title: actioncolumn: how to avoid that the action is triggered multiple
body: <p>I have a grid with an actioncolumn.
  If I make a doubleclick on a row an action should be triggered.
  If I make a click on the actioncolumn an action should be triggered.
  So far so good.
  If I make a doubleclick on the actioncolumn the action should be triggered once and not three times.</p>
  
  <p>So how can I avoid that the action is triggered multiple</p>
  
  <p>I use ExtJS 6.2</p>
  
  <pre><code>            text: 'RW',
              dataIndex: 'readonly',
              hideable: false,
              sortable: false,
              width: 30,
              handler: function(grid, rowIndex) {
                  var rec = grid.getStore().getAt(rowIndex);
                  grid.fireEvent('itemdblclick', grid, rec);
              }```
  
  
  controller
  
  ```'grid': {
                  itemdblclick: this.openItem
              },```
  </code></pre>