tkinter problem with treeview

[Wolfgang Meiners]

Hi all,

I have written some helper functions for the tkinter.ttk.treeview widget
(using python3, version 3.2). This functions dont work as i expect:

#! /usr/bin/env pyhon3
# -*- encoding: utf-8 -*-

from tkinter import *
from tkinter.ttk import * # now tkinter widgets get replaced by
                          # tkinter.ttk widgets
from tkinter.font import Font

def makeTreeview(root, fields, scrollbars=True, show='tree headings',
                 packOptions={'side': RIGHT, 'expand': YES,
                 'fill': BOTH, 'padx': 2, 'pady': 2},
                 **extras):
    """ root: the containing frame
        fields: [('name', {options})]
        field[0] is the tree label
        scrollbars: True: use scrollbars, False: dont use scrollbars
        show: 'tree' or 'headings' or 'tree headings'
    """

    # define Treeview
    # fiels[0] belongs to the tree label
    # fields[1:] belongs to the data values
    # t is a tuple ('name', {options})
    widget=Treeview(root, columns=[t[0] for t in fields[1:]], show=show)

    # define scrollbars is necessary
    if scrollbars:
        ybar=Scrollbar(root)
        ybar.config(command=widget.yview)
        ybar.pack(side=RIGHT, expand=YES, fill=Y) # pack ybar first
        xbar=Scrollbar(root,orient='horizontal')
        xbar.config(command=widget.xview)
        xbar.pack(side=BOTTOM, expand=YES, fill=X) # then xbar
        widget.config(yscrollcommand=ybar.set, xscrollcommand=xbar.set)
    widget.pack(packOptions) # pack widget last

    # process the header and the options
    # of the data values
    # (n,o) is a tuple consisting of a name and an option
    i=0
    for (n,o) in fields:
        widget.heading('#%s' % i, text=n)
        if o: widget.column('#%s' % i, **o)
        i += 1

    if extras: widget.config(**extras)
    return widget

def insert_node_to_treeview(tv, parent, subtree, resize=True, **extras):
    ''' tv: the treeview to insert the new values
        parent: the parent node
        subtree: a tuple (row, children) with
          row: list of values to insert into this node
          row[0] belongs to the tree label
          row[1:] belongs to the data values
          children: list of children to insert
          each child is a valid subtree
    '''
    (row, children) = subtree
    nd=tv.insert(parent, 'end', text=row[0], values=row[1:], **extras)

    # resize fields if necessary
    rowsize=[Font().measure(f) for f in row]

    i=0
    for s in rowsize:
        if tv.column('#%s' %i, option='width') < s:
            tv.column('#%s' %i, width=rowsize[i])
        i += 1

    # insert children recursivly
    if children:
        for t in children:
            insert_node_to_treeview(tv, nd, t, resize, **extras)

if __name__ == '__main__':

    class TestMixin(GuiMixin, Frame):
        def __init__(self, parent=None):
            Frame.__init__(self, parent)
            self.pack(expand=YES, fill=BOTH)


            longline=\
                  'This is a longer line that needs a little more space'
            MyTree=[(['1', 'Line 1'],
                       [(['1.1', 'Line 1.1'],[]),
                        (['1.2', 'Linee 1.2'],
                           [(['1.2.1', 'Linee 1.2.1'],[]),
                            (['1.2.2', 'Line 1.2.2'],[])])]),
                    (['2', 'Line 2'],
                       [(['2.1', longline],
                         [(['2.1.1', 'This is line 2.1.1'],[])])])]

            self.tv=makeTreeview(self,
                      fields=[('head', {}), ('zeile 1',{})],
                      scrollbars=True)

            for t in MyTree:
                insert_node_to_treeview(self.tv, '', t, open=True)

            top = self.tv.get_children()[0]
            self.tv.focus_set()
            self.tv.focus(top)
            self.tv.selection_set(top)

    TestMixin().mainloop()

There are some things i dont understand:
1) resizing of the field widths does work in principle, but the
resulting field is exactly one charakter to small.
2) I think, resizing should be clearer, but i have no idea, how.
3) The horizontal scrollbar does not work as expected. It does not react
on resizing the application window but only on resizing the headers of
the fields.

Maybe someone can give me some hints.
Wolfgang