Focusing one of the form fields after rendering the panel or changing the active tab with form items will make the filling process of the form faster. Users will not need to click on the appropriate field to begin the typing. The focusing feature was implemented as plugin.
There was a question in the sencha forum “Does anyone know how to add a form field that is an Ace code editor?”. So I decided to implement such a field. I have done it once in 2011 but forgotten already which lib was used and in which form it was done.