title: How to get the row index of selected checkbox on grid GXT
body: <p>I am working with GXT (2.2.5) and need to get the row index of chenged checkbox on the grid. What i am doing is to create a grid and apply a GridCellRender to show a checkBox in first column, then when any checkBox change their value (listener at the OnChange event), the row index of changed checkbox must be taken. This is a part of my code by the moment:</p>
  
  <pre><code>    checkColumn.setRenderer(new GridCellRenderer() {
          @Override
          public Object render(ModelData model, String property, ColumnData config, int rowIndex, int colIndex, ListStore store, Grid gri) {
              final CheckBox check = new CheckBox();
              check.addListener(Events.OnChange, new Listener&lt;BaseEvent&gt;() {
                  @Override
                  public void handleEvent(BaseEvent be) {
                      //Here we get the row index
                  }
              });
              return check;
          }
      });
  </code></pre>
  
  <p>Thanks.</p>