject();
-
-        //	// Ensure we use the appropriate newline sequence for the OS
-        //	string text = TextUtilities.NormalizeNewLines(GetText(), Environment.NewLine);
+        /// <summary>
+        /// Creates a data object containing the selection's text.
+        /// </summary>
+        public virtual DataObject CreateDataObject(TextArea textArea)
+        {
+            DataObject data = new DataObject();
 
-        //	// Enable drag/drop to Word, Notepad++ and others
-        //	if (EditingCommandHandler.ConfirmDataFormat(textArea, data, DataFormats.UnicodeText)) {
-        //		data.SetText(text);
-        //	}
+            // Ensure we use the appropriate newline sequence for the OS
+            string text = TextUtilities.NormalizeNewLines(GetText(), Environment.NewLine);
 
-        //	// Enable drag/drop to SciTe:
-        //	// We cannot use SetText, thus we need to use typeof(string).FullName as data format.
-        //	// new DataObject(object) calls SetData(object), which in turn calls SetData(Type, data),
-        //	// which then uses Type.FullName as format.
-        //	// We immitate that behavior here as well:
-        //	if (EditingCommandHandler.ConfirmDataFormat(textArea, data, typeof(string).FullName)) {
-        //		data.SetData(typeof(string).FullName, text);
-        //	}
+            // Enable drag/drop to Word, Notepad++ and others
+            if (EditingCommandHandler.ConfirmDataFormat(textArea, data, DataFormats.Text))
+            {
+                data.Set(DataFormats.Text, text);
+            }
 
-        //	// Also copy text in HTML format to clipboard - good for pasting text into Word
-        //	// or to the SharpDevelop forums.
-        //	if (EditingCommandHandler.ConfirmDataFormat(textArea, data, DataFormats.Html)) {
-        //		HtmlClipboard.SetHtml(data, CreateHtmlFragment(new HtmlOptions(textArea.Options)));
-        //	}
-        //	return data;
-        //}
+            // Enable drag/drop to SciTe:
+            // We cannot use SetText, thus we need to use typeof(string).FullName as data format.
+            // new DataObject(object) calls SetData(object), which in turn calls SetData(Type, data),
+            // which then uses Type.FullName as format.
+            // We immitate that behavior here as well:
+            ////if (EditingCommandHandler.ConfirmDataFormat(textArea, data, typeof(string).FullName))
+            ////{
+            ////    data.SetData(typeof(string).FullName, text);
+            ////}
+
+            // Also copy text in HTML format to clipboard - good for pasting text into Word
+            // or to the SharpDevelop forums.
+            ////if (EditingCommandHandler.ConfirmDataFormat(textArea, data, DataFormats.Html))
+            ////{
+            ////    HtmlClipboard.SetHtml(data, CreateHtmlFragment(new HtmlOptions(textArea.Options)));
+            ////}
+            return data;
+        }
     }
 }