Question

What I’m trying to do is intercept the Back button press from an external Class like this:

public class AnswerView extends RelativeLayout {

    public AnswerView(Context context) {
        super(context);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_BACK) {
            Log.i("AlleAntwoorden", "Back button pressed!");
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }
}

I’m adding it like this from my main Activity:

RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.main_layout);
mainLayout.addView(new AnswerView(this));

Answer 1

In order for a View to receive any event it needs to have focus. I don’t see any XML, so let’s add a couple characteristics at run time:

AnswerView layout = new AnswerView(this);
layout.setFocusableInTouchMode(true);
layout.requestFocus();
mainLayout.addView(layout);

Now your layout will intercept the back button in your OnKeyListener. But if another View has focus, even a child View, the event might be consumed by the child first.
To understand this, add an EditText to your AnswerView:

layout.addView(new EditText());

If you click the back button while the EditText has focus: the first click closes the soft keyboard, the second click will finish the current Activity like normal. The OnKeyListener event is not passed up through the View hierarchy by default.