Fix notification handler for winforms

src/Termission.WinForms/Controls/NotificationHandler.cs

@@ -0,0 +1,86 @@
+using Eto.Drawing;
+using Eto.Forms;
+using System;
+using swf = System.Windows.Forms;
+using sd = System.Drawing;
+using Eto;
+using Eto.WinForms;
+using Eto.WinForms.Forms;
+
+namespace Juniansoft.Termission.WinForms.Controls
+{
+	public class NotificationHandler : WidgetHandler<swf.Control, Notification, Notification.ICallback>, Notification.IHandler
+	{
+		public string Message { get; set; }
+
+		public bool RequiresTrayIndicator
+		{
+			get { return true; }
+		}
+
+		public string Title { get; set; }
+
+		public string UserData { get; set; }
+
+		public Image ContentImage { get; set; }
+
+		static TrayIndicator s_sharedIndicator;
+
+		TrayIndicator GetSharedIndicator()
+		{
+			if (s_sharedIndicator == null)
+			{
+				s_sharedIndicator = new TrayIndicator
+				{
+					Image = Application.Instance?.MainForm?.Icon ?? sd.SystemIcons.Application.ToEto()
+				};
+			}
+			s_sharedIndicator.Show();
+			return s_sharedIndicator;
+		}
+
+		static readonly object NotificationHandler_Key = new object();
+
+		public void Show(TrayIndicator indicator = null)
+		{
+			indicator = indicator ?? GetSharedIndicator();
+			var notifyIcon = TrayIndicatorHandler.GetControl(indicator);
+
+			var currentNotification = indicator.Properties.Get<NotificationHandler>(NotificationHandler_Key);
+			if (currentNotification != null)
+			{
+				currentNotification.Unhook(notifyIcon);
+				indicator.Properties.Remove(NotificationHandler_Key);
+			}
+
+			notifyIcon.ShowBalloonTip(3000, Title, Message, swf.ToolTipIcon.None);
+			notifyIcon.BalloonTipClicked += Tray_BalloonTipClicked;
+			notifyIcon.BalloonTipClosed += Tray_BalloonTipClosed;
+			indicator.Properties.Set(NotificationHandler_Key, this);
+		}
+
+		void Unhook(swf.NotifyIcon notifyIcon)
+		{
+			if (notifyIcon == null)
+				return;
+			notifyIcon.BalloonTipClicked -= Tray_BalloonTipClicked;
+			notifyIcon.BalloonTipClosed -= Tray_BalloonTipClosed;
+			notifyIcon = null;
+		}
+
+		void Tray_BalloonTipClosed(object sender, EventArgs e)
+		{
+			Unhook(sender as swf.NotifyIcon);
+			s_sharedIndicator?.Hide();
+		}
+
+		void Tray_BalloonTipClicked(object sender, EventArgs e)
+		{
+			Unhook(sender as swf.NotifyIcon);
+			s_sharedIndicator?.Hide();
+
+			var app = ApplicationHandler.Instance;
+			app?.Callback.OnNotificationActivated(app.Widget, new NotificationEventArgs(ID, UserData));
+		}
+	}
+}

src/Termission.WinForms/Program.cs

@@ -5,6 +5,7 @@
 using System.Threading.Tasks;
 using System.Windows.Forms;
 using Eto;
+using Eto.Forms;
 using Eto.WinForms.Forms;
 using Eto.WinForms.Forms.Controls;
 using Juniansoft.MvvmReady;
@@ -43,6 +44,7 @@ private static void RegisterServices()
 
         private static void RegisterUIHandlers(Platform platform)
         {
+            platform.Add<Notification.IHandler>(() => new Controls.NotificationHandler());
             platform.Add<SyntaxHightlightTextArea.ISyntaxHightlightTextArea>(() => new SyntaxHightlightTextAreaHandler());
         }