wxPython TreeCtrl: Get an treeitem's data by index

Question

How do I get a tree item's data by index of the tree?

I'm currently writing a GUI with wxPython (using Python 2.7). This GUI contains a CustomTreeCtrl that is build as follows:

    # Create Tree control
    widget_tree = CustomTreeCtrl(parent=self, id=ID_WIDGET_TREE, agwStyle=wx.TR_HIDE_ROOT | wx.TR_SINGLE | wx.TR_HAS_BUTTONS, 
                                 size=(UI_tree_width, -1))
    widget_tree.SetBackgroundColour(wx.WHITE)
    root = widget_tree.AddRoot(text="root")

# Create general
    item_general = widget_tree.AppendItem(parentId=root, text='General')
    item_main = widget_tree.AppendItem(parentId=item_general, text='Main', data={'tooltip': 'Main'})
    widget_tree.AppendItem(parentId=item_general, text='Manual', data={'tooltip': 'Manual'})
    widget_tree.AppendItem(parentId=item_general, text='Boundary conditions', data={'tooltip': 'BC'})

    # Create stiffeners
    item_stiffener = widget_tree.AppendItem(parentId=root, text='Stiffeners')
    widget_tree.AppendItem(parentId=item_stiffener, text='Stiffener 1', data={'tooltip': 'Stiffener 1'})
    widget_tree.AppendItem(parentId=item_stiffener, text='Stiffener 2', data={'tooltip': 'Stiffener 2'})
    widget_tree.AppendItem(parentId=item_stiffener, text='Add stiffener', data={'tooltip': 'Creates a new stiffener'})

The data will be extended with certain input by the user. Besides that clicking on 'Add stiffener' will insert an item above 'Add stiffener'. For the purpose of the tool I need to get this data from every stiffener. I was wondering if it is possible to call these like lists in lists. So for example I could call widget_tree.GetTreeItem[0][1][0] for [root][stiffeners][stiffener 1] and so on.

I've been looking for a while now and was hoping someone could help me out. Thanks in advance!

score 1 · Accepted Answer · answered May 05 '17 at 05:52

I inherited a project that had a massively complicated way to do what you're asking for, but your post gave me a new idea. Conceptually, I think you're talking about something similar to the get_item_by_indexes method in this example (I left in all the debug prints):

import wx
from wx.lib.agw.customtreectrl import CustomTreeCtrl

class IndexTree(CustomTreeCtrl):
def get_item_by_indexes(self, *args):
    args = list(args)  # copy so we don't modify original
    print("Trying tree index: %s" % str(args))
    if args[0] > 0:
        raise IndexError("Invalid root index")
    parent = self.GetRootItem()
    print("arg_index=0, tree_index=0, item=%s" % (parent.GetText()))
    for arg_index, tree_index in enumerate(args[1:], 1):
        parent = parent.GetChildren()[tree_index]
        print("arg_index=%d, tree_index=%d, item=%s" % (arg_index, tree_index, parent.GetText()))
    return parent

class MyFrame(wx.Frame):
    def __init__(self, parent, id, title):
        wx.Frame.__init__(self, parent, id, title, wx.DefaultPosition, wx.DefaultSize)
        widget_tree = IndexTree(parent=self, agwStyle=wx.TR_HIDE_ROOT | wx.TR_SINGLE | wx.TR_HAS_BUTTONS, 
                                 size=(400, -1))
        widget_tree.SetBackgroundColour(wx.WHITE)
        root = widget_tree.AddRoot(text="root")

    # Create general
        item_general = widget_tree.AppendItem(parentId=root, text='General')
        item_main = widget_tree.AppendItem(parentId=item_general, text='Main', data={'tooltip': 'Main'})
        widget_tree.AppendItem(parentId=item_general, text='Manual', data={'tooltip': 'Manual'})
        widget_tree.AppendItem(parentId=item_general, text='Boundary conditions', data={'tooltip': 'BC'})

        # Create stiffeners
        item_stiffener = widget_tree.AppendItem(parentId=root, text='Stiffeners')
        widget_tree.AppendItem(parentId=item_stiffener, text='Stiffener 1', data={'tooltip': 'Stiffener 1'})
        widget_tree.AppendItem(parentId=item_stiffener, text='Stiffener 2', data={'tooltip': 'Stiffener 2'})
        widget_tree.AppendItem(parentId=item_stiffener, text='Add stiffener', data={'tooltip': 'Creates a new stiffener'})

        widget_tree.get_item_by_indexes(0)
        widget_tree.get_item_by_indexes(0, 1)
        widget_tree.get_item_by_indexes(0, 0, 0)
        widget_tree.get_item_by_indexes(0, 1, 0)
        widget_tree.get_item_by_indexes(0, 1, 2)
        try:
            widget_tree.get_item_by_indexes(0, 1, 8)
        except IndexError, e:
            print(e)

class MyApp(wx.App):
    def OnInit(self):
        frame = MyFrame(None, -1, 'IndexTree')
        frame.Show(True)
        frame.Centre()
        return True

if __name__ == '__main__':
    app = MyApp(0)
    app.MainLoop()

which for the test cases produces:

Trying tree index: [0]
arg_index=0, tree_index=0, item=root
Trying tree index: [0, 1]
arg_index=0, tree_index=0, item=root
arg_index=1, tree_index=1, item=Stiffeners
Trying tree index: [0, 0, 0]
arg_index=0, tree_index=0, item=root
arg_index=1, tree_index=0, item=General
arg_index=2, tree_index=0, item=Main
Trying tree index: [0, 1, 0]
arg_index=0, tree_index=0, item=root
arg_index=1, tree_index=1, item=Stiffeners
arg_index=2, tree_index=0, item=Stiffener 1
Trying tree index: [0, 1, 2]
arg_index=0, tree_index=0, item=root
arg_index=1, tree_index=1, item=Stiffeners
arg_index=2, tree_index=2, item=Add stiffener
Trying tree index: [0, 1, 8]
arg_index=0, tree_index=0, item=root
arg_index=1, tree_index=1, item=Stiffeners
list index out of range

A big ol' caveat that I haven't used this in practice yet because I didn't have the idea before seeing your post just now. But I hacked this together and I am interested to see if I can replace my project's overly complicated method.

That looks very promising! Am I understanding it correctly that the function you wrote returns the item with the index that is given? I looks like it's giving all the parents as well, is it possible to just give the item with the asked index? And with that item I can just use item.GetPyData['data'] to get the data I want, right? By the way, funny to see you might be able to use it in your own project! — Jesper K., May 08 '17 at 07:34
It returns the `GenericTreeItem` instance; the output above is from the debug prints that I left in. In the sample code, I ignore the return value of `get_item_by_indexes` but you can use it instead. — robm, May 08 '17 at 17:00
Ah of course, should have noticed that. Will see if i can apply this. btw, i would upvote your post but don't have enough reputation yet so if i get another upvote you'll get the first upvote i'll give. — Jesper K., May 10 '17 at 07:00

wxPython TreeCtrl: Get an treeitem's data by index

1 Answers1