jython-users

[Jython-users] JComboBox.actionPerformed assignment fails

[Waclawczyk J. <Jan...@ic...>]

Hello,

I've got following problem:

	from javax.swing import JButton, JComboBox
	from java.awt import *

	def action(e):
		print "test"

	button = Button("Press")
	button.actionPerformed = action # IT WORKS

	cb = JComboBox(["VAL1"])
	cb.actionPerformed = action  # ERROR
		Traceback (innermost last):
		  File "<console>", line 1, in ?
		TypeError: can't assign to this attribute in java instance: actionPerformed

	#but the following works
	class AL(ActionListener):
	    def actionPerformed(self, e):
	        print "jan"
	al = AL()
	cb.addActionListener(al)

Is this a bug?

Regards
Janusz Waclawczyk

Re: [Jython-users] JComboBox.actionPerformed assignment fails

[Jeff E. <je...@ad...>]

Waclawczyk Janusch wrote:
>         cb = JComboBox(["VAL1"])
>         cb.actionPerformed = action  # ERROR
>                 Traceback (innermost last):
>                   File "<console>", line 1, in ?
>                 TypeError: can't assign to this attribute in java instance: actionPerformed
> 
> Is this a bug?

No, its an ambiguity.  JComboBox has a method named actionPerformed
because it implements ActionListener.  Most other classes that accept
ActionListeners don't also implement ActionListener, so they don't
have that problem.  There are other cases where assigning to the 
automatic bean properties also fails because the property or event name 
conflicts with a method or field.  The workaround would be to
actually implement an ActionListener and add it to the JComboBox as
you would in Java.


Jeff Emanuel                                             
Landmark Graphics Corporation                            
je...@ad...