title: QT5: RetranslateUi does not retranslate view
body: <p>I'm attempting to add dynamic localisation support to an application, however when calling <code>retranslateUi()</code> on the <code>MainWindow</code> nothing is translated. </p>
  
  <p>I use the code below in a preferences dialog to set the localisation to use:</p>
  
  <pre><code>if(translator.load(QDir::toNativeSeparators("localisation/") + m_localisations.at(ui-&gt;languageOptionsBox-&gt;currentIndex()).name() + "_v1"))
      qDebug() &lt;&lt; "Loaded translation";
  else
      qDebug() &lt;&lt; "Translation not loaded";
  
  qApp-&gt;installTranslator(&amp;translator);
  </code></pre>
  
  <p>Then handle the change event in my <code>MainWindow</code> class:</p>
  
  <pre><code>void MainWindow::changeEvent(QEvent *event)
  {
     qDebug() &lt;&lt; "Change event";
     if(event-&gt;type() == QEvent::LanguageChange)
     {
        qDebug() &lt;&lt; "Language Change event";
        ui-&gt;retranslateUi(this);
     }
  
     QMainWindow::changeEvent(event);
  }
  </code></pre>
  
  <p>The <code>retranslateUi()</code> function is called from the <code>ui_mainwindow.h</code>, but the UI isn't updated with the correct language, the localisation is definitely loaded according to the debug statements. Translation definitely works as I store the selected value as a <code>QSettings</code> value and check it on application load, and restarting the application does translate it correctly so I assume I'm missing something.</p>