怎么判断EditText输入结束

EditText tr = (EditText) findViewById(R.id.ett);
tr.addTextChangedListener(new TextWatcher(){

@Override
public void beforeTextChanged(CharSequence
s, int start, int count, int after) {
// TODO Auto-generated method stub

}

@Override
public void onTextChanged(CharSequence s,
int start, int before, int count) {
// TODO Auto-generated method stub

}

@Override
public void afterTextChanged(Editable s) {
// TODO Auto-generated method stub
Log.d("ET",s.toString().length()+"
");
}});