How to track clicks on the virtual keyboard?

Question

Android

editText.setOnKeyListener(new View.OnKeyListener() {
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                if ((event.getAction() == KeyEvent.ACTION_DOWN) &&
                        (keyCode == KeyEvent.KEYCODE_ENTER)) {
                    setMarker(editText);
                    return true;
                }
                return false;
            }
        });

A custom EditText component drawn on a Canvas.