    /**
     * A Grid header type which renders an icon, or a series of icons in a grid cell, and offers a scoped click
     * handler for each icon.
     *
     *     @example
     *     Ext.create('Ext.data.Store', {
     *         storeId:'employeeStore',
     *         fields:['firstname', 'lastname', 'seniority', 'dep', 'hired'],
     *         data:[
     *             {firstname:"Michael", lastname:"Scott"},
     *             {firstname:"Dwight", lastname:"Schrute"},
     *             {firstname:"Jim", lastname:"Halpert"},
     *             {firstname:"Kevin", lastname:"Malone"},
     *             {firstname:"Angela", lastname:"Martin"}
     *         ]
     *     });
     *
     *     Ext.create('Ext.grid.Panel', {
     *         title: 'Action Column Demo',
     *         store: Ext.data.StoreManager.lookup('employeeStore'),
     *         columns: [
     *             {text: 'First Name',  dataIndex:'firstname'},
     *             {text: 'Last Name',  dataIndex:'lastname'},
     *             {
     *                 xtype:'actioncolumn',
     *                 width:50,
     *                 items: [{
     *                     icon: 'extjs/examples/shared/icons/fam/cog_edit.png',  // Use a URL in the icon config
     *                     tooltip: 'Edit',
     *                     handler: function(grid, rowIndex, colIndex) {
     *                         var rec = grid.getStore().getAt(rowIndex);
     *                         alert("Edit " + rec.get('firstname'));
     *                     }
     *                 },{
     *                     icon: 'extjs/examples/restful/images/delete.png',
     *                     tooltip: 'Delete',
     *                     handler: function(grid, rowIndex, colIndex) {
     *                         var rec = grid.getStore().getAt(rowIndex);
     *                         alert("Terminate " + rec.get('firstname'));
     *                     }
     *                 }]
     *             }
     *         ],
     *         width: 250,
     *         renderTo: Ext.getBody()
     *     });
     *
     * The action column can be at any index in the columns array, and a grid can have any number of
     * action columns.
     */
    Ext.define('Ext.grid.column.Action', {
        extend: 'Ext.grid.column.Column',
        alias: ['widget.actioncolumn'],
        alternateClassName: 'Ext.grid.ActionColumn',

        /**
         * @cfg {String} icon
         * The URL of an image to display as the clickable element in the column.
         *
         * Defaults to `{@link Ext#BLANK_IMAGE_URL}`.
         */
        /**
         * @cfg {String} iconCls
         * A CSS class to apply to the icon image. To determine the class dynamically, configure the Column with
         * a `{@link #getClass}` function.
         */
        /**
         * @cfg {Function} handler
         * A function called when the icon is clicked.
         * @cfg {Ext.view.Table} handler.view The owning TableView.
         * @cfg {Number} handler.rowIndex The row index clicked on.
         * @cfg {Number} handler.colIndex The column index clicked on.
         * @cfg {Object} handler.item The clicked item (or this Column if multiple {@link #cfg-items} were not configured).
         * @cfg {Event} handler.e The click event.
         */
        /**
         * @cfg {Object} scope
         * The scope (**this** reference) in which the `{@link #handler}` and `{@link #getClass}` fuctions are executed.
         * Defaults to this Column.
         */
        /**
         * @cfg {String} tooltip
         * A tooltip message to be displayed on hover. {@link Ext.tip.QuickTipManager#init Ext.tip.QuickTipManager} must
         * have been initialized.
         */
        /**
         * @cfg {Boolean} disabled
         * If true, the action will not respond to click events, and will be displayed semi-opaque.
         */
        /**
         * @cfg {Boolean} [stopSelection=true]
         * Prevent grid selection upon mousedown.
         */
        /**
         * @cfg {Function} getClass
         * A function which returns the CSS class to apply to the icon image.
         *
         * @cfg {Object} getClass.v The value of the column's configured field (if any).
         *
         * @cfg {Object} getClass.metadata An object in which you may set the following attributes:
         * @cfg {String} getClass.metadata.css A CSS class name to add to the cell's TD element.
         * @cfg {String} getClass.metadata.attr An HTML attribute definition string to apply to the data container
         * element *within* the table cell (e.g. 'style="color:red;"').
         *
         * @cfg {Ext.data.Model} getClass.r The Record providing the data.
         *
         * @cfg {Number} getClass.rowIndex The row index..
         *
         * @cfg {Number} getClass.colIndex The column index.
         *
         * @cfg {Ext.data.Store} getClass.store The Store which is providing the data Model.
         */
        /**
         * @cfg {Object[]} items
         * An Array which may contain multiple icon definitions, each element of which may contain:
         *
         * @cfg {String} items.icon The url of an image to display as the clickable element in the column.
         *
         * @cfg {String} items.iconCls A CSS class to apply to the icon image. To determine the class dynamically,
         * configure the item with a `getClass` function.
         *
         * @cfg {Function} items.getClass A function which returns the CSS class to apply to the icon image.
         * @cfg {Object} items.getClass.v The value of the column's configured field (if any).
         * @cfg {Object} items.getClass.metadata An object in which you may set the following attributes:
         * @cfg {String} items.getClass.metadata.css A CSS class name to add to the cell's TD element.
         * @cfg {String} items.getClass.metadata.attr An HTML attribute definition string to apply to the data
         * container element _within_ the table cell (e.g. 'style="color:red;"').
         * @cfg {Ext.data.Model} items.getClass.r The Record providing the data.
         * @cfg {Number} items.getClass.rowIndex The row index..
         * @cfg {Number} items.getClass.colIndex The column index.
         * @cfg {Ext.data.Store} items.getClass.store The Store which is providing the data Model.
         *
         * @cfg {Function} items.handler A function called when the icon is clicked.
         *
         * @cfg {Object} items.scope The scope (`this` reference) in which the `handler` and `getClass` functions
         * are executed. Fallback defaults are this Column's configured scope, then this Column.
         *
         * @cfg {String} items.tooltip A tooltip message to be displayed on hover.
         * @cfg {Boolean} items.disabled If true, the action will not respond to click events, and will be displayed semi-opaque.
         * {@link Ext.tip.QuickTipManager#init Ext.tip.QuickTipManager} must have been initialized.
         */
        /**
         * @property {Array} items
         * An array of action items copied from the configured {@link #cfg-items items} configuration. Each will have
         * an `enable` and `disable` method added which will enable and disable the associated action, and
         * update the displayed icon accordingly.
         */

        actionIdRe: new RegExp(Ext.baseCSSPrefix + 'action-col-(\\d+)'),

        /**
         * @cfg {String} altText
         * The alt text to use for the image element.
         */
        altText: '',

        /**
         * @cfg {String} menuText=[<i>Actions</i>]
         * Text to display in this column's menu item if no {@link #text} was specified as a header.
         */
        menuText: '<i>Actions</i>',

        sortable: false,

        constructor: function(config) {
            var me = this,
                cfg = Ext.apply({}, config),
                items = cfg.items || [me];

            me.origRenderer = cfg.renderer || me.renderer;
            me.origScope = cfg.scope || me.scope;

            delete me.renderer;
            delete me.scope;
            delete cfg.renderer;
            delete cfg.scope;

            // This is a Container. Delete the items config to be reinstated after construction.
            delete cfg.items;
            me.callParent([cfg]);

            // Items is an array property of ActionColumns
            me.items = items;

            if (me.origRenderer) {
                me.hasCustomRenderer = true;
            }
        },

        // Renderer closure iterates through items creating an <img> element for each and tagging with an identifying
        // class name x-action-col-{n}
        defaultRenderer: function(v, meta){
            var me = this,
                prefix = Ext.baseCSSPrefix,
                scope = me.origScope || me,
                items = me.items,
                len = items.length,
                i = 0,
                item;

            // Allow a configured renderer to create initial value (And set the other values in the "metadata" argument!)
            v = Ext.isFunction(me.origRenderer) ? me.origRenderer.apply(scope, arguments) || '' : '';

            meta.tdCls += ' ' + Ext.baseCSSPrefix + 'action-col-cell';
            for (; i < len; i++) {
                item = items[i];

                // Only process the item action setup once.
                if (!item.hasActionConfiguration) {

                    // Apply our documented default to all items
                    item.stopSelection = me.stopSelection;
                    item.disable = Ext.Function.bind(me.disableAction, me, [i], 0);
                    item.enable = Ext.Function.bind(me.enableAction, me, [i], 0);
                    item.hasActionConfiguration = true;
                }

                v += '<img alt="' + (item.altText || me.altText) + '" src="' + (item.icon || Ext.BLANK_IMAGE_URL) +
                    '" class="' + prefix + 'action-col-icon ' + prefix + 'action-col-' + String(i) + ' ' + (item.disabled ? prefix + 'item-disabled' : ' ') +
                    ' ' + (Ext.isFunction(item.getClass) ? item.getClass.apply(item.scope || scope, arguments) : (item.iconCls || me.iconCls || '')) + '"' +
                    ((item.tooltip) ? ' data-qtip="' + item.tooltip + '"' : '') + ' />';
            }
            return v;
        },

        /**
         * Enables this ActionColumn's action at the specified index.
         * @param {Number/Ext.grid.column.Action} index
         * @param {Boolean} [silent=false]
         */
        enableAction: function(index, silent) {
            var me = this;

            if (!index) {
                index = 0;
            } else if (!Ext.isNumber(index)) {
                index = Ext.Array.indexOf(me.items, index);
            }
            me.items[index].disabled = false;
            me.up('tablepanel').el.select('.' + Ext.baseCSSPrefix + 'action-col-' + index).removeCls(me.disabledCls);
            if (!silent) {
                me.fireEvent('enable', me);
            }
        },

        /**
         * Disables this ActionColumn's action at the specified index.
         * @param {Number/Ext.grid.column.Action} index
         * @param {Boolean} [silent=false]
         */
        disableAction: function(index, silent) {
            var me = this;

            if (!index) {
                index = 0;
            } else if (!Ext.isNumber(index)) {
                index = Ext.Array.indexOf(me.items, index);
            }
            me.items[index].disabled = true;
            me.up('tablepanel').el.select('.' + Ext.baseCSSPrefix + 'action-col-' + index).addCls(me.disabledCls);
            if (!silent) {
                me.fireEvent('disable', me);
            }
        },

        destroy: function() {
            delete this.items;
            delete this.renderer;
            return this.callParent(arguments);
        },

        /**
         * @private
         * Process and refire events routed from the GridView's processEvent method.
         * Also fires any configured click handlers. By default, cancels the mousedown event to prevent selection.
         * Returns the event handler's status to allow canceling of GridView's bubbling process.
         */
        processEvent : function(type, view, cell, recordIndex, cellIndex, e, record, row){
            var me = this,
                target = e.getTarget(),
                match,
                item, fn,
                key = type == 'keydown' && e.getKey();

            // If the target was not within a cell (ie it's a keydown event from the View), then
            // rely on the selection data injected by View.processUIEvent to grab the
            // first action icon from the selected cell.
            if (key && !Ext.fly(target).findParent(view.cellSelector)) {
                target = Ext.fly(cell).down('.' + Ext.baseCSSPrefix + 'action-col-icon', true);
            }

            // NOTE: The statement below tests the truthiness of an assignment.
            if (target && (match = target.className.match(me.actionIdRe))) {
                item = me.items[parseInt(match[1], 10)];
                if (item) {
                    if (type == 'click' || (key == e.ENTER || key == e.SPACE)) {
                        fn = item.handler || me.handler;
                        if (fn && !item.disabled) {
                            fn.call(item.scope || me.scope || me, view, recordIndex, cellIndex, item, e, record, row);
                        }
                    } else if (type == 'mousedown' && item.stopSelection !== false) {
                        return false;
                    }
                }
            }
            return me.callParent(arguments);
        },

        cascade: function(fn, scope) {
            fn.call(scope||this, this);
        },

        // Private override because this cannot function as a Container, and it has an items property which is an Array, NOT a MixedCollection.
        getRefItems: function() {
            return [];
        }
    });