full IDisposable implementation (#34)

* full implementation of IDisposable, not stable, lock and still leaking

* override dispose in popper to handle _content not yet in graphic tree (when never shown), test focusedWidget when disposing

* prevent canceling thread multiple times causing a deadlock

* test parent type when trying to close window

1 files changed, 3 insertions, 5 deletions

diff --git a/src/CrowThread.cs b/src/CrowThread.cs
index fbcdc956..823fe1a6 100644
--- a/src/CrowThread.cs
+++ b/src/CrowThread.cs
@@ -33,7 +33,7 @@ namespace Crow
 	/// Thread monitored by current interface with Finished event when state==Stopped
 	/// </summary>
 	public class CrowThread {
-		public bool cancel = false;
+		public bool cancelRequested = false;
 		Thread thread;
 		public event EventHandler Finished;
 		public GraphicObject Host;
@@ -53,11 +53,9 @@ namespace Crow
 		}
 		public void Start() { thread.Start();}
 		public void Cancel(){
-			if (thread.IsAlive){
-				cancel = true;
-				//cancelLoading = true;
+			if (thread.IsAlive & !cancelRequested){
+				cancelRequested = true;
 				thread.Join ();
-				//cancelLoading = false;
 			}
 			lock (Host.currentInterface.CrowThreads)
 				Host.currentInterface.CrowThreads.Remove (this);