Fix expose event handling

library/x11/events.factor

@@ -4,6 +4,8 @@ IN: x11
 USING: alien arrays errors gadgets hashtables io kernel math
 namespaces prettyprint sequences strings threads ;
 
+GENERIC: expose-event ( event window -- )
+
 GENERIC: resize-event ( event window -- )
 
 GENERIC: button-down-event ( event window -- )
@@ -45,6 +47,7 @@ GENERIC: client-event ( event window -- )
 
 : handle-event ( event window -- )
     over XAnyEvent-type {
+        { [ dup Expose = ] [ drop expose-event ] }
         { [ dup ConfigureNotify = ] [ drop resize-event ] }
         { [ dup ButtonPress = ] [ drop button-down-event$ ] }
         { [ dup ButtonRelease = ] [ drop button-up-event$ ] }

library/x11/ui.factor

@@ -10,6 +10,8 @@ strings x11 ;
 ! The window is an X11 window ID, and the context is a
 ! GLX context pointer.
 
+M: world expose-event ( event world -- ) nip relayout ;
+
 M: world resize-event ( event world -- )
     >r
     dup XConfigureEvent-width swap XConfigureEvent-height 0

library/x11/windows.factor

@@ -12,7 +12,8 @@ USING: alien hashtables kernel math namespaces sequences ;
     XCreateColormap ;
 
 : event-mask ( -- n )
-    StructureNotifyMask
+    ExposureMask
+    StructureNotifyMask bitor
     KeyPressMask bitor
     KeyReleaseMask bitor
     ButtonPressMask	bitor