title: GXT 2.2.4 grid row editor
body: <p>I'm working on a 3 years old GXT project. I have an editable grid, I want while editing one cell, say cell A, another cell, say cell B, of the same row update it's value. In fact cell B must represent some computation based on cell A's field value. Here is the code I use to catch changes on cell A' field:</p>
  
  <pre><code>cellAField.addKeyListener(new KeyListener() {
      @Override
          public void componentKeyUp(ComponentEvent event) {
              try {
                  computeValueOfCellB(cellAField.getValue().doubleValue());
              } catch (Throwable e) {
                  Log.warn(e.getMessage());
              }
          }
  });
  </code></pre>
  
  <p>and here is what I do to compute and update cell B value:</p>
  
  <pre><code>private void computeValueOfCellB(Double value_of_A) {
      BeanModel bean = grid.getSelectionModel().getSelectedItem();
      bean.set("cell_A", value_of_A);
      bean.set("cell_B", value_of_A - someDoubleValue);
      grid.getStore().update(bean);
  }
  </code></pre>
  
  <p>Well as I update the store with the new bean, value of cell B is not showed in the grid's row editor, to show cell B's value I must call a <code>grid.getView().refresh(false);</code> to see cell B'value changing as I change value of cell A. Is there a way to achieve this without redrawing the entire grid? When I update the store, grid should show the new values doesn't it? I'm using GXT 2.2.4.</p>