    /**
     * @class Ext.layout.container.AbstractCard
     * @extends Ext.layout.container.Fit
     * <p>This layout manages multiple child Components, each is fit to the Container, where only a single child Component
     * can be visible at any given time.  This layout style is most commonly used for wizards, tab implementations, etc.
     * This class is intended to be extended or created via the layout:'card' {@link Ext.container.Container#layout} config,
     * and should generally not need to be created directly via the new keyword.</p>
     * <p>The CardLayout's focal method is {@link #setActiveItem}.  Since only one panel is displayed at a time,
     * the only way to move from one Component to the next is by calling setActiveItem, passing the id or index of
     * the next panel to display.  The layout itself does not provide a user interface for handling this navigation,
     * so that functionality must be provided by the developer.</p>
     * <p>Containers that are configured with a card layout will have a method setActiveItem dynamically added to it.
     * <pre><code>
          var p = new Ext.panel.Panel({
              fullscreen: true,
              layout: 'card',
              items: [{
                  html: 'Card 1'
              },{
                  html: 'Card 2'
              }]
          });
          p.setActiveItem(1);
       </code></pre>
     * </p>
     */

    Ext.define('Ext.layout.container.AbstractCard', {

        /* Begin Definitions */

        extend: 'Ext.layout.container.Fit',

        /* End Definitions */

        type: 'card',

        sizeAllCards: false,

        hideInactive: true,

        /**
         * @cfg {Boolean} deferredRender
         * True to render each contained item at the time it becomes active, false to render all contained items
         * as soon as the layout is rendered (defaults to false).  If there is a significant amount of content or
         * a lot of heavy controls being rendered into panels that are not displayed by default, setting this to
         * true might improve performance.
         */
        deferredRender : false,

        beforeLayout: function() {
            var me = this;
            me.activeItem = me.getActiveItem();
            if (me.activeItem && me.deferredRender) {
                me.renderItems([me.activeItem], me.getRenderTarget());
                return true;
            }
            else {
                return this.callParent(arguments);
            }
        },

        onLayout: function() {
            var me = this,
                activeItem = me.activeItem,
                items = me.getVisibleItems(),
                ln = items.length,
                targetBox = me.getTargetBox(),
                i, item;

            for (i = 0; i < ln; i++) {
                item = items[i];
                me.setItemBox(item, targetBox);
            }

            if (!me.firstActivated && activeItem) {
                if (activeItem.fireEvent('beforeactivate', activeItem) !== false) {
                    activeItem.fireEvent('activate', activeItem);
                }
                me.firstActivated = true;
            }
        },

        isValidParent : function(item, target, position) {
            // Note: Card layout does not care about order within the target because only one is ever visible.
            // We only care whether the item is a direct child of the target.
            var itemEl = item.el ? item.el.dom : Ext.getDom(item);
            return (itemEl && itemEl.parentNode === (target.dom || target)) || false;
        },

        /**
         * Return the active (visible) component in the layout.
         * @returns {Ext.Component}
         */
        getActiveItem: function() {
            var me = this;
            if (!me.activeItem && me.owner) {
                me.activeItem = me.parseActiveItem(me.owner.activeItem);
            }

            if (me.activeItem && me.owner.items.indexOf(me.activeItem) != -1) {
                return me.activeItem;
            }

            return null;
        },

        // @private
        parseActiveItem: function(item) {
            if (item && item.isComponent) {
                return item;
            }
            else if (typeof item == 'number' || item === undefined) {
                return this.getLayoutItems()[item || 0];
            }
            else {
                return this.owner.getComponent(item);
            }
        },

        // @private
        configureItem: function(item, position) {
            this.callParent([item, position]);
            if (this.hideInactive && this.activeItem !== item) {
                item.hide();
            }
            else {
                item.show();
            }
        },

        onRemove: function(component) {
            if (component === this.activeItem) {
                this.activeItem = null;
                if (this.owner.items.getCount() === 0) {
                    this.firstActivated = false;
                }
            }
        },

        // @private
        getAnimation: function(newCard, owner) {
            var newAnim = (newCard || {}).cardSwitchAnimation;
            if (newAnim === false) {
                return false;
            }
            return newAnim || owner.cardSwitchAnimation;
        },

        /**
         * Return the active (visible) component in the layout to the next card
         * @returns {Ext.Component}
         */
        getNext: function(wrap) {
            //NOTE: Removed the JSDoc for this function's arguments because it is not actually supported in 4.0. This
            //should come back in 4.1

            var items = this.getLayoutItems(),
                index = Ext.Array.indexOf(items, this.activeItem);
            return items[index + 1] || (wrap ? items[0] : false);
        },

        /**
         * Sets the active (visible) component in the layout to the next card
         */
        next: function(anim, wrap) {
            //NOTE: Removed the JSDoc for this function's arguments because it is not actually supported in 4.0. This
            //should come back in 4.1

            return this.setActiveItem(this.getNext(wrap), anim);
        },

        /**
         * Return the active (visible) component in the layout to the previous card
         * @returns {Ext.Component}
         */
        getPrev: function(wrap) {
            //NOTE: Removed the JSDoc for this function's arguments because it is not actually supported in 4.0. This
            //should come back in 4.1

            var items = this.getLayoutItems(),
                index = Ext.Array.indexOf(items, this.activeItem);
            return items[index - 1] || (wrap ? items[items.length - 1] : false);
        },

        /**
         * Sets the active (visible) component in the layout to the previous card
         */
        prev: function(anim, wrap) {
            //NOTE: Removed the JSDoc for this function's arguments because it is not actually supported in 4.0. This
            //should come back in 4.1

            return this.setActiveItem(this.getPrev(wrap), anim);
        }
    });