Re: Need to explicitly remove event handlers manually?
exactly that is what my workaround was ... on any place change I call unbind() on the active presenter before changing to the new one. But what I intend to have is no need for any unbind() method at all. In my opinion its the eventbusses concern to recognize that the eventHandler should be detached, when its presenter is not existent anymore. But perhaps this is way to much functionality or the wrong layer of abstraction I expect of something like the HandlerManager -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
Re: Need to explicitly remove event handlers manually?
I'd say that cleaning up no longer needed handlers is just as important as closing open files when you're done or freeing memory that you've allocated. You won't notice the effects at first, but eventually you will. How soon depends on the cases under which your application creates handlers). Eventually, you'll see event delivery taking longer and longer because your event bus is busy notifying handlers that you don't care about anymore. There's a reason why the handler manager goes to the trouble of returning a handler registration. There's no way for it to know that you're done with the handler. This is one of those cases where garbage collection wouldn't even help you because the handler manager has to hold a reference to the handler (unless you use weak references, but I'm pretty sure we don't have those in the JDK emulation layer). It's not too difficult to keep track of handler registrations. I often make a collection to hold them. Just add them all to the collection in your bind method and unregister everything (and clear the collection) in your unbind method. -Brian On Apr 12, 8:14 pm, rjcarr rjc...@gmail.com wrote: If you no longer need the handler then yeah, you should remove it, because you don't want to execute code blocks (onClick()) that are no longer needed or used. But it certainly isn't required. On Apr 12, 2:32 pm, macagain rgk...@gmail.com wrote: Is it required or even good practice to manually remove event handlers (say, on detach or unload)? I.e. keep the handlerRegistration around when returned from addHandler, then later call handlerManager.removeHandler(). Of course in the old world of manually managing listener collections, one had to do it, but in the new world of HandlerManagers? -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
Re: Need to explicitly remove event handlers manually?
This really is one more useful point which would make closures nice but we should wait for JDK 7 or later for this. I already ran into some of issues according handlers I missed to unbind. Therefore it would be nice to find a way to avoid this destructor-like (java uncommon) coding pattern. I think there should be an easy way, but actually I haven't had enough time to figure it out yet and provide an idea for a soultion. -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
Re: Need to explicitly remove event handlers manually?
I've stepped through the code and there is no requirement to unregister handlers explicitly. Each widget has a handler manager (as member variable) that manages its handlers. If a widget is removed from its parent or its parent explicitly clears it then the registered handlers will get cleaned up by normal garbage collection. This is not the case if you are using a global handler manager for say an event bus. If handlers are added that are specific to a particular presenter then the presenter needs to remove the handlers when it is destroyed. I implemented a Place Manager that takes care of all of this automatically along with history support. -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
Need to explicitly remove event handlers manually?
Is it required or even good practice to manually remove event handlers (say, on detach or unload)? I.e. keep the handlerRegistration around when returned from addHandler, then later call handlerManager.removeHandler(). Of course in the old world of manually managing listener collections, one had to do it, but in the new world of HandlerManagers? -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
Re: Need to explicitly remove event handlers manually?
If you no longer need the handler then yeah, you should remove it, because you don't want to execute code blocks (onClick()) that are no longer needed or used. But it certainly isn't required. On Apr 12, 2:32 pm, macagain rgk...@gmail.com wrote: Is it required or even good practice to manually remove event handlers (say, on detach or unload)? I.e. keep the handlerRegistration around when returned from addHandler, then later call handlerManager.removeHandler(). Of course in the old world of manually managing listener collections, one had to do it, but in the new world of HandlerManagers? -- You received this message because you are subscribed to the Google Groups Google Web Toolkit group. To post to this group, send email to google-web-tool...@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.
