Alternative Frames in wxPython - wxDialog (
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We've looked at dialogs several times so far, but what if we need to create our own dialog? By using the wxDialog class, we are able to do so. Let's create a dialog based on wxDialog that displays four radio buttons, asking the user to choose his or her favorite candidate. Additionally, we'll give our dialog a parent window:
from wxPython.wx import *
# Subclass wxDialog to create a dialog
class BallotDialog ( wxDialog ):
def __init__ ( self, parent ):
# Call wxDialog's __init__ method
wxDialog.__init__ ( self, parent, -1, 'Ballot', size = ( 200, 200 ) )
# Create a panel for our dialog
self.panel = wxPanel ( self, -1 )
# Create a label
self.label = wxStaticText ( self.panel, -1, 'Please choose a candidate:' )
# Create four radio buttons
self.candidate1 = wxRadioButton ( self.panel, -1, 'R.Q. Peters', style = wxRB_GROUP )
self.candidate2 = wxRadioButton ( self.panel, -1, 'P.M. Roger' )
self.candidate3 = wxRadioButton ( self.panel, -1, 'T.A. Waters' )
self.candidate4 = wxRadioButton ( self.panel, -1, 'M.W. Wise' )
# Create a button
self.button = wxButton ( self.panel, 100, 'Submit Ballot' )
# Link a button click to a method that destroys
EVT_BUTTON ( self.panel, 100, self.click )
# Put everything in a wxBoxSizer
self.sizer = wxBoxSizer ( wxVERTICAL )
self.sizer.Add ( ( 200, 5 ), 0 )
self.sizer.Add ( self.label, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
self.sizer.Add ( self.candidate1, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
self.sizer.Add ( self.candidate2, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
self.sizer.Add ( self.candidate3, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
self.sizer.Add ( self.candidate4, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
self.sizer.Add ( self.button, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
# Attach the sizer to the panel
self.panel.SetSizerAndFit ( self.sizer )
# Resize the dialog
self.sizer.Fit ( self )
# Handles a click to the button
def click ( self, event ):
self.EndModal ( wxID_OK )
# Create a window
class Window ( wxFrame ):
def __init__ ( self ):
wxFrame.__init__ ( self, None, -1, 'Parent Window' )
# Create a panel for the window
self.panel = wxPanel ( self, -1 )
# Add a wxTextCtrl
self.text = wxTextCtrl ( self.panel, -1 )
# Create the dialog
dialog = BallotDialog ( self )
# Show the window
self.Show ( True )
# Show the dialog ( AFTER we show the window )
dialog.ShowModal()
# Center the dialog
dialog.Center()
application = wxPySimpleApp()
Window()
application.MainLoop()
Try to type something in the wxTextCtrl on the window while the dialog is visible. It's not possible. This is because of the ShowModal method. The ShowModal method creates a modal dialog, causing clicks to other windows to be ignored. In most cases, this behavior is ideal. However, if you do not want this behavior, make a modeless dialog by using the Show method.
Another thing I would like to shed light on is the EndModal method of wxDialog. This exits the dialog and returns the value specified. In this case, we return wxID_OK. Alternatively, you can set the value you will return with SetReturnCode, which works with Show.
An interesting feature of wxDialog is the ability to put the dialog in help mode when using Windows. I'm sure you've seen this feature in other applications. By pressing a button at the top of the dialog, your cursor will change, allowing you to click controls and learn more about them. To access this functionality, we have to create the dialog differently. We have to pre-create it. Fortunately, however, this is fairly simple. Let's create an application that takes advantage of this special help functionality:
from wxPython.wx import *
class HelpDialog ( wxDialog ):
def __init__ ( self, parent ):
# Pre-create our dialog
preCreation = wxPreDialog()
# Set the wxDIALOG_EX_CONTEXTHELP style
# This allows for the help functionality
preCreation.SetExtraStyle ( wxDIALOG_EX_CONTEXTHELP )
# Create it
preCreation.Create ( parent, -1, 'Help Dialog' )
# Do post-creation
# This is required to get our dialog working
self.PostCreate ( preCreation )
# Set the help provider
# This is necessary to display anything
wxHelpProvider_Set ( wxSimpleHelpProvider() )
# Create a panel
self.panel = wxPanel ( self, -1 )
# Create a wxTextCtrl
self.text = wxTextCtrl ( self.panel, -1 )
# Set the help text
self.text.SetHelpText ( 'Nice, huh?' )
# Create a wxButton
self.button = wxButton ( self.panel, -1, 'Just A Button' )
# Set the help text
self.button.SetHelpText ( 'Yes, very nice.' )
# Add our controls to a sizer
self.sizer = wxBoxSizer ( wxVERTICAL )
self.sizer.Add ( ( 200, 5 ), 0 )
self.sizer.Add ( self.text, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
self.sizer.Add ( self.button, 0, wxALIGN_CENTER )
self.sizer.Add ( ( 5, 5 ), 0 )
# Attach the sizer to the panel
self.panel.SetSizerAndFit ( self.sizer )
# Resize the dialog
self.sizer.Fit ( self )
application = wxPySimpleApp()
dialog = HelpDialog ( None )
dialog.ShowModal()
