What are the advantages of Anonymous Inner Class (over non-anonymous inner class)?

Question

Consider this (anonymous):

speakBtn.setOnClickListener(new OnClickListener() {
    @Override
    public void onClick(View view) {
        mTts.speak(words.getText().toString(), TextToSpeech.QUEUE_ADD, null);
    }});

vs. this: (non-anonymous):

class MyOuterClass {
    private class MyOnClickListener implements OnClickListener {
        @Override
        public void onClick(View view) {
            mTts.speak(words.getText().toString(), TextToSpeech.QUEUE_ADD, null);
        }
    }

    // later (inside some method)...
        speakBtn.setOnClickListener(new MyOnClickListener());
}

Except for the fewer number of lines, is there any other advantage to the anonymous form?

Is there a performance advantage?

Answer 1

The anonymous inner class has advantage over the inner class (as in the question example code) in that it closes over the local variables of the method (although only final locals are usable).

Generally an inner class can be easily converted into a method with anonymous inner class, which helps reduce verbosity. If you've got an inner class that is so large that you want to make it non-local, you might want to think about battling with your IDE to put it in a new file as an outer class.

(The is also local classes, which are normal named inner classes defined within a method and that close over locals.)