wxPython – EnsureVisible() method in wx.TreeCtrl

Last Updated : 28 Jul, 2020

In this article we are going to learn about EnsureVisible() function associated with wx.TreeCtrl class of wxPython. EnsureVisible() method makes an item/root to be visible on screen. Scrolls and/or expands items to ensure that the given item is visible.

This method can be used, and will work, even while the window is frozen (see wx.Window.Freeze ).

Syntax: wx.TreeCtrl.EnsureVisible()

Parameters:

Parameter Type Description

item wx.TreeItemId item that we want to ensure to be visible.

Code Example:

Python3

import wx 
  
class TreePanel(wx.Panel): 
  
    def __init__(self, parent): 
        wx.Panel.__init__(self, parent) 
  
        self.tree = wx.TreeCtrl(self, wx.ID_ANY, wx.DefaultPosition, (100, 50), 
                           wx.TR_HAS_BUTTONS) 
        # create tree root 
        self.root = self.tree.AddRoot('root') 
        self.tree.SetPyData(self.root, ('key', 'value')) 
  
        # add items to root 
        item = self.tree.AppendItem(self.root, "Item") 
        item2 = self.tree.AppendItem(self.root, "Item") 
        item3 = self.tree.AppendItem(self.root, "Item") 
        item4 = self.tree.AppendItem(self.root, "Item") 
        focusitem = self.tree.AppendItem(self.root, "Focus Item") 
  
        # expand root 
        self.tree.Expand(self.root) 
  
        self.tree.EnsureVisible(focusitem) 
  
        sizer = wx.BoxSizer(wx.VERTICAL) 
        sizer.Add(self.tree, 0, wx.EXPAND) 
        self.SetSizer(sizer) 
  
    def onclick(self, e): 
        # Delete si2 from the tree 
        self.tree.Delete(self.si2) 
  
  
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() 