I am building a cross-platform app for Android and iOS. So far it's mostly Android and I am learning how to use j2objc to translate the code that will later be used by iOS.
On the question of architecture the app - how does one go around passing events in the code that is platform-agnostic. For example, I have a class that downloads a group of files and broadcasts a message using Android broadcast mechanism when each file is downloaded - is there a way to implement this notification exchange in pure Java? Are there any tutorials available?
Guava has an eventbus package, which may meet your needs and is included in the j2objc distribution. To use it, include dist/lib/guava-14.0.1.jar (where "dist" is the path to a recent J2ObjC release) in the j2objc command's -classpath, and link with the -lguava flag.