A Close Look at wxPython Controls - Password text boxes, read-only text boxes
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Another thing that interested me was creating text boxes for passwords, as well as text boxes that could not be modified. The wxTE_PASSWORD and wxTE_READONLY styles make this possible with the wxTextCtrl. We can also use the SetEditable method:
from wxPython.wx import *
class OurFrame ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, 'wxPython' )
self.panel = wxPanel ( self, -1 )
# Create a normal text box
self.text = wxTextCtrl ( self.panel, -1 )
# Create a password box
self.passw = wxTextCtrl ( self.panel, -1, style = wxTE_PASSWORD )
# Create a read-only box
self.disabled = wxTextCtrl ( self.panel, -1, 'Cannot be modified.', style = wxTE_READONLY )
# Create a read-only box
self.disabled2 = wxTextCtrl ( self.panel, -1, 'Nor can this.' )
self.disabled2.SetEditable ( False )
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.vertical.Add ( wxStaticText ( self.panel, wxID_ANY, 'A Simple wxTextCtrl:' ), 0, wxALIGN_CENTER )
# Add everything
self.vertical.Add ( self.text, 0, wxALIGN_CENTER )
self.vertical.Add ( self.passw, 0, wxALIGN_CENTER )
self.vertical.Add ( self.disabled, 0, wxALIGN_CENTER )
self.vertical.Add ( self.disabled2, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
application = wxPySimpleApp()
window = OurFrame()
application.MainLoop()
Multi-line text boxes are also very useful in applications. They can be created from a wxTextCtrl using the wxTE_MULTILINE style, and, optionally, the wxTE_DONTWRAP style:
from wxPython.wx import *
class OurFrame ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, 'wxPython' )
self.panel = wxPanel ( self, -1 )
# Create a text box
self.text = wxTextCtrl ( self.panel, -1 )
# Create a multi-line text box
self.multi = wxTextCtrl ( self.panel, -1, style = wxTE_MULTILINE )
# Create a multi-line text box that does not wrap lines
self.multi2 = wxTextCtrl ( self.panel, -1, style = wxTE_MULTILINE | wxTE_DONTWRAP )
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.vertical.Add ( wxStaticText ( self.panel, wxID_ANY, 'A Simple wxTextCtrl:' ), 0, wxALIGN_CENTER )
# Add everything
self.vertical.Add ( self.text, 0, wxALIGN_CENTER )
self.vertical.Add ( self.multi, 0, wxALIGN_CENTER )
self.vertical.Add ( self.multi2, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
application = wxPySimpleApp()
window = OurFrame()
application.MainLoop()
If we only want the user to be able to enter a certain amount of characters, we can do that with the SetMaxLength method:
from wxPython.wx import *
class OurFrame ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, 'wxPython' )
self.panel = wxPanel ( self, -1 )
# Create a text box
self.text = wxTextCtrl ( self.panel, -1 )
# Create a text box with a maximum length
self.max = wxTextCtrl ( self.panel, -1 )
self.max.SetMaxLength ( 10 )
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.vertical.Add ( wxStaticText ( self.panel, wxID_ANY, 'A Simple wxTextCtrl:' ), 0, wxALIGN_CENTER )
# Add everything
self.vertical.Add ( self.text, 0, wxALIGN_CENTER )
self.vertical.Add ( self.max, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
application = wxPySimpleApp()
window = OurFrame()
application.MainLoop()
If we want to trigger an event when the user presses the enter key on his or her keyboard, we can do so with the wxTE_PROCESS_ENTER style and the EVENT_TYPE_TEXT_ENTER_COMMAND event. When the user presses the enter key on our second text box, we'll write a few characters to the text box. When the user presses the enter key on our third text box, we'll set the value to something else. We'll also create two more text boxes. When the user presses the enter key while working with the third text box, its contents will be saved to a file, and the fourth text box will load the contents of that file:
from wxPython.wx import *
class OurFrame ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, 'wxPython' )
self.panel = wxPanel ( self, -1 )
# Create a text box
self.text = wxTextCtrl ( self.panel, -1 )
# Create a text box that triggers an event
self.enter = wxTextCtrl ( self.panel, 100, style = wxTE_PROCESS_ENTER )
EVT_TEXT_ENTER ( self.panel, 100, self.handleEnter1 )
# Create another text box that triggers an event
self.enter2 = wxTextCtrl ( self.panel, 200, style = wxTE_PROCESS_ENTER )
EVT_TEXT_ENTER ( self.panel, 200, self.handleEnter2 )
# Create another text box that triggers an event
self.save = wxTextCtrl ( self.panel, 300, style = wxTE_PROCESS_ENTER )
EVT_TEXT_ENTER ( self.panel, 300, self.handleEnter3 )
# Create another text box that triggers an event
self.load = wxTextCtrl ( self.panel, -1, style = wxTE_PROCESS_ENTER )
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.vertical.Add ( wxStaticText ( self.panel, wxID_ANY, 'A Simple wxTextCtrl:' ), 0, wxALIGN_CENTER )
# Add everything
self.vertical.Add ( self.text, 0, wxALIGN_CENTER )
self.vertical.Add ( self.enter, 0, wxALIGN_CENTER )
self.vertical.Add ( self.enter2, 0, wxALIGN_CENTER )
self.vertical.Add ( self.save, 0, wxALIGN_CENTER )
self.vertical.Add ( self.load, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1, wxEXPAND )
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
def handleEnter1 ( self, event ):
self.enter.AppendText ( '100%' )
def handleEnter2 ( self, event ):
self.enter2.SetValue ( '0%' )
def handleEnter3 ( self, event ):
self.save.SaveFile ( 'textctrl.txt' )
self.load.LoadFile ( 'textctrl.txt' )
application = wxPySimpleApp()
window = OurFrame()
application.MainLoop()
Conclusion
Now we know a bit more about the wxChoice, wxComboBox, wxListBox and wxTextCtrl controls, giving us more methods for gathering input from users, which is necessary in any application. We also know that although some wxPython controls seems simple on the surface, such as wxTextCtrl, they can be amazingly complex underneath, containing dozens of methods for us to use.
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