将关键事件分派到自己的应用程序内的通用上下文

Question

I am developing and Android app (in Java) that needs to receive a broadcast from another application and, according to the data received, dispatch some key events inside my own app. Basically, from inside my app, I need to control multiple Views and Activities to navigate through my interface using the key events.

I am trying the dispatchKeyEvent method that exists in both Activity and View. Below are the documentations:

https://developer.android.com/reference/android/view/View#dispatchKeyEvent(android.view.KeyEvent)

https://developer.android.com/reference/android/app/Activity#dispatchKeyEvent(android.view.KeyEvent)

The problem is: this function only dispatches events to be listened by objects inside the same View or Activity that generated the dispatch. Considering that my app has multiple Activities and Views, I cannot properly navigate because not all contexts are able to listen to these events. For example, I am able to control my homescreen, but as soon as I go to another screen, it stops controlling.

Is there a way of sending key events from my app to itself in a generic way, so that all context inside the app is able to receive these events?

Important: I cannot have root privileges.

Thanks for your time!

Answer 1

You're making your life harder on yourself. Forget key events. That's not the correct way to do anything on Android. And especially not to do anything across Activites. Instead, use something like an RxJava Observable to send events (NOT key events, specific events for things you want to do) and have each activity subscribe to that observable when in the foreground and translate incoming events to commands on that view.

Honestly, even if you could send key events you wouldn't want to. You would then have your API to external apps dependent on a specific implementation of a screen in some random activity that you don't know what its doing. That a massive snarl of bad code and mistakes waiting to happen. Instead, dispatch high level events and let the view itself turn those into view function calls so that all the translation is tightly coupled to the UI implementation, and not to the external API.