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Re: quick question

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On 01/03/2013 19:48, Eric Sosman allegedly wrote:
> On 3/1/2013 1:25 PM, Doug Mika wrote:
>> reading a book a came upon the following inside a 'myDialog extends
>> JDialog" class inside an actionlistener implemented as an anonymous
>> inner class.
>>
>> myDialog.this.dispose()
>>
>> why not simply write
>>
>> this.dispose()
> 
>     That would be perfectly all right, if you get your thrills
> from reading the compiler's error messages.  :)
> 
>> does it have anything do with the fact that this line is found within
>> an anonymous inner class that is an actionListener?
> 
>     Yes.  An unadorned `this' would refer to the instance of the
> class whose code is running.  That's the anonymous class that
> implements ActionListener, a class that doesn't even *have* a
> dispose() method (unless one's been added explicitly in the
> anonymous class, which would be awfully strange).
> 
>     Writing `this.dispose()' or simply `dispose()' would try
> to call the anonymous class' dispose() method, not any method
> belonging to the enclosing myDialog (poor choice of name, BTW).
> The intent, most likely, is to close the dialog -- so the code
> uses `myDialog.this' to mean "Not *this* `this', but the `this'
> of the enclosing class named `myDialog'."  It's that enclosing
> class' dispose() that's being called.
> 

For the record, it's called a "Qualified 'this'", and the specification
can be found here:
<http://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.8.4>

-- 
DF.

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quick question Doug Mika <dougmmika@gmail.com> - 2013-03-01 10:25 -0800
  Re: quick question Eric Sosman <esosman@comcast-dot-net.invalid> - 2013-03-01 13:48 -0500
    Re: quick question Daniele Futtorovic <da.futt.news@laposte-dot-net.invalid> - 2013-03-01 20:08 +0100
      Re: quick question Donkey Hottie <donkey@fredriksson.dy.fi> - 2013-03-01 22:52 +0200
        Re: quick question Joerg Meier <joergmmeier@arcor.de> - 2013-03-01 22:22 +0100
          Re: quick question Lew <lewbloch@gmail.com> - 2013-03-01 15:31 -0800
  Re: quick question Arne Vajhøj <arne@vajhoej.dk> - 2013-03-01 18:30 -0500
  Re: quick question Roedy Green <see_website@mindprod.com.invalid> - 2013-03-01 15:38 -0800

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