Custom Events with wx.PyEvent

[Das246]

I've been searching for information on using wx.PyEvent so I can create custom events that fire from within my code rather than needing the user to trigger them. There isn't much around. There is some information on using wx.PyCommandEvent but I believe that these events still require the user to trigger each event. Also, much of the code is now depreciated in the latest versions of Python so it was best to try and avoid these.

Anyhow, after much searching and experimenting I've finally got a working version. A lot of this was cobbled together from code snippets online that didn't work. Here's a tip - if you have a PyCommandEvent that you are trying to move to a PyEvent it is really important to know that the event_type and id are reversed within each command. That is why some of the online code problems didn't work. Simply reversing this got them to work.

So here's the code...
All it does is create a text control and then fires a process once a button is pushed. The process triggers events and the events are displayed in the text control. Hope it helps someone else. :)

#!/usr/bin/env python

import wx, time

# Create the custom event.
myEVT_CUSTOM_EVENT = wx.NewEventType()
EVT_CUSTOM_EVENT = wx.PyEventBinder(myEVT_CUSTOM_EVENT, 1)

class MyEvent(wx.PyEvent):
    def __init__(self, event_type, id):
        wx.PyEvent.__init__(self, id, event_type)
        # Note that the id and event_type are reversed 
        # from wx.PyCommandEvent
        self.myVal = "didn't fire properly."

    def setMyVal(self, val):
        self.myVal = val

    def getMyText(self):
        return self.myVal   

class MyProcess(object):
    # Process that creates events as it works
    def __init__(self, myWidget):
        self.myWidget = myWidget

    def process_data(self):
        for i in range(6):
            print "Outputting number %s" % i
            self.update_gui(i)
            time.sleep(.75)

    def update_gui(self, val):
        #create a custom event object and enter it in the event queue:
        evt = MyEvent(myEVT_CUSTOM_EVENT, self.myWidget.GetId() )
        evt.setMyVal(val)
        self.myWidget.GetEventHandler().ProcessEvent(evt)

class MyGUI(object):
    def __init__(self):
        frame = wx.Frame(None, -1, "Custom Events")
        panel = wx.Panel(frame, -1)
        button = wx.Button(panel, -1, "Start", pos=(100, 10))
        button.Bind(wx.EVT_BUTTON, self.onclick)
        self.text_ctrl = wx.TextCtrl(panel, -1, "Ready...\n",
            pos=(50, 50), size=(300, 120), style=wx.TE_MULTILINE)
        self.a = MyProcess(self.text_ctrl)
        self.text_ctrl.Bind(EVT_CUSTOM_EVENT, self.on_my_event, id=self.text_ctrl.GetId())
        frame.Show()

    def onclick(self, event):
        self.a.process_data()

    def on_my_event(self, event):
        self.text_ctrl.AppendText("Event %s\n" % (event.getMyText(), ))

if __name__ == '__main__':
    app = wx.PySimpleApp(redirect=False)
    MyGUI()
    app.MainLoop()

If anyone has a cleaner way of presenting this then please feel free to post revisions. :)