wxPython Event Handler

[Ene Uran]

What is the best way to establish a wxPython event handler for a mouse click, button and so on? I have looked at a number of sample codes and the event handlers differ all over the place.

[vegaseat]

I have looked up some of the wxPython event handlers I have used over time. You are right there are different versions, some are outdated, some are personal preference. I prefer the version used by button4 or the mouse clicks on the parent frame ...

# checking different versions of the wxPython event handler

import wx

ID_BTN1 = 1001  # give button1 a unique id number
ID_BTN2 = 1002

class MyFrame(wx.Frame):
    """make a frame with test buttons, inherits wx.Frame"""
    def __init__(self):
        # create a frame/window, no parent, default to wxID_ANY
        wx.Frame.__init__(self, None, wx.ID_ANY, 'wxPython', pos=(200, 150), size=(320, 250))
        self.SetBackgroundColour('green')
        
        self.button1 = wx.Button(self, id=ID_BTN1, label='Button1', pos=(8, 8), size=(175, 28))
        # older style event handler using the button's id number
        wx.EVT_BUTTON(self, ID_BTN1, self.button1Click)

        self.button2 = wx.Button(self, id=ID_BTN2, label='Button2', pos=(8, 38), size=(175, 28))
        # newer style event handler (wxPython version 2.5 and higher) using Bind() and button's id
        self.Bind(wx.EVT_BUTTON, self.button2Click, id=ID_BTN2)
        
        # button uses the default id of -1
        self.button3 = wx.Button(self, id=-1, label='Button3', pos=(8, 68), size=(175, 28))
        # another version of Bind() identifying the button by name
        self.Bind(wx.EVT_BUTTON, self.button3Click, self.button3)
        
        self.button4 = wx.Button(self, id=-1, label='Button4', pos=(8, 98), size=(175, 28))
        # one more version if Bind() identifying the button up front
        self.button4.Bind(wx.EVT_BUTTON, self.button4Click)

        # handle mouse events on frame
        self.Bind(wx.EVT_LEFT_DOWN, self.OnLeftDown)
        self.Bind(wx.EVT_RIGHT_DOWN, self.OnRightDown)
        
        # show the frame
        self.Show(True)
        
    def button1Click(self, event):
        self.SetTitle("Button1 clicked")
        
    def button2Click(self, event):
        self.SetTitle("Button2 clicked")
        
    def button3Click(self, event):
        self.SetTitle("Button3 clicked")

    def button4Click(self, event):
        self.SetTitle("Button4 clicked")

    def OnLeftDown(self, event):
        pt = event.GetPosition()  # position tuple
        self.SetTitle('left mouse = ' + str(pt))
        
    def OnRightDown(self, event):
        pt = event.GetPosition()
        self.SetTitle('right mouse = ' + str(pt))


application = wx.PySimpleApp()
# call class MyFrame
window = MyFrame()
# start the event loop
application.MainLoop()

[Ene Uran]

Thanks Vega,
I can use your code sample as a template, as I play around with the capabilities of the wxPython GUI.

You have used the frame directly to put your button widgets on. Other code samples seem to use a panel on a frame to put their widgets on. Any reason for that?

Also, why are you using self.button1 = Button( ... ) and not just button1 = Button( ... )?

[bumsfeld]

...
Also, why are you using self.button1 = Button( ... ) and not just button1 = Button( ... )?

The self. prefix makes the button global within the class, so it can be used by methods of the class.

[vegaseat]

Panels have some added flexibilty over just frames, things like sizers.

[Ene Uran]

Thanks, I will check the panels and the sizers out next!