The wxPython tutorial

http://www.zetcode.com/wxpython/tips/class MySheet(CSheet):def __init__(self, parent):CSheet.__init__(self, parent)Our example inherits from CSheet class. It is a grid widgetwith some additional logic.self.SetRowLabelAlignment(wx.ALIGN_CENTRE, wx.ALIGN_CENTRE)Here we center the labels in rows. By default, they arealigned to the right.r = event.GetRow()c = event.GetCol()text = self.GetCellValue(r, c)# self.text - text before change# text - text after changeundo = UndoText(self, self.text, text, r, c)stockUndo.append(undo)Every time we do some changes, an UndoText object iscreated and appended to the stockUndo list..if stockRedo:# this might be surprising, but it is a standard behaviour# in all spreadsheetsdel stockRedo[:]toolbar.EnableTool(ID_REDO, False)Yes, this behaviour was surprising for me. I did not knowthat it works this way, until I made this example. Basically,if you undo some changes and then start typing again, allredo changes are lost. OpenOffice Calc works this way.Gnumeric as well.if len(stockUndo) == 0:self.toolbar.EnableTool(ID_UNDO, False)...self.toolbar.EnableTool(ID_REDO, True)The undo and redo buttons are enabled or disabled10 de 15 27/04/2008 1:09