YUI.add('dom-screen', function (Y, NAME) {

(function(Y) {

/**

 * Adds position and region management functionality to DOM.

 * @module dom

 * @submodule dom-screen

 * @for DOM

 */

var DOCUMENT_ELEMENT = 'documentElement',

    COMPAT_MODE = 'compatMode',

    POSITION = 'position',

    FIXED = 'fixed',

    RELATIVE = 'relative',

    LEFT = 'left',

    TOP = 'top',

    _BACK_COMPAT = 'BackCompat',

    MEDIUM = 'medium',

    BORDER_LEFT_WIDTH = 'borderLeftWidth',

    BORDER_TOP_WIDTH = 'borderTopWidth',

    GET_BOUNDING_CLIENT_RECT = 'getBoundingClientRect',

    GET_COMPUTED_STYLE = 'getComputedStyle',

    Y_DOM = Y.DOM,

    // TODO: how about thead/tbody/tfoot/tr?

    // TODO: does caption matter?

    RE_TABLE = /^t(?:able|d|h)$/i,

    SCROLL_NODE;

if (Y.UA.ie) {

    if (Y.config.doc[COMPAT_MODE] !== 'BackCompat') {

        SCROLL_NODE = DOCUMENT_ELEMENT;

    } else {

        SCROLL_NODE = 'body';

    }

}

Y.mix(Y_DOM, {

    /**

     * Returns the inner height of the viewport (exludes scrollbar).

     * @method winHeight

     * @return {Number} The current height of the viewport.

     */

    winHeight: function(node) {

        var h = Y_DOM._getWinSize(node).height;

        return h;

    },

    /**

     * Returns the inner width of the viewport (exludes scrollbar).

     * @method winWidth

     * @return {Number} The current width of the viewport.

     */

    winWidth: function(node) {

        var w = Y_DOM._getWinSize(node).width;

        return w;

    },

    /**

     * Document height

     * @method docHeight

     * @return {Number} The current height of the document.

     */

    docHeight:  function(node) {

        var h = Y_DOM._getDocSize(node).height;

        return Math.max(h, Y_DOM._getWinSize(node).height);

    },

    /**

     * Document width

     * @method docWidth

     * @return {Number} The current width of the document.

     */

    docWidth:  function(node) {

        var w = Y_DOM._getDocSize(node).width;

        return Math.max(w, Y_DOM._getWinSize(node).width);

    },

    /**

     * Amount page has been scroll horizontally

     * @method docScrollX

     * @return {Number} The current amount the screen is scrolled horizontally.

     */

    docScrollX: function(node, doc) {

        doc = doc || (node) ? Y_DOM._getDoc(node) : Y.config.doc; // perf optimization

        var dv = doc.defaultView,

            pageOffset = (dv) ? dv.pageXOffset : 0;

        return Math.max(doc[DOCUMENT_ELEMENT].scrollLeft, doc.body.scrollLeft, pageOffset);

    },

    /**

     * Amount page has been scroll vertically

     * @method docScrollY

     * @return {Number} The current amount the screen is scrolled vertically.

     */

    docScrollY:  function(node, doc) {

        doc = doc || (node) ? Y_DOM._getDoc(node) : Y.config.doc; // perf optimization

        var dv = doc.defaultView,

            pageOffset = (dv) ? dv.pageYOffset : 0;

        return Math.max(doc[DOCUMENT_ELEMENT].scrollTop, doc.body.scrollTop, pageOffset);

    },

    /**

     * Gets the current position of an element based on page coordinates.

     * Element must be part of the DOM tree to have page coordinates

     * (display:none or elements not appended return false).

     * @method getXY

     * @param element The target element

     * @return {Array} The XY position of the element

     TODO: test inDocument/display?

     */

    getXY: function() {

        if (Y.config.doc[DOCUMENT_ELEMENT][GET_BOUNDING_CLIENT_RECT]) {

            return function(node) {

                var xy = null,

                    scrollLeft,

                    scrollTop,

                    mode,

                    box,

                    offX,

                    offY,

                    doc,

                    win,

                    inDoc,

                    rootNode;

                if (node && node.tagName) {

                    doc = node.ownerDocument;

                    mode = doc[COMPAT_MODE];

                    if (mode !== _BACK_COMPAT) {

                        rootNode = doc[DOCUMENT_ELEMENT];

                    } else {

                        rootNode = doc.body;

                    }

                    // inline inDoc check for perf

                    if (rootNode.contains) {

                        inDoc = rootNode.contains(node);

                    } else {

                        inDoc = Y.DOM.contains(rootNode, node);

                    }

                    if (inDoc) {

                        win = doc.defaultView;

                        // inline scroll calc for perf

                        if (win && 'pageXOffset' in win) {

                            scrollLeft = win.pageXOffset;

                            scrollTop = win.pageYOffset;

                        } else {

                            scrollLeft = (SCROLL_NODE) ? doc[SCROLL_NODE].scrollLeft : Y_DOM.docScrollX(node, doc);

                            scrollTop = (SCROLL_NODE) ? doc[SCROLL_NODE].scrollTop : Y_DOM.docScrollY(node, doc);

                        }

                        if (Y.UA.ie) { // IE < 8, quirks, or compatMode

                            if (!doc.documentMode || doc.documentMode < 8 || mode === _BACK_COMPAT) {

                                offX = rootNode.clientLeft;

                                offY = rootNode.clientTop;

                            }

                        }

                        box = node[GET_BOUNDING_CLIENT_RECT]();

                        xy = [box.left, box.top];

                        if (offX || offY) {

                                xy[0] -= offX;

                                xy[1] -= offY;

                        }

                        if ((scrollTop || scrollLeft)) {

                            if (!Y.UA.ios || (Y.UA.ios >= 4.2)) {

                                xy[0] += scrollLeft;

                                xy[1] += scrollTop;

                            }

                        }

                    } else {

                        xy = Y_DOM._getOffset(node);

                    }

                }

                return xy;

            };

        } else {

            return function(node) { // manually calculate by crawling up offsetParents

                //Calculate the Top and Left border sizes (assumes pixels)

                var xy = null,

                    doc,

                    parentNode,

                    bCheck,

                    scrollTop,

                    scrollLeft;

                if (node) {

                    if (Y_DOM.inDoc(node)) {

                        xy = [node.offsetLeft, node.offsetTop];

                        doc = node.ownerDocument;

                        parentNode = node;

                        // TODO: refactor with !! or just falsey

                        bCheck = ((Y.UA.gecko || Y.UA.webkit > 519) ? true : false);

                        // TODO: worth refactoring for TOP/LEFT only?

                        while ((parentNode = parentNode.offsetParent)) {

                            xy[0] += parentNode.offsetLeft;

                            xy[1] += parentNode.offsetTop;

                            if (bCheck) {

                                xy = Y_DOM._calcBorders(parentNode, xy);

                            }

                        }

                        // account for any scrolled ancestors

                        if (Y_DOM.getStyle(node, POSITION) != FIXED) {

                            parentNode = node;

                            while ((parentNode = parentNode.parentNode)) {

                                scrollTop = parentNode.scrollTop;

                                scrollLeft = parentNode.scrollLeft;

                                //Firefox does something funky with borders when overflow is not visible.

                                if (Y.UA.gecko && (Y_DOM.getStyle(parentNode, 'overflow') !== 'visible')) {

                                        xy = Y_DOM._calcBorders(parentNode, xy);

                                }

                                if (scrollTop || scrollLeft) {

                                    xy[0] -= scrollLeft;

                                    xy[1] -= scrollTop;

                                }

                            }

                            xy[0] += Y_DOM.docScrollX(node, doc);

                            xy[1] += Y_DOM.docScrollY(node, doc);

                        } else {

                            //Fix FIXED position -- add scrollbars

                            xy[0] += Y_DOM.docScrollX(node, doc);

                            xy[1] += Y_DOM.docScrollY(node, doc);

                        }

                    } else {

                        xy = Y_DOM._getOffset(node);

                    }

                }

                return xy;

            };

        }

    }(),// NOTE: Executing for loadtime branching

    /**

    Gets the width of vertical scrollbars on overflowed containers in the body

    content.

    @method getScrollbarWidth

    @return {Number} Pixel width of a scrollbar in the current browser

    **/

    getScrollbarWidth: Y.cached(function () {

        var doc      = Y.config.doc,

            testNode = doc.createElement('div'),

            body     = doc.getElementsByTagName('body')[0],

            // 0.1 because cached doesn't support falsy refetch values

            width    = 0.1;

        if (body) {

            testNode.style.cssText = "position:absolute;visibility:hidden;overflow:scroll;width:20px;";

            testNode.appendChild(doc.createElement('p')).style.height = '1px';

            body.insertBefore(testNode, body.firstChild);

            width = testNode.offsetWidth - testNode.clientWidth;

            body.removeChild(testNode);

        }

        return width;

    }, null, 0.1),

    /**

     * Gets the current X position of an element based on page coordinates.

     * Element must be part of the DOM tree to have page coordinates

     * (display:none or elements not appended return false).

     * @method getX

     * @param element The target element

     * @return {Number} The X position of the element

     */

    getX: function(node) {

        return Y_DOM.getXY(node)[0];

    },

    /**

     * Gets the current Y position of an element based on page coordinates.

     * Element must be part of the DOM tree to have page coordinates

     * (display:none or elements not appended return false).

     * @method getY

     * @param element The target element

     * @return {Number} The Y position of the element

     */

    getY: function(node) {

        return Y_DOM.getXY(node)[1];

    },

    /**

     * Set the position of an html element in page coordinates.

     * The element must be part of the DOM tree to have page coordinates (display:none or elements not appended return false).

     * @method setXY

     * @param element The target element

     * @param {Array} xy Contains X & Y values for new position (coordinates are page-based)

     * @param {Boolean} noRetry By default we try and set the position a second time if the first fails

     */

    setXY: function(node, xy, noRetry) {

        var setStyle = Y_DOM.setStyle,

            pos,

            delta,

            newXY,

            currentXY;

        if (node && xy) {

            pos = Y_DOM.getStyle(node, POSITION);

            delta = Y_DOM._getOffset(node);

            if (pos == 'static') { // default to relative

                pos = RELATIVE;

                setStyle(node, POSITION, pos);

            }

            currentXY = Y_DOM.getXY(node);

            if (xy[0] !== null) {

                setStyle(node, LEFT, xy[0] - currentXY[0] + delta[0] + 'px');

            }

            if (xy[1] !== null) {

                setStyle(node, TOP, xy[1] - currentXY[1] + delta[1] + 'px');

            }

            if (!noRetry) {

                newXY = Y_DOM.getXY(node);

                if (newXY[0] !== xy[0] || newXY[1] !== xy[1]) {

                    Y_DOM.setXY(node, xy, true);

                }

            }

        } else {

        }

    },

    /**

     * Set the X position of an html element in page coordinates, regardless of how the element is positioned.

     * The element(s) must be part of the DOM tree to have page coordinates (display:none or elements not appended return false).

     * @method setX

     * @param element The target element

     * @param {Number} x The X values for new position (coordinates are page-based)

     */

    setX: function(node, x) {

        return Y_DOM.setXY(node, [x, null]);

    },

    /**

     * Set the Y position of an html element in page coordinates, regardless of how the element is positioned.

     * The element(s) must be part of the DOM tree to have page coordinates (display:none or elements not appended return false).

     * @method setY

     * @param element The target element

     * @param {Number} y The Y values for new position (coordinates are page-based)

     */

    setY: function(node, y) {

        return Y_DOM.setXY(node, [null, y]);

    },

    /**

     * @method swapXY

     * @description Swap the xy position with another node

     * @param {Node} node The node to swap with

     * @param {Node} otherNode The other node to swap with

     * @return {Node}

     */

    swapXY: function(node, otherNode) {

        var xy = Y_DOM.getXY(node);

        Y_DOM.setXY(node, Y_DOM.getXY(otherNode));

        Y_DOM.setXY(otherNode, xy);