core: added a "_debug" signal:

this signal is a generic debugging signal which can be implemented in frontends to do specific actions, like printing data dumps.

sat_frontends/quick_frontend/quick_app.py

@@ -383,6 +383,8 @@ class QuickApp(object):
         self.registerSignal("chatStateReceived", iface="plugin")
         self.registerSignal("messageState", iface="plugin")
         self.registerSignal("psEvent", iface="plugin")
+        # useful for debugging
+        self.registerSignal("_debug", iface="core")
 
         # FIXME: do it dynamically
         quick_games.Tarot.registerSignals(self)
@@ -1099,6 +1101,14 @@ class QuickApp(object):
                 answer_data=(entity, profile),
             )
 
+    def _debugHandler(self, action, parameters, profile):
+        if action == u"widgets_dump":
+            from pprint import pformat
+            log.info(u"Widgets dump:\n{data}".format(data=pformat(self.widgets._widgets)))
+        else:
+            log.warning(u"Unknown debug action: {action}".format(action=action))
+
+
     def showDialog(self, message, title, type="info", answer_cb=None, answer_data=None):
         """Show a dialog to user