Re: Java Tip 68: Learn how to implement the Command pattern in Java - JavaWorld - February 1999

[Rick Beton <rdb@xxxxxxxxxx>]

"P.H.Welch" wrote:

<snip>

In JDK1.1, such event handling was deprecated and replaced with
a traditional (non-`object-oriented') listener-callback mecahnism.

If I understand correctly, it's not quite correct to call the listener-callback
mecahnism 'non object oriented' just because it doesn't use inheritance.
The term often used is the 'delegate model', I believe, as distinct from
the 'inheritance model'.
 
> <snip>

> My question is: does the un-thread-safeness of Swing
> configuration
> methods just mean that we can't invoke them safely from multiple
> threads?  <snip>

> OR ... does the declared un-thread-safeness of Swing
> configuration
> methods mean that they *must* be executed only by the JVM Event thread
> (i.e. using `invokeLater')?  <snip>
The latter is true, except for a very few exceptions. It has to run GUI
interactions in the JVM Event thread. I quote:
> Rule: Once a Swing component has been realized, all
> code that might affect
> or depend on the state of that component should be executed in the
> event-dispatching thread.
URL for further reading:
http://java.sun.com/docs/books/tutorial/uiswing/overview/threads.html

Rick
--
Richard Beton B.Sc. C.Phys. M.Inst.P.
Roke Manor Research Limited (http://www.roke.co.uk/)
--------- Standard Disclaimer about my own views etc etc --------
---------  My mail client accepts rich text (HTML) mail  --------
Welsh Highland Railway: http://www.whr.co.uk/WHR/WHR.html