I have a class PricingModel which needs to listen for bus events coming from a variety of UI elements. (The user will make choices, e.g. from drop down list, or checkboxes, etc. and I need to recompute a price plan as they modify their choices.) My PricingModel in turn needs to emit updated information for various parts of the UI to pick up. I know I want to use the GWT EventBus rather than amass spaghetti code of callback functions.
However, I've failed to turn up worthy code examples that employ SimpleEventBus. So I'm trying to understand what is intended from the javadocs for SimpleEventBus<http://google-web-toolkit.googlecode.com/svn/javadoc/2.3/com/google/gwt/event/shared/SimpleEventBus.html>, GwtEvent<http://google-web-toolkit.googlecode.com/svn/javadoc/2.3/com/google/gwt/event/shared/GwtEvent.html>, and EventHandler<http://google-web-toolkit.googlecode.com/svn/javadoc/2.3/com/google/gwt/event/shared/EventHandler.html> . I started by creating two classes, OnChangePlanHandler, and OnChangePlan extends GwtEvent<OnChangePlanHandler>. I see where my OnChangePlan.dispatch(OnChangePlanHander handler) will be invoked. Q1) I presume inside my dispatch() function I am probably supposed to call appropriate functions that I create in my OnChangePlanHander class? Q2) What do I return for OnChangePlan.getAssociatedType()? Do I need to create a subclass of GwtEvent.Type<OnChangePlanHandler> too? When would I ever create an instance of this subclass? Will I ever create more than one instance of this subclass? (i.e. where should I be storing this instance?) It looks like I might have just one such instance declared statically somewhere to return it from OnChangePlan.getAssociatedType(). Right? Q3) The javadocs for SimpleEventBus.addHandler() says it should *rarely* be called directly. (??) The alternative code snippet offered in the javadocs lacks enough context for me; I don't yet understand the entire scheme of how these classes are intended to work together. In all, I'm looking to understand how these classes are meant to work together. I can write up a full example for others if I can collect the bits of knowledge. -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-web-toolkit/-/M1V3MUhKQWhaQ3NK. To post to this group, send email to google-web-toolkit@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.
