wxPython – Collapse() method wx.TreeCtrl

In this article we are going to learn about Collapse() method associated with wx.TreeCtrl class of wxPython. Collapse() method is used to simply collapse the given item, that is, the root item gets folded and child items get invisible.
Collapse() method takes a wx.TreeItemId parameter.

Syntax: wx.TreeCtrl.Collapse(item)

Parameters

Parameter	Input Type	Description
item	wx.TreeItemId	item or root which we want to collapse

Code Example:

import wx


class MyTree(wx.TreeCtrl):

    def __init__(self, parent, id, pos, size, style):
        wx.TreeCtrl.__init__(self, parent, id, pos, size, style)


class TreePanel(wx.Panel):

    def __init__(self, parent):
        wx.Panel.__init__(self, parent)

        # create tree control
        self.tree = MyTree(self, wx.ID_ANY, wx.DefaultPosition, wx.DefaultSize,
                                                             wx.TR_HAS_BUTTONS)

        self.btn = wx.Button(self, 1, "Collapse", (50, 60))

        # add root to self.tree
        self.root = self.tree.AddRoot('Root')
        # add item to self.root
        item = self.tree.AppendItem(self.root, 'Item')

        # bind event with self.btn
        self.btn.Bind(wx.EVT_BUTTON, self.onclick)

        self.tree.Expand(self.root)

        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(self.tree, 0, wx.EXPAND)
        self.SetSizer(sizer)

    def onclick(self, e):
        # collapse root
        self.tree.Collapse(self.root)

class MainFrame(wx.Frame):

    def __init__(self):
        wx.Frame.__init__(self, parent = None, title ='TreeCtrl Demo')
        panel = TreePanel(self)
        self.Show()


if __name__ == '__main__':
    app = wx.App(redirect = False)
    frame = MainFrame()
    app.MainLoop()

Output Window:

before clicking button

after clicking button