    /**
     * @class Ext.form.field.Spinner
     * @extends Ext.form.field.Trigger
     * <p>A field with a pair of up/down spinner buttons. This class is not normally instantiated directly,
     * instead it is subclassed and the {@link #onSpinUp} and {@link #onSpinDown} methods are implemented
     * to handle when the buttons are clicked. A good example of this is the {@link Ext.form.field.Number} field
     * which uses the spinner to increment and decrement the field's value by its {@link Ext.form.field.Number#step step}
     * config value.</p>
     * {@img Ext.form.field.Spinner/Ext.form.field.Spinner.png Ext.form.field.Spinner field}
     * For example:
         Ext.define('Ext.ux.CustomSpinner', {
            extend: 'Ext.form.field.Spinner',
            alias: 'widget.customspinner',

            // override onSpinUp (using step isn't neccessary)
            onSpinUp: function() {
                var me = this;
                if (!me.readOnly) {
                    var val = me.step; // set the default value to the step value
                    if(me.getValue() !== '') {
                        val = parseInt(me.getValue().slice(0, -5)); // gets rid of " Pack"
                    }
                    me.setValue((val + me.step) + ' Pack');
                }
            },

            // override onSpinDown
            onSpinDown: function() {
                var me = this;
                if (!me.readOnly) {
                    if(me.getValue() !== '') {
                        val = parseInt(me.getValue().slice(0, -5)); // gets rid of " Pack"
                    }
                    me.setValue((val - me.step) + ' Pack');
                }
            }
        });

        Ext.create('Ext.form.FormPanel', {
            title: 'Form with SpinnerField',
            bodyPadding: 5,
            width: 350,
            renderTo: Ext.getBody(),
            items:[{
                xtype: 'customspinner',
                fieldLabel: 'How Much Beer?',
                step: 6
            }]
        });
     * <p>By default, pressing the up and down arrow keys will also trigger the onSpinUp and onSpinDown methods;
     * to prevent this, set <tt>{@link #keyNavEnabled} = false</tt>.</p>
     *
     * @constructor
     * Creates a new Spinner field
     * @param {Object} config Configuration options
     * @xtype spinnerfield
     */
    Ext.define('Ext.form.field.Spinner', {
        extend: 'Ext.form.field.Trigger',
        alias: 'widget.spinnerfield',
        alternateClassName: 'Ext.form.Spinner',
        requires: ['Ext.util.KeyNav'],

        trigger1Cls: Ext.baseCSSPrefix + 'form-spinner-up',
        trigger2Cls: Ext.baseCSSPrefix + 'form-spinner-down',

        /**
         * @cfg {Boolean} spinUpEnabled
         * Specifies whether the up spinner button is enabled. Defaults to <tt>true</tt>. To change this
         * after the component is created, use the {@link #setSpinUpEnabled} method.
         */
        spinUpEnabled: true,

        /**
         * @cfg {Boolean} spinDownEnabled
         * Specifies whether the down spinner button is enabled. Defaults to <tt>true</tt>. To change this
         * after the component is created, use the {@link #setSpinDownEnabled} method.
         */
        spinDownEnabled: true,

        /**
         * @cfg {Boolean} keyNavEnabled
         * Specifies whether the up and down arrow keys should trigger spinning up and down.
         * Defaults to <tt>true</tt>.
         */
        keyNavEnabled: true,

        /**
         * @cfg {Boolean} mouseWheelEnabled
         * Specifies whether the mouse wheel should trigger spinning up and down while the field has
         * focus. Defaults to <tt>true</tt>.
         */
        mouseWheelEnabled: true,

        /**
         * @cfg {Boolean} repeatTriggerClick Whether a {@link Ext.util.ClickRepeater click repeater} should be
         * attached to the spinner buttons. Defaults to <tt>true</tt>.
         */
        repeatTriggerClick: true,

        /**
         * This method is called when the spinner up button is clicked, or when the up arrow key is pressed
         * if {@link #keyNavEnabled} is <tt>true</tt>. Must be implemented by subclasses.
         */
        onSpinUp: Ext.emptyFn,

        /**
         * This method is called when the spinner down button is clicked, or when the down arrow key is pressed
         * if {@link #keyNavEnabled} is <tt>true</tt>. Must be implemented by subclasses.
         */
        onSpinDown: Ext.emptyFn,

        initComponent: function() {
            this.callParent();

            this.addEvents(
                /**
                 * @event spin
                 * Fires when the spinner is made to spin up or down.
                 * @param {Ext.form.field.Spinner} this
                 * @param {String} direction Either 'up' if spinning up, or 'down' if spinning down.
                 */
                'spin',

                /**
                 * @event spinup
                 * Fires when the spinner is made to spin up.
                 * @param {Ext.form.field.Spinner} this
                 */
                'spinup',

                /**
                 * @event spindown
                 * Fires when the spinner is made to spin down.
                 * @param {Ext.form.field.Spinner} this
                 */
                'spindown'
            );
        },

        /**
         * @private override
         */
        onRender: function() {
            var me = this,
                triggers;

            me.callParent(arguments);
            triggers = me.triggerEl;

            /**
             * @property spinUpEl
             * @type Ext.core.Element
             * The spinner up button element
             */
            me.spinUpEl = triggers.item(0);
            /**
             * @property spinDownEl
             * @type Ext.core.Element
             * The spinner down button element
             */
            me.spinDownEl = triggers.item(1);

            // Set initial enabled/disabled states
            me.setSpinUpEnabled(me.spinUpEnabled);
            me.setSpinDownEnabled(me.spinDownEnabled);

            // Init up/down arrow keys
            if (me.keyNavEnabled) {
                me.spinnerKeyNav = Ext.create('Ext.util.KeyNav', me.inputEl, {
                    scope: me,
                    up: me.spinUp,
                    down: me.spinDown
                });
            }

            // Init mouse wheel
            if (me.mouseWheelEnabled) {
                me.mon(me.bodyEl, 'mousewheel', me.onMouseWheel, me);
            }
        },

        /**
         * @private override
         * Since the triggers are stacked, only measure the width of one of them.
         */
        getTriggerWidth: function() {
            return this.hideTrigger || this.readOnly ? 0 : this.spinUpEl.getWidth() + this.triggerWrap.getFrameWidth('lr');
        },

        /**
         * @private Handles the spinner up button clicks.
         */
        onTrigger1Click: function() {
            this.spinUp();
        },

        /**
         * @private Handles the spinner down button clicks.
         */
        onTrigger2Click: function() {
            this.spinDown();
        },

        /**
         * Triggers the spinner to step up; fires the {@link #spin} and {@link #spinup} events and calls the
         * {@link #onSpinUp} method. Does nothing if the field is {@link #disabled} or if {@link #spinUpEnabled}
         * is false.
         */
        spinUp: function() {
            var me = this;
            if (me.spinUpEnabled && !me.disabled) {
                me.fireEvent('spin', me, 'up');
                me.fireEvent('spinup', me);
                me.onSpinUp();
            }
        },

        /**
         * Triggers the spinner to step down; fires the {@link #spin} and {@link #spindown} events and calls the
         * {@link #onSpinDown} method. Does nothing if the field is {@link #disabled} or if {@link #spinDownEnabled}
         * is false.
         */
        spinDown: function() {
            var me = this;
            if (me.spinDownEnabled && !me.disabled) {
                me.fireEvent('spin', me, 'down');
                me.fireEvent('spindown', me);
                me.onSpinDown();
            }
        },

        /**
         * Sets whether the spinner up button is enabled.
         * @param {Boolean} enabled true to enable the button, false to disable it.
         */
        setSpinUpEnabled: function(enabled) {
            var me = this,
                wasEnabled = me.spinUpEnabled;
            me.spinUpEnabled = enabled;
            if (wasEnabled !== enabled && me.rendered) {
                me.spinUpEl[enabled ? 'removeCls' : 'addCls'](me.trigger1Cls + '-disabled');
            }
        },

        /**
         * Sets whether the spinner down button is enabled.
         * @param {Boolean} enabled true to enable the button, false to disable it.
         */
        setSpinDownEnabled: function(enabled) {
            var me = this,
                wasEnabled = me.spinDownEnabled;
            me.spinDownEnabled = enabled;
            if (wasEnabled !== enabled && me.rendered) {
                me.spinDownEl[enabled ? 'removeCls' : 'addCls'](me.trigger2Cls + '-disabled');
            }
        },

        /**
         * @private
         * Handles mousewheel events on the field
         */
        onMouseWheel: function(e) {
            var me = this,
                delta;
            if (me.hasFocus) {
                delta = e.getWheelDelta();
                if (delta > 0) {
                    me.spinUp();
                }
                else if (delta < 0) {
                    me.spinDown();
                }
                e.stopEvent();
            }
        },

        onDestroy: function() {
            Ext.destroyMembers(this, 'spinnerKeyNav', 'spinUpEl', 'spinDownEl');
            this.callParent();
        }

    });