title: Why WindowStateChange event does not work with me
body: <p>I want when change the window state from state to another, for example: <code>WindowMaximized</code>, <code>WindowMinimized</code>, <code>WindowFullScreen</code>, when change the  window state performs something.</p>
  
  <p><strong>The function used</strong></p>
  
  <pre><code>void Widget::WindowStateChange(QEvent *event){
      if (event-&gt;WindowStateChange == Qt::WindowMaximized) {
          QMessageBox::information(this, "", "Something happen.");
      }
  }
  </code></pre>
  
  <p>There is nothing happening when implement the previous function.</p>