That is true, my design is based on the getInstance(), and I got a private constructor.
The new FontLoader() below is a sample that I meant just was needed to solve my listeners-problems ( when getInstance() is used in several classes with listeners setup) I am really questioning everything in my code, in which really isn't necessary, but I cant help it for now. The listeners-problem is solved if I always removes the listeners when the loading of fonts has been done, so that I can use the FontLoader-instance in another class without firing the other event-listeners in other classes. / martin -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of James O'Reilly Sent: den 28 oktober 2005 08:05 To: Flashcoders mailing list Subject: Re: [Flashcoders] Singleton and Listeners is a bad combination Maybe I'm misunderstanding the implementation of the Singleton but I thought a statement like this was impossible? Doesn't the singleton have a private constructor that only a public method such as getInstance() can access? I didn't think you could use "new" outside of the class itself like you did below: Class A private var fntController:FontLoader = new FontLoader(); Class B private var fntController:FontLoader = new FontLoader(); However, I think you're on the right track with making FontLoader a singlton. It sounds like something you probably don't need more than one of tho I don't really know what it does for sure. One way to get this to work, also mentioned by Alan, is having the FontLoader pass an event object back which could be examined by each of the listening classes. The other is for FontLoader to have multiple listener lists and have each class subscribe to a different list. Something like addPixelFontListener() and addNormalFontListener() for example would enable all of your class to subscribe to either one or both. Keep in mind this could get out of hand quickly if you keep adding more and more list types. There are probably other solutions as well. JOR ___________________________________ === James O'Reilly === === SynergyMedia, Inc. === www.synergymedia.net Martin Klasson wrote: > > > Hi Coders. > > > > I got a class which I thought would be improved by using the Singleton pattern. And it does, until I am adding in the EventDispatcher. > > The problem is that my application will using the FontLoader.getInstance() at several places in different classes and files. > > The problem arises since you can set addEventListeners to the instance. > > > > If you in class A has: > > fntController = FontLoader.getInstance() > > fntController.addEventListener('onFinished', fontsLoaded) > > > > And in Class B you have the same as class A, just to state an example of the problem... > > > > The problem is that since FontLoader.getInstance() returns exactly the same instance everytime. So when class B fontsLoaded is called, the fontsLoaded is also called in class A. > > The problem is that even though you can use removeEventListener, you might not want do that since you might still want the fontsLoaded to be working in class A another time. > > One solution is that you in class A and class B doesnt have the same name for the function that is given in the addEventListener -but that doesnt seem like a neat solution to depend on that when several developers might write the same. > > As well as boring for the EventDispatcher used in the FontLoader to call listener-function which might not exist in the different scopes/classes where the FontLoader istance is. > > > > So I thought the best way would be to do the class ALL static, but the problem would still be the same with the listeners. > > I can only come up with one solution, and that is to do the usual, that you will have to instanciate the class. > > > > class A > > private var fntController:FontLoader = new FontLoader(); // now I can have listeners which just would listen to this instance. > > class B > > private var fntController:FontLoader = new FontLoader(); // now I can have listeners which just would listen to this instance. > > > > This will make them able to have listeners that wont interfere with each other. Is this the best solution, or do you know of any other solution that you think would suit this scenario? > > Listeners are incredibly great, and I am thinking on the Key-class, that has addListener, which is a static class and should suffer just as well as my FontLoader-listeners does. But somehow it doesnt fit the FontLoader. > > What do you think, any general advices? > > > > Singleton and EventDispatcher doesnt come in handy when you are having the getInstance() at several places in an application, or am I wrong? > > Thanks. > > / martin > > > > ------------------------------------------------------------------------ > > _______________________________________________ > Flashcoders mailing list > [email protected] > http://chattyfig.figleaf.com/mailman/listinfo/flashcoders _______________________________________________ Flashcoders mailing list [email protected] http://chattyfig.figleaf.com/mailman/listinfo/flashcoders _______________________________________________ Flashcoders mailing list [email protected] http://chattyfig.figleaf.com/mailman/listinfo/flashcoders
