title: Extjs 4 - FormPanel inside menu - focus issue
body: <p>I have form panel as a menu item. The problem is that it constantly looses focus and standard navigation controls like tab are not working. Is there some kind of config to make this work? Notice i extend Ext.panel.Panel instead of Ext.form.Panel. When i use the second one i get <code>origin.on is not a function</code>. Here is code:</p>
  
  <pre><code>this.tbar = [{
      xtype: 'tbfill'
  }, {
      xtype: 'tbseparator'
  }, {
      xtype: 'button',
      text: 'Wyszukiwanie',
      iconCls: 'icon-magnifier',
      menu: {
          focusOnToFront: true,
          items: [{
              xtype: 'decision_quicksearch',
              title: 'Panel wyszukiwania',
              iconCls: 'icon-magnifier',
          }]
      },
      listeners: {
          afterrender: function () {
              //register this btn to quicksearch panel so we can hide menu when search button is clicked
              Ext.apply(this.menu.items.items[0], {
                  parentComponent: this
              });
          }
      }
  }];
  </code></pre>
  
  <p>And the form:</p>
  
  <pre><code>Ext.define('GSIP.view.decisions.DecisionQuickSearchPanel' ,{
      extend: 'Ext.form.Panel',   
      alias : 'widget.decision_quicksearch',
      layout:'anchor',
      title:'Wyszukiwanie decyzji',
      frame:true,
      width:300,
      defaults: {
          anchor: '100%'
      },
      style: {
          marginLeft: 'auto',
          marginRight: 'auto'
      },
      bodyPadding:20,
  
      initComponent: function() {
  
          this.addEvents('quicksearch');
  
          this.items = this.createForm();
  
          this.buttons = [{
              text:'Szukaj',
              iconCls:'icon-magnifier',
              scope:this,
              handler:this.processForm
          }],
  
          this.callParent(arguments);
  
      },
      createForm:function() {
  
  
          var items = [{
              xtype:'textfield',
              fieldLabel:'Znak',
              labelWidth:40,
              name:'sign'
          },{
              xtype:'textfield',
              fieldLabel:'Numer',
              labelWidth:40,
              name:'number'
          },{
              xtype:'textfield',
              fieldLabel:'Rok',
              labelWidth:40,
              name:'suffix',
          }];
  
          return items;
      },
      processForm:function() {
          var result = this.buildFilter();
          this.fireEvent('quicksearch', result);
          this.parentComponent.hideMenu();
      },
      buildFilter:function() {
          var sign =  this.down('textfield[name=sign]').getValue();
          var number =  this.down('textfield[name=number]').getValue();
          var suffix =  this.down('textfield[name=suffix]').getValue();
  
  
          var result = new Array();
          var res = {
                  name:'documents.sign',
                  valuesType:'string',
                  filterType:'like',
                  values:[{id:1, value:sign}]
          };
          result.push(res);
  
          var res = {
                  name:'documents.number',
                  valuesType:'string',
                  filterType:'like',
                  values:[{id:1, value:number}]
          };
          result.push(res);
  
          var res = {
                  name:'documents.suffix',
                  valuesType:'string',
                  filterType:'like',
                  values:[{id:1, value:suffix}]
          };
          result.push(res);
  
          return result;
      }
  });
  </code></pre>