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POautomatic update of wxPython's wx.TreeCtrl
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copied!<p>wx.TreeCtrl is used (in wxPython) to display data from a list. How to create a tree so, that the tree view is updated (i.e. by calling wx.TreeCtrl.Refresh) if data is changed in the list?</p> <p>The list itself (constructed from a database) is structured as:</p> <pre><code>data = [ 'item1', ['item2', ['item2.1','item2.2'],], ['item3', [['item3.1', ['item3.1.1','item3.1.2']]]],] </code></pre> <p>One solution I found that kind of works is to create a virtual tree and to override Refresh as:</p> <pre><code>def Refresh(self): self.CollapseAll() self.Expand(self.root) </code></pre> <p>As the tree is virtual, on expand all the nodes are read again from the list. But overriding Refresh is probably a hack and I'm looking for a cleaner solution. There are nice examples how to do it for a grid and table (http://svn.wxwidgets.org/viewvc/wx/wxPython/trunk/demo/Grid_MegaExample.py?view=markup) but I can't find anything for a tree.</p> <p><strong>EDIT & ANSWER</strong></p> <p>Sometimes to solve a problem it's best to formulate the question. I was using virtual tree as described in "wxPython in Action" by Rappin and Dunn. But that's a poor man's solution. Correct would be to derive a class from VirtualTree. Posting the solution here if anyone should stumble on the same problem. The solution is a pruned-down version from (http://wxwidgets2.8.sourcearchive.com/documentation/2.8.8.0/TreeMixin_8py-source.html).</p> <pre><code>import wx from wx.lib.mixins.treemixin import VirtualTree items = [('item 0', [('item 2', [('a1', []),('b1', [])]), ('item 3', [])]), ('item 1', [('item 4', [('a3', []),('b3', [])]), ('item 5', [])])] class MyTree(VirtualTree, wx.TreeCtrl): def __init__(self, *args, **kw): super(MyTree, self).__init__(*args, **kw) self.RefreshItems() #OnTest emulates event that causes data to change self.Bind(wx.EVT_KEY_DOWN, self.OnTest) def OnTest(self, evt): items[0]=('boo', [('item 2', [('a1', []),('b1', [])]), ('item 3', [])]) self.RefreshItems() def OnGetItemText(self, index): return self.GetText(index) def OnGetChildrenCount(self, indices): return self.GetChildrenCount(indices) def GetItem(self, indices): text, children = 'Hidden root', items for index in indices: text, children = children[index] return text, children def GetText(self, indices): return self.GetItem(indices)[0] def GetChildrenCount(self, indices): return len(self.GetChildren(indices)) def GetChildren(self, indices): return self.GetItem(indices)[1] class TreeFrame(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title='wxTree Test Program') self.tree = MyTree(self, style=wx.TR_DEFAULT_STYLE | wx.TR_HIDE_ROOT) if __name__ == '__main__': app = wx.PySimpleApp() frame = TreeFrame() frame.Show() app.MainLoop() </code></pre>

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