title: Qwt Realtime Dial
body: <p>I want to create a simple Qwt widget that only contains a dial. The value displayed on the dial (i.e. the position of the dial) should be updated according to some input data which I collect from a separate thread.</p>
  
  <p>I can generate my dial within a main window class, and I can create and start my data capture on a separate thread within the main window class, like this:</p>
  
  <pre><code>MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent)
  {
      // create the dial
      QDial* pDial = new QDial;
  
      // create the data class to capture data from an external source
      DataClass* pData = new DataClass;
  
      // start the data class thread
      pData-&gt;Start();
  
      // I can get the latest value of data at any instant like this:
      int x = pData-&gt;GetData();
  
      // I need to connect the data value to the dial, so that the
      // dial always displays the value of the data capture device.
  
  }
  </code></pre>
  
  <p>What can I insert so that GetData() is constantly called to update the value displayed on the dial?</p>