def __init__(self, filename=None):
        self.filename = None
        if filename:
            self.load(filename)
def activate(self, callingWindow, fullContext, mainItem, i):
        fitID = self.mainFrame.getActiveFit()
        Fit.getInstance().setAsPattern(fitID, mainItem)
        wx.PostEvent(self.mainFrame, GE.FitChanged(fitIDs=(fitID,)))