YUI.add('scrollview-scrollbars', function (Y, NAME) {

/**

 * Provides a plugin, which adds support for a scroll indicator to ScrollView instances

 *

 * @module scrollview

 * @submodule scrollview-scrollbars

 */

var getClassName = Y.ClassNameManager.getClassName,

    _classNames,

    Transition = Y.Transition,

    NATIVE_TRANSITIONS = Transition.useNative,

    SCROLLBAR = 'scrollbar',

    SCROLLVIEW = 'scrollview',

    VERTICAL_NODE = "verticalNode",

    HORIZONTAL_NODE = "horizontalNode",

    CHILD_CACHE = "childCache",

    TOP = "top",

    LEFT = "left",

    WIDTH = "width",

    HEIGHT = "height",

    HORIZ_CACHE = "_sbh",

    VERT_CACHE = "_sbv",

    TRANSITION_PROPERTY = Y.ScrollView._TRANSITION.PROPERTY,

    TRANSFORM = "transform",

    TRANSLATE_X = "translateX(",

    TRANSLATE_Y = "translateY(",

    SCALE_X = "scaleX(",

    SCALE_Y = "scaleY(",

    SCROLL_X = "scrollX",

    SCROLL_Y = "scrollY",

    PX = "px",

    CLOSE = ")",

    PX_CLOSE = PX + CLOSE;

/**

 * ScrollView plugin that adds scroll indicators to ScrollView instances

 *

 * @class ScrollViewScrollbars

 * @namespace Plugin

 * @extends Plugin.Base

 * @constructor

 */

function ScrollbarsPlugin() {

    ScrollbarsPlugin.superclass.constructor.apply(this, arguments);

}

ScrollbarsPlugin.CLASS_NAMES = {

    showing: getClassName(SCROLLVIEW, SCROLLBAR, 'showing'),

    scrollbar: getClassName(SCROLLVIEW, SCROLLBAR),

    scrollbarV: getClassName(SCROLLVIEW, SCROLLBAR, 'vert'),

    scrollbarH: getClassName(SCROLLVIEW, SCROLLBAR, 'horiz'),

    scrollbarVB: getClassName(SCROLLVIEW, SCROLLBAR, 'vert', 'basic'),

    scrollbarHB: getClassName(SCROLLVIEW, SCROLLBAR, 'horiz', 'basic'),

    child: getClassName(SCROLLVIEW, 'child'),

    first: getClassName(SCROLLVIEW, 'first'),

    middle: getClassName(SCROLLVIEW, 'middle'),

    last: getClassName(SCROLLVIEW, 'last')

};

_classNames = ScrollbarsPlugin.CLASS_NAMES;

/**

 * The identity of the plugin

 *

 * @property NAME

 * @type String

 * @default 'pluginScrollViewScrollbars'

 * @static

 */

ScrollbarsPlugin.NAME = 'pluginScrollViewScrollbars';

/**

 * The namespace on which the plugin will reside.

 *

 * @property NS

 * @type String

 * @default 'scrollbars'

 * @static

 */

ScrollbarsPlugin.NS = 'scrollbars';

/**

 * HTML template for the scrollbar

 *

 * @property SCROLLBAR_TEMPLATE

 * @type Object

 * @static

 */

ScrollbarsPlugin.SCROLLBAR_TEMPLATE = [

    '<div>',

    '<span class="' + _classNames.child + ' ' + _classNames.first + '"></span>',

    '<span class="' + _classNames.child + ' ' + _classNames.middle + '"></span>',

    '<span class="' + _classNames.child + ' ' + _classNames.last + '"></span>',

    '</div>'

].join('');

/**

 * The default attribute configuration for the plugin

 *

 * @property ATTRS

 * @type Object

 * @static

 */

ScrollbarsPlugin.ATTRS = {

    /**

     * Vertical scrollbar node

     *

     * @attribute verticalNode

     * @type Y.Node

     */

    verticalNode: {

        setter: '_setNode',

        valueFn: '_defaultNode'

    },

    /**

     * Horizontal scrollbar node

     *

     * @attribute horizontalNode

     * @type Y.Node

     */

    horizontalNode: {

        setter: '_setNode',

        valueFn: '_defaultNode'

    }

};

Y.namespace("Plugin").ScrollViewScrollbars = Y.extend(ScrollbarsPlugin, Y.Plugin.Base, {

    /**

     * Designated initializer

     *

     * @method initializer

     */

    initializer: function() {

        this._host = this.get("host");

        this.afterHostEvent('scrollEnd', this._hostScrollEnd);

        this.afterHostMethod('scrollTo', this._update);

        this.afterHostMethod('_uiDimensionsChange', this._hostDimensionsChange);

    },

    /**

     * Set up the DOM nodes for the scrollbars. This method is invoked whenever the

     * host's _uiDimensionsChange fires, giving us the opportunity to remove un-needed

     * scrollbars, as well as add one if necessary.

     *

     * @method _hostDimensionsChange

     * @protected

     */

    _hostDimensionsChange: function() {

        var host = this._host,

            axis = host._cAxis,

            scrollX = host.get(SCROLL_X),

            scrollY = host.get(SCROLL_Y);

        this._dims = host._getScrollDims();

        if (axis && axis.y) {

            this._renderBar(this.get(VERTICAL_NODE), true, 'vert');

        }

        if (axis && axis.x) {

            this._renderBar(this.get(HORIZONTAL_NODE), true, 'horiz');

        }

        this._update(scrollX, scrollY);

        Y.later(500, this, 'flash', true);

    },

    /**

     * Handler for the scrollEnd event fired by the host. Default implementation flashes the scrollbar

     *

     * @method _hostScrollEnd

     * @param {EventFacade} e The event facade.

     * @protected

     */

    _hostScrollEnd : function() {

        var host = this._host,

            scrollX = host.get(SCROLL_X),

            scrollY = host.get(SCROLL_Y);

        this.flash();

        this._update(scrollX, scrollY);

    },

    /**

     * Adds or removes a scrollbar node from the document.

     *

     * @method _renderBar

     * @private

     * @param {Node} bar The scrollbar node

     * @param {boolean} add true, to add the node, false to remove it

     */

    _renderBar: function(bar, add) {

        var inDoc = bar.inDoc(),

            bb = this._host._bb,

            className = bar.getData("isHoriz") ? _classNames.scrollbarHB : _classNames.scrollbarVB;

        if (add && !inDoc) {

            bb.append(bar);

            bar.toggleClass(className, this._basic);

            this._setChildCache(bar);

        } else if(!add && inDoc) {

            bar.remove();

            this._clearChildCache(bar);

        }

    },

    /**

     * Caches scrollbar child element information,

     * to optimize _update implementation

     *

     * @method _setChildCache

     * @private

     * @param {Node} node

     */

    _setChildCache : function(node) {

        var c = node.get("children"),

            fc = c.item(0),

            mc = c.item(1),

            lc = c.item(2),

            size = node.getData("isHoriz") ? "offsetWidth" : "offsetHeight";

        node.setStyle(TRANSITION_PROPERTY, TRANSFORM);

        mc.setStyle(TRANSITION_PROPERTY, TRANSFORM);

        lc.setStyle(TRANSITION_PROPERTY, TRANSFORM);

        node.setData(CHILD_CACHE, {

            fc : fc,

            lc : lc,

            mc : mc,

            fcSize : fc && fc.get(size),

            lcSize : lc && lc.get(size)

        });

    },

    /**

     * Clears child cache

     *

     * @method _clearChildCache

     * @private

     * @param {Node} node

     */

    _clearChildCache : function(node) {

        node.clearData(CHILD_CACHE);

    },

    /**

     * Utility method, to move/resize either vertical or horizontal scrollbars

     *

     * @method _updateBar

     * @private

     *

     * @param {Node} scrollbar The scrollbar node.

     * @param {Number} current The current scroll position.

     * @param {Number} duration The transition duration.

     * @param {boolean} horiz true if horizontal, false if vertical.

     */

    _updateBar : function(scrollbar, current, duration, horiz) {

        var host = this._host,

            basic = this._basic,

            scrollbarSize = 0,

            scrollbarPos = 1,

            childCache = scrollbar.getData(CHILD_CACHE),

            lastChild = childCache.lc,

            middleChild = childCache.mc,

            firstChildSize = childCache.fcSize,

            lastChildSize = childCache.lcSize,

            middleChildSize,

            lastChildPosition,

            transition,

            translate,

            scale,

            dim,

            dimOffset,

            dimCache,

            widgetSize,

            contentSize;

        if (horiz) {

            dim = WIDTH;

            dimOffset = LEFT;

            dimCache = HORIZ_CACHE;

            widgetSize = this._dims.offsetWidth;

            contentSize = this._dims.scrollWidth;

            translate = TRANSLATE_X;

            scale = SCALE_X;

            current = (current !== undefined) ? current : host.get(SCROLL_X);

        } else {

            dim = HEIGHT;

            dimOffset = TOP;

            dimCache = VERT_CACHE;

            widgetSize = this._dims.offsetHeight;

            contentSize = this._dims.scrollHeight;

            translate = TRANSLATE_Y;

            scale = SCALE_Y;

            current = (current !== undefined) ? current : host.get(SCROLL_Y);

        }

        scrollbarSize = Math.floor(widgetSize * (widgetSize/contentSize));

        scrollbarPos = Math.floor((current/(contentSize - widgetSize)) * (widgetSize - scrollbarSize));

        if (scrollbarSize > widgetSize) {

            scrollbarSize = 1;

        }

        if (scrollbarPos > (widgetSize - scrollbarSize)) {

            scrollbarSize = scrollbarSize - (scrollbarPos - (widgetSize - scrollbarSize));

        } else if (scrollbarPos < 0) {

            scrollbarSize = scrollbarPos + scrollbarSize;

            scrollbarPos = 0;

        } else if (isNaN(scrollbarPos)) {

            scrollbarPos = 0;

        }

        middleChildSize = (scrollbarSize - (firstChildSize + lastChildSize));

        if (middleChildSize < 0) {

            middleChildSize = 0;

        }

        if (middleChildSize === 0 && scrollbarPos !== 0) {

            scrollbarPos = widgetSize - (firstChildSize + lastChildSize) - 1;

        }

        if (duration !== 0) {

            // Position Scrollbar

            transition = {

                duration : duration

            };

            if (NATIVE_TRANSITIONS) {

                transition.transform = translate + scrollbarPos + PX_CLOSE;

            } else {

                transition[dimOffset] = scrollbarPos + PX;

            }

            scrollbar.transition(transition);

        } else {

            if (NATIVE_TRANSITIONS) {

                scrollbar.setStyle(TRANSFORM, translate + scrollbarPos + PX_CLOSE);

            } else {

                scrollbar.setStyle(dimOffset, scrollbarPos + PX);

            }

        }

        // Resize Scrollbar Middle Child

        if (this[dimCache] !== middleChildSize) {

            this[dimCache] = middleChildSize;

            if (middleChildSize > 0) {

                if (duration !== 0) {

                    transition = {

                        duration : duration

                    };

                    if(NATIVE_TRANSITIONS) {

                        transition.transform = scale + middleChildSize + CLOSE;

                    } else {

                        transition[dim] = middleChildSize + PX;

                    }

                    middleChild.transition(transition);

                } else {

                    if (NATIVE_TRANSITIONS) {

                        middleChild.setStyle(TRANSFORM, scale + middleChildSize + CLOSE);