From d31efbe4cf9de97e9893e467fd47564755b64e7f Mon Sep 17 00:00:00 2001
From: Steven Kirk <grokys@gmail.com>
Date: Wed, 20 Apr 2016 13:41:05 +0200
Subject: [PATCH] Use weak reference in for Gesture last press.

---
 src/Perspex.Input/Gestures.cs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/Perspex.Input/Gestures.cs b/src/Perspex.Input/Gestures.cs
index 48e9d87f86..fb68cc5d69 100644
--- a/src/Perspex.Input/Gestures.cs
+++ b/src/Perspex.Input/Gestures.cs
@@ -18,7 +18,7 @@ namespace Perspex.Input
             RoutingStrategies.Bubble,
             typeof(Gestures));
 
-        private static IInteractive s_lastPress;
+        private static WeakReference s_lastPress;
 
         static Gestures()
         {
@@ -34,9 +34,9 @@ namespace Perspex.Input
 
                 if (e.ClickCount <= 1)
                 {
-                    s_lastPress = e.Source;
+                    s_lastPress = new WeakReference(e.Source);
                 }
-                else if (e.ClickCount == 2 && s_lastPress == e.Source)
+                else if (s_lastPress?.IsAlive == true && e.ClickCount == 2 && s_lastPress.Target == e.Source)
                 {
                     e.Source.RaiseEvent(new RoutedEventArgs(DoubleTappedEvent));
                 }
@@ -49,9 +49,9 @@ namespace Perspex.Input
             {
                 var e = (PointerReleasedEventArgs)ev;
 
-                if (s_lastPress == e.Source)
+                if (s_lastPress?.IsAlive == true && s_lastPress.Target == e.Source)
                 {
-                    s_lastPress.RaiseEvent(new RoutedEventArgs(TappedEvent));
+                    ((IInteractive)s_lastPress.Target).RaiseEvent(new RoutedEventArgs(TappedEvent));
                 }
             }
         }