/*
This file is part of Ext JS 4.2

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

Commercial Usage
Licensees holding valid commercial licenses may use this file in accordance with the Commercial
Software License Agreement provided with the Software or, alternatively, in accordance with the
terms contained in a written agreement between you and Sencha.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-09-18 17:18:59 (940c324ac822b840618a3a8b2b4b873f83a1a9b1)
*/
/**
 * A specialized {@link Ext.util.KeyNav} implementation for navigating a {@link Ext.view.BoundList} using
 * the keyboard. The up, down, pageup, pagedown, home, and end keys move the active highlight
 * through the list. The enter key invokes the selection model's select action using the highlighted item.
 */
Ext.define('Ext.view.BoundListKeyNav', {
    extend: 'Ext.util.KeyNav',
    requires: 'Ext.view.BoundList',

    /**
     * @cfg {Ext.view.BoundList} boundList (required)
     * The {@link Ext.view.BoundList} instance for which key navigation will be managed.
     */

    constructor: function(el, config) {
        var me = this;
        me.boundList = config.boundList;
        me.callParent([el, Ext.apply({}, config, me.defaultHandlers)]);
    },

    defaultHandlers: {
        up: function() {
            var me = this,
                boundList = me.boundList,
                allItems = boundList.all,
                oldItem = boundList.highlightedItem,
                oldItemIdx = oldItem ? boundList.indexOf(oldItem) : -1,
                newItemIdx = oldItemIdx > 0 ? oldItemIdx - 1 : allItems.getCount() - 1; //wraps around
            me.highlightAt(newItemIdx);
        },

        down: function() {
            var me = this,
                boundList = me.boundList,
                allItems = boundList.all,
                oldItem = boundList.highlightedItem,
                oldItemIdx = oldItem ? boundList.indexOf(oldItem) : -1,
                newItemIdx = oldItemIdx < allItems.getCount() - 1 ? oldItemIdx + 1 : 0; //wraps around
            me.highlightAt(newItemIdx);
        },

        pageup: function() {
            //TODO
        },

        pagedown: function() {
            //TODO
        },

        home: function() {
            this.highlightAt(0);
        },

        end: function() {
            var me = this;
            me.highlightAt(me.boundList.all.getCount() - 1);
        },

        enter: function(e) {
            this.selectHighlighted(e);
        }
    },

    /**
     * Highlights the item at the given index.
     * @param {Number} index
     */
    highlightAt: function(index) {
        var boundList = this.boundList,
            item = boundList.all.item(index);
        if (item) {
            item = item.dom;
            boundList.highlightItem(item);
            boundList.getTargetEl().scrollChildIntoView(item, false);
        }
    },

    /**
     * Triggers selection of the currently highlighted item according to the behavior of
     * the configured SelectionModel.
     */
    selectHighlighted: function(e) {
        var boundList = this.boundList,
            selModel = boundList.getSelectionModel(),
            highlighted, highlightedRec;

        highlighted = boundList.highlightedItem;
        if (highlighted) {
            highlightedRec = boundList.getRecord(highlighted);    

            // Select if not already selected.
            // If already selected, selecting with no CTRL flag will deselect the record.
            if (e.getKey() === e.ENTER || !selModel.isSelected(highlightedRec)) {
                selModel.selectWithEvent(highlightedRec, e);
            }
        }
    }

});
