core-jgi/org.adempiere.ui.zk/js/html2canvas.js

/*
 html2canvas 0.4.1 <http://html2canvas.hertzen.com>
 Copyright (c) 2013 Niklas von Hertzen

 Released under MIT License
 */

(function(window, document, undefined){

    "use strict";

    var _html2canvas = {},
        previousElement,
        computedCSS,
        html2canvas;

    _html2canvas.Util = {};

    _html2canvas.Util.log = function(a) {
        if (_html2canvas.logging && window.console && window.console.log) {
            window.console.log(a);
        }
    };

    _html2canvas.Util.trimText = (function(isNative){
        return function(input) {
            return isNative ? isNative.apply(input) : ((input || '') + '').replace( /^\s+|\s+$/g , '' );
        };
    })(String.prototype.trim);

    _html2canvas.Util.asFloat = function(v) {
        return parseFloat(v);
    };

    (function() {
        // TODO: support all possible length values
        var TEXT_SHADOW_PROPERTY = /((rgba|rgb)\([^\)]+\)(\s-?\d+px){0,})/g;
        var TEXT_SHADOW_VALUES = /(-?\d+px)|(#.+)|(rgb\(.+\))|(rgba\(.+\))/g;
        _html2canvas.Util.parseTextShadows = function (value) {
            if (!value || value === 'none') {
                return [];
            }

            // find multiple shadow declarations
            var shadows = value.match(TEXT_SHADOW_PROPERTY),
                results = [];
            for (var i = 0; shadows && (i < shadows.length); i++) {
                var s = shadows[i].match(TEXT_SHADOW_VALUES);
                results.push({
                    color: s[0],
                    offsetX: s[1] ? s[1].replace('px', '') : 0,
                    offsetY: s[2] ? s[2].replace('px', '') : 0,
                    blur: s[3] ? s[3].replace('px', '') : 0
                });
            }
            return results;
        };
    })();


    _html2canvas.Util.parseBackgroundImage = function (value) {
        var whitespace = ' \r\n\t',
            method, definition, prefix, prefix_i, block, results = [],
            c, mode = 0, numParen = 0, quote, args;

        var appendResult = function(){
            if(method) {
                if(definition.substr( 0, 1 ) === '"') {
                    definition = definition.substr( 1, definition.length - 2 );
                }
                if(definition) {
                    args.push(definition);
                }
                if(method.substr( 0, 1 ) === '-' &&
                    (prefix_i = method.indexOf( '-', 1 ) + 1) > 0) {
                    prefix = method.substr( 0, prefix_i);
                    method = method.substr( prefix_i );
                }
                results.push({
                    prefix: prefix,
                    method: method.toLowerCase(),
                    value: block,
                    args: args
                });
            }
            args = []; //for some odd reason, setting .length = 0 didn't work in safari
            method =
                prefix =
                    definition =
                        block = '';
        };

        appendResult();
        for(var i = 0, ii = value.length; i<ii; i++) {
            c = value[i];
            if(mode === 0 && whitespace.indexOf( c ) > -1){
                continue;
            }
            switch(c) {
                case '"':
                    if(!quote) {
                        quote = c;
                    }
                    else if(quote === c) {
                        quote = null;
                    }
                    break;

                case '(':
                    if(quote) { break; }
                    else if(mode === 0) {
                        mode = 1;
                        block += c;
                        continue;
                    } else {
                        numParen++;
                    }
                    break;

                case ')':
                    if(quote) { break; }
                    else if(mode === 1) {
                        if(numParen === 0) {
                            mode = 0;
                            block += c;
                            appendResult();
                            continue;
                        } else {
                            numParen--;
                        }
                    }
                    break;

                case ',':
                    if(quote) { break; }
                    else if(mode === 0) {
                        appendResult();
                        continue;
                    }
                    else if (mode === 1) {
                        if(numParen === 0 && !method.match(/^url$/i)) {
                            args.push(definition);
                            definition = '';
                            block += c;
                            continue;
                        }
                    }
                    break;
            }

            block += c;
            if(mode === 0) { method += c; }
            else { definition += c; }
        }
        appendResult();

        return results;
    };

    _html2canvas.Util.Bounds = function (element) {
        var clientRect, bounds = {};

        if (element.getBoundingClientRect){
            clientRect = element.getBoundingClientRect();

            // TODO add scroll position to bounds, so no scrolling of window necessary
            bounds.top = clientRect.top;
            bounds.bottom = clientRect.bottom || (clientRect.top + clientRect.height);
            bounds.left = clientRect.left;

            bounds.width = element.offsetWidth;
            bounds.height = element.offsetHeight;
        }

        return bounds;
    };

// TODO ideally, we'd want everything to go through this function instead of Util.Bounds,
// but would require further work to calculate the correct positions for elements with offsetParents
    _html2canvas.Util.OffsetBounds = function (element) {
        var parent = element.offsetParent ? _html2canvas.Util.OffsetBounds(element.offsetParent) : {top: 0, left: 0};

        return {
            top: element.offsetTop + parent.top,
            bottom: element.offsetTop + element.offsetHeight + parent.top,
            left: element.offsetLeft + parent.left,
            width: element.offsetWidth,
            height: element.offsetHeight
        };
    };

    function toPX(element, attribute, value ) {
        var rsLeft = element.runtimeStyle && element.runtimeStyle[attribute],
            left,
            style = element.style;

        // Check if we are not dealing with pixels, (Opera has issues with this)
        // Ported from jQuery css.js
        // From the awesome hack by Dean Edwards
        // http://erik.eae.net/archives/2007/07/27/18.54.15/#comment-102291

        // If we're not dealing with a regular pixel number
        // but a number that has a weird ending, we need to convert it to pixels

        if ( !/^-?[0-9]+\.?[0-9]*(?:px)?$/i.test( value ) && /^-?\d/.test(value) ) {
            // Remember the original values
            left = style.left;

            // Put in the new values to get a computed value out
            if (rsLeft) {
                element.runtimeStyle.left = element.currentStyle.left;
            }
            style.left = attribute === "fontSize" ? "1em" : (value || 0);
            value = style.pixelLeft + "px";

            // Revert the changed values
            style.left = left;
            if (rsLeft) {
                element.runtimeStyle.left = rsLeft;
            }
        }

        if (!/^(thin|medium|thick)$/i.test(value)) {
            return Math.round(parseFloat(value)) + "px";
        }

        return value;
    }

    function asInt(val) {
        return parseInt(val, 10);
    }

    function parseBackgroundSizePosition(value, element, attribute, index) {
        value = (value || '').split(',');
        value = value[index || 0] || value[0] || 'auto';
        value = _html2canvas.Util.trimText(value).split(' ');

        if(attribute === 'backgroundSize' && (!value[0] || value[0].match(/cover|contain|auto/))) {
            //these values will be handled in the parent function
        } else {
            value[0] = (value[0].indexOf( "%" ) === -1) ? toPX(element, attribute + "X", value[0]) : value[0];
            if(value[1] === undefined) {
                if(attribute === 'backgroundSize') {
                    value[1] = 'auto';
                    return value;
                } else {
                    // IE 9 doesn't return double digit always
                    value[1] = value[0];
                }
            }
            value[1] = (value[1].indexOf("%") === -1) ? toPX(element, attribute + "Y", value[1]) : value[1];
        }
        return value;
    }

    _html2canvas.Util.getCSS = function (element, attribute, index) {
        if (previousElement !== element) {
            computedCSS = document.defaultView.getComputedStyle(element, null);
        }

        var value = computedCSS[attribute];

        if (/^background(Size|Position)$/.test(attribute)) {
            return parseBackgroundSizePosition(value, element, attribute, index);
        } else if (/border(Top|Bottom)(Left|Right)Radius/.test(attribute)) {
            var arr = value.split(" ");
            if (arr.length <= 1) {
                arr[1] = arr[0];
            }
            return arr.map(asInt);
        }

        return value;
    };

    _html2canvas.Util.resizeBounds = function( current_width, current_height, target_width, target_height, stretch_mode ){
        var target_ratio = target_width / target_height,
            current_ratio = current_width / current_height,
            output_width, output_height;

        if(!stretch_mode || stretch_mode === 'auto') {
            output_width = target_width;
            output_height = target_height;
        } else if(target_ratio < current_ratio ^ stretch_mode === 'contain') {
            output_height = target_height;
            output_width = target_height * current_ratio;
        } else {
            output_width = target_width;
            output_height = target_width / current_ratio;
        }

        return {
            width: output_width,
            height: output_height
        };
    };

    function backgroundBoundsFactory( prop, el, bounds, image, imageIndex, backgroundSize ) {
        var bgposition =  _html2canvas.Util.getCSS( el, prop, imageIndex ) ,
            topPos,
            left,
            percentage,
            val;

        if (bgposition.length === 1){
            val = bgposition[0];

            bgposition = [];

            bgposition[0] = val;
            bgposition[1] = val;
        }

        if (bgposition[0].toString().indexOf("%") !== -1){
            percentage = (parseFloat(bgposition[0])/100);
            left = bounds.width * percentage;
            if(prop !== 'backgroundSize') {
                left -= (backgroundSize || image).width*percentage;
            }
        } else {
            if(prop === 'backgroundSize') {
                if(bgposition[0] === 'auto') {
                    left = image.width;
                } else {
                    if (/contain|cover/.test(bgposition[0])) {
                        var resized = _html2canvas.Util.resizeBounds(image.width, image.height, bounds.width, bounds.height, bgposition[0]);
                        left = resized.width;
                        topPos = resized.height;
                    } else {
                        left = parseInt(bgposition[0], 10);
                    }
                }
            } else {
                left = parseInt( bgposition[0], 10);
            }
        }


        if(bgposition[1] === 'auto') {
            topPos = left / image.width * image.height;
        } else if (bgposition[1].toString().indexOf("%") !== -1){
            percentage = (parseFloat(bgposition[1])/100);
            topPos =  bounds.height * percentage;
            if(prop !== 'backgroundSize') {
                topPos -= (backgroundSize || image).height * percentage;
            }

        } else {
            topPos = parseInt(bgposition[1],10);
        }

        return [left, topPos];
    }

    _html2canvas.Util.BackgroundPosition = function( el, bounds, image, imageIndex, backgroundSize ) {
        var result = backgroundBoundsFactory( 'backgroundPosition', el, bounds, image, imageIndex, backgroundSize );
        return { left: result[0], top: result[1] };
    };

    _html2canvas.Util.BackgroundSize = function( el, bounds, image, imageIndex ) {
        var result = backgroundBoundsFactory( 'backgroundSize', el, bounds, image, imageIndex );
        return { width: result[0], height: result[1] };
    };

    _html2canvas.Util.Extend = function (options, defaults) {
        for (var key in options) {
            if (options.hasOwnProperty(key)) {
                defaults[key] = options[key];
            }
        }
        return defaults;
    };


    /*
     * Derived from jQuery.contents()
     * Copyright 2010, John Resig
     * Dual licensed under the MIT or GPL Version 2 licenses.
     * http://jquery.org/license
     */
    _html2canvas.Util.Children = function( elem ) {
        var children;
        try {
            children = (elem.nodeName && elem.nodeName.toUpperCase() === "IFRAME") ? elem.contentDocument || elem.contentWindow.document : (function(array) {
                var ret = [];
                if (array !== null) {
                    (function(first, second ) {
                        var i = first.length,
                            j = 0;

                        if (typeof second.length === "number") {
                            for (var l = second.length; j < l; j++) {
                                first[i++] = second[j];
                            }
                        } else {
                            while (second[j] !== undefined) {
                                first[i++] = second[j++];
                            }
                        }

                        first.length = i;

                        return first;
                    })(ret, array);
                }
                return ret;
            })(elem.childNodes);

        } catch (ex) {
            _html2canvas.Util.log("html2canvas.Util.Children failed with exception: " + ex.message);
            children = [];
        }
        return children;
    };

    _html2canvas.Util.isTransparent = function(backgroundColor) {
        return (backgroundColor === "transparent" || backgroundColor === "rgba(0, 0, 0, 0)");
    };
    _html2canvas.Util.Font = (function () {

        var fontData = {};

        return function(font, fontSize, doc) {
            if (fontData[font + "-" + fontSize] !== undefined) {
                return fontData[font + "-" + fontSize];
            }

            var container = doc.createElement('div'),
                img = doc.createElement('img'),
                span = doc.createElement('span'),
                sampleText = 'Hidden Text',
                baseline,
                middle,
                metricsObj;

            container.style.visibility = "hidden";
            container.style.fontFamily = font;
            container.style.fontSize = fontSize;
            container.style.margin = 0;
            container.style.padding = 0;

            doc.body.appendChild(container);

            // http://probablyprogramming.com/2009/03/15/the-tiniest-gif-ever (handtinywhite.gif)
            img.src = "data:image/gif;base64,R0lGODlhAQABAIABAP///wAAACwAAAAAAQABAAACAkQBADs=";
            img.width = 1;
            img.height = 1;

            img.style.margin = 0;
            img.style.padding = 0;
            img.style.verticalAlign = "baseline";

            span.style.fontFamily = font;
            span.style.fontSize = fontSize;
            span.style.margin = 0;
            span.style.padding = 0;

            span.appendChild(doc.createTextNode(sampleText));
            container.appendChild(span);
            container.appendChild(img);
            baseline = (img.offsetTop - span.offsetTop) + 1;

            container.removeChild(span);
            container.appendChild(doc.createTextNode(sampleText));

            container.style.lineHeight = "normal";
            img.style.verticalAlign = "super";

            middle = (img.offsetTop-container.offsetTop) + 1;
            metricsObj = {
                baseline: baseline,
                lineWidth: 1,
                middle: middle
            };

            fontData[font + "-" + fontSize] = metricsObj;

            doc.body.removeChild(container);

            return metricsObj;
        };
    })();

    (function(){
        var Util = _html2canvas.Util,
            Generate = {};

        _html2canvas.Generate = Generate;

        var reGradients = [
            /^(-webkit-linear-gradient)\(([a-z\s]+)([\w\d\.\s,%\(\)]+)\)$/,
            /^(-o-linear-gradient)\(([a-z\s]+)([\w\d\.\s,%\(\)]+)\)$/,
            /^(-webkit-gradient)\((linear|radial),\s((?:\d{1,3}%?)\s(?:\d{1,3}%?),\s(?:\d{1,3}%?)\s(?:\d{1,3}%?))([\w\d\.\s,%\(\)\-]+)\)$/,
            /^(-moz-linear-gradient)\(((?:\d{1,3}%?)\s(?:\d{1,3}%?))([\w\d\.\s,%\(\)]+)\)$/,
            /^(-webkit-radial-gradient)\(((?:\d{1,3}%?)\s(?:\d{1,3}%?)),\s(\w+)\s([a-z\-]+)([\w\d\.\s,%\(\)]+)\)$/,
            /^(-moz-radial-gradient)\(((?:\d{1,3}%?)\s(?:\d{1,3}%?)),\s(\w+)\s?([a-z\-]*)([\w\d\.\s,%\(\)]+)\)$/,
            /^(-o-radial-gradient)\(((?:\d{1,3}%?)\s(?:\d{1,3}%?)),\s(\w+)\s([a-z\-]+)([\w\d\.\s,%\(\)]+)\)$/
        ];

        /*
         * TODO: Add IE10 vendor prefix (-ms) support
         * TODO: Add W3C gradient (linear-gradient) support
         * TODO: Add old Webkit -webkit-gradient(radial, ...) support
         * TODO: Maybe some RegExp optimizations are possible ;o)
         */
        Generate.parseGradient = function(css, bounds) {
            var gradient, i, len = reGradients.length, m1, stop, m2, m2Len, step, m3, tl,tr,br,bl;

            for(i = 0; i < len; i+=1){
                m1 = css.match(reGradients[i]);
                if(m1) {
                    break;
                }
            }

            if(m1) {
                switch(m1[1]) {
                    case '-webkit-linear-gradient':
                    case '-o-linear-gradient':

                        gradient = {
                            type: 'linear',
                            x0: null,
                            y0: null,
                            x1: null,
                            y1: null,
                            colorStops: []
                        };

                        // get coordinates
                        m2 = m1[2].match(/\w+/g);
                        if(m2){
                            m2Len = m2.length;
                            for(i = 0; i < m2Len; i+=1){
                                switch(m2[i]) {
                                    case 'top':
                                        gradient.y0 = 0;
                                        gradient.y1 = bounds.height;
                                        break;

                                    case 'right':
                                        gradient.x0 = bounds.width;
                                        gradient.x1 = 0;
                                        break;

                                    case 'bottom':
                                        gradient.y0 = bounds.height;
                                        gradient.y1 = 0;
                                        break;

                                    case 'left':
                                        gradient.x0 = 0;
                                        gradient.x1 = bounds.width;
                                        break;
                                }
                            }
                        }
                        if(gradient.x0 === null && gradient.x1 === null){ // center
                            gradient.x0 = gradient.x1 = bounds.width / 2;
                        }
                        if(gradient.y0 === null && gradient.y1 === null){ // center
                            gradient.y0 = gradient.y1 = bounds.height / 2;
                        }

                        // get colors and stops
                        m2 = m1[3].match(/((?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\)(?:\s\d{1,3}(?:%|px))?)+/g);
                        if(m2){
                            m2Len = m2.length;
                            step = 1 / Math.max(m2Len - 1, 1);
                            for(i = 0; i < m2Len; i+=1){
                                m3 = m2[i].match(/((?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\))\s*(\d{1,3})?(%|px)?/);
                                if(m3[2]){
                                    stop = parseFloat(m3[2]);
                                    if(m3[3] === '%'){
                                        stop /= 100;
                                    } else { // px - stupid opera
                                        stop /= bounds.width;
                                    }
                                } else {
                                    stop = i * step;
                                }
                                gradient.colorStops.push({
                                    color: m3[1],
                                    stop: stop
                                });
                            }
                        }
                        break;

                    case '-webkit-gradient':

                        gradient = {
                            type: m1[2] === 'radial' ? 'circle' : m1[2], // TODO: Add radial gradient support for older mozilla definitions
                            x0: 0,
                            y0: 0,
                            x1: 0,
                            y1: 0,
                            colorStops: []
                        };

                        // get coordinates
                        m2 = m1[3].match(/(\d{1,3})%?\s(\d{1,3})%?,\s(\d{1,3})%?\s(\d{1,3})%?/);
                        if(m2){
                            gradient.x0 = (m2[1] * bounds.width) / 100;
                            gradient.y0 = (m2[2] * bounds.height) / 100;
                            gradient.x1 = (m2[3] * bounds.width) / 100;
                            gradient.y1 = (m2[4] * bounds.height) / 100;
                        }

                        // get colors and stops
                        m2 = m1[4].match(/((?:from|to|color-stop)\((?:[0-9\.]+,\s)?(?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\)\))+/g);
                        if(m2){
                            m2Len = m2.length;
                            for(i = 0; i < m2Len; i+=1){
                                m3 = m2[i].match(/(from|to|color-stop)\(([0-9\.]+)?(?:,\s)?((?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\))\)/);
                                stop = parseFloat(m3[2]);
                                if(m3[1] === 'from') {
                                    stop = 0.0;
                                }
                                if(m3[1] === 'to') {
                                    stop = 1.0;
                                }
                                gradient.colorStops.push({
                                    color: m3[3],
                                    stop: stop
                                });
                            }
                        }
                        break;

                    case '-moz-linear-gradient':

                        gradient = {
                            type: 'linear',
                            x0: 0,
                            y0: 0,
                            x1: 0,
                            y1: 0,
                            colorStops: []
                        };

                        // get coordinates
                        m2 = m1[2].match(/(\d{1,3})%?\s(\d{1,3})%?/);

                        // m2[1] == 0%   -> left
                        // m2[1] == 50%  -> center
                        // m2[1] == 100% -> right

                        // m2[2] == 0%   -> top
                        // m2[2] == 50%  -> center
                        // m2[2] == 100% -> bottom

                        if(m2){
                            gradient.x0 = (m2[1] * bounds.width) / 100;
                            gradient.y0 = (m2[2] * bounds.height) / 100;
                            gradient.x1 = bounds.width - gradient.x0;
                            gradient.y1 = bounds.height - gradient.y0;
                        }

                        // get colors and stops
                        m2 = m1[3].match(/((?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\)(?:\s\d{1,3}%)?)+/g);
                        if(m2){
                            m2Len = m2.length;
                            step = 1 / Math.max(m2Len - 1, 1);
                            for(i = 0; i < m2Len; i+=1){
                                m3 = m2[i].match(/((?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\))\s*(\d{1,3})?(%)?/);
                                if(m3[2]){
                                    stop = parseFloat(m3[2]);
                                    if(m3[3]){ // percentage
                                        stop /= 100;
                                    }
                                } else {
                                    stop = i * step;
                                }
                                gradient.colorStops.push({
                                    color: m3[1],
                                    stop: stop
                                });
                            }
                        }
                        break;

                    case '-webkit-radial-gradient':
                    case '-moz-radial-gradient':
                    case '-o-radial-gradient':

                        gradient = {
                            type: 'circle',
                            x0: 0,
                            y0: 0,
                            x1: bounds.width,
                            y1: bounds.height,
                            cx: 0,
                            cy: 0,
                            rx: 0,
                            ry: 0,
                            colorStops: []
                        };

                        // center
                        m2 = m1[2].match(/(\d{1,3})%?\s(\d{1,3})%?/);
                        if(m2){
                            gradient.cx = (m2[1] * bounds.width) / 100;
                            gradient.cy = (m2[2] * bounds.height) / 100;
                        }

                        // size
                        m2 = m1[3].match(/\w+/);
                        m3 = m1[4].match(/[a-z\-]*/);
                        if(m2 && m3){
                            switch(m3[0]){
                                case 'farthest-corner':
                                case 'cover': // is equivalent to farthest-corner
                                case '': // mozilla removes "cover" from definition :(
                                    tl = Math.sqrt(Math.pow(gradient.cx, 2) + Math.pow(gradient.cy, 2));
                                    tr = Math.sqrt(Math.pow(gradient.cx, 2) + Math.pow(gradient.y1 - gradient.cy, 2));
                                    br = Math.sqrt(Math.pow(gradient.x1 - gradient.cx, 2) + Math.pow(gradient.y1 - gradient.cy, 2));
                                    bl = Math.sqrt(Math.pow(gradient.x1 - gradient.cx, 2) + Math.pow(gradient.cy, 2));
                                    gradient.rx = gradient.ry = Math.max(tl, tr, br, bl);
                                    break;
                                case 'closest-corner':
                                    tl = Math.sqrt(Math.pow(gradient.cx, 2) + Math.pow(gradient.cy, 2));
                                    tr = Math.sqrt(Math.pow(gradient.cx, 2) + Math.pow(gradient.y1 - gradient.cy, 2));
                                    br = Math.sqrt(Math.pow(gradient.x1 - gradient.cx, 2) + Math.pow(gradient.y1 - gradient.cy, 2));
                                    bl = Math.sqrt(Math.pow(gradient.x1 - gradient.cx, 2) + Math.pow(gradient.cy, 2));
                                    gradient.rx = gradient.ry = Math.min(tl, tr, br, bl);
                                    break;
                                case 'farthest-side':
                                    if(m2[0] === 'circle'){
                                        gradient.rx = gradient.ry = Math.max(
                                            gradient.cx,
                                            gradient.cy,
                                            gradient.x1 - gradient.cx,
                                            gradient.y1 - gradient.cy
                                        );
                                    } else { // ellipse

                                        gradient.type = m2[0];

                                        gradient.rx = Math.max(
                                            gradient.cx,
                                            gradient.x1 - gradient.cx
                                        );
                                        gradient.ry = Math.max(
                                            gradient.cy,
                                            gradient.y1 - gradient.cy
                                        );
                                    }
                                    break;
                                case 'closest-side':
                                case 'contain': // is equivalent to closest-side
                                    if(m2[0] === 'circle'){
                                        gradient.rx = gradient.ry = Math.min(
                                            gradient.cx,
                                            gradient.cy,
                                            gradient.x1 - gradient.cx,
                                            gradient.y1 - gradient.cy
                                        );
                                    } else { // ellipse

                                        gradient.type = m2[0];

                                        gradient.rx = Math.min(
                                            gradient.cx,
                                            gradient.x1 - gradient.cx
                                        );
                                        gradient.ry = Math.min(
                                            gradient.cy,
                                            gradient.y1 - gradient.cy
                                        );
                                    }
                                    break;

                                // TODO: add support for "30px 40px" sizes (webkit only)
                            }
                        }

                        // color stops
                        m2 = m1[5].match(/((?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\)(?:\s\d{1,3}(?:%|px))?)+/g);
                        if(m2){
                            m2Len = m2.length;
                            step = 1 / Math.max(m2Len - 1, 1);
                            for(i = 0; i < m2Len; i+=1){
                                m3 = m2[i].match(/((?:rgb|rgba)\(\d{1,3},\s\d{1,3},\s\d{1,3}(?:,\s[0-9\.]+)?\))\s*(\d{1,3})?(%|px)?/);
                                if(m3[2]){
                                    stop = parseFloat(m3[2]);
                                    if(m3[3] === '%'){
                                        stop /= 100;
                                    } else { // px - stupid opera
                                        stop /= bounds.width;
                                    }
                                } else {
                                    stop = i * step;
                                }
                                gradient.colorStops.push({
                                    color: m3[1],
                                    stop: stop
                                });
                            }
                        }
                        break;
                }
            }

            return gradient;
        };

        function addScrollStops(grad) {
            return function(colorStop) {
                try {
                    grad.addColorStop(colorStop.stop, colorStop.color);
                }
                catch(e) {
                    Util.log(['failed to add color stop: ', e, '; tried to add: ', colorStop]);
                }
            };
        }

        Generate.Gradient = function(src, bounds) {
            if(bounds.width === 0 || bounds.height === 0) {
                return;
            }

            var canvas = document.createElement('canvas'),
                ctx = canvas.getContext('2d'),
                gradient, grad;

            canvas.width = bounds.width;
            canvas.height = bounds.height;

            // TODO: add support for multi defined background gradients
            gradient = _html2canvas.Generate.parseGradient(src, bounds);

            if(gradient) {
                switch(gradient.type) {
                    case 'linear':
                        grad = ctx.createLinearGradient(gradient.x0, gradient.y0, gradient.x1, gradient.y1);
                        gradient.colorStops.forEach(addScrollStops(grad));
                        ctx.fillStyle = grad;
                        ctx.fillRect(0, 0, bounds.width, bounds.height);
                        break;

                    case 'circle':
                        grad = ctx.createRadialGradient(gradient.cx, gradient.cy, 0, gradient.cx, gradient.cy, gradient.rx);
                        gradient.colorStops.forEach(addScrollStops(grad));
                        ctx.fillStyle = grad;
                        ctx.fillRect(0, 0, bounds.width, bounds.height);
                        break;

                    case 'ellipse':
                        var canvasRadial = document.createElement('canvas'),
                            ctxRadial = canvasRadial.getContext('2d'),
                            ri = Math.max(gradient.rx, gradient.ry),
                            di = ri * 2;

                        canvasRadial.width = canvasRadial.height = di;

                        grad = ctxRadial.createRadialGradient(gradient.rx, gradient.ry, 0, gradient.rx, gradient.ry, ri);
                        gradient.colorStops.forEach(addScrollStops(grad));

                        ctxRadial.fillStyle = grad;
                        ctxRadial.fillRect(0, 0, di, di);

                        ctx.fillStyle = gradient.colorStops[gradient.colorStops.length - 1].color;
                        ctx.fillRect(0, 0, canvas.width, canvas.height);
                        ctx.drawImage(canvasRadial, gradient.cx - gradient.rx, gradient.cy - gradient.ry, 2 * gradient.rx, 2 * gradient.ry);
                        break;
                }
            }

            return canvas;
        };

        Generate.ListAlpha = function(number) {
            var tmp = "",
                modulus;

            do {
                modulus = number % 26;
                tmp = String.fromCharCode((modulus) + 64) + tmp;
                number = number / 26;
            }while((number*26) > 26);

            return tmp;
        };

        Generate.ListRoman = function(number) {
            var romanArray = ["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"],
                decimal = [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1],
                roman = "",
                v,
                len = romanArray.length;

            if (number <= 0 || number >= 4000) {
                return number;
            }

            for (v=0; v < len; v+=1) {
                while (number >= decimal[v]) {
                    number -= decimal[v];
                    roman += romanArray[v];
                }
            }

            return roman;
        };
    })();
    function h2cRenderContext(width, height) {
        var storage = [];
        return {
            storage: storage,
            width: width,
            height: height,
            clip: function() {
                storage.push({
                    type: "function",
                    name: "clip",
                    'arguments': arguments
                });
            },
            translate: function() {
                storage.push({
                    type: "function",
                    name: "translate",
                    'arguments': arguments
                });
            },
            fill: function() {
                storage.push({
                    type: "function",
                    name: "fill",
                    'arguments': arguments
                });
            },
            save: function() {
                storage.push({
                    type: "function",
                    name: "save",
                    'arguments': arguments
                });
            },
            restore: function() {
                storage.push({
                    type: "function",
                    name: "restore",
                    'arguments': arguments
                });
            },
            fillRect: function () {
                storage.push({
                    type: "function",
                    name: "fillRect",
                    'arguments': arguments
                });
            },
            createPattern: function() {
                storage.push({
                    type: "function",
                    name: "createPattern",
                    'arguments': arguments
                });
            },
            drawShape: function() {

                var shape = [];

                storage.push({
                    type: "function",
                    name: "drawShape",
                    'arguments': shape
                });

                return {
                    moveTo: function() {
                        shape.push({
                            name: "moveTo",
                            'arguments': arguments
                        });
                    },
                    lineTo: function() {
                        shape.push({
                            name: "lineTo",
                            'arguments': arguments
                        });
                    },
                    arcTo: function() {
                        shape.push({
                            name: "arcTo",
                            'arguments': arguments
                        });
                    },
                    bezierCurveTo: function() {
                        shape.push({
                            name: "bezierCurveTo",
                            'arguments': arguments
                        });
                    },
                    quadraticCurveTo: function() {
                        shape.push({
                            name: "quadraticCurveTo",
                            'arguments': arguments
                        });
                    }
                };

            },
            drawImage: function () {
                storage.push({
                    type: "function",
                    name: "drawImage",
                    'arguments': arguments
                });
            },
            fillText: function () {
                storage.push({
                    type: "function",
                    name: "fillText",
                    'arguments': arguments
                });
            },
            setVariable: function (variable, value) {
                storage.push({
                    type: "variable",
                    name: variable,
                    'arguments': value
                });
                return value;
            }
        };
    }
    _html2canvas.Parse = function (images, options) {
        window.scroll(0,0);

        var element = (( options.elements === undefined ) ? document.body : options.elements[0]), // select body by default
            numDraws = 0,
            doc = element.ownerDocument,
            Util = _html2canvas.Util,
            support = Util.Support(options, doc),
            ignoreElementsRegExp = new RegExp("(" + options.ignoreElements + ")"),
            body = doc.body,
            getCSS = Util.getCSS,
            pseudoHide = "___html2canvas___pseudoelement",
            hidePseudoElements = doc.createElement('style');

        hidePseudoElements.innerHTML = '.' + pseudoHide + '-before:before { content: "" !important; display: none !important; }' +
            '.' + pseudoHide + '-after:after { content: "" !important; display: none !important; }';

        body.appendChild(hidePseudoElements);

        images = images || {};

        function documentWidth () {
            return Math.max(
                Math.max(doc.body.scrollWidth, doc.documentElement.scrollWidth),
                Math.max(doc.body.offsetWidth, doc.documentElement.offsetWidth),
                Math.max(doc.body.clientWidth, doc.documentElement.clientWidth)
            );
        }

        function documentHeight () {
            return Math.max(
                Math.max(doc.body.scrollHeight, doc.documentElement.scrollHeight),
                Math.max(doc.body.offsetHeight, doc.documentElement.offsetHeight),
                Math.max(doc.body.clientHeight, doc.documentElement.clientHeight)
            );
        }

        function getCSSInt(element, attribute) {
            var val = parseInt(getCSS(element, attribute), 10);
            return (isNaN(val)) ? 0 : val; // borders in old IE are throwing 'medium' for demo.html
        }

        function renderRect (ctx, x, y, w, h, bgcolor) {
            if (bgcolor !== "transparent"){
                ctx.setVariable("fillStyle", bgcolor);
                ctx.fillRect(x, y, w, h);
                numDraws+=1;
            }
        }

        function capitalize(m, p1, p2) {
            if (m.length > 0) {
                return p1 + p2.toUpperCase();
            }
        }

        function textTransform (text, transform) {
            switch(transform){
                case "lowercase":
                    return text.toLowerCase();
                case "capitalize":
                    return text.replace( /(^|\s|:|-|\(|\))([a-z])/g, capitalize);
                case "uppercase":
                    return text.toUpperCase();
                default:
                    return text;
            }
        }

        function noLetterSpacing(letter_spacing) {
            return (/^(normal|none|0px)$/.test(letter_spacing));
        }

        function drawText(currentText, x, y, ctx){
            if (currentText !== null && Util.trimText(currentText).length > 0) {
                ctx.fillText(currentText, x, y);
                numDraws+=1;
            }
        }

        function setTextVariables(ctx, el, text_decoration, color) {
            var align = false,
                bold = getCSS(el, "fontWeight"),
                family = getCSS(el, "fontFamily"),
                size = getCSS(el, "fontSize"),
                shadows = Util.parseTextShadows(getCSS(el, "textShadow"));

            switch(parseInt(bold, 10)){
                case 401:
                    bold = "bold";
                    break;
                case 400:
                    bold = "normal";
                    break;
            }

            ctx.setVariable("fillStyle", color);
            ctx.setVariable("font", [getCSS(el, "fontStyle"), getCSS(el, "fontVariant"), bold, size, family].join(" "));
            ctx.setVariable("textAlign", (align) ? "right" : "left");

            if (shadows.length) {
                // TODO: support multiple text shadows
                // apply the first text shadow
                ctx.setVariable("shadowColor", shadows[0].color);
                ctx.setVariable("shadowOffsetX", shadows[0].offsetX);
                ctx.setVariable("shadowOffsetY", shadows[0].offsetY);
                ctx.setVariable("shadowBlur", shadows[0].blur);
            }

            if (text_decoration !== "none"){
                return Util.Font(family, size, doc);
            }
        }

        function renderTextDecoration(ctx, text_decoration, bounds, metrics, color) {
            switch(text_decoration) {
                case "underline":
                    // Draws a line at the baseline of the font
                    // TODO As some browsers display the line as more than 1px if the font-size is big, need to take that into account both in position and size
                    renderRect(ctx, bounds.left, Math.round(bounds.top + metrics.baseline + metrics.lineWidth), bounds.width, 1, color);
                    break;
                case "overline":
                    renderRect(ctx, bounds.left, Math.round(bounds.top), bounds.width, 1, color);
                    break;
                case "line-through":
                    // TODO try and find exact position for line-through
                    renderRect(ctx, bounds.left, Math.ceil(bounds.top + metrics.middle + metrics.lineWidth), bounds.width, 1, color);
                    break;
            }
        }

        function getTextBounds(state, text, textDecoration, isLast, transform) {
            var bounds;
            if (support.rangeBounds && !transform) {
                if (textDecoration !== "none" || Util.trimText(text).length !== 0) {
                    bounds = textRangeBounds(text, state.node, state.textOffset);
                }
                state.textOffset += text.length;
            } else if (state.node && typeof state.node.nodeValue === "string" ){
                var newTextNode = (isLast) ? state.node.splitText(text.length) : null;
                bounds = textWrapperBounds(state.node, transform);
                state.node = newTextNode;
            }
            return bounds;
        }

        function textRangeBounds(text, textNode, textOffset) {
            var range = doc.createRange();
            range.setStart(textNode, textOffset);
            range.setEnd(textNode, textOffset + text.length);
            return range.getBoundingClientRect();
        }

        function textWrapperBounds(oldTextNode, transform) {
            var parent = oldTextNode.parentNode,
                wrapElement = doc.createElement('wrapper'),
                backupText = oldTextNode.cloneNode(true);

            wrapElement.appendChild(oldTextNode.cloneNode(true));
            parent.replaceChild(wrapElement, oldTextNode);

            var bounds = transform ? Util.OffsetBounds(wrapElement) : Util.Bounds(wrapElement);
            parent.replaceChild(backupText, wrapElement);
            return bounds;
        }

        function renderText(el, textNode, stack) {
            var ctx = stack.ctx,
                color = getCSS(el, "color"),
                textDecoration = getCSS(el, "textDecoration"),
                textAlign = getCSS(el, "textAlign"),
                metrics,
                textList,
                state = {
                    node: textNode,
                    textOffset: 0
                };

            if (Util.trimText(textNode.nodeValue).length > 0) {
                textNode.nodeValue = textTransform(textNode.nodeValue, getCSS(el, "textTransform"));
                textAlign = textAlign.replace(["-webkit-auto"],["auto"]);

                textList = (!options.letterRendering && /^(left|right|justify|auto)$/.test(textAlign) && noLetterSpacing(getCSS(el, "letterSpacing"))) ?
                    textNode.nodeValue.split(/(\b| )/)
                    : textNode.nodeValue.split("");

                metrics = setTextVariables(ctx, el, textDecoration, color);

                if (options.chinese) {
                    textList.forEach(function(word, index) {
                        if (/.*[\u4E00-\u9FA5].*$/.test(word)) {
                            word = word.split("");
                            word.unshift(index, 1);
                            textList.splice.apply(textList, word);
                        }
                    });
                }

                textList.forEach(function(text, index) {
                    var bounds = getTextBounds(state, text, textDecoration, (index < textList.length - 1), stack.transform.matrix);
                    if (bounds) {
                        drawText(text, bounds.left, bounds.bottom, ctx);
                        renderTextDecoration(ctx, textDecoration, bounds, metrics, color);
                    }
                });
            }
        }

        function listPosition (element, val) {
            var boundElement = doc.createElement( "boundelement" ),
                originalType,
                bounds;

            boundElement.style.display = "inline";

            originalType = element.style.listStyleType;
            element.style.listStyleType = "none";

            boundElement.appendChild(doc.createTextNode(val));

            element.insertBefore(boundElement, element.firstChild);

            bounds = Util.Bounds(boundElement);
            element.removeChild(boundElement);
            element.style.listStyleType = originalType;
            return bounds;
        }

        function elementIndex(el) {
            var i = -1,
                count = 1,
                childs = el.parentNode.childNodes;

            if (el.parentNode) {
                while(childs[++i] !== el) {
                    if (childs[i].nodeType === 1) {
                        count++;
                    }
                }
                return count;
            } else {
                return -1;
            }
        }

        function listItemText(element, type) {
            var currentIndex = elementIndex(element), text;
            switch(type){
                case "decimal":
                    text = currentIndex;
                    break;
                case "decimal-leading-zero":
                    text = (currentIndex.toString().length === 1) ? currentIndex = "0" + currentIndex.toString() : currentIndex.toString();
                    break;
                case "upper-roman":
                    text = _html2canvas.Generate.ListRoman( currentIndex );
                    break;
                case "lower-roman":
                    text = _html2canvas.Generate.ListRoman( currentIndex ).toLowerCase();
                    break;
                case "lower-alpha":
                    text = _html2canvas.Generate.ListAlpha( currentIndex ).toLowerCase();
                    break;
                case "upper-alpha":
                    text = _html2canvas.Generate.ListAlpha( currentIndex );
                    break;
            }

            return text + ". ";
        }

        function renderListItem(element, stack, elBounds) {
            var x,
                text,
                ctx = stack.ctx,
                type = getCSS(element, "listStyleType"),
                listBounds;

            if (/^(decimal|decimal-leading-zero|upper-alpha|upper-latin|upper-roman|lower-alpha|lower-greek|lower-latin|lower-roman)$/i.test(type)) {
                text = listItemText(element, type);
                listBounds = listPosition(element, text);
                setTextVariables(ctx, element, "none", getCSS(element, "color"));

                if (getCSS(element, "listStylePosition") === "inside") {
                    ctx.setVariable("textAlign", "left");
                    x = elBounds.left;
                } else {
                    return;
                }

                drawText(text, x, listBounds.bottom, ctx);
            }
        }

        function loadImage (src){
            var img = images[src];
            return (img && img.succeeded === true) ? img.img : false;
        }

        function clipBounds(src, dst){
            var x = Math.max(src.left, dst.left),
                y = Math.max(src.top, dst.top),
                x2 = Math.min((src.left + src.width), (dst.left + dst.width)),
                y2 = Math.min((src.top + src.height), (dst.top + dst.height));

            return {
                left:x,
                top:y,
                width:x2-x,
                height:y2-y
            };
        }

        function setZ(element, stack, parentStack){
            var newContext,
                isPositioned = stack.cssPosition !== 'static',
                zIndex = isPositioned ? getCSS(element, 'zIndex') : 'auto',
                opacity = getCSS(element, 'opacity'),
                isFloated = getCSS(element, 'cssFloat') !== 'none';

            // https://developer.mozilla.org/en-US/docs/Web/Guide/CSS/Understanding_z_index/The_stacking_context
            // When a new stacking context should be created:
            // the root element (HTML),
            // positioned (absolutely or relatively) with a z-index value other than "auto",
            // elements with an opacity value less than 1. (See the specification for opacity),
            // on mobile WebKit and Chrome 22+, position: fixed always creates a new stacking context, even when z-index is "auto" (See this post)

            stack.zIndex = newContext = h2czContext(zIndex);
            newContext.isPositioned = isPositioned;
            newContext.isFloated = isFloated;
            newContext.opacity = opacity;
            newContext.ownStacking = (zIndex !== 'auto' || opacity < 1);

            if (parentStack) {
                parentStack.zIndex.children.push(stack);
            }
        }

        function renderImage(ctx, element, image, bounds, borders) {

            var paddingLeft = getCSSInt(element, 'paddingLeft'),
                paddingTop = getCSSInt(element, 'paddingTop'),
                paddingRight = getCSSInt(element, 'paddingRight'),
                paddingBottom = getCSSInt(element, 'paddingBottom');

            drawImage(
                ctx,
                image,
                0, //sx
                0, //sy
                image.width, //sw
                image.height, //sh
                bounds.left + paddingLeft + borders[3].width, //dx
                bounds.top + paddingTop + borders[0].width, // dy
                bounds.width - (borders[1].width + borders[3].width + paddingLeft + paddingRight), //dw
                bounds.height - (borders[0].width + borders[2].width + paddingTop + paddingBottom) //dh
            );
        }

        function getBorderData(element) {
            return ["Top", "Right", "Bottom", "Left"].map(function(side) {
                return {
                    width: getCSSInt(element, 'border' + side + 'Width'),
                    color: getCSS(element, 'border' + side + 'Color')
                };
            });
        }

        function getBorderRadiusData(element) {
            return ["TopLeft", "TopRight", "BottomRight", "BottomLeft"].map(function(side) {
                return getCSS(element, 'border' + side + 'Radius');
            });
        }

        var getCurvePoints = (function(kappa) {

            return function(x, y, r1, r2) {
                var ox = (r1) * kappa, // control point offset horizontal
                    oy = (r2) * kappa, // control point offset vertical
                    xm = x + r1, // x-middle
                    ym = y + r2; // y-middle
                return {
                    topLeft: bezierCurve({
                        x:x,
                        y:ym
                    }, {
                        x:x,
                        y:ym - oy
                    }, {
                        x:xm - ox,
                        y:y
                    }, {
                        x:xm,
                        y:y
                    }),
                    topRight: bezierCurve({
                        x:x,
                        y:y
                    }, {
                        x:x + ox,
                        y:y
                    }, {
                        x:xm,
                        y:ym - oy
                    }, {
                        x:xm,
                        y:ym
                    }),
                    bottomRight: bezierCurve({
                        x:xm,
                        y:y
                    }, {
                        x:xm,
                        y:y + oy
                    }, {
                        x:x + ox,
                        y:ym
                    }, {
                        x:x,
                        y:ym
                    }),
                    bottomLeft: bezierCurve({
                        x:xm,
                        y:ym
                    }, {
                        x:xm - ox,
                        y:ym
                    }, {
                        x:x,
                        y:y + oy
                    }, {
                        x:x,
                        y:y
                    })
                };
            };
        })(4 * ((Math.sqrt(2) - 1) / 3));

        function bezierCurve(start, startControl, endControl, end) {

            var lerp = function (a, b, t) {
                return {
                    x:a.x + (b.x - a.x) * t,
                    y:a.y + (b.y - a.y) * t
                };
            };

            return {
                start: start,
                startControl: startControl,
                endControl: endControl,
                end: end,
                subdivide: function(t) {
                    var ab = lerp(start, startControl, t),
                        bc = lerp(startControl, endControl, t),
                        cd = lerp(endControl, end, t),
                        abbc = lerp(ab, bc, t),
                        bccd = lerp(bc, cd, t),
                        dest = lerp(abbc, bccd, t);
                    return [bezierCurve(start, ab, abbc, dest), bezierCurve(dest, bccd, cd, end)];
                },
                curveTo: function(borderArgs) {
                    borderArgs.push(["bezierCurve", startControl.x, startControl.y, endControl.x, endControl.y, end.x, end.y]);
                },
                curveToReversed: function(borderArgs) {
                    borderArgs.push(["bezierCurve", endControl.x, endControl.y, startControl.x, startControl.y, start.x, start.y]);
                }
            };
        }

        function parseCorner(borderArgs, radius1, radius2, corner1, corner2, x, y) {
            if (radius1[0] > 0 || radius1[1] > 0) {
                borderArgs.push(["line", corner1[0].start.x, corner1[0].start.y]);
                corner1[0].curveTo(borderArgs);
                corner1[1].curveTo(borderArgs);
            } else {
                borderArgs.push(["line", x, y]);
            }

            if (radius2[0] > 0 || radius2[1] > 0) {
                borderArgs.push(["line", corner2[0].start.x, corner2[0].start.y]);
            }
        }

        function drawSide(borderData, radius1, radius2, outer1, inner1, outer2, inner2) {
            var borderArgs = [];

            if (radius1[0] > 0 || radius1[1] > 0) {
                borderArgs.push(["line", outer1[1].start.x, outer1[1].start.y]);
                outer1[1].curveTo(borderArgs);
            } else {
                borderArgs.push([ "line", borderData.c1[0], borderData.c1[1]]);
            }

            if (radius2[0] > 0 || radius2[1] > 0) {
                borderArgs.push(["line", outer2[0].start.x, outer2[0].start.y]);
                outer2[0].curveTo(borderArgs);
                borderArgs.push(["line", inner2[0].end.x, inner2[0].end.y]);
                inner2[0].curveToReversed(borderArgs);
            } else {
                borderArgs.push([ "line", borderData.c2[0], borderData.c2[1]]);
                borderArgs.push([ "line", borderData.c3[0], borderData.c3[1]]);
            }

            if (radius1[0] > 0 || radius1[1] > 0) {
                borderArgs.push(["line", inner1[1].end.x, inner1[1].end.y]);
                inner1[1].curveToReversed(borderArgs);
            } else {
                borderArgs.push([ "line", borderData.c4[0], borderData.c4[1]]);
            }

            return borderArgs;
        }

        function calculateCurvePoints(bounds, borderRadius, borders) {

            var x = bounds.left,
                y = bounds.top,
                width = bounds.width,
                height = bounds.height,

                tlh = borderRadius[0][0],
                tlv = borderRadius[0][1],
                trh = borderRadius[1][0],
                trv = borderRadius[1][1],
                brh = borderRadius[2][0],
                brv = borderRadius[2][1],
                blh = borderRadius[3][0],
                blv = borderRadius[3][1],

                topWidth = width - trh,
                rightHeight = height - brv,
                bottomWidth = width - brh,
                leftHeight = height - blv;

            return {
                topLeftOuter: getCurvePoints(
                    x,
                    y,
                    tlh,
                    tlv
                ).topLeft.subdivide(0.5),

                topLeftInner: getCurvePoints(
                    x + borders[3].width,
                    y + borders[0].width,
                    Math.max(0, tlh - borders[3].width),
                    Math.max(0, tlv - borders[0].width)
                ).topLeft.subdivide(0.5),

                topRightOuter: getCurvePoints(
                    x + topWidth,
                    y,
                    trh,
                    trv
                ).topRight.subdivide(0.5),

                topRightInner: getCurvePoints(
                    x + Math.min(topWidth, width + borders[3].width),
                    y + borders[0].width,
                    (topWidth > width + borders[3].width) ? 0 :trh - borders[3].width,
                    trv - borders[0].width
                ).topRight.subdivide(0.5),

                bottomRightOuter: getCurvePoints(
                    x + bottomWidth,
                    y + rightHeight,
                    brh,
                    brv
                ).bottomRight.subdivide(0.5),

                bottomRightInner: getCurvePoints(
                    x + Math.min(bottomWidth, width + borders[3].width),
                    y + Math.min(rightHeight, height + borders[0].width),
                    Math.max(0, brh - borders[1].width),
                    Math.max(0, brv - borders[2].width)
                ).bottomRight.subdivide(0.5),

                bottomLeftOuter: getCurvePoints(
                    x,
                    y + leftHeight,
                    blh,
                    blv
                ).bottomLeft.subdivide(0.5),

                bottomLeftInner: getCurvePoints(
                    x + borders[3].width,
                    y + leftHeight,
                    Math.max(0, blh - borders[3].width),
                    Math.max(0, blv - borders[2].width)
                ).bottomLeft.subdivide(0.5)
            };
        }

        function getBorderClip(element, borderPoints, borders, radius, bounds) {
            var backgroundClip = getCSS(element, 'backgroundClip'),
                borderArgs = [];

            switch(backgroundClip) {
                case "content-box":
                case "padding-box":
                    parseCorner(borderArgs, radius[0], radius[1], borderPoints.topLeftInner, borderPoints.topRightInner, bounds.left + borders[3].width, bounds.top + borders[0].width);
                    parseCorner(borderArgs, radius[1], radius[2], borderPoints.topRightInner, borderPoints.bottomRightInner, bounds.left + bounds.width - borders[1].width, bounds.top + borders[0].width);
                    parseCorner(borderArgs, radius[2], radius[3], borderPoints.bottomRightInner, borderPoints.bottomLeftInner, bounds.left + bounds.width - borders[1].width, bounds.top + bounds.height - borders[2].width);
                    parseCorner(borderArgs, radius[3], radius[0], borderPoints.bottomLeftInner, borderPoints.topLeftInner, bounds.left + borders[3].width, bounds.top + bounds.height - borders[2].width);
                    break;

                default:
                    parseCorner(borderArgs, radius[0], radius[1], borderPoints.topLeftOuter, borderPoints.topRightOuter, bounds.left, bounds.top);
                    parseCorner(borderArgs, radius[1], radius[2], borderPoints.topRightOuter, borderPoints.bottomRightOuter, bounds.left + bounds.width, bounds.top);
                    parseCorner(borderArgs, radius[2], radius[3], borderPoints.bottomRightOuter, borderPoints.bottomLeftOuter, bounds.left + bounds.width, bounds.top + bounds.height);
                    parseCorner(borderArgs, radius[3], radius[0], borderPoints.bottomLeftOuter, borderPoints.topLeftOuter, bounds.left, bounds.top + bounds.height);
                    break;
            }

            return borderArgs;
        }

        function parseBorders(element, bounds, borders){
            var x = bounds.left,
                y = bounds.top,
                width = bounds.width,
                height = bounds.height,
                borderSide,
                bx,
                by,
                bw,
                bh,
                borderArgs,
            // http://www.w3.org/TR/css3-background/#the-border-radius
                borderRadius = getBorderRadiusData(element),
                borderPoints = calculateCurvePoints(bounds, borderRadius, borders),
                borderData = {
                    clip: getBorderClip(element, borderPoints, borders, borderRadius, bounds),
                    borders: []
                };

            for (borderSide = 0; borderSide < 4; borderSide++) {

                if (borders[borderSide].width > 0) {
                    bx = x;
                    by = y;
                    bw = width;
                    bh = height - (borders[2].width);

                    switch(borderSide) {
                        case 0:
                            // top border
                            bh = borders[0].width;

                            borderArgs = drawSide({
                                    c1: [bx, by],
                                    c2: [bx + bw, by],
                                    c3: [bx + bw - borders[1].width, by + bh],
                                    c4: [bx + borders[3].width, by + bh]
                                }, borderRadius[0], borderRadius[1],
                                borderPoints.topLeftOuter, borderPoints.topLeftInner, borderPoints.topRightOuter, borderPoints.topRightInner);
                            break;
                        case 1:
                            // right border
                            bx = x + width - (borders[1].width);
                            bw = borders[1].width;

                            borderArgs = drawSide({
                                    c1: [bx + bw, by],
                                    c2: [bx + bw, by + bh + borders[2].width],
                                    c3: [bx, by + bh],
                                    c4: [bx, by + borders[0].width]
                                }, borderRadius[1], borderRadius[2],
                                borderPoints.topRightOuter, borderPoints.topRightInner, borderPoints.bottomRightOuter, borderPoints.bottomRightInner);
                            break;
                        case 2:
                            // bottom border
                            by = (by + height) - (borders[2].width);
                            bh = borders[2].width;

                            borderArgs = drawSide({
                                    c1: [bx + bw, by + bh],
                                    c2: [bx, by + bh],
                                    c3: [bx + borders[3].width, by],
                                    c4: [bx + bw - borders[3].width, by]
                                }, borderRadius[2], borderRadius[3],
                                borderPoints.bottomRightOuter, borderPoints.bottomRightInner, borderPoints.bottomLeftOuter, borderPoints.bottomLeftInner);
                            break;
                        case 3:
                            // left border
                            bw = borders[3].width;

                            borderArgs = drawSide({
                                    c1: [bx, by + bh + borders[2].width],
                                    c2: [bx, by],
                                    c3: [bx + bw, by + borders[0].width],
                                    c4: [bx + bw, by + bh]
                                }, borderRadius[3], borderRadius[0],
                                borderPoints.bottomLeftOuter, borderPoints.bottomLeftInner, borderPoints.topLeftOuter, borderPoints.topLeftInner);
                            break;
                    }

                    borderData.borders.push({
                        args: borderArgs,
                        color: borders[borderSide].color
                    });

                }
            }

            return borderData;
        }

        function createShape(ctx, args) {
            var shape = ctx.drawShape();
            args.forEach(function(border, index) {
                shape[(index === 0) ? "moveTo" : border[0] + "To" ].apply(null, border.slice(1));
            });
            return shape;
        }

        function renderBorders(ctx, borderArgs, color) {
            if (color !== "transparent") {
                ctx.setVariable( "fillStyle", color);
                createShape(ctx, borderArgs);
                ctx.fill();
                numDraws+=1;
            }
        }

        function renderFormValue (el, bounds, stack){

            var valueWrap = doc.createElement('valuewrap'),
                cssPropertyArray = ['lineHeight','textAlign','fontFamily','color','fontSize','paddingLeft','paddingTop','width','height','border','borderLeftWidth','borderTopWidth'],
                textValue,
                textNode;

            cssPropertyArray.forEach(function(property) {
                try {
                    valueWrap.style[property] = getCSS(el, property);
                } catch(e) {
                    // Older IE has issues with "border"
                    Util.log("html2canvas: Parse: Exception caught in renderFormValue: " + e.message);
                }
            });

            valueWrap.style.borderColor = "black";
            valueWrap.style.borderStyle = "solid";
            valueWrap.style.display = "block";
            valueWrap.style.position = "absolute";

            if (/^(submit|reset|button|text|password)$/.test(el.type) || el.nodeName === "SELECT"){
                valueWrap.style.lineHeight = getCSS(el, "height");
            }

            valueWrap.style.top = bounds.top + "px";
            valueWrap.style.left = bounds.left + "px";

            textValue = (el.nodeName === "SELECT") ? (el.options[el.selectedIndex] || 0).text : el.value;
            if(!textValue) {
                textValue = el.placeholder;
            }

            textNode = doc.createTextNode(textValue);

            valueWrap.appendChild(textNode);
            body.appendChild(valueWrap);

            renderText(el, textNode, stack);
            body.removeChild(valueWrap);
        }

        function drawImage (ctx) {
            ctx.drawImage.apply(ctx, Array.prototype.slice.call(arguments, 1));
            numDraws+=1;
        }

        function getPseudoElement(el, which) {
            var elStyle = window.getComputedStyle(el, which);
            if(!elStyle || !elStyle.content || elStyle.content === "none" || elStyle.content === "-moz-alt-content" || elStyle.display === "none") {
                return;
            }
            var content = elStyle.content + '',
                first = content.substr( 0, 1 );
            //strips quotes
            if(first === content.substr( content.length - 1 ) && first.match(/'|"/)) {
                content = content.substr( 1, content.length - 2 );
            }

            var isImage = content.substr( 0, 3 ) === 'url',
                elps = document.createElement( isImage ? 'img' : 'span' );

            elps.className = pseudoHide + "-before " + pseudoHide + "-after";

            Object.keys(elStyle).filter(indexedProperty).forEach(function(prop) {
                // Prevent assigning of read only CSS Rules, ex. length, parentRule
                try {
                    elps.style[prop] = elStyle[prop];
                } catch (e) {
                    Util.log(['Tried to assign readonly property ', prop, 'Error:', e]);
                }
            });

            if(isImage) {
                elps.src = Util.parseBackgroundImage(content)[0].args[0];
            } else {
                elps.innerHTML = content;
            }
            return elps;
        }

        function indexedProperty(property) {
            return (isNaN(window.parseInt(property, 10)));
        }

        function injectPseudoElements(el, stack) {
            var before = getPseudoElement(el, ':before'),
                after = getPseudoElement(el, ':after');
            if(!before && !after) {
                return;
            }

            if(before) {
                el.className += " " + pseudoHide + "-before";
                el.parentNode.insertBefore(before, el);
                parseElement(before, stack, true);
                el.parentNode.removeChild(before);
                el.className = el.className.replace(pseudoHide + "-before", "").trim();
            }

            if (after) {
                el.className += " " + pseudoHide + "-after";
                el.appendChild(after);
                parseElement(after, stack, true);
                el.removeChild(after);
                el.className = el.className.replace(pseudoHide + "-after", "").trim();
            }

        }

        function renderBackgroundRepeat(ctx, image, backgroundPosition, bounds) {
            var offsetX = Math.round(bounds.left + backgroundPosition.left),
                offsetY = Math.round(bounds.top + backgroundPosition.top);

            ctx.createPattern(image);
            ctx.translate(offsetX, offsetY);
            ctx.fill();
            ctx.translate(-offsetX, -offsetY);
        }

        function backgroundRepeatShape(ctx, image, backgroundPosition, bounds, left, top, width, height) {
            var args = [];
            args.push(["line", Math.round(left), Math.round(top)]);
            args.push(["line", Math.round(left + width), Math.round(top)]);
            args.push(["line", Math.round(left + width), Math.round(height + top)]);
            args.push(["line", Math.round(left), Math.round(height + top)]);
            createShape(ctx, args);
            ctx.save();
            ctx.clip();
            renderBackgroundRepeat(ctx, image, backgroundPosition, bounds);
            ctx.restore();
        }

        function renderBackgroundColor(ctx, backgroundBounds, bgcolor) {
            renderRect(
                ctx,
                backgroundBounds.left,
                backgroundBounds.top,
                backgroundBounds.width,
                backgroundBounds.height,
                bgcolor
            );
        }

        function renderBackgroundRepeating(el, bounds, ctx, image, imageIndex) {
            var backgroundSize = Util.BackgroundSize(el, bounds, image, imageIndex),
                backgroundPosition = Util.BackgroundPosition(el, bounds, image, imageIndex, backgroundSize),
                backgroundRepeat = getCSS(el, "backgroundRepeat").split(",").map(Util.trimText);

            image = resizeImage(image, backgroundSize);

            backgroundRepeat = backgroundRepeat[imageIndex] || backgroundRepeat[0];

            switch (backgroundRepeat) {
                case "repeat-x":
                    backgroundRepeatShape(ctx, image, backgroundPosition, bounds,
                        bounds.left, bounds.top + backgroundPosition.top, 99999, image.height);
                    break;

                case "repeat-y":
                    backgroundRepeatShape(ctx, image, backgroundPosition, bounds,
                        bounds.left + backgroundPosition.left, bounds.top, image.width, 99999);
                    break;

                case "no-repeat":
                    backgroundRepeatShape(ctx, image, backgroundPosition, bounds,
                        bounds.left + backgroundPosition.left, bounds.top + backgroundPosition.top, image.width, image.height);
                    break;

                default:
                    renderBackgroundRepeat(ctx, image, backgroundPosition, {
                        top: bounds.top,
                        left: bounds.left,
                        width: image.width,
                        height: image.height
                    });
                    break;
            }
        }

        function renderBackgroundImage(element, bounds, ctx) {
            var backgroundImage = getCSS(element, "backgroundImage"),
                backgroundImages = Util.parseBackgroundImage(backgroundImage),
                image,
                imageIndex = backgroundImages.length;

            while(imageIndex--) {
                backgroundImage = backgroundImages[imageIndex];

                if (!backgroundImage.args || backgroundImage.args.length === 0) {
                    continue;
                }

                var key = backgroundImage.method === 'url' ?
                    backgroundImage.args[0] :
                    backgroundImage.value;

                image = loadImage(key);

                // TODO add support for background-origin
                if (image) {
                    renderBackgroundRepeating(element, bounds, ctx, image, imageIndex);
                } else {
                    Util.log("html2canvas: Error loading background:", backgroundImage);
                }
            }
        }

        function resizeImage(image, bounds) {
            if(image.width === bounds.width && image.height === bounds.height) {
                return image;
            }

            var ctx, canvas = doc.createElement('canvas');
            canvas.width = bounds.width;
            canvas.height = bounds.height;
            ctx = canvas.getContext("2d");
            drawImage(ctx, image, 0, 0, image.width, image.height, 0, 0, bounds.width, bounds.height );
            return canvas;
        }

        function setOpacity(ctx, element, parentStack) {
            return ctx.setVariable("globalAlpha", getCSS(element, "opacity") * ((parentStack) ? parentStack.opacity : 1));
        }

        function removePx(str) {
            return str.replace("px", "");
        }

        var transformRegExp = /(matrix)\((.+)\)/;

        function getTransform(element, parentStack) {
            var transform = getCSS(element, "transform") || getCSS(element, "-webkit-transform") || getCSS(element, "-moz-transform") || getCSS(element, "-ms-transform") || getCSS(element, "-o-transform");
            var transformOrigin = getCSS(element, "transform-origin") || getCSS(element, "-webkit-transform-origin") || getCSS(element, "-moz-transform-origin") || getCSS(element, "-ms-transform-origin") || getCSS(element, "-o-transform-origin") || "0px 0px";

            transformOrigin = transformOrigin.split(" ").map(removePx).map(Util.asFloat);

            var matrix;
            if (transform && transform !== "none") {
                var match = transform.match(transformRegExp);
                if (match) {
                    switch(match[1]) {
                        case "matrix":
                            matrix = match[2].split(",").map(Util.trimText).map(Util.asFloat);
                            break;
                    }
                }
            }

            return {
                origin: transformOrigin,
                matrix: matrix
            };
        }

        function createStack(element, parentStack, bounds, transform) {
            var ctx = h2cRenderContext((!parentStack) ? documentWidth() : bounds.width , (!parentStack) ? documentHeight() : bounds.height),
                stack = {
                    ctx: ctx,
                    opacity: setOpacity(ctx, element, parentStack),
                    cssPosition: getCSS(element, "position"),
                    borders: getBorderData(element),
                    transform: transform,
                    clip: (parentStack && parentStack.clip) ? Util.Extend( {}, parentStack.clip ) : null
                };

            setZ(element, stack, parentStack);

            // TODO correct overflow for absolute content residing under a static position
            if (options.useOverflow === true && /(hidden|scroll|auto)/.test(getCSS(element, "overflow")) === true && /(BODY)/i.test(element.nodeName) === false){
                stack.clip = (stack.clip) ? clipBounds(stack.clip, bounds) : bounds;
            }

            return stack;
        }

        function getBackgroundBounds(borders, bounds, clip) {
            var backgroundBounds = {
                left: bounds.left + borders[3].width,
                top: bounds.top + borders[0].width,
                width: bounds.width - (borders[1].width + borders[3].width),
                height: bounds.height - (borders[0].width + borders[2].width)
            };

            if (clip) {
                backgroundBounds = clipBounds(backgroundBounds, clip);
            }

            return backgroundBounds;
        }

        function getBounds(element, transform) {
            var bounds = (transform.matrix) ? Util.OffsetBounds(element) : Util.Bounds(element);
            transform.origin[0] += bounds.left;
            transform.origin[1] += bounds.top;
            return bounds;
        }

        function renderElement(element, parentStack, pseudoElement, ignoreBackground) {
            var transform = getTransform(element, parentStack),
                bounds = getBounds(element, transform),
                image,
                stack = createStack(element, parentStack, bounds, transform),
                borders = stack.borders,
                ctx = stack.ctx,
                backgroundBounds = getBackgroundBounds(borders, bounds, stack.clip),
                borderData = parseBorders(element, bounds, borders),
                backgroundColor = (ignoreElementsRegExp.test(element.nodeName)) ? "#efefef" : getCSS(element, "backgroundColor");


            createShape(ctx, borderData.clip);

            ctx.save();
            ctx.clip();

            if (backgroundBounds.height > 0 && backgroundBounds.width > 0 && !ignoreBackground) {
                renderBackgroundColor(ctx, bounds, backgroundColor);
                renderBackgroundImage(element, backgroundBounds, ctx);
            } else if (ignoreBackground) {
                stack.backgroundColor =  backgroundColor;
            }

            ctx.restore();

            borderData.borders.forEach(function(border) {
                renderBorders(ctx, border.args, border.color);
            });

            if (!pseudoElement) {
                injectPseudoElements(element, stack);
            }

            switch(element.nodeName){
                case "IMG":
                    if ((image = loadImage(element.getAttribute('src')))) {
                        renderImage(ctx, element, image, bounds, borders);
                    } else {
                        Util.log("html2canvas: Error loading <img>:" + element.getAttribute('src'));
                    }
                    break;
                case "INPUT":
                    // TODO add all relevant type's, i.e. HTML5 new stuff
                    // todo add support for placeholder attribute for browsers which support it
                    if (/^(text|url|email|submit|button|reset)$/.test(element.type) && (element.value || element.placeholder || "").length > 0){
                        renderFormValue(element, bounds, stack);
                    }
                    break;
                case "TEXTAREA":
                    if ((element.value || element.placeholder || "").length > 0){
                        renderFormValue(element, bounds, stack);
                    }
                    break;
                case "SELECT":
                    if ((element.options||element.placeholder || "").length > 0){
                        renderFormValue(element, bounds, stack);
                    }
                    break;
                case "LI":
                    renderListItem(element, stack, backgroundBounds);
                    break;
                case "CANVAS":
                    renderImage(ctx, element, element, bounds, borders);
                    break;
            }

            return stack;
        }

        function isElementVisible(element) {
            return (getCSS(element, 'display') !== "none" && getCSS(element, 'visibility') !== "hidden" && !element.hasAttribute("data-html2canvas-ignore"));
        }

        function parseElement (element, stack, pseudoElement) {
            if (isElementVisible(element)) {
                stack = renderElement(element, stack, pseudoElement, false) || stack;
                if (!ignoreElementsRegExp.test(element.nodeName)) {
                    parseChildren(element, stack, pseudoElement);
                }
            }
        }

        function parseChildren(element, stack, pseudoElement) {
            Util.Children(element).forEach(function(node) {
                if (node.nodeType === node.ELEMENT_NODE) {
                    parseElement(node, stack, pseudoElement);
                } else if (node.nodeType === node.TEXT_NODE) {
                    renderText(element, node, stack);
                }
            });
        }

        function init() {
            var background = getCSS(document.documentElement, "backgroundColor"),
                transparentBackground = (Util.isTransparent(background) && element === document.body),
                stack = renderElement(element, null, false, transparentBackground);
            parseChildren(element, stack);

            if (transparentBackground) {
                background = stack.backgroundColor;
            }

            body.removeChild(hidePseudoElements);
            return {
                backgroundColor: background,
                stack: stack
            };
        }

        return init();
    };

    function h2czContext(zindex) {
        return {
            zindex: zindex,
            children: []
        };
    }

    _html2canvas.Preload = function( options ) {

        var images = {
                numLoaded: 0,   // also failed are counted here
                numFailed: 0,
                numTotal: 0,
                cleanupDone: false
            },
            pageOrigin,
            Util = _html2canvas.Util,
            methods,
            i,
            count = 0,
            element = options.elements[0] || document.body,
            doc = element.ownerDocument,
            domImages = element.getElementsByTagName('img'), // Fetch images of the present element only
            imgLen = domImages.length,
            link = doc.createElement("a"),
            supportCORS = (function( img ){
                return (img.crossOrigin !== undefined);
            })(new Image()),
            timeoutTimer;

        link.href = window.location.href;
        pageOrigin  = link.protocol + link.host;

        function isSameOrigin(url){
            link.href = url;
            link.href = link.href; // YES, BELIEVE IT OR NOT, that is required for IE9 - http://jsfiddle.net/niklasvh/2e48b/
            var origin = link.protocol + link.host;
            return (origin === pageOrigin);
        }

        function start(){
            Util.log("html2canvas: start: images: " + images.numLoaded + " / " + images.numTotal + " (failed: " + images.numFailed + ")");
            if (!images.firstRun && images.numLoaded >= images.numTotal){
                Util.log("Finished loading images: # " + images.numTotal + " (failed: " + images.numFailed + ")");

                if (typeof options.complete === "function"){
                    options.complete(images);
                }

            }
        }

        // TODO modify proxy to serve images with CORS enabled, where available
        function proxyGetImage(url, img, imageObj){
            var callback_name,
                scriptUrl = options.proxy,
                script;

            link.href = url;
            url = link.href; // work around for pages with base href="" set - WARNING: this may change the url

            callback_name = 'html2canvas_' + (count++);
            imageObj.callbackname = callback_name;

            if (scriptUrl.indexOf("?") > -1) {
                scriptUrl += "&";
            } else {
                scriptUrl += "?";
            }
            scriptUrl += 'url=' + encodeURIComponent(url) + '&callback=' + callback_name;
            script = doc.createElement("script");

            window[callback_name] = function(a){
                if (a.substring(0,6) === "error:"){
                    imageObj.succeeded = false;
                    images.numLoaded++;
                    images.numFailed++;
                    start();
                } else {
                    setImageLoadHandlers(img, imageObj);
                    img.src = a;
                }
                window[callback_name] = undefined; // to work with IE<9  // NOTE: that the undefined callback property-name still exists on the window object (for IE<9)
                try {
                    delete window[callback_name];  // for all browser that support this
                } catch(ex) {}
                script.parentNode.removeChild(script);
                script = null;
                delete imageObj.script;
                delete imageObj.callbackname;
            };

            script.setAttribute("type", "text/javascript");
            script.setAttribute("src", scriptUrl);
            imageObj.script = script;
            window.document.body.appendChild(script);

        }

        function loadPseudoElement(element, type) {
            var style = window.getComputedStyle(element, type),
                content = style.content;
            if (content.substr(0, 3) === 'url') {
                methods.loadImage(_html2canvas.Util.parseBackgroundImage(content)[0].args[0]);
            }
            loadBackgroundImages(style.backgroundImage, element);
        }

        function loadPseudoElementImages(element) {
            loadPseudoElement(element, ":before");
            loadPseudoElement(element, ":after");
        }

        function loadGradientImage(backgroundImage, bounds) {
            var img = _html2canvas.Generate.Gradient(backgroundImage, bounds);

            if (img !== undefined){
                images[backgroundImage] = {
                    img: img,
                    succeeded: true
                };
                images.numTotal++;
                images.numLoaded++;
                start();
            }
        }

        function invalidBackgrounds(background_image) {
            return (background_image && background_image.method && background_image.args && background_image.args.length > 0 );
        }

        function loadBackgroundImages(background_image, el) {
            var bounds;

            _html2canvas.Util.parseBackgroundImage(background_image).filter(invalidBackgrounds).forEach(function(background_image) {
                if (background_image.method === 'url') {
                    methods.loadImage(background_image.args[0]);
                } else if(background_image.method.match(/\-?gradient$/)) {
                    if(bounds === undefined) {
                        bounds = _html2canvas.Util.Bounds(el);
                    }
                    loadGradientImage(background_image.value, bounds);
                }
            });
        }

        function getImages (el) {
            var elNodeType = false;

            // Firefox fails with permission denied on pages with iframes
            try {
                Util.Children(el).forEach(getImages);
            }
            catch( e ) {}

            try {
                elNodeType = el.nodeType;
            } catch (ex) {
                elNodeType = false;
                Util.log("html2canvas: failed to access some element's nodeType - Exception: " + ex.message);
            }

            if (elNodeType === 1 || elNodeType === undefined) {
                loadPseudoElementImages(el);
                try {
                    loadBackgroundImages(Util.getCSS(el, 'backgroundImage'), el);
                } catch(e) {
                    Util.log("html2canvas: failed to get background-image - Exception: " + e.message);
                }
                loadBackgroundImages(el);
            }
        }

        function setImageLoadHandlers(img, imageObj) {
            img.onload = function() {
                if ( imageObj.timer !== undefined ) {
                    // CORS succeeded
                    window.clearTimeout( imageObj.timer );
                }

                images.numLoaded++;
                imageObj.succeeded = true;
                img.onerror = img.onload = null;
                start();
            };
            img.onerror = function() {
                if (img.crossOrigin === "anonymous") {
                    // CORS failed
                    window.clearTimeout( imageObj.timer );

                    // let's try with proxy instead
                    if ( options.proxy ) {
                        var src = img.src;
                        img = new Image();
                        imageObj.img = img;
                        img.src = src;

                        proxyGetImage( img.src, img, imageObj );
                        return;
                    }
                }

                images.numLoaded++;
                images.numFailed++;
                imageObj.succeeded = false;
                img.onerror = img.onload = null;
                start();
            };
        }

        methods = {
            loadImage: function( src ) {
                var img, imageObj;
                if ( src && images[src] === undefined ) {
                    img = new Image();
                    if ( src.match(/data:image\/.*;base64,/i) ) {
                        img.src = src.replace(/url\(['"]{0,}|['"]{0,}\)$/ig, '');
                        imageObj = images[src] = {
                            img: img
                        };
                        images.numTotal++;
                        setImageLoadHandlers(img, imageObj);
                    } else if ( isSameOrigin( src ) || options.allowTaint ===  true ) {
                        imageObj = images[src] = {
                            img: img
                        };
                        images.numTotal++;
                        setImageLoadHandlers(img, imageObj);
                        img.src = src;
                    } else if ( supportCORS && !options.allowTaint && options.useCORS ) {
                        // attempt to load with CORS

                        img.crossOrigin = "anonymous";
                        imageObj = images[src] = {
                            img: img
                        };
                        images.numTotal++;
                        setImageLoadHandlers(img, imageObj);
                        img.src = src;
                    } else if ( options.proxy ) {
                        imageObj = images[src] = {
                            img: img
                        };
                        images.numTotal++;
                        proxyGetImage( src, img, imageObj );
                    }
                }

            },
            cleanupDOM: function(cause) {
                var img, src;
                if (!images.cleanupDone) {
                    if (cause && typeof cause === "string") {
                        Util.log("html2canvas: Cleanup because: " + cause);
                    } else {
                        Util.log("html2canvas: Cleanup after timeout: " + options.timeout + " ms.");
                    }

                    for (src in images) {
                        if (images.hasOwnProperty(src)) {
                            img = images[src];
                            if (typeof img === "object" && img.callbackname && img.succeeded === undefined) {
                                // cancel proxy image request
                                window[img.callbackname] = undefined; // to work with IE<9  // NOTE: that the undefined callback property-name still exists on the window object (for IE<9)
                                try {
                                    delete window[img.callbackname];  // for all browser that support this
                                } catch(ex) {}
                                if (img.script && img.script.parentNode) {
                                    img.script.setAttribute("src", "about:blank");  // try to cancel running request
                                    img.script.parentNode.removeChild(img.script);
                                }
                                images.numLoaded++;
                                images.numFailed++;
                                Util.log("html2canvas: Cleaned up failed img: '" + src + "' Steps: " + images.numLoaded + " / " + images.numTotal);
                            }
                        }
                    }

                    // cancel any pending requests
                    if(window.stop !== undefined) {
                        window.stop();
                    } else if(document.execCommand !== undefined) {
                        document.execCommand("Stop", false);
                    }
                    if (document.close !== undefined) {
                        document.close();
                    }
                    images.cleanupDone = true;
                    if (!(cause && typeof cause === "string")) {
                        start();
                    }
                }
            },

            renderingDone: function() {
                if (timeoutTimer) {
                    window.clearTimeout(timeoutTimer);
                }
            }
        };

        if (options.timeout > 0) {
            timeoutTimer = window.setTimeout(methods.cleanupDOM, options.timeout);
        }

        Util.log('html2canvas: Preload starts: finding background-images');
        images.firstRun = true;

        getImages(element);

        Util.log('html2canvas: Preload: Finding images');
        // load <img> images
        for (i = 0; i < imgLen; i+=1){
            methods.loadImage( domImages[i].getAttribute( "src" ) );
        }

        images.firstRun = false;
        Util.log('html2canvas: Preload: Done.');
        if (images.numTotal === images.numLoaded) {
            start();
        }

        return methods;
    };

    _html2canvas.Renderer = function(parseQueue, options){

        // http://www.w3.org/TR/CSS21/zindex.html
        function createRenderQueue(parseQueue) {
            var queue = [],
                rootContext;

            rootContext = (function buildStackingContext(rootNode) {
                var rootContext = {};
                function insert(context, node, specialParent) {
                    var zi = (node.zIndex.zindex === 'auto') ? 0 : Number(node.zIndex.zindex),
                        contextForChildren = context, // the stacking context for children
                        isPositioned = node.zIndex.isPositioned,
                        isFloated = node.zIndex.isFloated,
                        stub = {node: node},
                        childrenDest = specialParent; // where children without z-index should be pushed into

                    if (node.zIndex.ownStacking) {
                        // '!' comes before numbers in sorted array
                        contextForChildren = stub.context = { '!': [{node:node, children: []}]};
                        childrenDest = undefined;
                    } else if (isPositioned || isFloated) {
                        childrenDest = stub.children = [];
                    }

                    if (zi === 0 && specialParent) {
                        specialParent.push(stub);
                    } else {
                        if (!context[zi]) { context[zi] = []; }
                        context[zi].push(stub);
                    }

                    node.zIndex.children.forEach(function(childNode) {
                        insert(contextForChildren, childNode, childrenDest);
                    });
                }
                insert(rootContext, rootNode);
                return rootContext;
            })(parseQueue);

            function sortZ(context) {
                Object.keys(context).sort().forEach(function(zi) {
                    var nonPositioned = [],
                        floated = [],
                        positioned = [],
                        list = [];

                    // positioned after static
                    context[zi].forEach(function(v) {
                        if (v.node.zIndex.isPositioned || v.node.zIndex.opacity < 1) {
                            // http://www.w3.org/TR/css3-color/#transparency
                            // non-positioned element with opactiy < 1 should be stacked as if it were a positioned element with ‘z-index: 0’ and ‘opacity: 1’.
                            positioned.push(v);
                        } else if (v.node.zIndex.isFloated) {
                            floated.push(v);
                        } else {
                            nonPositioned.push(v);
                        }
                    });

                    (function walk(arr) {
                        arr.forEach(function(v) {
                            list.push(v);
                            if (v.children) { walk(v.children); }
                        });
                    })(nonPositioned.concat(floated, positioned));

                    list.forEach(function(v) {
                        if (v.context) {
                            sortZ(v.context);
                        } else {
                            queue.push(v.node);
                        }
                    });
                });
            }

            sortZ(rootContext);

            return queue;
        }

        function getRenderer(rendererName) {
            var renderer;

            if (typeof options.renderer === "string" && _html2canvas.Renderer[rendererName] !== undefined) {
                renderer = _html2canvas.Renderer[rendererName](options);
            } else if (typeof rendererName === "function") {
                renderer = rendererName(options);
            } else {
                throw new Error("Unknown renderer");
            }

            if ( typeof renderer !== "function" ) {
                throw new Error("Invalid renderer defined");
            }
            return renderer;
        }

        return getRenderer(options.renderer)(parseQueue, options, document, createRenderQueue(parseQueue.stack), _html2canvas);
    };

    _html2canvas.Util.Support = function (options, doc) {

        function supportSVGRendering() {
            var img = new Image(),
                canvas = doc.createElement("canvas"),
                ctx = (canvas.getContext === undefined) ? false : canvas.getContext("2d");
            if (ctx === false) {
                return false;
            }
            canvas.width = canvas.height = 10;
            img.src = [
                "data:image/svg+xml,",
                "<svg xmlns='http://www.w3.org/2000/svg' width='10' height='10'>",
                "<foreignObject width='10' height='10'>",
                "<div xmlns='http://www.w3.org/1999/xhtml' style='width:10;height:10;'>",
                "sup",
                "</div>",
                "</foreignObject>",
                "</svg>"
            ].join("");
            try {
                ctx.drawImage(img, 0, 0);
                canvas.toDataURL();
            } catch(e) {
                return false;
            }
            _html2canvas.Util.log('html2canvas: Parse: SVG powered rendering available');
            return true;
        }

        // Test whether we can use ranges to measure bounding boxes
        // Opera doesn't provide valid bounds.height/bottom even though it supports the method.

        function supportRangeBounds() {
            var r, testElement, rangeBounds, rangeHeight, support = false;

            if (doc.createRange) {
                r = doc.createRange();
                if (r.getBoundingClientRect) {
                    testElement = doc.createElement('boundtest');
                    testElement.style.height = "123px";
                    testElement.style.display = "block";
                    doc.body.appendChild(testElement);

                    r.selectNode(testElement);
                    rangeBounds = r.getBoundingClientRect();
                    rangeHeight = rangeBounds.height;

                    if (rangeHeight === 123) {
                        support = true;
                    }
                    doc.body.removeChild(testElement);
                }
            }

            return support;
        }

        return {
            rangeBounds: supportRangeBounds(),
            svgRendering: options.svgRendering && supportSVGRendering()
        };
    };
    window.html2canvas = function(elements, opts) {
        elements = (elements.length) ? elements : [elements];
        var queue,
            canvas,
            options = {
                // general
                logging: false,
                elements: elements,
                background: "#fff",

                // preload options
                proxy: null,
                timeout: 0,    // no timeout
                useCORS: false, // try to load images as CORS (where available), before falling back to proxy
                allowTaint: false, // whether to allow images to taint the canvas, won't need proxy if set to true

                // parse options
                svgRendering: false, // use svg powered rendering where available (FF11+)
                ignoreElements: "IFRAME|OBJECT|PARAM",
                useOverflow: true,
                letterRendering: false,
                chinese: false,

                // render options

                width: null,
                height: null,
                taintTest: true, // do a taint test with all images before applying to canvas
                renderer: "Canvas"
            };

        options = _html2canvas.Util.Extend(opts, options);

        _html2canvas.logging = options.logging;
        options.complete = function( images ) {

            if (typeof options.onpreloaded === "function") {
                if ( options.onpreloaded( images ) === false ) {
                    return;
                }
            }
            queue = _html2canvas.Parse( images, options );

            if (typeof options.onparsed === "function") {
                if ( options.onparsed( queue ) === false ) {
                    return;
                }
            }

            canvas = _html2canvas.Renderer( queue, options );

            if (typeof options.onrendered === "function") {
                options.onrendered( canvas );
            }


        };

        // for pages without images, we still want this to be async, i.e. return methods before executing
        window.setTimeout( function(){
            _html2canvas.Preload( options );
        }, 0 );

        return {
            render: function( queue, opts ) {
                return _html2canvas.Renderer( queue, _html2canvas.Util.Extend(opts, options) );
            },
            parse: function( images, opts ) {
                return _html2canvas.Parse( images, _html2canvas.Util.Extend(opts, options) );
            },
            preload: function( opts ) {
                return _html2canvas.Preload( _html2canvas.Util.Extend(opts, options) );
            },
            log: _html2canvas.Util.log
        };
    };

    window.html2canvas.log = _html2canvas.Util.log; // for renderers
    window.html2canvas.Renderer = {
        Canvas: undefined // We are assuming this will be used
    };
    _html2canvas.Renderer.Canvas = function(options) {
        options = options || {};

        var doc = document,
            safeImages = [],
            testCanvas = document.createElement("canvas"),
            testctx = testCanvas.getContext("2d"),
            Util = _html2canvas.Util,
            canvas = options.canvas || doc.createElement('canvas');

        function createShape(ctx, args) {
            ctx.beginPath();
            args.forEach(function(arg) {
                ctx[arg.name].apply(ctx, arg['arguments']);
            });
            ctx.closePath();
        }

        function safeImage(item) {
            if (safeImages.indexOf(item['arguments'][0].src ) === -1) {
                testctx.drawImage(item['arguments'][0], 0, 0);
                try {
                    testctx.getImageData(0, 0, 1, 1);
                } catch(e) {
                    testCanvas = doc.createElement("canvas");
                    testctx = testCanvas.getContext("2d");
                    return false;
                }
                safeImages.push(item['arguments'][0].src);
            }
            return true;
        }

        function renderItem(ctx, item) {
            switch(item.type){
                case "variable":
                    ctx[item.name] = item['arguments'];
                    break;
                case "function":
                    switch(item.name) {
                        case "createPattern":
                            if (item['arguments'][0].width > 0 && item['arguments'][0].height > 0) {
                                try {
                                    ctx.fillStyle = ctx.createPattern(item['arguments'][0], "repeat");
                                }
                                catch(e) {
                                    Util.log("html2canvas: Renderer: Error creating pattern", e.message);
                                }
                            }
                            break;
                        case "drawShape":
                            createShape(ctx, item['arguments']);
                            break;
                        case "drawImage":
                            if (item['arguments'][8] > 0 && item['arguments'][7] > 0) {
                                if (!options.taintTest || (options.taintTest && safeImage(item))) {
                                    ctx.drawImage.apply( ctx, item['arguments'] );
                                }
                            }
                            break;
                        default:
                            ctx[item.name].apply(ctx, item['arguments']);
                    }
                    break;
            }
        }

        return function(parsedData, options, document, queue, _html2canvas) {
            var ctx = canvas.getContext("2d"),
                newCanvas,
                bounds,
                fstyle,
                zStack = parsedData.stack;

            canvas.width = canvas.style.width =  options.width || zStack.ctx.width;
            canvas.height = canvas.style.height = options.height || zStack.ctx.height;

            fstyle = ctx.fillStyle;
            ctx.fillStyle = (Util.isTransparent(zStack.backgroundColor) && options.background !== undefined) ? options.background : parsedData.backgroundColor;
            ctx.fillRect(0, 0, canvas.width, canvas.height);
            ctx.fillStyle = fstyle;

            queue.forEach(function(storageContext) {
                // set common settings for canvas
                ctx.textBaseline = "bottom";
                ctx.save();

                if (storageContext.transform.matrix) {
                    ctx.translate(storageContext.transform.origin[0], storageContext.transform.origin[1]);
                    ctx.transform.apply(ctx, storageContext.transform.matrix);
                    ctx.translate(-storageContext.transform.origin[0], -storageContext.transform.origin[1]);
                }

                if (storageContext.clip){
                    ctx.beginPath();
                    ctx.rect(storageContext.clip.left, storageContext.clip.top, storageContext.clip.width, storageContext.clip.height);
                    ctx.clip();
                }

                if (storageContext.ctx.storage) {
                    storageContext.ctx.storage.forEach(function(item) {
                        renderItem(ctx, item);
                    });
                }

                ctx.restore();
            });

            Util.log("html2canvas: Renderer: Canvas renderer done - returning canvas obj");

            if (options.elements.length === 1) {
                if (typeof options.elements[0] === "object" && options.elements[0].nodeName !== "BODY") {
                    // crop image to the bounds of selected (single) element
                    bounds = _html2canvas.Util.Bounds(options.elements[0]);
                    newCanvas = document.createElement('canvas');
                    newCanvas.width = Math.ceil(bounds.width);
                    newCanvas.height = Math.ceil(bounds.height);
                    ctx = newCanvas.getContext("2d");

                    ctx.drawImage(canvas, bounds.left, bounds.top, bounds.width, bounds.height, 0, 0, bounds.width, bounds.height);
                    canvas = null;
                    return newCanvas;
                }
            }

            return canvas;
        };
    };
})(window,document);