Validation in onFocusChange
<p>I have multi <code>EditTexts</code>.
How can i validate the <code>EditText</code> from having "" in the <code>EditText</code> and if the <code>EditText</code> is "" then i want the user to must enter a number before it goes to edittext2
How can this be done?</p>

<pre><code>case R.id.P2Throw1Set2:
    p212r.setText(String.valueOf(Integer.parseInt(p2score.getText().toString()) - Integer.parseInt(p212.getText().toString())));
    p2score.setText(String.valueOf(Integer.parseInt(p212r.getText().toString())));
    break;
case R.id.P2Throw2Set2:
    p222r.setText(String.valueOf(Integer.parseInt(p2score.getText().toString()) - Integer.parseInt(p222.getText().toString())));
    p2score.setText(String.valueOf(Integer.parseInt(p222r.getText().toString())));
    break;
case R.id.P2Throw3Set2:
    p232r.setText(String.valueOf(Integer.parseInt(p2score.getText().toString()) - Integer.parseInt(p232.getText().toString())));
    p2score.setText(String.valueOf(Integer.parseInt(p232r.getText().toString())));
    break;
case R.id.P2Throw4Set2:
    p242r.setText(String.valueOf(Integer.parseInt(p2score.getText().toString()) - Integer.parseInt(p242.getText().toString())));
    p2score.setText(String.valueOf(Integer.parseInt(p242r.getText().toString())));
    break;
</code></pre>
