title: QTableView - Not Getting Selection Changed Signal
body: <p>I am fairly new to QT, and am having trouble understanding how the <code>QTableView</code> selection changed signal is handled.  I have setup a window with an openGL widget and a <code>QTableView</code>.  I have a data model class that is correctly populating the tableview, so I added a public slot to that class:</p>
  
  <pre><code>class APartsTableModel : public QAbstractTableModel
  {
  public:
      AVehicleModel *vehicle;
      explicit APartsTableModel(QObject *parent = 0);
  
      //MVC functions
      int rowCount(const QModelIndex &amp;parent) const;
      int columnCount(const QModelIndex &amp;paret) const;
      QVariant data(const QModelIndex &amp;index, int role) const;
      QVariant headerData(int section, Qt::Orientation orientation, int role) const;
  
  public slots:
      void selectionChangedSlot(const QItemSelection &amp;newSelection,
                                const QItemSelection &amp;oldSelection);
  
  };
  </code></pre>
  
  <p>When I am ready to show the window with the table view, I allocate/initialize it like this:</p>
  
  <pre><code>//create the display view
  AStarModelView *displayWindow = new AStarModelView(this,
                                                     starModel-&gt;vehicle);
  
  //create the datamodel for the table view
  APartsTableModel *dataModel = new APartsTableModel(displayWindow);
  dataModel-&gt;vehicle = starModel-&gt;vehicle;
  
  //create selection model for table view
  QItemSelectionModel *selModel = new QItemSelectionModel(dataModel);
  displayWindow-&gt;materialsTable-&gt;setSelectionModel(selModel);
  
  //setup model and signal
  displayWindow-&gt;materialsTable-&gt;setModel(dataModel);
  
  connect(selModel,
          SIGNAL(selectionChanged(const QItemSelection &amp;, const QItemSelection &amp;)),
          dataModel,
          SLOT(selectionChangedSlot(const QItemSelection &amp;, const QItemSelection &amp;)));
  
  //show the view
  displayWindow-&gt;show();
  </code></pre>
  
  <p>When I set a breakpoint in the implementation of the slot function, I never hit it.  I've also tried not allocating a new <code>QItemSelectionModel</code>, but that didn't work either.  I'm really not sure what I'm doing wrong here.</p>