title: Replace a widget in Qt
body: <p>I have a base class which has some gui items that i have set positions of using the designer in Qt creator. Those items are:</p>
  
  <pre><code>QWidget* w1;
  QWidget* w2;
  QWidget* w3;
  </code></pre>
  
  <p>Now in a class that inherits that base class, I would like to "transform" those widgets into lineEdit items, that would keep all the geometrical parameters of that widgets. So I do something like this:</p>
  
  <pre><code>QLineEdit* leAmplitude;
  leAmplitude = new QLineEdit(ui-&gt;w1);
  leAmplitude-&gt;setGeometry(ui-&gt;w1-&gt;geometry());
  ui-&gt;glControls-&gt;addWidget(leAmplitude);
  </code></pre>
  
  <p>But the added <code>QLineEdit</code> item doesn't appear in the exact same place as w1 item. Its just added at the bottom of other controls in the <code>QGridLayout</code> glControls. How to make the lineEdit to take all geometric parameters from w1?</p>