== Doing mouse-overs ==
Process the EVT_ENTER_WINDOW and EVT_LEAVE_WINDOW events.

=== Example ===
Originator of this item: please feel free to delete this example 
once you can supply the one that you want. - [[Bill Bell]]

This script is an extension of CreatingCollectionOfControls, you might wish 
to read that one first. This example shows how to use EVT_ENTER_WINDOW 
and EVT_LEAVE_WINDOW so that when the user's mouse is over a button in
the collection a message is displayed in the status bar, and when
the mouse is moved away the message is removed.

{{{
#!python
from   wxPython . wx     import *

class ButtonColumn ( wxPanel ):
    '''Create aligned column of equal-sized buttons with distinct labels and OnClick destinations.

    Illustrates use of nested classes for creating a collection of controls.
    Also illustrates use of mouse over and mouse leave events.
    '''
    class aButton ( wxButton ):
        '''Nested button class for use by ButtonColumn class.'''
        def __init__ ( self, parent, label, whotocall, whotonotify, msg ):
            """Expects reference to 'ButtonColumn', list of labels for buttons and list of functions to be called for OnClick events"""
            id = wxNewId ( )
            wxButton . __init__ ( self, parent, id, label, wxDefaultPosition, wxDefaultSize, 1 )
            self . whotocall = whotocall
            self . whotonotify = whotonotify
            self . msg = msg
            EVT_BUTTON ( self, id, self . OnClick )
            EVT_ENTER_WINDOW ( self, self . OnEnter )
            EVT_LEAVE_WINDOW ( self, self . OnLeave )

        def OnClick ( self, event ):
            if self . whotocall: self . whotocall ( )
            
        def OnEnter ( self, event ) :
            if self . whotonotify : self . whotonotify ( 1, self . msg )
        
        def OnLeave ( self, event ) :
            if self . whotonotify : self . whotonotify ( 0, self . msg )

    def __init__ ( self, parent, width, buttons, Bottom = 0 ):
        """Expects reference to 'parent' of 'ButtonColumn', button column 'width', list of button descriptor tuples, and number of buttons to be displayed at the bottom of the column.

        Each button descriptor consists of a label for the button and a reference to the function to be called when the button is clicked.
        """
        wxPanel . __init__ ( self, parent, -1, wxDefaultPosition, ( 100, 200 ) )
        self . parent = parent

        """Create the upper collection of buttons"""
        previous = None
        for button in buttons [ 0 : len ( buttons ) -Bottom ]:
            oneButton = self . aButton ( self, button [ 0 ], button [ 1 ], button [ 2 ], button [ 3 ] )
            lc = wxLayoutConstraints ( )
            lc . left . SameAs ( self, wxLeft, 5 )
            lc . right . SameAs ( self, wxRight, 5 )
            lc . height . AsIs ( )
            if previous: lc . top . SameAs ( previous, wxBottom, 5 )
            else: lc . top . SameAs ( self, wxTop, 5 )
            oneButton . SetConstraints ( lc )
            previous = oneButton

        """Create the lower collection of buttons"""
        buttons . reverse ( )
        previous = None
        for button in buttons [ 0 : Bottom ]:
            oneButton = self . aButton ( self, button [ 0 ], button [ 1 ], button [ 2 ], button [ 3 ] )
            lc = wxLayoutConstraints ( )
            lc . left . SameAs ( self, wxLeft, 5 )
            lc . right . SameAs ( self, wxRight, 5 )
            lc . height . AsIs ( )
            if previous: lc . bottom . SameAs ( previous, wxTop, 5 )
            else: lc . bottom . SameAs ( self, wxBottom, 5 )
            oneButton . SetConstraints ( lc )
            previous = oneButton

if __name__ == '__main__':
    class TestFrame(wxFrame):
        def __init__(self):
            wxFrame . __init__ (
                self, None, -1, "Button Column Test",
                size = ( 450, 300 ),
                style = wxDEFAULT_FRAME_STYLE | wxNO_FULL_REPAINT_ON_RESIZE
                )
            self . SetAutoLayout ( true )
            buttons = [
                ( 'OK', self . OKClicked, self . OnMessage, 'OK button text', ),
                ( 'Cancel', self . CancelClicked, self . OnMessage, 'Cancel button text', ),
                ( 'Re-invert', self . ReinvertClicked, self . OnMessage, 'Re-invert button text', ),
                ( 'Exit', self . ExitClicked, self . OnMessage, 'Exit button text', ),
                ]

            self . tp = ButtonColumn ( self, 45, buttons, 2 )

            lc = wxLayoutConstraints ( )
            lc . right . SameAs ( self, wxRight)
            lc . width . AsIs ( )
            lc . top . SameAs ( self, wxTop )
            lc . bottom . SameAs ( self, wxBottom )
            self . tp . SetConstraints ( lc )

            self . CreateStatusBar ( )
            
        def OnMessage ( self, on, msg ) :
            if not on : msg = ""
            self . SetStatusText ( msg )

        def OKClicked ( self ):
            print "OKClicked"

        def CancelClicked ( self ):
            print "CancelClicked"

        def ReinvertClicked ( self ):
            print "ReInvertClicked"

        def ExitClicked ( self ):
            print "ExitClicked"
            self . Close ( )

    app = wxPySimpleApp()
    frame = TestFrame()
    frame . Show(true)
    app . MainLoop()

}}}