@Override
        public void afterTextChanged(final Editable s) {
            if (currentFormat == CoordInputFormatEnum.Plain) {
                return;
            }

            final EditText editText = editTextRef.get();
            if (editText == null) {
                return;
            }
            if (!editText.hasFocus()) {
                return;
            }

            if (s.length() == getMaxLengthFromCurrentField(editText)) {
                focusNextVisibleInput(editText);
            }
        }
weak reference, such that garbage collector can do its work
main/src/main/java/cgeo/geocaching/ui/dialog/CoordinatesInputDialog.java