Re: [Jython-users] Explicitly creating listeners from callables

[Samuele P. <ped...@bl...>]

Hi. Without messing with the internals one can do:

<adapter.py>
import new

_adapt_u=0

def adapt(listenerClass, **bindings):
   global _adapt_u
   _adapt_u +=1
   return new.classobj("_%s" % _adapt_u,( listenerClass,),bindings)()

</adapter.py>

then one can do:

>>> from javax.swing import JButton,JFrame
>>> f=JFrame("exp")
>>> from java.awt.event import ActionListener
>>> def doIt(self,e): print "ok!"
...
>>> from adapter import adapt
>>> b=JButton("Ok",actionListener=adapt(ActionListener,actionPerformed=doIt))
>>> f.contentPane.add(b)
[snipped output]
>>> f.pack()
>>> f.visible=1 # click on the button
>>> ok!

regards, Samuele Pedroni.

----- Original Message ----- 
From: Kevin Butler <kb...@ca...>
To: Michael Haggerty <hag...@jp...>
Cc: <jyt...@li...>
Sent: Friday, January 18, 2002 10:34 PM
Subject: Re: [Jython-users] Explicitly creating listeners from callables


> Michael Haggerty wrote:
> >
> > Is there a way to access jython's "callable-to-listener" conversion
> > explicitly?  
> 
> You can (cheat a lot and) actually modify the JComboBox.__dict__:
> 
> """
> adapter.py - demo how to explicitly create an adapter for a Java interface.
> 
> This adds the capability to set 'actionPerformed=callable' in a JComboBox
> constructor.
> 
> Note that this hides the 'JComboBox.actionPerformed' method which
> caused the trouble in the first place, but you're not supposed to do
> anything with that method, so it is probably OK...
> 
> *WARNING* This is a hack - it works for Jython 2.1, but probably won't work
> with future releases.
> """
> from org.python.core import PyBeanEventProperty, PyBeanEvent
> 
> def addEventProperty( objectClass, addMethodName, eventName, eventClass ):
>     """Add the ability to call 'method=callable' in a constructor call.
>     objectClass   - class to modify
>     addMethodName - objectClass method to add a listener
>     eventName     - name of event listener property ('actionListener')
>     eventClass    - class of event listener interface
>     """
>     # code stolen from PyJavaClass.addEvent
>     addMethod = objectClass.getMethod( addMethodName, [eventClass] )
> 
>     # add support for assigning individual event handlers in constructor
>     for eventMethod in eventClass.getMethods():
>         prop = PyBeanEventProperty(
>             eventName,
>             eventClass,
>             addMethod,
>             eventMethod
>             )
>         objectClass.__dict__.__setitem__( prop.__name__, prop )
> 
>     # add support for assigning 'whateverListener=WhateverListenerImpl'
>     event = PyBeanEvent(eventName, eventClass, addMethod);
>     objectClass.__dict__.__setitem__(event.__name__, event);
> 
> 
> 
> # demo code
> from javax.swing import JComboBox, JFrame
> from java.awt.event import ActionListener
> from java.awt import Dimension, BorderLayout
> def showWidget( widget, name="Demo" ):
>         f = JFrame( name )
>         p = f.getContentPane()
>         p.add( widget, BorderLayout.NORTH )
>         f.setSize( 300, 300 )
>         f.show()
> 
> 
> def test():
>     # allow JComboBox( actionPerformed=callable )
>     addEventProperty(
>         JComboBox,
>         'addActionListener',
>         'actionListener',
>         ActionListener
>         )
> 
>     def doit( event ):
>         print "doit:", event
> 
>     jc = JComboBox( range( 10 ), actionPerformed=doit )
>     showWidget( jc )
> 
> 
> 
> Cool.  :-)
> 
> kb
> 
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