Overwritten TreeCtrl.OnCompareItems() not called in Python3/wxPython4

Thomas Krull <[email protected]> Wed, 7 Mar 2018 00:33:02 -0800 (PST)

Newsgroups	gmane.comp.python.wxpython.devel
Message-ID	<[email protected]>

 

I have a wx.TreeCtrl structure where the user can sort the items by 
different criteria (date, name, id, descending, ascending, ...). This 
worked fine in Python 2, but Python 3 (with wxPython 4) refuses sorting. 
The method CTreeCtrl.OnCompareItems() is called in Python 2, but never in 
Python 3.


In the functools.cmp_to_key() documentation (
https://docs.python.org/3/library/functools.html) I found a hint: Python 3 
does not support comparison functions. Confusing: in the description of 
wx.TreeCtrl (wxPython 4) there *is* a comparison method OnCompareItems() (
https://docs.wxpython.org/wx.TreeCtrl.html#wx.TreeCtrl.OnCompareItems). The 
description says, that together with this method I must use the RTTI macros 
DECLARE_DYNAMIC_CLASS and IMPLEMENT_DYNAMIC_CLASS since the baseclass does 
not know that I overwrote OnCompareItems(). I found descriptions of how to 
use this macros in C++, but nothing for python.


Now I have no idea how I could make my program calling my OnCompareItems() 
method in Python3/wxPython 4.


The file compare_or_not.py contains a small sample programm which reflects 
the problem. It runs with Python 2 and Python 3 as well. The print( 'in 
CTreeCtrl.OnCompareItems()' ) shows, that this method is called (in py2) or 
not called (in py3).


Can anybody help?


Regards, Humbalan




-- 
You received this message because you are subscribed to the Google Groups "wxPython-dev" group.
To unsubscribe from this group and stop receiving emails from it, send an email to [email protected].
For more options, visit https://groups.google.com/d/optout.

compare_or_not.py (text/x-python, 1.7 KB)

import sys
import wx

class CTreeCtrl( wx.TreeCtrl ):
    def __init__( self, parent ):
        super( CTreeCtrl, self ).__init__( parent=parent, style=wx.TR_HIDE_ROOT )

    def OnCompareItems( self, item1, item2 ):
        print( 'in CTreeCtrl.OnCompareItems()' )
        if sys.version_info.major < 3:
            d1 = self.GetItemData( item1 ).Data
            d2 = self.GetItemData( item2 ).Data
        else:
            d1 = self.GetItemData( item1 )
            d2 = self.GetItemData( item2 )

        if   d1 < d2:  return -1
        elif d1 > d2:  return 1
        else        :  return 0


class CSettingsTree( wx.Dialog  ):

    def __init__( self, parent, settings ) :

        size = wx.Size(200,150)

        wx.Dialog.__init__( self, parent, title='all settings', size=size )
        bSizer_main = wx.BoxSizer( wx.VERTICAL )

        self.m_treeCtrl = CTreeCtrl( self  )
        bSizer_main.Add( self.m_treeCtrl, 0, wx.ALL|wx.EXPAND, 5 )

        self.SetSizer( bSizer_main )
        bSizer_main.Fit( self )

        root = self.m_treeCtrl.AddRoot( 'Settings' )

        for key, name in settings :
            if sys.version_info.major < 3 :  sort_key = wx.TreeItemData( name )
            else                          :  sort_key = name

            self.m_treeCtrl.AppendItem( root, '{}: {}'.format(key, name), data=sort_key )

        self.m_treeCtrl.ExpandAll()
        self.m_treeCtrl.SortChildren( root )

        
#---------------------------------------------------------------------------
if __name__=="__main__":

    app = wx.App( redirect=False )

    settings = [(50,'Taylor'),(200,'Mueller'),(101,'Baker'),(102,'Smith')]

    dlg = CSettingsTree( wx.Frame( None ), settings )
    dlg.ShowModal()