    /**
     * @class Ext.form.field.Radio
     * @extends Ext.form.field.Checkbox

    Single radio field. Similar to checkbox, but automatically handles making sure only one radio is checked
    at a time within a group of radios with the same name.

    __Labeling:__
    In addition to the {@link Ext.form.Labelable standard field labeling options}, radio buttons
    may be given an optional {@link #boxLabel} which will be displayed immediately to the right of the input. Also
    see {@link Ext.form.RadioGroup} for a convenient method of grouping related radio buttons.

    __Values:__
    The main value of a Radio field is a boolean, indicating whether or not the radio is checked.

    The following values will check the radio:
    * `true`
    * `'true'`
    * `'1'`
    * `'on'`

    Any other value will uncheck it.

    In addition to the main boolean value, you may also specify a separate {@link #inputValue}. This will be sent
    as the parameter value when the form is {@link Ext.form.Basic#submit submitted}. You will want to set this
    value if you have multiple radio buttons with the same {@link #name}, as is almost always the case.
    {@img Ext.form.Radio/Ext.form.Radio.png Ext.form.Radio component}
    __Example usage:__

        Ext.create('Ext.form.Panel', {
            title      : 'Order Form',
            width      : 300,
            bodyPadding: 10,
            renderTo   : Ext.getBody(),
            items: [
                {
                    xtype      : 'fieldcontainer',
                    fieldLabel : 'Size',
                    defaultType: 'radiofield',
                    defaults: {
                        flex: 1
                    },
                    layout: 'hbox',
                    items: [
                        {
                            boxLabel  : 'M',
                            name      : 'size',
                            inputValue: 'm',
                            id        : 'radio1'
                        }, {
                            boxLabel  : 'L',
                            name      : 'size',
                            inputValue: 'l',
                            id        : 'radio2'
                        }, {
                            boxLabel  : 'XL',
                            name      : 'size',
                            inputValue: 'xl',
                            id        : 'radio3'
                        }
                    ]
                },
                {
                    xtype      : 'fieldcontainer',
                    fieldLabel : 'Color',
                    defaultType: 'radiofield',
                    defaults: {
                        flex: 1
                    },
                    layout: 'hbox',
                    items: [
                        {
                            boxLabel  : 'Blue',
                            name      : 'color',
                            inputValue: 'blue',
                            id        : 'radio4'
                        }, {
                            boxLabel  : 'Grey',
                            name      : 'color',
                            inputValue: 'grey',
                            id        : 'radio5'
                        }, {
                            boxLabel  : 'Black',
                            name      : 'color',
                            inputValue: 'black',
                            id        : 'radio6'
                        }
                    ]
                }
            ],
            bbar: [
                {
                    text: 'Smaller Size',
                    handler: function() {
                        var radio1 = Ext.getCmp('radio1'),
                            radio2 = Ext.getCmp('radio2'),
                            radio3 = Ext.getCmp('radio3');

                        //if L is selected, change to M
                        if (radio2.getValue()) {
                            radio1.setValue(true);
                            return;
                        }

                        //if XL is selected, change to L
                        if (radio3.getValue()) {
                            radio2.setValue(true);
                            return;
                        }

                        //if nothing is set, set size to S
                        radio1.setValue(true);
                    }
                },
                {
                    text: 'Larger Size',
                    handler: function() {
                        var radio1 = Ext.getCmp('radio1'),
                            radio2 = Ext.getCmp('radio2'),
                            radio3 = Ext.getCmp('radio3');

                        //if M is selected, change to L
                        if (radio1.getValue()) {
                            radio2.setValue(true);
                            return;
                        }

                        //if L is selected, change to XL
                        if (radio2.getValue()) {
                            radio3.setValue(true);
                            return;
                        }

                        //if nothing is set, set size to XL
                        radio3.setValue(true);
                    }
                },
                '-',
                {
                    text: 'Select color',
                    menu: {
                        indent: false,
                        items: [
                            {
                                text: 'Blue',
                                handler: function() {
                                    var radio = Ext.getCmp('radio4');
                                    radio.setValue(true);
                                }
                            },
                            {
                                text: 'Grey',
                                handler: function() {
                                    var radio = Ext.getCmp('radio5');
                                    radio.setValue(true);
                                }
                            },
                            {
                                text: 'Black',
                                handler: function() {
                                    var radio = Ext.getCmp('radio6');
                                    radio.setValue(true);
                                }
                            }
                        ]
                    }
                }
            ]
        });

     * @constructor
     * Creates a new Radio
     * @param {Object} config Configuration options
     * @xtype radio
     * @docauthor Robert Dougan <rob@sencha.com>
     * @markdown
     */
    Ext.define('Ext.form.field.Radio', {
        extend:'Ext.form.field.Checkbox',
        alias: ['widget.radiofield', 'widget.radio'],
        alternateClassName: 'Ext.form.Radio',
        requires: ['Ext.form.RadioManager'],

        isRadio: true,

        /**
         * @cfg {String} uncheckedValue @hide
         */

        // private
        inputType: 'radio',
        ariaRole: 'radio',

        /**
         * If this radio is part of a group, it will return the selected value
         * @return {String}
         */
        getGroupValue: function() {
            var selected = this.getManager().getChecked(this.name);
            return selected ? selected.inputValue : null;
        },

        /**
         * @private Handle click on the radio button
         */
        onBoxClick: function(e) {
            var me = this;
            if (!me.disabled && !me.readOnly) {
                this.setValue(true);
            }
        },

        /**
         * Sets either the checked/unchecked status of this Radio, or, if a string value
         * is passed, checks a sibling Radio of the same name whose value is the value specified.
         * @param value {String/Boolean} Checked value, or the value of the sibling radio button to check.
         * @return {Ext.form.field.Radio} this
         */
        setValue: function(v) {
            var me = this,
                active;

            if (Ext.isBoolean(v)) {
                me.callParent(arguments);
            } else {
                active = me.getManager().getWithValue(me.name, v).getAt(0);
                if (active) {
                    active.setValue(true);
                }
            }
            return me;
        },

        /**
         * Returns the submit value for the checkbox which can be used when submitting forms.
         * @return {Boolean/null} True if checked, null if not.
         */
        getSubmitValue: function() {
            return this.checked ? this.inputValue : null;
        },

        // inherit docs
        onChange: function(newVal, oldVal) {
            var me = this;
            me.callParent(arguments);

            if (newVal) {
                this.getManager().getByName(me.name).each(function(item){
                    if (item !== me) {
                        item.setValue(false);
                    }
                }, me);
            }
        },

        // inherit docs
        beforeDestroy: function(){
            this.callParent();
            this.getManager().removeAtKey(this.id);
        },

        // inherit docs
        getManager: function() {
            return Ext.form.RadioManager;
        }
    });