fd3f2efe79
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@24634 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
519 lines
17 KiB
Python
519 lines
17 KiB
Python
#---------------------------------------------------------------------------
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# Name: wxPython.lib.evtmgr
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# Purpose: An easier, more "Pythonic" and more OO method of registering
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# handlers for wxWindows events using the Publish/Subscribe
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# pattern.
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#
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# Author: Robb Shecter and Robin Dunn
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#
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# Created: 12-December-2002
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# RCS-ID: $Id$
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# Copyright: (c) 2003 by db-X Corporation
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# Licence: wxWindows license
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#---------------------------------------------------------------------------
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"""
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A module that allows multiple handlers to respond to single wxWindows
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events. This allows true NxN Observer/Observable connections: One
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event can be received by multiple handlers, and one handler can
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receive multiple events.
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There are two ways to register event handlers. The first way is
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similar to standard wxPython handler registration:
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from wxPython.lib.evtmgr import eventManager
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eventManager.Register(handleEvents, EVT_BUTTON, win=frame, id=101)
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There's also a new object-oriented way to register for events. This
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invocation is equivalent to the one above, but does not require the
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programmer to declare or track control ids or parent containers:
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eventManager.Register(handleEvents, EVT_BUTTON, myButton)
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This module is Python 2.1+ compatible.
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"""
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from wxPython import wx
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import pubsub
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#---------------------------------------------------------------------------
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class EventManager:
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"""
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This is the main class in the module, and is the only class that
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the application programmer needs to use. There is a pre-created
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instance of this class called 'eventManager'. It should not be
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necessary to create other instances.
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"""
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def __init__(self):
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self.eventAdapterDict = {}
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self.messageAdapterDict = {}
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self.windowTopicLookup = {}
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self.listenerTopicLookup = {}
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self.__publisher = pubsub.Publisher()
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self.EMPTY_LIST = []
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def Register(self, listener, event, source=None, win=None, id=None):
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"""
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Registers a listener function (or any callable object) to
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receive events of type event coming from the source window.
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For example:
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eventManager.Register(self.OnButton, EVT_BUTTON, theButton)
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Alternatively, the specific window where the event is
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delivered, and/or the ID of the event source can be specified.
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For example:
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eventManager.Register(self.OnButton, EVT_BUTTON, win=self, id=ID_BUTTON)
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or
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eventManager.Register(self.OnButton, EVT_BUTTON, theButton, self)
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"""
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# 1. Check if the 'event' is actually one of the multi-
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# event macros.
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if _macroInfo.isMultiEvent(event):
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raise 'Cannot register the macro, '+`event`+'. Register instead the individual events.'
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# Support a more OO API. This allows the GUI widget itself to
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# be specified, and the id to be retrieved from the system,
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# instead of kept track of explicitly by the programmer.
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# (Being used to doing GUI work with Java, this seems to me to be
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# the natural way of doing things.)
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if source is not None:
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id = source.GetId()
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if win is None:
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# Some widgets do not function as their own windows.
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win = self._determineWindow(source)
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topic = (event, win, id)
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# Create an adapter from the PS system back to wxEvents, and
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# possibly one from wxEvents:
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if not self.__haveMessageAdapter(listener, topic):
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messageAdapter = MessageAdapter(eventHandler=listener, topicPattern=topic)
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try:
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self.messageAdapterDict[topic][listener] = messageAdapter
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except KeyError:
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self.messageAdapterDict[topic] = {}
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self.messageAdapterDict[topic][listener] = messageAdapter
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if not self.eventAdapterDict.has_key(topic):
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self.eventAdapterDict[topic] = EventAdapter(event, win, id)
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else:
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# Throwing away a duplicate request
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pass
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# For time efficiency when deregistering by window:
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try:
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self.windowTopicLookup[win].append(topic)
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except KeyError:
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self.windowTopicLookup[win] = []
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self.windowTopicLookup[win].append(topic)
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# For time efficiency when deregistering by listener:
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try:
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self.listenerTopicLookup[listener].append(topic)
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except KeyError:
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self.listenerTopicLookup[listener] = []
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self.listenerTopicLookup[listener].append(topic)
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# See if the source understands the listeningFor protocol.
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# This is a bit of a test I'm working on - it allows classes
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# to know when their events are being listened to. I use
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# it to enable chaining events from contained windows only
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# when needed.
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if source is not None:
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try:
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# Let the source know that we're listening for this
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# event.
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source.listeningFor(event)
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except AttributeError:
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pass
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# Some aliases for Register, just for kicks
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Bind = Register
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Subscribe = Register
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def DeregisterWindow(self, win):
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"""
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Deregister all events coming from the given window.
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"""
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win = self._determineWindow(win)
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topics = self.__getTopics(win)
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if topics:
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for aTopic in topics:
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self.__deregisterTopic(aTopic)
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del self.windowTopicLookup[win]
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def DeregisterListener(self, listener):
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"""
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Deregister all event notifications for the given listener.
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"""
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try:
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topicList = self.listenerTopicLookup[listener]
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except KeyError:
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return
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for topic in topicList:
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topicDict = self.messageAdapterDict[topic]
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if topicDict.has_key(listener):
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topicDict[listener].Destroy()
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del topicDict[listener]
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if len(topicDict) == 0:
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self.eventAdapterDict[topic].Destroy()
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del self.eventAdapterDict[topic]
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del self.messageAdapterDict[topic]
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del self.listenerTopicLookup[listener]
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def GetStats(self):
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"""
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Return a dictionary with data about my state.
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"""
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stats = {}
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stats['Adapters: Message'] = reduce(lambda x,y: x+y, [0] + map(len, self.messageAdapterDict.values()))
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stats['Adapters: Event'] = len(self.eventAdapterDict)
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stats['Topics: Total'] = len(self.__getTopics())
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stats['Topics: Dead'] = len(self.GetDeadTopics())
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return stats
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def DeregisterDeadTopics(self):
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"""
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Deregister any entries relating to dead
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wxPython objects. Not sure if this is an
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important issue; 1) My app code always de-registers
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listeners it doesn't need. 2) I don't think
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that lingering references to these dead objects
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is a problem.
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"""
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for topic in self.GetDeadTopics():
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self.__deregisterTopic(topic)
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def GetDeadTopics(self):
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"""
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Return a list of topics relating to dead wxPython
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objects.
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"""
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return filter(self.__isDeadTopic, self.__getTopics())
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def __winString(self, aWin):
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"""
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A string rep of a window for debugging
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"""
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try:
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name = aWin.GetClassName()
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i = id(aWin)
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return '%s #%d' % (name, i)
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except wx.wxPyDeadObjectError:
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return '(dead wxObject)'
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def __topicString(self, aTopic):
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"""
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A string rep of a topic for debugging
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"""
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return '[%-26s %s]' % (aTopic[0].__name__, self.winString(aTopic[1]))
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def __listenerString(self, aListener):
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"""
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A string rep of a listener for debugging
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"""
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try:
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return aListener.im_class.__name__ + '.' + aListener.__name__
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except:
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return 'Function ' + aListener.__name__
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def __deregisterTopic(self, aTopic):
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try:
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messageAdapterList = self.messageAdapterDict[aTopic].values()
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except KeyError:
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# This topic isn't valid. Probably because it was deleted
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# by listener.
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return
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for messageAdapter in messageAdapterList:
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messageAdapter.Destroy()
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self.eventAdapterDict[aTopic].Destroy()
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del self.messageAdapterDict[aTopic]
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del self.eventAdapterDict[aTopic]
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def __getTopics(self, win=None):
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if win is None:
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return self.messageAdapterDict.keys()
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if win is not None:
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try:
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return self.windowTopicLookup[win]
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except KeyError:
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return self.EMPTY_LIST
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def __isDeadWxObject(self, anObject):
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return isinstance(anObject, wx._wxPyDeadObject)
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def __isDeadTopic(self, aTopic):
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return self.__isDeadWxObject(aTopic[1])
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def __haveMessageAdapter(self, eventHandler, topicPattern):
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"""
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Return True if there's already a message adapter
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with these specs.
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"""
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try:
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return self.messageAdapterDict[topicPattern].has_key(eventHandler)
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except KeyError:
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return 0
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def _determineWindow(self, aComponent):
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"""
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Return the window that corresponds to this component.
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A window is something that supports the Connect protocol.
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Most things registered with the event manager are a window,
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but there are apparently some exceptions. If more are
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discovered, the implementation can be changed to a dictionary
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lookup along the lines of class : function-to-get-window.
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"""
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if isinstance(aComponent, wx.wxMenuItem):
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return aComponent.GetMenu()
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else:
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return aComponent
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#---------------------------------------------------------------------------
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# From here down is implementaion and support classes, although you may
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# find some of them useful in other contexts.
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#---------------------------------------------------------------------------
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class EventMacroInfo:
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"""
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A class that provides information about event macros.
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"""
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def __init__(self):
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self.lookupTable = {}
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def getEventTypes(self, eventMacro):
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"""
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Return the list of event types that the given
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macro corresponds to.
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"""
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try:
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return self.lookupTable[eventMacro]
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except KeyError:
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win = FakeWindow()
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try:
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eventMacro(win, None, None)
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except (TypeError, AssertionError):
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eventMacro(win, None)
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self.lookupTable[eventMacro] = win.eventTypes
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return win.eventTypes
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def eventIsA(self, event, macroList):
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"""
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Return True if the event is one of the given
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macros.
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"""
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eventType = event.GetEventType()
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for macro in macroList:
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if eventType in self.getEventTypes(macro):
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return 1
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return 0
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def macroIsA(self, macro, macroList):
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"""
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Return True if the macro is in the macroList.
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The added value of this method is that it takes
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multi-events into account. The macroList parameter
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will be coerced into a sequence if needed.
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"""
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if callable(macroList):
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macroList = (macroList,)
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testList = self.getEventTypes(macro)
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eventList = []
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for m in macroList:
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eventList.extend(self.getEventTypes(m))
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# Return True if every element in testList is in eventList
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for element in testList:
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if element not in eventList:
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return 0
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return 1
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def isMultiEvent(self, macro):
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"""
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Return True if the given macro actually causes
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multiple events to be registered.
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"""
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return len(self.getEventTypes(macro)) > 1
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#---------------------------------------------------------------------------
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class FakeWindow:
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"""
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Used internally by the EventMacroInfo class. The FakeWindow is
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the most important component of the macro-info utility: it
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implements the Connect() protocol of wxWindow, but instead of
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registering for events, it keeps track of what parameters were
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passed to it.
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"""
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def __init__(self):
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self.eventTypes = []
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def Connect(self, id1, id2, eventType, handlerFunction):
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self.eventTypes.append(eventType)
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#---------------------------------------------------------------------------
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class EventAdapter:
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"""
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A class that adapts incoming wxWindows events to
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Publish/Subscribe messages.
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In other words, this is the object that's seen by the
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wxWindows system. Only one of these registers for any
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particular wxWindows event. It then relays it into the
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PS system, which lets many listeners respond.
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"""
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def __init__(self, func, win, id):
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"""
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Instantiate a new adapter. Pre-compute my Publish/Subscribe
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topic, which is constant, and register with wxWindows.
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"""
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self.publisher = pubsub.Publisher()
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self.topic = ((func, win, id),)
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self.id = id
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self.win = win
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self.eventType = _macroInfo.getEventTypes(func)[0]
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# Register myself with the wxWindows event system
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try:
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func(win, id, self.handleEvent)
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self.callStyle = 3
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except (TypeError, AssertionError):
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func(win, self.handleEvent)
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self.callStyle = 2
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def disconnect(self):
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if self.callStyle == 3:
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return self.win.Disconnect(self.id, -1, self.eventType)
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else:
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return self.win.Disconnect(-1, -1, self.eventType)
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def handleEvent(self, event):
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"""
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In response to a wxWindows event, send a PS message
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"""
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self.publisher.sendMessage(topic=self.topic, data=event)
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def Destroy(self):
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try:
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if not self.disconnect():
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print 'disconnect failed'
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except wx.wxPyDeadObjectError:
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print 'disconnect failed: dead object' ##????
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#---------------------------------------------------------------------------
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class MessageAdapter:
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"""
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A class that adapts incoming Publish/Subscribe messages
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to wxWindows event calls.
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This class works opposite the EventAdapter, and
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retrieves the information an EventAdapter has sent in a message.
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Strictly speaking, this class is not required: Event listeners
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could pull the original wxEvent object out of the PS Message
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themselves.
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However, by pairing an instance of this class with each wxEvent
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handler, the handlers can use the standard API: they receive an
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event as a parameter.
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"""
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def __init__(self, eventHandler, topicPattern):
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"""
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Instantiate a new MessageAdapter that send wxEvents to the
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given eventHandler.
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"""
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self.eventHandler = eventHandler
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pubsub.Publisher().subscribe(listener=self.deliverEvent, topic=(topicPattern,))
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def deliverEvent(self, message):
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event = message.data # Extract the wxEvent
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self.eventHandler(event) # Perform the call as wxWindows would
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def Destroy(self):
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pubsub.Publisher().unsubscribe(listener=self.deliverEvent)
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#---------------------------------------------------------------------------
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# Create globals
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_macroInfo = EventMacroInfo()
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# For now a singleton is not enforced. Should it be or can we trust
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# the programmers?
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eventManager = EventManager()
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#---------------------------------------------------------------------------
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# simple test code
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if __name__ == '__main__':
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from wxPython.wx import wxPySimpleApp, wxFrame, wxToggleButton, wxBoxSizer, wxHORIZONTAL, EVT_MOTION, EVT_LEFT_DOWN, EVT_TOGGLEBUTTON, wxALL
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app = wxPySimpleApp()
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frame = wxFrame(None, -1, 'Event Test', size=(300,300))
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button = wxToggleButton(frame, -1, 'Listen for Mouse Events')
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sizer = wxBoxSizer(wxHORIZONTAL)
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sizer.Add(button, 0, 0 | wxALL, 10)
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frame.SetAutoLayout(1)
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frame.SetSizer(sizer)
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#
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# Demonstrate 1) register/deregister, 2) Multiple listeners receiving
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# one event, and 3) Multiple events going to one listener.
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#
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def printEvent(event):
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print 'Name:',event.GetClassName(),'Timestamp',event.GetTimestamp()
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def enableFrameEvents(event):
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# Turn the output of mouse events on and off
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if event.IsChecked():
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print '\nEnabling mouse events...'
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eventManager.Register(printEvent, EVT_MOTION, frame)
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eventManager.Register(printEvent, EVT_LEFT_DOWN, frame)
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else:
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print '\nDisabling mouse events...'
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eventManager.DeregisterWindow(frame)
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# Send togglebutton events to both the on/off code as well
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# as the function that prints to stdout.
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eventManager.Register(printEvent, EVT_TOGGLEBUTTON, button)
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eventManager.Register(enableFrameEvents, EVT_TOGGLEBUTTON, button)
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frame.CenterOnScreen()
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frame.Show(1)
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app.MainLoop()
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