--- a/GDBEventSubscription.st	Wed Sep 26 11:16:56 2018 +0100
+++ b/GDBEventSubscription.st	Fri Sep 28 09:56:36 2018 +0100
@@ -63,14 +63,53 @@
         args = 2 ifTrue: [ ^[ :anAnnouncement :anAnnouncer | anObject sensor pushUserEvent: aSelector for: anObject withArguments: (Array with: anAnnouncement with: anAnnouncer) ] ].
         self error: 'Couldn''t create block'.        
     ].
-    (anObject isKindOf: ApplicationModel) ifTrue:[ 
-        args = 0 ifTrue: [ ^[ anObject window sensor pushUserEvent: aSelector for: anObject ] ].
-        args = 1 ifTrue: [ ^[ :anAnnouncement | anObject window sensor pushUserEvent: aSelector for: anObject withArgument: anAnnouncement ] ].
-        args = 2 ifTrue: [ ^[ :anAnnouncement :anAnnouncer | anObject window sensor pushUserEvent: aSelector for: anObject withArguments: (Array with: anAnnouncement with: anAnnouncer) ] ].
+
+    "/ If the observer (receiver of events) is an application,
+    "/ then push the event processing to application's event
+    "/ queue. This avoids blocking of event dispatcher and ensures
+    "/ that UI is synchronized.
+    "/
+    "/ However, we must be carefull since application windows may 
+    "/ not yet be opened or fully initialized so we have to check
+    "/ for existence of sensor. If application/window is not fully 
+    "/ initialized, process the event as usual.
+    (anObject isKindOf: ApplicationModel) ifTrue:[
+        args = 0 ifTrue: [  ^[  | window |
+
+                                window := anObject window.
+                                window notNil 
+                                    ifTrue:[ window sensor pushUserEvent: aSelector for: anObject ]
+                                    ifFalse:[ anObject perform: aSelector ]
+                             ]
+        ].
+        args = 1 ifTrue: [  ^[ :anAnnouncement | | window |
+
+                                window := anObject window.
+                                window notNil 
+                                    ifTrue:[ window sensor pushUserEvent: aSelector for: anObject withArgument: anAnnouncement ]
+                                    ifFalse:[ anObject perform: aSelector with: anAnnouncement ]
+                             ]
+        ].
+        args = 1 ifTrue: [  ^[ :anAnnouncement :anAnnouncer | | window |
+        
+                                window := anObject window.
+                                window notNil 
+                                    ifTrue:[ window sensor pushUserEvent: aSelector for: anObject withArguments: (Array with: anAnnouncement with: anAnnouncer) ]
+                                    ifFalse:[ anObject perform: aSelector with: anAnnouncement with: anAnnouncer ]
+                             ].
+        ].
         self error: 'Couldn''t create block'.        
     ].
     ^ super blockFor: anObject withSelector: aSelector
 
     "Created: / 18-09-2014 / 00:10:31 / Jan Vrany <jan.vrany@fit.cvut.cz>"
+    "Modified: / 01-10-2018 / 17:30:56 / jv"
 ! !
 
+!GDBEventSubscription class methodsFor:'documentation'!
+
+version_HG
+
+    ^ '$Changeset: <not expanded> $'
+! !
+