    /**
     * A composite Sprite handles a group of sprites with common methods to a sprite
     * such as `hide`, `show`, `setAttributes`. These methods are applied to the set of sprites
     * added to the group.
     *
     * CompositeSprite extends {@link Ext.util.MixedCollection} so you can use the same methods
     * in `MixedCollection` to iterate through sprites, add and remove elements, etc.
     *
     * In order to create a CompositeSprite, one has to provide a handle to the surface where it is
     * rendered:
     *
     *     var group = Ext.create('Ext.draw.CompositeSprite', {
     *         surface: drawComponent.surface
     *     });
     *
     * Then just by using `MixedCollection` methods it's possible to add {@link Ext.draw.Sprite}s:
     *
     *     group.add(sprite1);
     *     group.add(sprite2);
     *     group.add(sprite3);
     *
     * And then apply common Sprite methods to them:
     *
     *     group.setAttributes({
     *         fill: '#f00'
     *     }, true);
     */
    Ext.define('Ext.draw.CompositeSprite', {

        /* Begin Definitions */

        extend: 'Ext.util.MixedCollection',
        mixins: {
            animate: 'Ext.util.Animate'
        },
        autoDestroy: false,

        /* End Definitions */
        isCompositeSprite: true,
        constructor: function(config) {
            var me = this;

            config = config || {};
            Ext.apply(me, config);

            me.addEvents(
                /**
                 * @event
                 * @inheritdoc Ext.draw.Sprite#mousedown
                 */
                'mousedown',
                /**
                 * @event
                 * @inheritdoc Ext.draw.Sprite#mouseup
                 */
                'mouseup',
                /**
                 * @event
                 * @inheritdoc Ext.draw.Sprite#mouseover
                 */
                'mouseover',
                /**
                 * @event
                 * @inheritdoc Ext.draw.Sprite#mouseout
                 */
                'mouseout',
                /**
                 * @event
                 * @inheritdoc Ext.draw.Sprite#click
                 */
                'click'
            );
            me.id = Ext.id(null, 'ext-sprite-group-');
            me.callParent();
        },

        // @private
        onClick: function(e) {
            this.fireEvent('click', e);
        },

        // @private
        onMouseUp: function(e) {
            this.fireEvent('mouseup', e);
        },

        // @private
        onMouseDown: function(e) {
            this.fireEvent('mousedown', e);
        },

        // @private
        onMouseOver: function(e) {
            this.fireEvent('mouseover', e);
        },

        // @private
        onMouseOut: function(e) {
            this.fireEvent('mouseout', e);
        },

        attachEvents: function(o) {
            var me = this;

            o.on({
                scope: me,
                mousedown: me.onMouseDown,
                mouseup: me.onMouseUp,
                mouseover: me.onMouseOver,
                mouseout: me.onMouseOut,
                click: me.onClick
            });
        },

        // Inherit docs from MixedCollection
        add: function(key, o) {
            var result = this.callParent(arguments);
            this.attachEvents(result);
            return result;
        },

        insert: function(index, key, o) {
            return this.callParent(arguments);
        },

        // Inherit docs from MixedCollection
        remove: function(o) {
            var me = this;

            o.un({
                scope: me,
                mousedown: me.onMouseDown,
                mouseup: me.onMouseUp,
                mouseover: me.onMouseOver,
                mouseout: me.onMouseOut,
                click: me.onClick
            });
            return me.callParent(arguments);
        },

        /**
         * Returns the group bounding box.
         * Behaves like {@link Ext.draw.Sprite#getBBox} method.
         * @return {Object} an object with x, y, width, and height properties.
         */
        getBBox: function() {
            var i = 0,
                sprite,
                bb,
                items = this.items,
                len = this.length,
                infinity = Infinity,
                minX = infinity,
                maxHeight = -infinity,
                minY = infinity,
                maxWidth = -infinity,
                maxWidthBBox, maxHeightBBox;

            for (; i < len; i++) {
                sprite = items[i];
                if (sprite.el && ! sprite.bboxExcluded) {
                    bb = sprite.getBBox();
                    minX = Math.min(minX, bb.x);
                    minY = Math.min(minY, bb.y);
                    maxHeight = Math.max(maxHeight, bb.height + bb.y);
                    maxWidth = Math.max(maxWidth, bb.width + bb.x);
                }
            }

            return {
                x: minX,
                y: minY,
                height: maxHeight - minY,
                width: maxWidth - minX
            };
        },

        /**
         * Iterates through all sprites calling `setAttributes` on each one. For more information {@link Ext.draw.Sprite}
         * provides a description of the attributes that can be set with this method.
         * @param {Object} attrs Attributes to be changed on the sprite.
         * @param {Boolean} redraw Flag to immediately draw the change.
         * @return {Ext.draw.CompositeSprite} this
         */
        setAttributes: function(attrs, redraw) {
            var i = 0,
                items = this.items,
                len = this.length;

            for (; i < len; i++) {
                items[i].setAttributes(attrs, redraw);
            }
            return this;
        },

        /**
         * Hides all sprites. If `true` is passed then a redraw will be forced for each sprite.
         * @param {Boolean} redraw Flag to immediately draw the change.
         * @return {Ext.draw.CompositeSprite} this
         */
        hide: function(redraw) {
            var i = 0,
                items = this.items,
                len = this.length;

            for (; i < len; i++) {
                items[i].hide(redraw);
            }
            return this;
        },

        /**
         * Shows all sprites. If `true` is passed then a redraw will be forced for each sprite.
         * @param {Boolean} redraw Flag to immediately draw the change.
         * @return {Ext.draw.CompositeSprite} this
         */
        show: function(redraw) {
            var i = 0,
                items = this.items,
                len = this.length;

            for (; i < len; i++) {
                items[i].show(redraw);
            }
            return this;
        },

        /**
         * Force redraw of all sprites.
         */
        redraw: function() {
            var me = this,
                i = 0,
                items = me.items,
                surface = me.getSurface(),
                len = me.length;

            if (surface) {
                for (; i < len; i++) {
                    surface.renderItem(items[i]);
                }
            }
            return me;
        },

        /**
         * Sets style for all sprites.
         * @param {String} style CSS Style definition.
         */
        setStyle: function(obj) {
            var i = 0,
                items = this.items,
                len = this.length,
                item, el;

            for (; i < len; i++) {
                item = items[i];
                el = item.el;
                if (el) {
                    el.setStyle(obj);
                }
            }
        },

        /**
         * Adds class to all sprites.
         * @param {String} cls CSS class name
         */
        addCls: function(obj) {
            var i = 0,
                items = this.items,
                surface = this.getSurface(),
                len = this.length;

            if (surface) {
                for (; i < len; i++) {
                    surface.addCls(items[i], obj);
                }
            }
        },

        /**
         * Removes class from all sprites.
         * @param {String} cls CSS class name
         */
        removeCls: function(obj) {
            var i = 0,
                items = this.items,
                surface = this.getSurface(),
                len = this.length;

            if (surface) {
                for (; i < len; i++) {
                    surface.removeCls(items[i], obj);
                }
            }
        },

        /**
         * Grab the surface from the items
         * @private
         * @return {Ext.draw.Surface} The surface, null if not found
         */
        getSurface: function(){
            var first = this.first();
            if (first) {
                return first.surface;
            }
            return null;
        },

        /**
         * Destroys this CompositeSprite.
         */
        destroy: function(){
            var me = this,
                surface = me.getSurface(),
                destroySprites = me.autoDestroy,
                item;

            if (surface) {
                while (me.getCount() > 0) {
                    item = me.first();
                    me.remove(item);
                    surface.remove(item, destroySprites);
                }
            }
            me.clearListeners();
        }
    });