    /**
     * @class Ext.grid.property.Grid
     * @extends Ext.grid.Panel
     * A specialized grid implementation intended to mimic the traditional property grid as typically seen in
     * development IDEs.  Each row in the grid represents a property of some object, and the data is stored
     * as a set of name/value pairs in {@link Ext.grid.property.Property Properties}.  Example usage:
     * <pre><code>
    var grid = new Ext.grid.property.Grid({
        title: 'Properties Grid',
        width: 300,
        renderTo: 'grid-ct',
        source: {
            "(name)": "My Object",
            "Created": Ext.Date.parse('10/15/2006', 'm/d/Y'),
            "Available": false,
            "Version": .01,
            "Description": "A test object"
        }
    });
    </code></pre>
     * @constructor
     * @param {Object} config The grid config object
     * @xtype propertygrid
     */
    Ext.define('Ext.grid.property.Grid', {

        extend: 'Ext.grid.Panel',

        alias: 'widget.propertygrid',

        alternateClassName: 'Ext.grid.PropertyGrid',

        uses: [
           'Ext.grid.plugin.CellEditing',
           'Ext.grid.property.Store',
           'Ext.grid.property.HeaderContainer',
           'Ext.XTemplate',
           'Ext.grid.CellEditor',
           'Ext.form.field.Date',
           'Ext.form.field.Text',
           'Ext.form.field.Number'
        ],

       /**
        * @cfg {Object} propertyNames An object containing custom property name/display name pairs.
        * If specified, the display name will be shown in the name column instead of the property name.
        */

        /**
        * @cfg {Object} source A data object to use as the data source of the grid (see {@link #setSource} for details).
        */

        /**
        * @cfg {Object} customEditors An object containing name/value pairs of custom editor type definitions that allow
        * the grid to support additional types of editable fields.  By default, the grid supports strongly-typed editing
        * of strings, dates, numbers and booleans using built-in form editors, but any custom type can be supported and
        * associated with a custom input control by specifying a custom editor.  The name of the editor
        * type should correspond with the name of the property that will use the editor.  Example usage:
        * <pre><code>
    var grid = new Ext.grid.property.Grid({

        // Custom editors for certain property names
        customEditors: {
            evtStart: Ext.create('Ext.form.TimeField' {selectOnFocus:true})
        },

        // Displayed name for property names in the source
        propertyNames: {
            evtStart: 'Start Time'
        },

        // Data object containing properties to edit
        source: {
            evtStart: '10:00 AM'
        }
    });
    </code></pre>
        */

        /**
        * @cfg {Object} source A data object to use as the data source of the grid (see {@link #setSource} for details).
        */

        /**
        * @cfg {Object} customRenderers An object containing name/value pairs of custom renderer type definitions that allow
        * the grid to support custom rendering of fields.  By default, the grid supports strongly-typed rendering
        * of strings, dates, numbers and booleans using built-in form editors, but any custom type can be supported and
        * associated with the type of the value.  The name of the renderer type should correspond with the name of the property
        * that it will render.  Example usage:
        * <pre><code>
    var grid = Ext.create('Ext.grid.property.Grid', {
        customRenderers: {
            Available: function(v){
                if (v) {
                    return '<span style="color: green;">Yes</span>';
                } else {
                    return '<span style="color: red;">No</span>';
                }
            }
        },
        source: {
            Available: true
        }
    });
    </code></pre>
        */

        /**
         * @cfg {String} valueField
         * Optional. The name of the field from the property store to use as the value field name. Defaults to <code>'value'</code>
         * This may be useful if you do not configure the property Grid from an object, but use your own store configuration.
         */
        valueField: 'value',

        /**
         * @cfg {String} nameField
         * Optional. The name of the field from the property store to use as the property field name. Defaults to <code>'name'</code>
         * This may be useful if you do not configure the property Grid from an object, but use your own store configuration.
         */
        nameField: 'name',

        // private config overrides
        enableColumnMove: false,
        columnLines: true,
        stripeRows: false,
        trackMouseOver: false,
        clicksToEdit: 1,
        enableHdMenu: false,

        // private
        initComponent : function(){
            var me = this;

            me.addCls(Ext.baseCSSPrefix + 'property-grid');
            me.plugins = me.plugins || [];

            // Enable cell editing. Inject a custom startEdit which always edits column 1 regardless of which column was clicked.
            me.plugins.push(Ext.create('Ext.grid.plugin.CellEditing', {
                clicksToEdit: me.clicksToEdit,

                // Inject a startEdit which always edits the value column
                startEdit: function(record, column) {
                    // Maintainer: Do not change this 'this' to 'me'! It is the CellEditing object's own scope.
                    Ext.grid.plugin.CellEditing.prototype.startEdit.call(this, record, me.headerCt.child('#' + me.valueField));
                }
            }));

            me.selModel = {
                selType: 'cellmodel',
                onCellSelect: function(position) {
                    if (position.column != 1) {
                        position.column = 1;
                        Ext.selection.CellModel.prototype.onCellSelect.call(this, position);
                    }
                }
            };
            me.customRenderers = me.customRenderers || {};
            me.customEditors = me.customEditors || {};

            // Create a property.Store from the source object unless configured with a store
            if (!me.store) {
                me.propStore = me.store = Ext.create('Ext.grid.property.Store', me, me.source);
            }

            me.store.sort('name', 'ASC');
            me.columns = Ext.create('Ext.grid.property.HeaderContainer', me, me.store);

            me.addEvents(
                /**
                 * @event beforepropertychange
                 * Fires before a property value changes.  Handlers can return false to cancel the property change
                 * (this will internally call {@link Ext.data.Record#reject} on the property's record).
                 * @param {Object} source The source data object for the grid (corresponds to the same object passed in
                 * as the {@link #source} config property).
                 * @param {String} recordId The record's id in the data store
                 * @param {Mixed} value The current edited property value
                 * @param {Mixed} oldValue The original property value prior to editing
                 */
                'beforepropertychange',
                /**
                 * @event propertychange
                 * Fires after a property value has changed.
                 * @param {Object} source The source data object for the grid (corresponds to the same object passed in
                 * as the {@link #source} config property).
                 * @param {String} recordId The record's id in the data store
                 * @param {Mixed} value The current edited property value
                 * @param {Mixed} oldValue The original property value prior to editing
                 */
                'propertychange'
            );
            me.callParent();

            // Inject a custom implementation of walkCells which only goes up or down
            me.getView().walkCells = this.walkCells;

            // Set up our default editor set for the 4 atomic data types
            me.editors = {
                'date'    : Ext.create('Ext.grid.CellEditor', { field: Ext.create('Ext.form.field.Date',   {selectOnFocus: true})}),
                'string'  : Ext.create('Ext.grid.CellEditor', { field: Ext.create('Ext.form.field.Text',   {selectOnFocus: true})}),
                'number'  : Ext.create('Ext.grid.CellEditor', { field: Ext.create('Ext.form.field.Number', {selectOnFocus: true})}),
                'boolean' : Ext.create('Ext.grid.CellEditor', { field: Ext.create('Ext.form.field.ComboBox', {
                    editable: false,
                    store: [[ true, me.headerCt.trueText ], [false, me.headerCt.falseText ]]
                })})
            };

            // Track changes to the data so we can fire our events.
            this.store.on('update', me.onUpdate, me);
        },

        // private
        onUpdate : function(store, record, operation) {
            var me = this,
                v, oldValue;

            if (operation == Ext.data.Model.EDIT) {
                v = record.get(me.valueField);
                oldValue = record.modified.value;
                if (me.fireEvent('beforepropertychange', me.source, record.getId(), v, oldValue) !== false) {
                    if (me.source) {
                        me.source[record.getId()] = v;
                    }
                    record.commit();
                    me.fireEvent('propertychange', me.source, record.getId(), v, oldValue);
                } else {
                    record.reject();
                }
            }
        },

        // Custom implementation of walkCells which only goes up and down.
        walkCells: function(pos, direction, e, preventWrap, verifierFn, scope) {
            if (direction == 'left') {
                direction = 'up';
            } else if (direction == 'right') {
                direction = 'down';
            }
            pos = Ext.view.Table.prototype.walkCells.call(this, pos, direction, e, preventWrap, verifierFn, scope);
            if (!pos.column) {
                pos.column = 1;
            }
            return pos;
        },

        // private
        // returns the correct editor type for the property type, or a custom one keyed by the property name
        getCellEditor : function(record, column) {
            var me = this,
                propName = record.get(me.nameField),
                val = record.get(me.valueField),
                editor = me.customEditors[propName];

            // A custom editor was found. If not already wrapped with a CellEditor, wrap it, and stash it back
            // If it's not even a Field, just a config object, instantiate it before wrapping it.
            if (editor) {
                if (!(editor instanceof Ext.grid.CellEditor)) {
                    if (!(editor instanceof Ext.form.field.Base)) {
                        editor = Ext.ComponentManager.create(editor, 'textfield');
                    }
                    editor = me.customEditors[propName] = Ext.create('Ext.grid.CellEditor', { field: editor });
                }
            } else if (Ext.isDate(val)) {
                editor = me.editors.date;
            } else if (Ext.isNumber(val)) {
                editor = me.editors.number;
            } else if (Ext.isBoolean(val)) {
                editor = me.editors['boolean'];
            } else {
                editor = me.editors.string;
            }

            // Give the editor a unique ID because the CellEditing plugin caches them
            editor.editorId = propName;
            return editor;
        },

        beforeDestroy: function() {
            var me = this;
            me.callParent();
            me.destroyEditors(me.editors);
            me.destroyEditors(me.customEditors);
            delete me.source;
        },

        destroyEditors: function (editors) {
            for (var ed in editors) {
                if (editors.hasOwnProperty(ed)) {
                    Ext.destroy(editors[ed]);
                }
            }
        },

        /**
         * Sets the source data object containing the property data.  The data object can contain one or more name/value
         * pairs representing all of the properties of an object to display in the grid, and this data will automatically
         * be loaded into the grid's {@link #store}.  The values should be supplied in the proper data type if needed,
         * otherwise string type will be assumed.  If the grid already contains data, this method will replace any
         * existing data.  See also the {@link #source} config value.  Example usage:
         * <pre><code>
    grid.setSource({
        "(name)": "My Object",
        "Created": Ext.Date.parse('10/15/2006', 'm/d/Y'),  // date type
        "Available": false,  // boolean type
        "Version": .01,      // decimal type
        "Description": "A test object"
    });
    </code></pre>
         * @param {Object} source The data object
         */
        setSource: function(source) {
            this.source = source;
            this.propStore.setSource(source);
        },

        /**
         * Gets the source data object containing the property data.  See {@link #setSource} for details regarding the
         * format of the data object.
         * @return {Object} The data object
         */
        getSource: function() {
            return this.propStore.getSource();
        },

        /**
         * Sets the value of a property.
         * @param {String} prop The name of the property to set
         * @param {Mixed} value The value to test
         * @param {Boolean} create (Optional) True to create the property if it doesn't already exist. Defaults to <tt>false</tt>.
         */
        setProperty: function(prop, value, create) {
            this.propStore.setValue(prop, value, create);
        },

        /**
         * Removes a property from the grid.
         * @param {String} prop The name of the property to remove
         */
        removeProperty: function(prop) {
            this.propStore.remove(prop);
        }

        /**
         * @cfg store
         * @hide
         */
        /**
         * @cfg colModel
         * @hide
         */
        /**
         * @cfg cm
         * @hide
         */
        /**
         * @cfg columns
         * @hide
         */
    });