Is it always safe to cast Context to Activity within View

Question

May I know, is it safe for me to always cast Context to Activity within a View ?

View {
    Activity activity = (Activity)this.getContext();
}

So far, it works fine all the moment. I was wondering, is there any edge cases that the above code will fail?

Answer 1

As I know, It is not always safe because, the context also can be passed from os to a Service, BroadcastReceiver, etc. But, almost of case, that is not a problem. just check with this code

if(context instanceof Activity)

and feel free to use.

Answer 2

I think you can use following snippet:

/**
 * Get activity instance from desired context.
 */
public static Activity getActivity(Context context) {
    if (context == null) return null;
    if (context instanceof Activity) return (Activity) context;
    if (context instanceof ContextWrapper) return getActivity(((ContextWrapper)context).getBaseContext());
    return null;
}

Answer 3

Technically, Views can be created with any Context (via the LayoutInflater )

So unless you are super sure that your Views are only instantiated by Activities, I wouldn't suggest this. Doing this is not a clean idea.

Answer 4

While I can't think of such case, I think it is not such a great idea for two reasons:

1. Why would you want to do that, when do you explicitly need Activity?
2. What if tomorrow this will be changed, and there will be other context for View ?