wxPython - TextCtrl Class

Previous
Quiz
Next

In a GUI interface, the input is most commonly collected in a text box where the user can type using the keyboard. In wxPython, an object of wx.TextCtrl class serves this purpose. It is a control in which the text can be displayed and edited. The TextCtrl widget can be a single line, multi-line or a password field. TextCtrl class constructor takes the following form −

wx.TextCtrl(parent, id, value, pos, size, style)

The style parameter takes one or more constants from the following list −

S.N. Parameters & Description
1

wx.TE_MULTILINE

The text control allows multiple lines. If this style is not specified, the line break characters should not be used in the controls value.
2

wx.TE_PASSWORD

The text will be echoed as asterisks
3

wx.TE_READONLY

The text will not be user-editable
4

wxTE_LEFT

The text in the control will be left-justified (default)
5

wxTE_CENTRE

The text in the control will be centered
6

wxTE_RIGHT

The text in the control will be right-justified

The important methods of wx.TextCtrl class are −

S.N. Methods & Description
1

AppendText()

Adds text to the end of text control
2

Clear()

Clears the contents
3

GetValue()

Returns the contents of the text box
4

Replace()

Replaces the entire or portion of text in the box
5

SetEditable()

Makes the text box editable or read-only
6

SetMaxLength()

Sets maximum number of characters the control can hold
7

SetValue()

Sets the contents in the text box programmatically
8

IsMultiLine()

Returns true if set to TE_MULTILINE

The following event binders are responsible for event handling related to entering text in TextCtrl box −

S.N. Events & Description
1

EVT_TEXT

Responds to changes in the contents of text box, either by manually keying in, or programmatically
2

EVT_TEXT_ENTER

Invokes associated handler when Enter key is pressed in the text box
3

EVT_TEXT_MAXLEN

Triggers associated handler as soon as the length of text entered reaches the value of SetMaxLength() function

Example

In the following example, four objects of wx.TextCtrl class with different attributes are placed on the panel.

self.t1 = wx.TextCtrl(panel) 
self.t2 = wx.TextCtrl(panel,style = wx.TE_PASSWORD) 
self.t3 = wx.TextCtrl(panel,size = (200,100),style = wx.TE_MULTILINE) 
self.t4 = wx.TextCtrl ( panel, value = "ReadOnly Text",
   style = wx.TE_READONLY | wx.TE_CENTER )

While the first is a normal text box, the second is a password field. The third one is a multiline text box and the last text box is non-editable.

EVT_TEXT binder on first box triggers OnKeyTyped() method for each key stroke in it. The second box is having its MaxLength set to 5. EVT_TEXT_MAXLEN binder sends OnMaxLen() function running as soon as the user tries to type more than 5 characters. The multiline text box responds to Enter key pressed because of EVT_TEXT_ENTER binder.

The complete code is as follows −

import wx
  
class Mywin(wx.Frame): 
   def __init__(self, parent, title): 
      super(Mywin, self).__init__(parent, title = title,size = (350,250))
		
      panel = wx.Panel(self) 
      vbox = wx.BoxSizer(wx.VERTICAL) 
         
      hbox1 = wx.BoxSizer(wx.HORIZONTAL) 
      l1 = wx.StaticText(panel, -1, "Text Field") 
		
      hbox1.Add(l1, 1, wx.EXPAND|wx.ALIGN_LEFT|wx.ALL,5) 
      self.t1 = wx.TextCtrl(panel) 
		
      hbox1.Add(self.t1,1,wx.EXPAND|wx.ALIGN_LEFT|wx.ALL,5) 
      self.t1.Bind(wx.EVT_TEXT,self.OnKeyTyped) 
      vbox.Add(hbox1) 
		
      hbox2 = wx.BoxSizer(wx.HORIZONTAL)
      l2 = wx.StaticText(panel, -1, "password field") 
		
      hbox2.Add(l2, 1, wx.ALIGN_LEFT|wx.ALL,5) 
      self.t2 = wx.TextCtrl(panel,style = wx.TE_PASSWORD) 
      self.t2.SetMaxLength(5) 
		
      hbox2.Add(self.t2,1,wx.EXPAND|wx.ALIGN_LEFT|wx.ALL,5) 
      vbox.Add(hbox2) 
      self.t2.Bind(wx.EVT_TEXT_MAXLEN,self.OnMaxLen)
		
      hbox3 = wx.BoxSizer(wx.HORIZONTAL) 
      l3 = wx.StaticText(panel, -1, "Multiline Text") 
		
      hbox3.Add(l3,1, wx.EXPAND|wx.ALIGN_LEFT|wx.ALL,5) 
      self.t3 = wx.TextCtrl(panel,size = (200,100),style = wx.TE_MULTILINE) 
		
      hbox3.Add(self.t3,1,wx.EXPAND|wx.ALIGN_LEFT|wx.ALL,5) 
      vbox.Add(hbox3) 
      self.t3.Bind(wx.EVT_TEXT_ENTER,self.OnEnterPressed)  
		
      hbox4 = wx.BoxSizer(wx.HORIZONTAL) 
      l4 = wx.StaticText(panel, -1, "Read only text") 
		
      hbox4.Add(l4, 1, wx.EXPAND|wx.ALIGN_LEFT|wx.ALL,5) 
      self.t4 = wx.TextCtrl(panel, value = "ReadOnly  
         Text",style = wx.TE_READONLY|wx.TE_CENTER) 
			
      hbox4.Add(self.t4,1,wx.EXPAND|wx.ALIGN_LEFT|wx.ALL,5) 
      vbox.Add(hbox4) 
      panel.SetSizer(vbox) 
        
      self.Centre() 
      self.Show() 
      self.Fit()  
		
   def OnKeyTyped(self, event): 
      print event.GetString() 
		
   def OnEnterPressed(self,event): 
      print "Enter pressed" 
		
   def OnMaxLen(self,event): 
      print "Maximum length reached" 
		
app = wx.App() 
Mywin(None,  'TextCtrl demo')
app.MainLoop()

The above code produces the following output −

TextCtrl Output
wxpython_major_classes.htm
Print Page
Previous
Next
Advertisements