This article assumes that you have basic knowledge of wxPython – how to create a frame, populate it with controls and organize them. Make sure you understand these tasks before you dive into this article.
wxCheckBox
Checkboxes are useful in applications. Besides looking nice and neat, they can be used for more than one purpose. For example, in one application, checkboxes could allow a user to select all the items that apply, and in another application, checkboxes could give the user the option to turn things on and off. They are also very easy to work with and aren’t over-complicated by too many methods and events.
Let’s take a look at a very simple application that uses checkboxes to gather input from the user:
from wxPython.wx import *
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, ‘Survey’, size = ( 400, 200 ) )
# Create a panel to house everything
self.panel = wxPanel ( self, -1 )
# Create a wxGridBagSizer to organize our widgets
self.sizer = wxGridBagSizer ( 5, 5 )
# Create a label for our application
self.label = wxStaticText ( self.panel, -1, ‘What electronics do you plan to buy in the next year?’ +
’nCheck all that apply.’, style = wxTE_CENTER )
# Create a few wxCheckBox instances
self.camera = wxCheckBox ( self.panel, -1, ‘Digital Camera’ )
self.music = wxCheckBox ( self.panel, -1, ‘Music-related Device’ )
self.hardware = wxCheckBox ( self.panel, -1, ‘Computer Hardware’ )
self.television = wxCheckBox ( self.panel, -1, ‘Television’ )
self.dvd = wxCheckBox ( self.panel, -1, ‘DVDPlayer’ )
self.other = wxCheckBox ( self.panel, -1, ‘Other’ )
# Create a button
self.button = wxButton ( self.panel, 100, ‘Submit’ )
# Catch a click to the button
EVT_BUTTON ( self.panel, 100, self.submit )
# Add everything to the sizer
self.sizer.Add ( self.label, ( 0, 0 ), ( 1, 3 ), wxALIGN_CENTER )
self.sizer.Add ( self.camera, ( 1, 0 ) )
self.sizer.Add ( self.music, ( 1, 1 ) )
self.sizer.Add ( self.hardware, ( 1, 2 ) )
self.sizer.Add ( self.television, ( 2, 0 ) )
self.sizer.Add ( self.dvd, ( 2, 1 ) )
self.sizer.Add ( self.other, ( 2, 2 ) )
self.sizer.Add ( self.button, ( 3, 0 ), ( 1, 3 ), wxALIGN_CENTER )
# Center everything
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1 )
self.horizontal.Add ( self.sizer )
self.horizontal.Add ( ( 0, 0 ), 1 )
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0, ), 1 )
self.vertical.Add ( self.horizontal, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1 )
# Attach the sizer to the panel
self.panel.SetSizerAndFit ( self.vertical )
self.Show ( True )
# This method is triggered when the button is clicked
# It checks whether or not each checkbox is clicked
def submit ( self, event ):
message = ‘You plan to get the following items in the next year:’
# Check whether or not each checkbox is clicked
# If one is, add a string to the message variable
if self.camera.GetValue():
message = message + ‘nDigital Camera’
if self.music.GetValue():
message = message + ‘nMusic-related Device’
if self.hardware.GetValue():
message = message + ‘nComputer Hardware’
if self.television.GetValue():
message = message + ‘nTelevision’
if self.dvd.GetValue():
message = message + ‘nDVD Player’
if self.other.GetValue():
message = message + ‘nOther’
# Display a dialog with the results
dialog = wxMessageDialog ( self, message, ‘Results’, style = wxOK )
dialog.ShowModal()
dialog.Destroy()
application = wxPySimpleApp()
Window()
application.MainLoop()
It is also possible to catch a click on a checkbox and set the value of the checkbox. We’ll create a simple application that combines both of these functions:
from wxPython.wx import *
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, ‘Checkbox Test’, size = ( 200, 200 ) )
# Create a panel
self.panel = wxPanel ( self, -1 )
# Create a vertical sizer
self.vertical = wxBoxSizer ( wxVERTICAL )
# Add a space
self.vertical.Add ( ( 0, 0 ), 1 )
# Create and add two checkboxes
self.first = wxCheckBox ( self.panel, 1, ‘First’ )
self.second = wxCheckBox ( self.panel, 2, ‘Second’ )
self.vertical.Add ( self.first, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.second, 0, wxALIGN_CENTER )
# Catch events
EVT_CHECKBOX ( self.panel, 1, self.firstHandle )
EVT_CHECKBOX ( self.panel, 2, self.secondHandle )
# Add another space
self.vertical.Add ( ( 0, 0 ), 1 )
# Center it with a horizontal sizer
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1 )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1 )
# Add the sizer
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
# This method unchecks the other checkbox if it is checked
def firstHandle ( self, event ):
self.second.SetValue ( False )
# This method does the same thing
def secondHandle ( self, event ):
self.first.SetValue ( False )
application = wxPySimpleApp()
Window()
application.MainLoop()
A normal checkbox has two states. It is possible, however, to create a checkbox with three states:
from wxPython.wx import *
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, ‘Checkbox Test’, size = ( 200, 200 ) )
# Create a panel
self.panel = wxPanel ( self, -1 )
# Create a checkbox with three states
self.checkbox = wxCheckBox ( self.panel, 1, ‘Tri-state border’, style = wxCHK_3STATE | wxCHK_ALLOW_3RD_STATE_FOR_USER )
# Catch a click
EVT_CHECKBOX ( self.panel, 1, self.handle )
self.Show ( True )
# Handle a click event
def handle ( self, event ):
# Print the value of the checkbox
print self.checkbox.Get3StateValue()
application = wxPySimpleApp()
Window()
application.MainLoop()
{mospagebreak title=wxCheckListBox}
The wxCheckListBox is a combination of wxCheckBox and wxListBox. It is basically a list of checkboxes that users can click. It’s useful if you have a large amount of checkboxes. Let’s create an application that shows off wxCheckListBox‘s features:
from wxPython.wx import *
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, ‘Dinner’, size = ( 300, 300 ) )
# Create a status bar
self.CreateStatusBar()
# Create a panel
self.panel = wxPanel ( self, -1 )
# Create a label
self.label = wxStaticText ( self.panel, -1, ‘Configure your dinner:’ )
# Define a list of items to place in the wxCheckListBox
self.dinner = [ 'Ravioli', 'Apple Pie', 'Dr. Pepper', 'Soup', 'Salad', 'Ham Sandwich', 'Pizza',
'Macaroni and Cheese', 'Carrot Cake', 'Spinach', 'Potato Salad ( Southern Style )' ]
# Create a wxCheckListBox
self.box = wxCheckListBox ( self.panel, 100, size = ( 150, 100 ), choices = self.dinner, style = wxLB_HSCROLL )
# Hook up an event handling method
EVT_CHECKLISTBOX ( self.panel, 100, self.clickHandler )
# Create a button
self.button = wxButton ( self.panel, 200, ‘Prepare’ )
# Hook up an event handling method
EVT_BUTTON ( self.panel, 200, self.buttonHandler )
# Create two sizers to make everything pretty
# The usual
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0 ), 1 )
self.vertical.Add ( self.label, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.box, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.button, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1 )
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1 )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1 )
# Attach the sizer
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
# This method is called when an item is clicked
def clickHandler ( self, event ):
if self.box.IsChecked ( event.GetSelection() ):
message = ‘ will be prepared.’
else:
message = ‘ will not be prepared.’
# Update the status bar of the window
self.SetStatusText ( self.box.GetString ( event.GetSelection() ) + message )
# This method will be called when the button is clicked
def buttonHandler ( self, event ):
message = ‘The following items have been prepared:’
# Check to see what has been selected and what has not
x = 0
for choice in self.dinner:
if self.box.IsChecked ( x ):
message = message + ‘n’ + choice
x = x + 1
# Display a dialog
dialog = wxMessageDialog ( self, message, ‘Your dinner is ready.’, style = wxOK )
dialog.ShowModal()
dialog.Destroy()
application = wxPySimpleApp()
Window()
application.MainLoop()
{mospagebreak title=wxRadioButton}
Radio buttons are useful when you want the user to select one item out of a list of multiple items. Alternatively, the user can check a single radio button that cannot be unchecked. A group of radio buttons is started by setting the style wxRB_GROUP on the first button, and a lone radio button is created by setting wxRB_SINGLE as the style. Let’s put together an application that uses radio buttons:
from wxPython.wx import *
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, ‘Ballot’ )
# Create a panel, like we always do
self.panel = wxPanel ( self, -1 )
# Create a grid layout
self.sizer = wxGridBagSizer ( 2, 10 )
# Create one group of buttons ( plus a label ) and add them
# We mark the beginning of the group with wxRB_GROUP
self.president1 = wxRadioButton ( self.panel, -1, ‘CharlesFagundes’, style = wxRB_GROUP )
self.president2 = wxRadioButton ( self.panel, -1, ‘TerriWells’ )
self.sizer.Add ( wxStaticText ( self.panel, -1, ‘President’ ), ( 0, 0 ) )
self.sizer.Add ( self.president1, ( 1, 0 ) )
self.sizer.Add ( self.president2, ( 2, 0 ) )
# Create another group of radio buttons
self.senator1 = wxRadioButton ( self.panel, -1, ‘Peyton McCullough’, style = wxRB_GROUP )
self.senator2 = wxRadioButton ( self.panel, -1, ‘Alejandro Gervasio’ )
self.senator3 = wxRadioButton ( self.panel, -1, ‘Jagadish Chatarji’ )
self.senator4 = wxRadioButton ( self.panel, -1, ‘Michael Swanson’ )
self.sizer.Add ( wxStaticText ( self.panel, -1, ‘Senator’ ), ( 0, 1 ) )
self.sizer.Add ( self.senator1, ( 1, 1 ) )
self.sizer.Add ( self.senator2, ( 2, 1 ) )
self.sizer.Add ( self.senator3, ( 3, 1 ) )
self.sizer.Add ( self.senator4, ( 4, 1 ) )
# Create yet another group of radio buttons
# These will not be in a group
# We’ll also create a button, which will be activated if both boxes are checked
self.term1 = wxRadioButton ( self.panel, 1, ‘This is my only ballot.’, style = wxRB_SINGLE )
self.term2 = wxRadioButton ( self.panel, 1, ‘I swear it is!’, style = wxRB_SINGLE )
self.button = wxButton ( self.panel, 2, ‘Submit’ )
self.button.Disable()
self.sizer.Add ( wxStaticText ( self.panel, -1, ‘Agreement’ ), ( 0, 2 ) )
self.sizer.Add ( self.term1, ( 1, 2 ) )
self.sizer.Add ( self.term2, ( 2, 2 ) )
self.sizer.Add ( self.button, ( 3, 2 ), ( 2, 1 ), wxALIGN_CENTER )
# Hook up events to the three controls above
EVT_RADIOBUTTON ( self.panel, 1, self.confirm )
EVT_BUTTON ( self.panel, 2, self.vote )
# Attach our sizer to our panel
self.panel.SetSizerAndFit ( self.sizer )
# Resize the window
self.sizer.Fit ( self )
self.Show ( True )
# This will check to see if term1 and term2 have both been clicked
# If so, the button will be disabled
def confirm ( self, event ):
if ( self.term1.GetValue() == True ) & ( self.term2.GetValue() == True ):
self.button.Enable()
# Here, we will send a message to the user and reset everything
def vote ( self, event ):
# Show a dialog
dialog = wxMessageDialog ( self, ‘Thank you for your vote.’, ‘Thank You’, style = wxOK )
dialog.ShowModal()
dialog.Destroy()
# Reset things
self.president1.SetValue ( True )
self.senator1.SetValue ( True )
self.term1.SetValue ( False )
self.term2.SetValue ( False )
self.button.Disable()
application = wxPySimpleApp()
Window()
application.MainLoop()
Simple, huh?
{mospagebreak title=wxRadioBox}
By using wxRadioBox, it is possible to create a boxed group of radio buttons. The result looks like a group of radio buttons surrounded by a wxStaticBox and is visually appealing.The creation of a wxRadioBox is incredibly simple because the labels of each radio box are passed in the form of a list. The rows and columns of the wxRadioBox are then determined by the majorDimension variable and either the wxRA_SPECIFY_ROWS or the wxRA_SPECIFY_COLS style. If wxRA_SPECIFY_ROWS is passed, the value in majorDimension will be the number of rows. The same thing works for wxRA_SPECIFY_COLS and columns. Let’s take a closer look at how it all works:
from wxPython.wx import *
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, ‘wxRadioBox’, size = ( 300, 300 ) )
# Create a status bar
self.CreateStatusBar()
# Create a panel
self.panel = wxPanel ( self, -1 )
# Create a list of radio buttons
self.radioList = [ 'This', 'Is', 'A', 'Box', 'Full', 'Of', 'Radio', 'Buttons' ]
# Create a wxRadioBox with two rows
self.radioBox1 = wxRadioBox ( self.panel, 1, ‘Radio Box 1′, choices = self.radioList, majorDimension = 2, style = wxRA_SPECIFY_ROWS )
# Create a wxRadoiBox with two columns
self.radioBox2 = wxRadioBox ( self.panel, 1, ‘Radio Box 2′, choices = self.radioList, majorDimension = 2, style = wxRA_SPECIFY_COLS )
# Tie in methods to handle a click
EVT_RADIOBOX ( self.panel, 1, self.radioClick )
# Center everything
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0 ), 1 )
self.vertical.Add ( self.radioBox1, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.radioBox2, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1 )
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1 )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1 )
# Attach the sizer
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
def radioClick ( self, event ):
# Get the wxRadioBox
radioBox = event.GetEventObject()
# Get the index of the selected button
radioIndex = radioBox.GetSelection()
# Get the string of the selected button
radioString = radioBox.GetStringSelection()
# Update the status bar
self.SetStatusText ( str ( radioIndex ) + ‘: ‘ + radioString )
application = wxPySimpleApp()
Window()
application.MainLoop()
There are other things you can do with a wxRadioBox, too. You can disable a wxRadioBox, find the location of a label, count the buttons, get the label of a button, set the label of a button and set the current selection. Let’s take a look at these features:
from wxPython.wx import *
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, ‘wxRadioBox Features’, size = ( 300, 300 ) )
# Create a panel
self.panel = wxPanel ( self, -1 )
# Create a wxRadioBox to experiment on
self.box = wxRadioBox ( self.panel, 100, ‘A Radio Box’, choices = [ 'A', 'B', 'C', 'D' ], majorDimension = 2, style = wxRA_SPECIFY_COLS )
# Handle a click with a method
EVT_RADIOBOX ( self.panel, 100, self.radioClick )
# Create a label to count the items in our wxRadioBox
self.count = wxStaticText ( self.panel, -1, ‘Count: ‘ + str ( self.box.GetCount() ) )
# Create a label to display the label of the currently selected button
self.label = wxStaticText ( self.panel, -1, ‘Label: ‘ + str ( self.box.GetItemLabel ( self.box.GetSelection() ) ) )
# Create a label to display the position of the radio button whose label is “A”:
self.find = wxStaticText ( self.panel, -1, ‘”A”: ‘ + str ( self.box.FindString ( ‘A’ ) ) )
# Create a button that disables the entire wxRadioBox and attach a handler
self.disableBoxButton = wxButton ( self.panel, 200, ‘Disable Box’ )
EVT_BUTTON ( self.panel, 200, self.disableBox )
# Create a button that disables the currently selected item and attach a handler
self.disableItemButton = wxButton ( self.panel, 300, ‘Disable Item’ )
EVT_BUTTON ( self.panel, 300, self.disableItem )
# Create a button that changes the label of the currently selected item and attach a handler
self.changeLabelButton = wxButton ( self.panel, 400, ‘Change Label’ )
EVT_BUTTON ( self.panel, 400, self.changeLabel )
# Center things in two sizers
self.vertical = wxBoxSizer ( wxVERTICAL )
self.vertical.Add ( ( 0, 0 ), 1 )
self.vertical.Add ( self.box, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.count, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.label, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.find, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.disableBoxButton, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.disableItemButton, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 5, 5 ), 0 )
self.vertical.Add ( self.changeLabelButton, 0, wxALIGN_CENTER )
self.vertical.Add ( ( 0, 0 ), 1 )
self.horizontal = wxBoxSizer ( wxHORIZONTAL )
self.horizontal.Add ( ( 0, 0 ), 1 )
self.horizontal.Add ( self.vertical, 0, wxALIGN_CENTER )
self.horizontal.Add ( ( 0, 0 ), 1 )
# Attach our horizontal sizer
self.panel.SetSizerAndFit ( self.horizontal )
self.Show ( True )
# This method is called when a radio button is clicked
def radioClick ( self, event ):
# Update the label label
self.label.SetLabel ( ‘Label: ‘ + str ( self.box.GetItemLabel ( self.box.GetSelection() ) ) )
# This method is called when the “Disable Box” button is clicked
def disableBox ( self, event ):
# Disable the wxRadioBox
self.box.Enable ( False )
# This method is called when the “Disable Item” button is clicked
def disableItem ( self, event ):
# Disable the currently selected item
self.box.EnableItem ( self.box.GetSelection(), False )
# This method is called when the “Set Label” button is clicked
def changeLabel ( self, event ):
# Set the label of the currently selected button to “Q”
self.box.SetItemLabel ( self.box.GetSelection(), ‘Q’ )
# Update the find label
self.find.SetLabel ( ‘”A”: ‘ + str ( self.box.FindString ( ‘A’ ) ) )
application = wxPySimpleApp()
Window()
application.MainLoop()
Conclusion
Several “box” controls are offered in wxPython, and they can serve multiple purposes as I mentioned earlier. It’s all up to your creativity. These controls are very simple to use, featuring only a few methods and styles, yet they offer you a large amount of flexibility. These controls can improve your applications when necessary, pleasing their users – the goal of your graphical user interfaces.