Problem with custom events in wxpython

[7stud]

On May 11, 7:23 am, Jimmy <mcknight0... at gmail.com> wrote:
> hi, all
>
> I'm having a problem with creating custom events in wxpython.
>
> I have a class A handling some data processing work and another class
> B of GUI matter. I need GUI to display information when data in A is
> updated.
> I know cutom events in wxpython may work. But I found no material
> paricularly
> helpful :(
>
> can anyone write me some demo code to show how to do this ...


This example works for me:


import wx

class MyCustomEvent(wx.PyCommandEvent): #or wx.PyEvent
    def __init__(self, event_type, id):
        wx.PyCommandEvent.__init__(self, event_type, id)

class A(object):  #Data Processing class
    def __init__(self, widget_to_update):
        self.widget_to_update = widget_to_update

        #create the custom event:
        self.my_event_type = wx.NewEventType()
        self.EVT_MY_CUSTOM_EVENT =
wx.PyEventBinder(self.my_event_type, 1)
	#Note: you need to make EVT_MY_CUSTOM_EVENT persist so that you
        #can refer to it in a later call to Bind()

    def process_data(self): #create thread here
        finished = True

	if finished:
            self.update_gui()


    def update_gui(self):
        #create a custom event object and enter it in the event queue:
        my_evt_obj = MyCustomEvent(self.my_event_type,
self.widget_to_update.GetId() )
 
self.widget_to_update.GetEventHandler().ProcessEvent(my_evt_obj)


class B(object):  #Gui class
    def __init__(self):
        frame = wx.Frame(None, -1, "My Window")

        panel = wx.Panel(frame, -1)
        button = wx.Button(panel, -1, "Start Data Processing",
pos=(100, 10))
        button.Bind(wx.EVT_BUTTON, self.onclick)

        self.text_ctrl = wx.TextCtrl(panel, -1, "Hello World",
pos=(100, 50), size=(200, 20))

        self.a = A(self.text_ctrl)
        frame.Bind(self.a.EVT_MY_CUSTOM_EVENT,
self.on_my_custom_event)

        frame.Show()

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

    def on_my_custom_event(self, event):
        self.text_ctrl.SetValue("Finished Processing Data")


app = wx.PySimpleApp(redirect=False)
b = B()
app.MainLoop()




However, I couldn't get similar code to work when I derived the event
class from wx.PyEvent and used Bind() directly on the TextCtrl
(command events propagate up the container hierarchy while regular
events don't):

import wx

class MyCustomEvent(wx.PyEvent): #or wx.PyEvent
    def __init__(self, event_type, id):
        wx.PyEvent.__init__(self, event_type, id)

class A(object):  #Data Processing class
    def __init__(self, widget_to_update):
        self.widget_to_update = widget_to_update

        #create the custom event:
        self.my_event_type = wx.NewEventType()
        self.EVT_MY_CUSTOM_EVENT =
wx.PyEventBinder(self.my_event_type, 1)

    def process_data(self): #create thread here
        finished = True
        if finished:
            self.update_gui()


    def update_gui(self):
        #create a custom event object and enter it in the event queue:
        my_evt_obj = MyCustomEvent(self.my_event_type,
self.widget_to_update.GetId() )
 
self.widget_to_update.GetEventHandler().ProcessEvent(my_evt_obj)


class B(object):  #Gui class
    def __init__(self):
        frame = wx.Frame(None, -1, "My Window")

        panel = wx.Panel(frame, -1)
        button = wx.Button(panel, -1, "Start Data Processing",
pos=(100, 10))
        button.Bind(wx.EVT_BUTTON, self.onclick)

        self.text_ctrl = wx.TextCtrl(panel, -1, "Hello World",
pos=(100, 50), size=(200, 20))

        self.a = A(self.text_ctrl)
        self.text_ctrl.Bind(self.a.EVT_MY_CUSTOM_EVENT,
self.on_my_custom_event)

        frame.Show()

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

    def on_my_custom_event(self, event):
        self.text_ctrl.SetValue("Finished Processing Data")

app = wx.PySimpleApp(redirect=False)
b = B()
app.MainLoop()