Usage:

new Ext.ux.form.MaskFormattedTextField({
  fieldLabel: 'Phone Number',
  name: 'phone',
  width:100
  //mask: "(###)###-####", //vtype is created out of the mask
  //invalidMessage: "This field is invalid" //custom validation tooltips will override the generated tooltip,
  //vtype: 'phone' //can still set a custom vtype if you wish
})

Download: