title: how set dynamic height for combobox
body: <p>Is there any way to set dynamic height of combobox. I got the problem that the combobox only show the first option of the list. I want to make the dynamic height to show many option in list. Below is my code:</p>
  
  <pre><code>xtype           : 'pet.filtermulticombobox',
                          hideOnSelect    : false,
                          name            : 'category',
                          triggerAction   : 'all',
                          emptyTextKey    : _('Categories'),
                          ref             : '../url',
                          store           : new Ext.data.Store({
                                              autoLoad: true,
                                              proxy: new Ext.data.HttpProxy({url: '/url'}),
                                              reader: new Ext.data.JsonReader({
                                                  totalProperty: 'total',
                                                  root:'records'
                                              },
                                              [{name: 'id'}, {name: 'name'}, {name: 'name_en'}, {name: 'class'}])
                                            }),
                          valueField      : 'id',
                          minChars        : 3,
                          displayField    : 'name_en',
                          classField      : 'class',
                          mode            : 'local',
                          width           : 125,
                          listWidth       : 400,
                          typeAhead       : true,
                          listeners       : {
                              scope   : this,
                              select  : function() {
                                  this.fireEvent('filter');
                              }
                          },
                          filter: {
                              anyMatch: true,
                              caseSensitive: true
                          }
  </code></pre>