wxPython - How to get the ID of a widget when you passed in -1?

Question

I'm doing a little wxPython work today and I've got this piece of code (I've stripped out the irrelevant parts):

        def CreateRowOne(self, pan):
            hbox1 = wx.BoxSizer(wx.HORIZONTAL)
            hbox1.Add(wx.Button(pan, -1, "250 Words"), 1, wx.EXPAND | wx.ALL)
            hbox1.Add(wx.Button(pan, -1, "500 Words"), 1, wx.EXPAND | wx.ALL)
            hbox1.Add(wx.Button(pan, -1, "750 Words"), 1, wx.EXPAND | wx.ALL)
            return hbox1

How do you get the ID of the buttons that were created, so I can bind them to a handler? Normally, I'd do this:

            button1 = wx.Button(...)
            button2 = wx.Button(...)

            ...

            self.Bind(wx.EVT_BUTTON, self.Blah, button1.GetID())
            self.Bind(wx.EVT_BUTTON, self.Blah2, button2.GetID())

but I didn't give an identifier to any of the buttons. Am I going to have to manually assign the ID numbers?

Answer 1

Am I going to have to manually assign the ID numbers?

No, putting -1 or using wx.NewId() will give you autogenerated ID.

and You can always get id with button1.GetID() or button1.Id back anytime.

--

UPDATE:

ID_BUTTON1 = wx.NewId()

hbox1.Add(wx.Button(pan, ID_BUTTON1, "250 Words"), 1, wx.EXPAND | wx.ALL)

self.Bind(wx.EVT_BUTTON, self.Blah, ID_BUTTON1)

Answer 2

I recommend not doing "sizer.Add(wx.Button(...))". It's better to separate widget creation and layout. Is there a compelling reason to write your code the way you have? Why not write it like this:

button1=wx.Button(pan, wx.ID_ANY, ...)
button2=wx.Button(pan, wx.ID_ANY, ...)
...
hbox1.Add(button1)
hbox1.Add(button2)
...
self.Bind(wx.EVT_BUTTON, self.Blah, button1.GetID())
self.Bind(wx.EVT_BUTTON, self.Blah2, button2.GetID())

There's simply no gain in combining button creation and adding it to a sizer in one line.

Personally I see even greater value in assigning IDs, but that can be onerous for a large number of widgets. I generally only do that for "significant" widgets -- widgets I refer to in other parts of the code. My code typically looks like:

ID_BUTTON1 = wx.NewID()
IO_BUTTON2 = wx.NewID()

class ...:
   ...
   button1 = wx.Button(self, ID_BUTTON1, ...)
   ...
   self.Bind(wx.EVT_BUTTON, ID_BUTTON1, ...)
   ...

I think this makes the code easier to understand and easier to maintain over time.

Answer 3

You can get id by control.GetID() but you do not need to get ID to bind, you can just do this

self.btn.Bind(wx.EVT_BUTTON, self._onBtnClick)

It is preferable(id should be implementation detail) and short e.g. in this sample

import wx

app = wx.PySimpleApp()
frame = wx.Frame(None)
btn = wx.Button(frame, -1, "anurag")
btn.Bind(wx.EVT_BUTTON, lambda e:wx.MessageBox("Wow it works"))
frame.Show()
app.SetTopWindow(frame)
app.MainLoop()