Reply to thread

Message: [QUOTE="Tom Hawtin, post: 2848221"] The pattern is called "Observer". That doesn't mean you have to use the interface named Observer. IMO, Observer and Observable should have been deprecated in 1.1. The 1.1+ idiom is event listeners. If you use event listener, you can have one observer (the listener) with a number of methods. However, using listeners that try to work out what has changed is going to be a disaster. Swing is packed full of little bugs because of this problem, and it also has lots of hacks to prevent the problem. The best way is to assume everything that could have led to the event did cause it. Duplicate no state. If there is a performance problem, optimise but don't assume that the original state + event information gives you the current state. You could create a log of changes (as a database does). Then when a listener receives an event, process the entire log since last update. I have never seen this done. Tom Hawtin [/QUOTE]