wxPython, how do I fire events?

Question

Hi, I am making my own button class, subclass of a panel where I draw with a DC, and I need to fire wx.EVT_BUTTON when my custom button is pressed. How do I do it?

Answer 1

Create a wx.CommandEvent object, call its setters to set the appropriate attributes, and pass it to wx.PostEvent.

http://docs.wxwidgets.org/stable/wx_wxcommandevent.html#wxcommandeventctor

http://docs.wxwidgets.org/stable/wx_miscellany.html#wxpostevent

This is a duplicate, there is more information here on constructing these objects:

http://stackoverflow.com/questions/747781/wxpython-calling-an-event-manually/747805

Answer 2

The Wiki is pretty nice for reference. Andrea Gavana has a pretty complete recipe for building your own custom controls. The following is taken directly from there and extends what FogleBird answered with (note self is referring to a subclass of wx.PyControl):

def SendCheckBoxEvent(self):
    """ Actually sends the wx.wxEVT_COMMAND_CHECKBOX_CLICKED event. """

    # This part of the code may be reduced to a 3-liner code
    # but it is kept for better understanding the event handling.
    # If you can, however, avoid code duplication; in this case,
    # I could have done:
    #
    # self._checked = not self.IsChecked()
    # checkEvent = wx.CommandEvent(wx.wxEVT_COMMAND_CHECKBOX_CLICKED,
    #                              self.GetId())
    # checkEvent.SetInt(int(self._checked))
    if self.IsChecked():

        # We were checked, so we should become unchecked
        self._checked = False

        # Fire a wx.CommandEvent: this generates a
        # wx.wxEVT_COMMAND_CHECKBOX_CLICKED event that can be caught by the
        # developer by doing something like:
        # MyCheckBox.Bind(wx.EVT_CHECKBOX, self.OnCheckBox)
        checkEvent = wx.CommandEvent(wx.wxEVT_COMMAND_CHECKBOX_CLICKED,
                                     self.GetId())

        # Set the integer event value to 0 (we are switching to unchecked state)
        checkEvent.SetInt(0)

    else:

        # We were unchecked, so we should become checked
        self._checked = True

        checkEvent = wx.CommandEvent(wx.wxEVT_COMMAND_CHECKBOX_CLICKED,
                                     self.GetId())

        # Set the integer event value to 1 (we are switching to checked state)
        checkEvent.SetInt(1)

    # Set the originating object for the event (ourselves)
    checkEvent.SetEventObject(self)

    # Watch for a possible listener of this event that will catch it and
    # eventually process it
    self.GetEventHandler().ProcessEvent(checkEvent)

    # Refresh ourselves: the bitmap has changed
    self.Refresh()