Simplify get_toplevel_window method

issue6995
review39951002

tryton/common/common.py

@@ -293,13 +293,11 @@ def request_server(server_widget):
 
 
 def get_toplevel_window():
-    windows = [x for x in gtk.window_list_toplevels()
-        if x.get_window() and x.props.visible
-        and x.props.type == gtk.WINDOW_TOPLEVEL]
-    trans2windows = dict((x.get_transient_for(), x) for x in windows)
-    for window in set(windows) - set(trans2windows.iterkeys()):
-        return window
-    return trans2windows[None]
+    for window in gtk.window_list_toplevels():
+        if window.is_active():
+            return window
+    from tryton.gui.main import Main
+    return Main.get_main().window
 
 
 def get_sensible_widget(window):