Fix up Clipboard on all platforms to behave similarly.

- Wpf: Can now specify more than one type in the clipboard by setting various properties.
- Wpf: Added protection when getting the value and retries 10 times after 100ms delay as some times it throws a com exception that it cannot open the clipboard.
- Gtk: Fix up Clipboard.Image so it doesn't wipe all other values in the clipboard
- Gtk: Setting Clipboard.Text sets all text variants, not just utf8.
- Gtk: Getting/Setting Clipboard.Html now works correctly
- Added unit tests to verify behaviour

Source/Eto.Gtk/Forms/ClipboardHandler.cs

@@ -4,6 +4,7 @@
 using System.Linq;
 using Eto.GtkSharp.Drawing;
 using System.Collections.Generic;
+using System.Text;
 
 namespace Eto.GtkSharp.Forms
 {
@@ -13,19 +14,20 @@ public class ClipboardHandler : WidgetHandler<Gtk.Clipboard, Clipboard>, Clipboa
 
 		class ClipboardData
 		{
-			public Gtk.TargetEntry Target { get; set; }
+			public string Type { get; set; }
 
 			public object Data { get; set; }
 
 			public GetClipboardData GetClipboardData { get; set; }
 
 			public void GetData(Gtk.SelectionData selectionData)
 			{
-				if (GetClipboardData != null)
-					GetClipboardData(this, selectionData);
+				GetClipboardData?.Invoke(this, selectionData);
 			}
 		}
 
+		Gtk.TargetList targets = new Gtk.TargetList();
+
 		readonly List<ClipboardData> clipboard = new List<ClipboardData>();
 
 		public ClipboardHandler()
@@ -35,8 +37,7 @@ public ClipboardHandler()
 
 		void Update()
 		{
-			var targets = clipboard.Select(r => r.Target);
-			Control.SetWithData(targets.ToArray(), (clip, selectionData, info) =>
+			Control.SetWithData((Gtk.TargetEntry[])targets, (clip, selectionData, info) =>
 			{
 				if (info < clipboard.Count)
 				{
@@ -45,15 +46,38 @@ void Update()
 				}
 			}, clip =>
 			{
-				
+
 			});
 		}
 
 		void AddEntry(string type, object data, GetClipboardData getData)
 		{
+			targets.Add(type, 0, (uint)clipboard.Count);
+			clipboard.Add(new ClipboardData
+			{
+				Type = type,
+				Data = data,
+				GetClipboardData = getData
+			});
+			Update();
+		}
+
+		void AddTextEntry(string data, GetClipboardData getData)
+		{
+			targets.AddTextTargets((uint)clipboard.Count);
+			clipboard.Add(new ClipboardData
+			{
+				Data = data,
+				GetClipboardData = getData
+			});
+			Update();
+		}
+
+		void AddImageEntry(object data, GetClipboardData getData)
+		{
+			targets.AddImageTargets((uint)clipboard.Count, false);
 			clipboard.Add(new ClipboardData
 			{
-				Target = new Gtk.TargetEntry(type, 0, (uint)clipboard.Count),
 				Data = data,
 				GetClipboardData = getData
 			});
@@ -74,44 +98,29 @@ Gtk.SelectionData GetSelectionData(string type)
 
 		public void SetString(string value, string type)
 		{
-			AddEntry(type, value, (data, selection) => selection.Text = data.Data as string);
+			AddEntry(type, value, (data, selection) => selection.Set(Gdk.Atom.Intern(data.Type, false), 8, Encoding.UTF8.GetBytes(data.Data as string)));
 		}
 
 		public string Html
 		{
-			set
-			{ 
-				AddEntry("text/html", value, (data, selection) => selection.Text = data.Data as string);
-			}
-			get
-			{
-				var selection = GetSelectionData("text/html");
-				return selection != null ? selection.Text : null;
-			}
+			set { SetString(value, "text/html"); }
+			get { return GetString("text/html"); }
 		}
 
 		public string Text
 		{
-			set
-			{ 
-				AddEntry("UTF8_STRING", value, (data, selection) => selection.Text = data.Data as string);
-			}
+			set { AddTextEntry(value, (data, selection) => selection.Text = data.Data as string); }
 			get { return Control.WaitForText(); }
-
 		}
 
 		public Image Image
 		{
 			set
 			{
-				var pixbuf = value.ControlObject as Gdk.Pixbuf;
-				/* TODO: AddEntry(type, value, delegate(ClipboardData data, Gtk.SelectionData selection) {
-					selection = value;	
-				});*/
-				if (pixbuf != null)
-					Control.Image = pixbuf;
-				else
+				var pixbuf = value.ToGdk();
+				if (pixbuf == null)
 					throw new NotSupportedException();
+				AddImageEntry(pixbuf, (data, selection) => selection.SetPixbuf(data.Data as Gdk.Pixbuf));
 			}
 			get
 			{
@@ -132,8 +141,12 @@ public void SetData(byte[] value, string type)
 
 		public string GetString(string type)
 		{
-			var selection = GetSelectionData(type);
-			return selection != null ? selection.Text : null;
+			var data = GetSelectionData(type)?.Data;
+			if (data != null)
+			{
+				return Encoding.UTF8.GetString(data);
+			}
+			return null;
 		}
 
 		public byte[] GetData(string type)
@@ -145,7 +158,9 @@ public byte[] GetData(string type)
 		public void Clear()
 		{
 			Control.Clear();
+			targets = new Gtk.TargetList();
 			clipboard.Clear();
+			Update();
 		}
 
 		public string[] Types

Source/Eto.Test/Eto.Test/Eto.Test - pcl.csproj

@@ -135,6 +135,7 @@
     <Compile Include="UnitTests\Drawing\FontTests.cs" />
     <Compile Include="UnitTests\Drawing\GraphicsTests.cs" />
     <Compile Include="UnitTests\Drawing\MatrixTests.cs" />
+    <Compile Include="UnitTests\Forms\ClipboardTests.cs" />
     <Compile Include="UnitTests\Forms\Controls\ComboBoxTests.cs" />
     <Compile Include="UnitTests\Forms\Controls\CustomCellTests.cs" />
     <Compile Include="UnitTests\Forms\Controls\NumericStepperTests.cs" />

Source/Eto.Test/Eto.Test/Sections/Behaviors/ClipboardSection.cs

@@ -19,6 +19,12 @@ public ClipboardSection()
 				clipboard.Text = "Some text";
 				Update();
 			};
+			var copyHtmlButton = new Button { Text = "Copy Html" };
+			copyHtmlButton.Click += (sender, e) =>
+			{
+				clipboard.Html = "Some <strong style='color:blue'>HTML</strong>";
+				Update();
+			};
 			var copyImageButton = new Button { Text = "Copy Image" };
 			copyImageButton.Click += (sender, e) =>
 			{
@@ -47,7 +53,7 @@ public ClipboardSection()
 						Orientation = Orientation.Horizontal, 
 						Spacing = 5,
 						Padding = new Padding(10),
-						Items = { copyTextButton, copyImageButton, pasteTextButton, clearButton }
+						Items = { copyTextButton, copyHtmlButton, copyImageButton, pasteTextButton, clearButton }
 					},
 					new StackLayoutItem(pasteData, expand: true)
 				}

Source/Eto.Test/Eto.Test/UnitTests/Forms/ClipboardTests.cs

@@ -0,0 +1,85 @@
+using Eto.Forms;
+using NUnit.Framework;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Eto.Test.UnitTests.Forms
+{
+	[TestFixture]
+	public class ClipboardTests : TestBase
+	{
+		[Test]
+		public void GettingAndSettingTextShouldNotCrash()
+		{
+			Invoke(() =>
+			{
+				for (int i = 0; i < 100; i++)
+				{
+					// this crashes on WPF on some machines.. don't know why as I can't repro the issue.
+					var clipboard = new Clipboard();
+					var val = "Hello" + i;
+					clipboard.Text = val;
+					Assert.AreEqual(val, clipboard.Text);
+				}
+			});
+		}
+
+		[Test]
+		public void SettingMultipleFormatsShouldWork()
+		{
+			Invoke(() =>
+			{
+				var byteData = new byte[] { 10, 20, 30 };
+				using (var clipboard = new Clipboard())
+				{
+					clipboard.Text = "Text";
+					clipboard.Html = "<strong>Some Html</strong>";
+					clipboard.SetString("woot", "eto-woot");
+					clipboard.SetData(byteData, "eto-byte-data");
+
+					Assert.AreEqual("Text", clipboard.Text);
+					Assert.AreEqual("<strong>Some Html</strong>", clipboard.Html);
+					Assert.AreEqual("woot", clipboard.GetString("eto-woot"));
+					Assert.AreEqual(byteData, clipboard.GetData("eto-byte-data"));
+
+					Assert.Contains("eto-woot", clipboard.Types);
+					Assert.Contains("eto-byte-data", clipboard.Types);
+				}
+
+				using (var clipboard = new Clipboard())
+				{
+					Assert.AreEqual("Text", clipboard.Text);
+					Assert.AreEqual("<strong>Some Html</strong>", clipboard.Html);
+					Assert.AreEqual("woot", clipboard.GetString("eto-woot"));
+					Assert.AreEqual(byteData, clipboard.GetData("eto-byte-data"));
+
+					Assert.Contains("eto-woot", clipboard.Types);
+					Assert.Contains("eto-byte-data", clipboard.Types);
+
+					clipboard.Clear();
+					CollectionAssert.DoesNotContain("eto-woot", clipboard.Types);
+					CollectionAssert.DoesNotContain("eto-byte-data", clipboard.Types);
+					Assert.AreEqual(null, clipboard.Text);
+					Assert.AreEqual(null, clipboard.Html);
+					Assert.AreEqual(null, clipboard.Image);
+					Assert.AreEqual(null, clipboard.GetString("eto-woot"));
+					Assert.AreEqual(null, clipboard.GetData("eto-byte-data"));
+				}
+
+				using (var clipboard = new Clipboard())
+				{
+					CollectionAssert.DoesNotContain("eto-woot", clipboard.Types);
+					CollectionAssert.DoesNotContain("eto-byte-data", clipboard.Types);
+					Assert.AreEqual(null, clipboard.Text);
+					Assert.AreEqual(null, clipboard.Html);
+					Assert.AreEqual(null, clipboard.Image);
+					Assert.AreEqual(null, clipboard.GetString("eto-woot"));
+					Assert.AreEqual(null, clipboard.GetData("eto-byte-data"));
+				}
+			});
+		}
+	}
+}

Source/Eto.WinForms/Forms/ClipboardHandler.cs

@@ -40,12 +40,12 @@ public string Html
 		{
 			set
 			{
-				Control.SetText(value ?? string.Empty, System.Windows.Forms.TextDataFormat.Html);
+				Control.SetText(value ?? string.Empty, swf.TextDataFormat.Html);
 				Update();
 			}
 			get
 			{
-				return swf.Clipboard.ContainsText(swf.TextDataFormat.Html) ? swf.Clipboard.GetText(swf.TextDataFormat.Html) : null;
+				return swf.Clipboard.ContainsText(swf.TextDataFormat.Html) ? swf.Clipboard.GetText(swf.TextDataFormat.Html)?.TrimEnd('\0') : null;
 			}
 		}
 
@@ -76,22 +76,22 @@ public Image Image
 			get
 			{
 				Image result = null;
-				
+
 				try
 				{
 					var sdimage = GetImageFromClipboard() as sd.Bitmap;
-					
+
 					if (sdimage != null)
 					{
 						var handler = new BitmapHandler(sdimage);
-						
+
 						result = new Bitmap(handler);
 					}
 				}
 				catch
 				{
 				}
-				
+
 				return result;
 			}
 		}
@@ -203,14 +203,7 @@ public string GetString(string type)
 			return null;
 		}
 
-		public string[] Types
-		{
-			get
-			{
-				var data = swf.Clipboard.GetDataObject();
-				return data != null ? data.GetFormats() : null;
-			}
-		}
+		public string[] Types => swf.Clipboard.GetDataObject()?.GetFormats();
 
 		public void Clear()
 		{