I would like to learn about wx.EventFilter.I have these codes as following,but it doesn’t work. why?
class LastActivityTimeDetector(wx.EventFilter):
def __init__(self):
wx.EventFilter.__init__(self)
wx.EvtHandler.AddFilter(self)
self.last = wx.DateTime.Now()
def __del__(self):
wx.EvtHandler.RemoveFilter(self)
def FilterEvent(self, event):
t = event.GetEventType()
if t == wx.EVT_KEY_DOWN.typeId or t == wx.EVT_MOTION.typeId or \
t == wx.EVT_LEFT_DOWN.typeId or t == wx.EVT_RIGHT_DOWN.typeId or \
t == wx.EVT_MIDDLE_DOWN.typeId:
self.last = wx.DateTime.Now()
print(self.last)
return self.Event_Skip
def IsInactiveFor(self, diff):
return wx.DateTime.Now()
class MyFrame7(wx.Frame):
def init(self):
wx.Frame.__init__(self,None,-1)
LastActivityTimeDetector()
if name == ‘main’:
app = wx.App()
frame = MyFrame7()
frame.Show()
app.MainLoop()
I want to know about wx.EventFilter how to filter the events.I mean the way how it work in real situations . Does it work like conditional statement if ? Or it plays the same role in judging choice as conditional statement if.
I already have an example of the wx.EventFilter.I created an app which is derived from wx.App and I overrided the function of self.FilterEvent().In function,I called my own filterevent.
class myapp(wx.App):
def __init__(self):
wx.App.__init__(self)
self.a=LastActivityTimeDetector()
def FilterEvent(self, event):
self.a.FilterEvent(self.evt)
return self.Event_Skip
Now, my own filterevent can run .But I found if I use Bind(),I can get the same result。I want to read source code，but can’t find its. Could you do me a favor?
I’ve to say you work yourself down to the knuckels, but if Bind() does the same there must be a damned good reason for wx.EventFilter still being there, mustn’t it ? 
I do it just for trying to understand it how to work,not intend to use it in real situation.
it’s the number 1 the dispatcher looks at (according to the docu)
g l o b a l
import wx
class Gui(wx.Frame):
def __init__(self, parent):
super().__init__(parent, title='wx.EventFilter (global)')
btn = wx.Button(self, label='left click me, please')
btn.Bind(wx.EVT_BUTTON, self.test)
self.Centre()
self.Show()
def test(self, _):
with Test(self, 'lalala') as dlg:
dlg.ShowModal()
class Test(wx.TextEntryDialog):
def __init__(self, parent, msg):
super().__init__(parent, msg)
self.Show()
class WxApp(wx.App):
def __init__(self):
super().__init__(filename=None)
def FilterEvent( self, evt):
print(f'{evt.GetId()} --> {evt}')
return self.Event_Skip
def OnInit(self):
Gui(None)
self.MainLoop()
return True
WxApp()
l o c a l
import wx
class EventFilter(wx.EventFilter):
def __init__(self):
super().__init__()
wx.EvtHandler.AddFilter(self)
def FilterEvent(self, evt):
print(f'{evt.GetId()} --> {evt}')
return self.Event_Skip
def __del__(self):
wx.EvtHandler.RemoveFilter(self)
class Gui(wx.Frame):
def __init__(self, parent):
super().__init__(parent, title='wx.EventFilter (local)')
btn = wx.Button(self, label='left click me, please')
btn.Bind(wx.EVT_BUTTON, self.test)
self.Centre()
self.Show()
def test(self, _):
with Test(self, 'lalala') as dlg:
dlg.ShowModal()
class Test(wx.TextEntryDialog):
def __init__(self, parent, msg):
super().__init__(parent, msg)
self.evf = EventFilter()
self.Show()
def __del__(self):
del self.evf
app = wx.App()
Gui(None)
app.MainLoop()
One more thing,I compared your example of local and my example that I first gave.They differ in whether they are assigned at call time.e.g I gave it likeLastActivityTimeDetector(),you use it like self.evf = EventFilter().I find if I also assign values like self.evf=LastActivityTimeDetector(), my program will run normally.So the key question is why it need to be assigned to run.
this may be a less mystical version of what’s going on (the documentation sometimes sheds light upon a black box)
import wx
class EventFilter(wx.EventFilter):
def __init__(self):
super().__init__()
def FilterEvent(self, evt):
print(f'{evt.GetId()} --> {evt}')
return self.Event_Skip
class Gui(wx.Frame):
def __init__(self, parent):
super().__init__(parent, title='wx.EventFilter (local)')
btn = wx.Button(self, label='left click me, please')
btn.Bind(wx.EVT_BUTTON, self.test)
self.Centre()
self.Show()
def test(self, _):
with Test(self, 'lalala') as dlg:
dlg.ShowModal()
class Test(wx.TextEntryDialog):
def __init__(self, parent, msg):
super().__init__(parent, msg)
self.evf = EventFilter()
self.AddFilter(self.evf)
self.Show()
def __del__(self):
self.RemoveFilter(self.evf)
app = wx.App()
Gui(None)
app.MainLoop()
Thanks for your hard work!
well, on the way I got interested myself, what made it bearable and as a farewell hint set up the typeId’s at the init like this (membership testing, or are you one who likes to see the machine sweat) 
class EventFilter(wx.EventFilter):
def __init__(self):
super().__init__()
self.internals = {
wx.EVT_UPDATE_UI._getEvtType(),
wx.EVT_IDLE._getEvtType()}
def FilterEvent(self, evt):
if evt.GetEventType() not in self.internals:
print(f'{evt.GetEventType()} --> {evt}')
return self.Event_Skip
Thanks for you ! I got it ! 
