title: Set up hotkey for collapse a panel without using widgetVar
body: <p>I'm trying to figure out how to invoke, by focusing with <kbd>Tab</kbd> key the plus sign on the panel and then pressing <kbd>Space</kbd> on keyboard, the <code>toggle()</code> method. Assuming that I've got more than one panel and can't use the <code>widgetVar</code> attribute.</p>
  
  <pre><code>&lt;ui:composition
     xmlns="http://www.w3.org/1999/xhtml"
     xmlns:h="http://java.sun.com/jsf/html"
     xmlns:f="http://java.sun.com/jsf/core"
     xmlns:ui="http://java.sun.com/jsf/facelets"
     xmlns:p="http://primefaces.org/ui"&gt;
  
     &lt;p:panel
          header="panel-1"
          id="panel-1"
          toggleable="true"
          collapsed="true"&gt;
     &lt;/p:panel&gt;
  
    &lt;p:panel
          header="panel-2"
          id="panel-2"
          toggleable="true"
          collapsed="true"&gt;
     &lt;/p:panel&gt;
  
  &lt;/ui:composition&gt;
  </code></pre>