Is it possible to pass arguments into event bindings?

crystalattice picture crystalattice · Oct 6, 2008 · Viewed 17.2k times · Source

I haven't found an answer elsewhere and this doesn't appear to have been asked yet on SO.

When creating an event binding in wxPython, is it possible to pass additional arguments to the event? For example, this is the normal way:

b = wx.Button(self, 10, "Default Button", (20, 20))
        self.Bind(wx.EVT_BUTTON, self.OnClick, b)
def OnClick(self, event):
        self.log.write("Click! (%d)\n" % event.GetId())

But is it possible to have another argument passed to the method? Such that the method can tell if more than one widget is calling it but still return the same value?

It would greatly reduce copy & pasting the same code but with different callers.

Answer

Florian Bösch picture Florian Bösch · Oct 6, 2008

You can always use a lambda or another function to wrap up your method and pass another argument, not WX specific.

b = wx.Button(self, 10, "Default Button", (20, 20))
        self.Bind(wx.EVT_BUTTON, lambda event: self.OnClick(event, 'somevalue'), b)
def OnClick(self, event, somearg):
        self.log.write("Click! (%d)\n" % event.GetId())

If you're out to reduce the amount of code to type, you might also try a little automatism like:

class foo(whateverwxobject):
    def better_bind(self, type, instance, handler, *args, **kwargs):
        self.Bind(type, lambda event: handler(event, *args, **kwargs), instance)

    def __init__(self):
        self.better_bind(wx.EVT_BUTTON, b, self.OnClick, 'somevalue')