title: Multiple EditText listener
body: <p>I have 3 <em>EditText's</em> (one for length, other for width and other for height), and the objective is: </p>
  
  <p>When all the three <em>editTexts</em> are edited, automatically one <em>textField</em> is updated with a result (the result is a equation with that three numbers).</p>
  
  <p>I made this with a button, when I click the button, he checks the values on the 3 editext, and set text on result TextField. Like this:</p>
  
  <pre><code>private void Calculator(View view){
          EditText length = (EditText)view.findViewById(R.id.length);
          EditText width = (EditText)view.findViewById(R.id.width);
          EditText height = (EditText)view.findViewById(R.id.height);
  
          Button button = (Button)view.findViewById(R.id.button);
          button.setOnClickListener(new OnClickListener() {
  
              @Override
              public void onClick(View v) {
                  // TODO Auto-generated method stub
                  int calc = calculator(length.getText(),width.getText(),height.getText());
                  TextView result = (TextView)view.findViewById(R.id.result);
                  result.setText(calc);
              }
          });
      }
  
  }
  </code></pre>
  
  <p>But I dont want that, I want dyanmic update.</p>