text: // Copyright 2006 Google Inc.
  
  //
  
  // Licensed under the Apache License, Version 2.0 (the "License");
  
  // you may not use this file except in compliance with the License.
  
  // You may obtain a copy of the License at
  
  //
  
  //   http://www.apache.org/licenses/LICENSE-2.0
  
  //
  
  // Unless required by applicable law or agreed to in writing, software
  
  // distributed under the License is distributed on an "AS IS" BASIS,
  
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  
  // See the License for the specific language governing permissions and
  
  // limitations under the License.
  
  
  
  
  
  // Known Issues:
  
  //
  
  // * Patterns only support repeat.
  
  // * Radial gradient are not implemented. The VML version of these look very
  
  //   different from the canvas one.
  
  // * Clipping paths are not implemented.
  
  // * Coordsize. The width and height attribute have higher priority than the
  
  //   width and height style values which isn't correct.
  
  // * Painting mode isn't implemented.
  
  // * Canvas width/height should is using content-box by default. IE in
  
  //   Quirks mode will draw the canvas using border-box. Either change your
  
  //   doctype to HTML5
  
  //   (http://www.whatwg.org/specs/web-apps/current-work/#the-doctype)
  
  //   or use Box Sizing Behavior from WebFX
  
  //   (http://webfx.eae.net/dhtml/boxsizing/boxsizing.html)
  
  // * Non uniform scaling does not correctly scale strokes.
  
  // * Filling very large shapes (above 5000 points) is buggy.
  
  // * Optimize. There is always room for speed improvements.
  
  
  
  // Only add this code if we do not already have a canvas implementation
  
  if (!document.createElement('canvas').getContext) {
  
  
  
  (function() {
  
  
  
    // alias some functions to make (compiled) code shorter
  
    var m = Math;
  
    var mr = m.round;
  
    var ms = m.sin;
  
    var mc = m.cos;
  
    var abs = m.abs;
  
    var sqrt = m.sqrt;
  
  
  
    // this is used for sub pixel precision
  
    var Z = 10;
  
    var Z2 = Z / 2;
  
  
  
    var IE_VERSION = +navigator.userAgent.match(/MSIE ([\d.]+)?/)[1];
  
  
  
    /**
  
     * This funtion is assigned to the <canvas> elements as element.getContext().
  
     * @this {HTMLElement}
  
     * @return {CanvasRenderingContext2D_}
  
     */
  
    function getContext() {
  
      return this.context_ ||
  
          (this.context_ = new CanvasRenderingContext2D_(this));
  
    }
  
  
  
    var slice = Array.prototype.slice;
  
  
  
    /**
  
     * Binds a function to an object. The returned function will always use the
  
     * passed in {@code obj} as {@code this}.
  
     *
  
     * Example:
  
     *
  
     *   g = bind(f, obj, a, b)
  
     *   g(c, d) // will do f.call(obj, a, b, c, d)
  
     *
  
     * @param {Function} f The function to bind the object to
  
     * @param {Object} obj The object that should act as this when the function
  
     *     is called
  
     * @param {*} var_args Rest arguments that will be used as the initial
  
     *     arguments when the function is called
  
     * @return {Function} A new function that has bound this
  
     */
  
    function bind(f, obj, var_args) {
  
      var a = slice.call(arguments, 2);
  
      return function() {
  
        return f.apply(obj, a.concat(slice.call(arguments)));
  
      };
  
    }
  
  
  
    function encodeHtmlAttribute(s) {
  
      return String(s).replace(/&/g, '&amp;').replace(/"/g, '&quot;');
  
    }
  
  
  
    function addNamespace(doc, prefix, urn) {
  
      if (!doc.namespaces[prefix]) {
  
        doc.namespaces.add(prefix, urn, '#default#VML');
  
      }
  
    }
  
  
  
    function addNamespacesAndStylesheet(doc) {
  
      addNamespace(doc, 'g_vml_', 'urn:schemas-microsoft-com:vml');
  
      addNamespace(doc, 'g_o_', 'urn:schemas-microsoft-com:office:office');
  
  
  
      // Setup default CSS.  Only add one style sheet per document
  
      if (!doc.styleSheets['ex_canvas_']) {
  
        var ss = doc.createStyleSheet();
  
        ss.owningElement.id = 'ex_canvas_';
  
        ss.cssText = 'canvas{display:inline-block;overflow:hidden;' +
  
            // default size is 300x150 in Gecko and Opera
  
            'text-align:left;width:300px;height:150px}';
  
      }
  
    }
  
  
  
    // Add namespaces and stylesheet at startup.
  
    addNamespacesAndStylesheet(document);
  
  
  
    var G_vmlCanvasManager_ = {
  
      init: function(opt_doc) {
  
        var doc = opt_doc || document;
  
        // Create a dummy element so that IE will allow canvas elements to be
  
        // recognized.
  
        doc.createElement('canvas');
  
        doc.attachEvent('onreadystatechange', bind(this.init_, this, doc));
  
      },
  
  
  
      init_: function(doc) {
  
        // find all canvas elements
  
        var els = doc.getElementsByTagName('canvas');
  
        for (var i = 0; i < els.length; i++) {
  
          this.initElement(els[i]);
  
        }
  
      },
  
  
  
      /**
  
       * Public initializes a canvas element so that it can be used as canvas
  
       * element from now on. This is called automatically before the page is
  
       * loaded but if you are creating elements using createElement you need to
  
       * make sure this is called on the element.
  
       * @param {HTMLElement} el The canvas element to initialize.
  
       * @return {HTMLElement} the element that was created.
  
       */
  
      initElement: function(el) {
  
        if (!el.getContext) {
  
          el.getContext = getContext;
  
  
  
          // Add namespaces and stylesheet to document of the element.
  
          addNamespacesAndStylesheet(el.ownerDocument);
  
  
  
          // Remove fallback content. There is no way to hide text nodes so we
  
          // just remove all childNodes. We could hide all elements and remove
  
          // text nodes but who really cares about the fallback content.
  
          el.innerHTML = '';
  
  
  
          // do not use inline function because that will leak memory
  
          el.attachEvent('onpropertychange', onPropertyChange);
  
          el.attachEvent('onresize', onResize);
  
  
  
          var attrs = el.attributes;
  
          if (attrs.width && attrs.width.specified) {
  
            // TODO: use runtimeStyle and coordsize
  
            // el.getContext().setWidth_(attrs.width.nodeValue);
  
            el.style.width = attrs.width.nodeValue + 'px';
  
          } else {
  
            el.width = el.clientWidth;
  
          }
  
          if (attrs.height && attrs.height.specified) {
  
            // TODO: use runtimeStyle and coordsize
  
            // el.getContext().setHeight_(attrs.height.nodeValue);
  
            el.style.height = attrs.height.nodeValue + 'px';
  
          } else {
  
            el.height = el.clientHeight;
  
          }
  
          //el.getContext().setCoordsize_()
  
        }
  
        return el;
  
      }
  
    };
  
  
  
    function onPropertyChange(e) {
  
      var el = e.srcElement;
  
  
  
      switch (e.propertyName) {
  
        case 'width':
  
          el.getContext().clearRect();
  
          el.style.width = el.attributes.width.nodeValue + 'px';
  
          // In IE8 this does not trigger onresize.
  
          el.firstChild.style.width =  el.clientWidth + 'px';
  
          break;
  
        case 'height':
  
          el.getContext().clearRect();
  
          el.style.height = el.attributes.height.nodeValue + 'px';
  
          el.firstChild.style.height = el.clientHeight + 'px';
  
          break;
  
      }
  
    }
  
  
  
    function onResize(e) {
  
      var el = e.srcElement;
  
      if (el.firstChild) {
  
        el.firstChild.style.width =  el.clientWidth + 'px';
  
        el.firstChild.style.height = el.clientHeight + 'px';
  
      }
  
    }
  
  
  
    G_vmlCanvasManager_.init();
  
  
  
    // precompute "00" to "FF"
  
    var decToHex = [];
  
    for (var i = 0; i < 16; i++) {
  
      for (var j = 0; j < 16; j++) {
  
        decToHex[i * 16 + j] = i.toString(16) + j.toString(16);
  
      }
  
    }
  
  
  
    function createMatrixIdentity() {
  
      return [
  
        [1, 0, 0],
  
        [0, 1, 0],
  
        [0, 0, 1]
  
      ];
  
    }
  
  
  
    function matrixMultiply(m1, m2) {
  
      var result = createMatrixIdentity();
  
  
  
      for (var x = 0; x < 3; x++) {
  
        for (var y = 0; y < 3; y++) {
  
          var sum = 0;
  
  
  
          for (var z = 0; z < 3; z++) {
  
            sum += m1[x][z] * m2[z][y];
  
          }
  
  
  
          result[x][y] = sum;
  
        }
  
      }
  
      return result;
  
    }
  
  
  
    function copyState(o1, o2) {
  
      o2.fillStyle     = o1.fillStyle;
  
      o2.lineCap       = o1.lineCap;
  
      o2.lineJoin      = o1.lineJoin;
  
      o2.lineWidth     = o1.lineWidth;
  
      o2.miterLimit    = o1.miterLimit;
  
      o2.shadowBlur    = o1.shadowBlur;
  
      o2.shadowColor   = o1.shadowColor;
  
      o2.shadowOffsetX = o1.shadowOffsetX;
  
      o2.shadowOffsetY = o1.shadowOffsetY;
  
      o2.strokeStyle   = o1.strokeStyle;
  
      o2.globalAlpha   = o1.globalAlpha;
  
      o2.font          = o1.font;
  
      o2.textAlign     = o1.textAlign;
  
      o2.textBaseline  = o1.textBaseline;
  
      o2.arcScaleX_    = o1.arcScaleX_;
  
      o2.arcScaleY_    = o1.arcScaleY_;
  
      o2.lineScale_    = o1.lineScale_;
  
    }
  
  
  
    var colorData = {
  
      aliceblue: '#F0F8FF',
  
      antiquewhite: '#FAEBD7',
  
      aquamarine: '#7FFFD4',
  
      azure: '#F0FFFF',
  
      beige: '#F5F5DC',
  
      bisque: '#FFE4C4',
  
      black: '#000000',
  
      blanchedalmond: '#FFEBCD',
  
      blueviolet: '#8A2BE2',
  
      brown: '#A52A2A',
  
      burlywood: '#DEB887',
  
      cadetblue: '#5F9EA0',
  
      chartreuse: '#7FFF00',
  
      chocolate: '#D2691E',
  
      coral: '#FF7F50',
  
      cornflowerblue: '#6495ED',
  
      cornsilk: '#FFF8DC',
  
      crimson: '#DC143C',
  
      cyan: '#00FFFF',
  
      darkblue: '#00008B',
  
      darkcyan: '#008B8B',
  
      darkgoldenrod: '#B8860B',
  
      darkgray: '#A9A9A9',
  
      darkgreen: '#006400',
  
      darkgrey: '#A9A9A9',
  
      darkkhaki: '#BDB76B',
  
      darkmagenta: '#8B008B',
  
      darkolivegreen: '#556B2F',
  
      darkorange: '#FF8C00',
  
      darkorchid: '#9932CC',
  
      darkred: '#8B0000',
  
      darksalmon: '#E9967A',
  
      darkseagreen: '#8FBC8F',
  
      darkslateblue: '#483D8B',
  
      darkslategray: '#2F4F4F',
  
      darkslategrey: '#2F4F4F',
  
      darkturquoise: '#00CED1',
  
      darkviolet: '#9400D3',
  
      deeppink: '#FF1493',
  
      deepskyblue: '#00BFFF',
  
      dimgray: '#696969',
  
      dimgrey: '#696969',
  
      dodgerblue: '#1E90FF',
  
      firebrick: '#B22222',
  
      floralwhite: '#FFFAF0',
  
      forestgreen: '#228B22',
  
      gainsboro: '#DCDCDC',
  
      ghostwhite: '#F8F8FF',
  
      gold: '#FFD700',
  
      goldenrod: '#DAA520',
  
      grey: '#808080',
  
      greenyellow: '#ADFF2F',
  
      honeydew: '#F0FFF0',
  
      hotpink: '#FF69B4',
  
      indianred: '#CD5C5C',
  
      indigo: '#4B0082',
  
      ivory: '#FFFFF0',
  
      khaki: '#F0E68C',
  
      lavender: '#E6E6FA',
  
      lavenderblush: '#FFF0F5',
  
      lawngreen: '#7CFC00',
  
      lemonchiffon: '#FFFACD',
  
      lightblue: '#ADD8E6',
  
      lightcoral: '#F08080',
  
      lightcyan: '#E0FFFF',
  
      lightgoldenrodyellow: '#FAFAD2',
  
      lightgreen: '#90EE90',
  
      lightgrey: '#D3D3D3',
  
      lightpink: '#FFB6C1',
  
      lightsalmon: '#FFA07A',
  
      lightseagreen: '#20B2AA',
  
      lightskyblue: '#87CEFA',
  
      lightslategray: '#778899',
  
      lightslategrey: '#778899',
  
      lightsteelblue: '#B0C4DE',
  
      lightyellow: '#FFFFE0',
  
      limegreen: '#32CD32',
  
      linen: '#FAF0E6',
  
      magenta: '#FF00FF',
  
      mediumaquamarine: '#66CDAA',
  
      mediumblue: '#0000CD',
  
      mediumorchid: '#BA55D3',
  
      mediumpurple: '#9370DB',
  
      mediumseagreen: '#3CB371',
  
      mediumslateblue: '#7B68EE',
  
      mediumspringgreen: '#00FA9A',
  
      mediumturquoise: '#48D1CC',
  
      mediumvioletred: '#C71585',
  
      midnightblue: '#191970',
  
      mintcream: '#F5FFFA',
  
      mistyrose: '#FFE4E1',
  
      moccasin: '#FFE4B5',
  
      navajowhite: '#FFDEAD',
  
      oldlace: '#FDF5E6',
  
      olivedrab: '#6B8E23',
  
      orange: '#FFA500',
  
      orangered: '#FF4500',
  
      orchid: '#DA70D6',
  
      palegoldenrod: '#EEE8AA',
  
      palegreen: '#98FB98',
  
      paleturquoise: '#AFEEEE',
  
      palevioletred: '#DB7093',
  
      papayawhip: '#FFEFD5',
  
      peachpuff: '#FFDAB9',
  
      peru: '#CD853F',
  
      pink: '#FFC0CB',
  
      plum: '#DDA0DD',
  
      powderblue: '#B0E0E6',
  
      rosybrown: '#BC8F8F',
  
      royalblue: '#4169E1',
  
      saddlebrown: '#8B4513',
  
      salmon: '#FA8072',
  
      sandybrown: '#F4A460',
  
      seagreen: '#2E8B57',
  
      seashell: '#FFF5EE',
  
      sienna: '#A0522D',
  
      skyblue: '#87CEEB',
  
      slateblue: '#6A5ACD',
  
      slategray: '#708090',
  
      slategrey: '#708090',
  
      snow: '#FFFAFA',
  
      springgreen: '#00FF7F',
  
      steelblue: '#4682B4',
  
      tan: '#D2B48C',
  
      thistle: '#D8BFD8',
  
      tomato: '#FF6347',
  
      turquoise: '#40E0D0',
  
      violet: '#EE82EE',
  
      wheat: '#F5DEB3',
  
      whitesmoke: '#F5F5F5',
  
      yellowgreen: '#9ACD32'
  
    };
  
  
  
  
  
    function getRgbHslContent(styleString) {
  
      var start = styleString.indexOf('(', 3);
  
      var end = styleString.indexOf(')', start + 1);
  
      var parts = styleString.substring(start + 1, end).split(',');
  
      // add alpha if needed
  
      if (parts.length != 4 || styleString.charAt(3) != 'a') {
  
        parts[3] = 1;
  
      }
  
      return parts;
  
    }
  
  
  
    function percent(s) {
  
      return parseFloat(s) / 100;
  
    }
  
  
  
    function clamp(v, min, max) {
  
      return Math.min(max, Math.max(min, v));
  
    }
  
  
  
    function hslToRgb(parts){
  
      var r, g, b, h, s, l;
  
      h = parseFloat(parts[0]) / 360 % 360;
  
      if (h < 0)
  
        h++;
  
      s = clamp(percent(parts[1]), 0, 1);
  
      l = clamp(percent(parts[2]), 0, 1);
  
      if (s == 0) {
  
        r = g = b = l; // achromatic
  
      } else {
  
        var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
  
        var p = 2 * l - q;
  
        r = hueToRgb(p, q, h + 1 / 3);
  
        g = hueToRgb(p, q, h);
  
        b = hueToRgb(p, q, h - 1 / 3);
  
      }
  
  
  
      return '#' + decToHex[Math.floor(r * 255)] +
  
          decToHex[Math.floor(g * 255)] +
  
          decToHex[Math.floor(b * 255)];
  
    }
  
  
  
    function hueToRgb(m1, m2, h) {
  
      if (h < 0)
  
        h++;
  
      if (h > 1)
  
        h--;
  
  
  
      if (6 * h < 1)
  
        return m1 + (m2 - m1) * 6 * h;
  
      else if (2 * h < 1)
  
        return m2;
  
      else if (3 * h < 2)
  
        return m1 + (m2 - m1) * (2 / 3 - h) * 6;
  
      else
  
        return m1;
  
    }
  
  
  
    var processStyleCache = {};
  
  
  
    function processStyle(styleString) {
  
      if (styleString in processStyleCache) {
  
        return processStyleCache[styleString];
  
      }
  
  
  
      var str, alpha = 1;
  
  
  
      styleString = String(styleString);
  
      if (styleString.charAt(0) == '#') {
  
        str = styleString;
  
      } else if (/^rgb/.test(styleString)) {
  
        var parts = getRgbHslContent(styleString);
  
        var str = '#', n;
  
        for (var i = 0; i < 3; i++) {
  
          if (parts[i].indexOf('%') != -1) {
  
            n = Math.floor(percent(parts[i]) * 255);
  
          } else {
  
            n = +parts[i];
  
          }
  
          str += decToHex[clamp(n, 0, 255)];
  
        }
  
        alpha = +parts[3];
  
      } else if (/^hsl/.test(styleString)) {
  
        var parts = getRgbHslContent(styleString);
  
        str = hslToRgb(parts);
  
        alpha = parts[3];
  
      } else {
  
        str = colorData[styleString] || styleString;
  
      }
  
      return processStyleCache[styleString] = {color: str, alpha: alpha};
  
    }
  
  
  
    var DEFAULT_STYLE = {
  
      style: 'normal',
  
      variant: 'normal',
  
      weight: 'normal',
  
      size: 10,
  
      family: 'sans-serif'
  
    };
  
  
  
    // Internal text style cache
  
    var fontStyleCache = {};
  
  
  
    function processFontStyle(styleString) {
  
      if (fontStyleCache[styleString]) {
  
        return fontStyleCache[styleString];
  
      }
  
  
  
      var el = document.createElement('div');
  
      var style = el.style;
  
      try {
  
        style.font = styleString;
  
      } catch (ex) {
  
        // Ignore failures to set to invalid font.
  
      }
  
  
  
      return fontStyleCache[styleString] = {
  
        style: style.fontStyle || DEFAULT_STYLE.style,
  
        variant: style.fontVariant || DEFAULT_STYLE.variant,
  
        weight: style.fontWeight || DEFAULT_STYLE.weight,
  
        size: style.fontSize || DEFAULT_STYLE.size,
  
        family: style.fontFamily || DEFAULT_STYLE.family
  
      };
  
    }
  
  
  
    function getComputedStyle(style, element) {
  
      var computedStyle = {};
  
  
  
      for (var p in style) {
  
        computedStyle[p] = style[p];
  
      }
  
  
  
      // Compute the size
  
      var canvasFontSize = parseFloat(element.currentStyle.fontSize),
  
          fontSize = parseFloat(style.size);
  
  
  
      if (typeof style.size == 'number') {
  
        computedStyle.size = style.size;
  
      } else if (style.size.indexOf('px') != -1) {
  
        computedStyle.size = fontSize;
  
      } else if (style.size.indexOf('em') != -1) {
  
        computedStyle.size = canvasFontSize * fontSize;
  
      } else if(style.size.indexOf('%') != -1) {
  
        computedStyle.size = (canvasFontSize / 100) * fontSize;
  
      } else if (style.size.indexOf('pt') != -1) {
  
        computedStyle.size = fontSize / .75;
  
      } else {
  
        computedStyle.size = canvasFontSize;
  
      }
  
  
  
      // Different scaling between normal text and VML text. This was found using
  
      // trial and error to get the same size as non VML text.
  
      computedStyle.size *= 0.981;
  
  
  
      return computedStyle;
  
    }
  
  
  
    function buildStyle(style) {
  
      return style.style + ' ' + style.variant + ' ' + style.weight + ' ' +
  
          style.size + 'px ' + style.family;
  
    }
  
  
  
    var lineCapMap = {
  
      'butt': 'flat',
  
      'round': 'round'
  
    };
  
  
  
    function processLineCap(lineCap) {
  
      return lineCapMap[lineCap] || 'square';
  
    }
  
  
  
    /**
  
     * This class implements CanvasRenderingContext2D interface as described by
  
     * the WHATWG.
  
     * @param {HTMLElement} canvasElement The element that the 2D context should
  
     * be associated with
  
     */
  
    function CanvasRenderingContext2D_(canvasElement) {
  
      this.m_ = createMatrixIdentity();
  
  
  
      this.mStack_ = [];
  
      this.aStack_ = [];
  
      this.currentPath_ = [];
  
  
  
      // Canvas context properties
  
      this.strokeStyle = '#000';
  
      this.fillStyle = '#000';
  
  
  
      this.lineWidth = 1;
  
      this.lineJoin = 'miter';
  
      this.lineCap = 'butt';
  
      this.miterLimit = Z * 1;
  
      this.globalAlpha = 1;
  
      this.font = '10px sans-serif';
  
      this.textAlign = 'left';
  
      this.textBaseline = 'alphabetic';
  
      this.canvas = canvasElement;
  
  
  
      var cssText = 'width:' + canvasElement.clientWidth + 'px;height:' +
  
          canvasElement.clientHeight + 'px;overflow:hidden;position:absolute';
  
      var el = canvasElement.ownerDocument.createElement('div');
  
      el.style.cssText = cssText;
  
      canvasElement.appendChild(el);
  
  
  
      var overlayEl = el.cloneNode(false);
  
      // Use a non transparent background.
  
      overlayEl.style.backgroundColor = 'red';
  
      overlayEl.style.filter = 'alpha(opacity=0)';
  
      canvasElement.appendChild(overlayEl);
  
  
  
      this.element_ = el;
  
      this.arcScaleX_ = 1;
  
      this.arcScaleY_ = 1;
  
      this.lineScale_ = 1;
  
    }
  
  
  
    var contextPrototype = CanvasRenderingContext2D_.prototype;
  
    contextPrototype.clearRect = function() {
  
      if (this.textMeasureEl_) {
  
        this.textMeasureEl_.removeNode(true);
  
        this.textMeasureEl_ = null;
  
      }
  
      this.element_.innerHTML = '';
  
    };
  
  
  
    contextPrototype.beginPath = function() {
  
      // TODO: Branch current matrix so that save/restore has no effect
  
      //       as per safari docs.
  
      this.currentPath_ = [];
  
    };
  
  
  
    contextPrototype.moveTo = function(aX, aY) {
  
      var p = getCoords(this, aX, aY);
  
      this.currentPath_.push({type: 'moveTo', x: p.x, y: p.y});
  
      this.currentX_ = p.x;
  
      this.currentY_ = p.y;
  
    };
  
  
  
    contextPrototype.lineTo = function(aX, aY) {
  
      var p = getCoords(this, aX, aY);
  
      this.currentPath_.push({type: 'lineTo', x: p.x, y: p.y});
  
  
  
      this.currentX_ = p.x;
  
      this.currentY_ = p.y;
  
    };
  
  
  
    contextPrototype.bezierCurveTo = function(aCP1x, aCP1y,
  
                                              aCP2x, aCP2y,
  
                                              aX, aY) {
  
      var p = getCoords(this, aX, aY);
  
      var cp1 = getCoords(this, aCP1x, aCP1y);
  
      var cp2 = getCoords(this, aCP2x, aCP2y);
  
      bezierCurveTo(this, cp1, cp2, p);
  
    };
  
  
  
    // Helper function that takes the already fixed cordinates.
  
    function bezierCurveTo(self, cp1, cp2, p) {
  
      self.currentPath_.push({
  
        type: 'bezierCurveTo',
  
        cp1x: cp1.x,
  
        cp1y: cp1.y,
  
        cp2x: cp2.x,
  
        cp2y: cp2.y,
  
        x: p.x,
  
        y: p.y
  
      });
  
      self.currentX_ = p.x;
  
      self.currentY_ = p.y;
  
    }
  
  
  
    contextPrototype.quadraticCurveTo = function(aCPx, aCPy, aX, aY) {
  
      // the following is lifted almost directly from
  
      // http://developer.mozilla.org/en/docs/Canvas_tutorial:Drawing_shapes
  
  
  
      var cp = getCoords(this, aCPx, aCPy);
  
      var p = getCoords(this, aX, aY);
  
  
  
      var cp1 = {
  
        x: this.currentX_ + 2.0 / 3.0 * (cp.x - this.currentX_),
  
        y: this.currentY_ + 2.0 / 3.0 * (cp.y - this.currentY_)
  
      };
  
      var cp2 = {
  
        x: cp1.x + (p.x - this.currentX_) / 3.0,
  
        y: cp1.y + (p.y - this.currentY_) / 3.0
  
      };
  
  
  
      bezierCurveTo(this, cp1, cp2, p);
  
    };
  
  
  
    contextPrototype.arc = function(aX, aY, aRadius,
  
                                    aStartAngle, aEndAngle, aClockwise) {
  
      aRadius *= Z;
  
      var arcType = aClockwise ? 'at' : 'wa';
  
  
  
      var xStart = aX + mc(aStartAngle) * aRadius - Z2;
  
      var yStart = aY + ms(aStartAngle) * aRadius - Z2;
  
  
  
      var xEnd = aX + mc(aEndAngle) * aRadius - Z2;
  
      var yEnd = aY + ms(aEndAngle) * aRadius - Z2;
  
  
  
      // IE won't render arches drawn counter clockwise if xStart == xEnd.
  
      if (xStart == xEnd && !aClockwise) {
  
        xStart += 0.125; // Offset xStart by 1/80 of a pixel. Use something
  
                         // that can be represented in binary
  
      }
  
  
  
      var p = getCoords(this, aX, aY);
  
      var pStart = getCoords(this, xStart, yStart);
  
      var pEnd = getCoords(this, xEnd, yEnd);
  
  
  
      this.currentPath_.push({type: arcType,
  
                             x: p.x,
  
                             y: p.y,
  
                             radius: aRadius,
  
                             xStart: pStart.x,
  
                             yStart: pStart.y,
  
                             xEnd: pEnd.x,
  
                             yEnd: pEnd.y});
  
  
  
    };
  
  
  
    contextPrototype.rect = function(aX, aY, aWidth, aHeight) {
  
      this.moveTo(aX, aY);
  
      this.lineTo(aX + aWidth, aY);
  
      this.lineTo(aX + aWidth, aY + aHeight);
  
      this.lineTo(aX, aY + aHeight);
  
      this.closePath();
  
    };
  
  
  
    contextPrototype.strokeRect = function(aX, aY, aWidth, aHeight) {
  
      var oldPath = this.currentPath_;
  
      this.beginPath();
  
  
  
      this.moveTo(aX, aY);
  
      this.lineTo(aX + aWidth, aY);
  
      this.lineTo(aX + aWidth, aY + aHeight);
  
      this.lineTo(aX, aY + aHeight);
  
      this.closePath();
  
      this.stroke();
  
  
  
      this.currentPath_ = oldPath;
  
    };
  
  
  
    contextPrototype.fillRect = function(aX, aY, aWidth, aHeight) {
  
      var oldPath = this.currentPath_;
  
      this.beginPath();
  
  
  
      this.moveTo(aX, aY);
  
      this.lineTo(aX + aWidth, aY);
  
      this.lineTo(aX + aWidth, aY + aHeight);
  
      this.lineTo(aX, aY + aHeight);
  
      this.closePath();
  
      this.fill();
  
  
  
      this.currentPath_ = oldPath;
  
    };
  
  
  
    contextPrototype.createLinearGradient = function(aX0, aY0, aX1, aY1) {
  
      var gradient = new CanvasGradient_('gradient');
  
      gradient.x0_ = aX0;
  
      gradient.y0_ = aY0;
  
      gradient.x1_ = aX1;
  
      gradient.y1_ = aY1;
  
      return gradient;
  
    };
  
  
  
    contextPrototype.createRadialGradient = function(aX0, aY0, aR0,
  
                                                     aX1, aY1, aR1) {
  
      var gradient = new CanvasGradient_('gradientradial');
  
      gradient.x0_ = aX0;
  
      gradient.y0_ = aY0;
  
      gradient.r0_ = aR0;
  
      gradient.x1_ = aX1;
  
      gradient.y1_ = aY1;
  
      gradient.r1_ = aR1;
  
      return gradient;
  
    };
  
  
  
    contextPrototype.drawImage = function(image, var_args) {
  
      var dx, dy, dw, dh, sx, sy, sw, sh;
  
  
  
      // to find the original width we overide the width and height
  
      var oldRuntimeWidth = image.runtimeStyle.width;
  
      var oldRuntimeHeight = image.runtimeStyle.height;
  
      image.runtimeStyle.width = 'auto';
  
      image.runtimeStyle.height = 'auto';
  
  
  
      // get the original size
  
      var w = image.width;
  
      var h = image.height;
  
  
  
      // and remove overides
  
      image.runtimeStyle.width = oldRuntimeWidth;
  
      image.runtimeStyle.height = oldRuntimeHeight;
  
  
  
      if (arguments.length == 3) {
  
        dx = arguments[1];
  
        dy = arguments[2];
  
        sx = sy = 0;
  
        sw = dw = w;
  
        sh = dh = h;
  
      } else if (arguments.length == 5) {
  
        dx = arguments[1];
  
        dy = arguments[2];
  
        dw = arguments[3];
  
        dh = arguments[4];
  
        sx = sy = 0;
  
        sw = w;
  
        sh = h;
  
      } else if (arguments.length == 9) {
  
        sx = arguments[1];
  
        sy = arguments[2];
  
        sw = arguments[3];
  
        sh = arguments[4];
  
        dx = arguments[5];
  
        dy = arguments[6];
  
        dw = arguments[7];
  
        dh = arguments[8];
  
      } else {
  
        throw Error('Invalid number of arguments');
  
      }
  
  
  
      var d = getCoords(this, dx, dy);
  
  
  
      var w2 = sw / 2;
  
      var h2 = sh / 2;
  
  
  
      var vmlStr = [];
  
  
  
      var W = 10;
  
      var H = 10;
  
  
  
      // For some reason that I've now forgotten, using divs didn't work
  
      vmlStr.push(' <g_vml_:group',
  
                  ' coordsize="', Z * W, ',', Z * H, '"',
  
                  ' coordorigin="0,0"' ,
  
                  ' style="width:', W, 'px;height:', H, 'px;position:absolute;');
  
  
  
      // If filters are necessary (rotation exists), create them
  
      // filters are bog-slow, so only create them if abbsolutely necessary
  
      // The following check doesn't account for skews (which don't exist
  
      // in the canvas spec (yet) anyway.
  
  
  
      if (this.m_[0][0] != 1 || this.m_[0][1] ||
  
          this.m_[1][1] != 1 || this.m_[1][0]) {
  
        var filter = [];
  
  
  
        // Note the 12/21 reversal
  
        filter.push('M11=', this.m_[0][0], ',',
  
                    'M12=', this.m_[1][0], ',',
  
                    'M21=', this.m_[0][1], ',',
  
                    'M22=', this.m_[1][1], ',',
  
                    'Dx=', mr(d.x / Z), ',',
  
                    'Dy=', mr(d.y / Z), '');
  
  
  
        // Bounding box calculation (need to minimize displayed area so that
  
        // filters don't waste time on unused pixels.
  
        var max = d;
  
        var c2 = getCoords(this, dx + dw, dy);
  
        var c3 = getCoords(this, dx, dy + dh);
  
        var c4 = getCoords(this, dx + dw, dy + dh);
  
  
  
        max.x = m.max(max.x, c2.x, c3.x, c4.x);
  
        max.y = m.max(max.y, c2.y, c3.y, c4.y);
  
  
  
        vmlStr.push('padding:0 ', mr(max.x / Z), 'px ', mr(max.y / Z),
  
                    'px 0;filter:progid:DXImageTransform.Microsoft.Matrix(',
  
                    filter.join(''), ", sizingmethod='clip');");
  
  
  
      } else {
  
        vmlStr.push('top:', mr(d.y / Z), 'px;left:', mr(d.x / Z), 'px;');
  
      }
  
  
  
      vmlStr.push(' ">' ,
  
                  '<g_vml_:image src="', image.src, '"',
  
                  ' style="width:', Z * dw, 'px;',
  
                  ' height:', Z * dh, 'px"',
  
                  ' cropleft="', sx / w, '"',
  
                  ' croptop="', sy / h, '"',
  
                  ' cropright="', (w - sx - sw) / w, '"',
  
                  ' cropbottom="', (h - sy - sh) / h, '"',
  
                  ' />',
  
                  '</g_vml_:group>');
  
  
  
      this.element_.insertAdjacentHTML('BeforeEnd', vmlStr.join(''));
  
    };
  
  
  
    contextPrototype.stroke = function(aFill) {
  
      var W = 10;
  
      var H = 10;
  
      // Divide the shape into chunks if it's too long because IE has a limit
  
      // somewhere for how long a VML shape can be. This simple division does
  
      // not work with fills, only strokes, unfortunately.
  
      var chunkSize = 5000;
  
  
  
      var min = {x: null, y: null};
  
      var max = {x: null, y: null};
  
  
  
      for (var j = 0; j < this.currentPath_.length; j += chunkSize) {
  
        var lineStr = [];
  
        var lineOpen = false;
  
  
  
        lineStr.push('<g_vml_:shape',
  
                     ' filled="', !!aFill, '"',
  
                     ' style="position:absolute;width:', W, 'px;height:', H, 'px;"',
  
                     ' coordorigin="0,0"',
  
                     ' coordsize="', Z * W, ',', Z * H, '"',
  
                     ' stroked="', !aFill, '"',
  
                     ' path="');
  
  
  
        var newSeq = false;
  
  
  
        for (var i = j; i < Math.min(j + chunkSize, this.currentPath_.length); i++) {
  
          if (i % chunkSize == 0 && i > 0) { // move into position for next chunk
  
            lineStr.push(' m ', mr(this.currentPath_[i-1].x), ',', mr(this.currentPath_[i-1].y));
  
          }
  
  
  
          var p = this.currentPath_[i];
  
          var c;
  
  
  
          switch (p.type) {
  
            case 'moveTo':
  
              c = p;
  
              lineStr.push(' m ', mr(p.x), ',', mr(p.y));
  
              break;
  
            case 'lineTo':
  
              lineStr.push(' l ', mr(p.x), ',', mr(p.y));
  
              break;
  
            case 'close':
  
              lineStr.push(' x ');
  
              p = null;
  
              break;
  
            case 'bezierCurveTo':
  
              lineStr.push(' c ',
  
                           mr(p.cp1x), ',', mr(p.cp1y), ',',
  
                           mr(p.cp2x), ',', mr(p.cp2y), ',',
  
                           mr(p.x), ',', mr(p.y));
  
              break;
  
            case 'at':
  
            case 'wa':
  
              lineStr.push(' ', p.type, ' ',
  
                           mr(p.x - this.arcScaleX_ * p.radius), ',',
  
                           mr(p.y - this.arcScaleY_ * p.radius), ' ',
  
                           mr(p.x + this.arcScaleX_ * p.radius), ',',
  
                           mr(p.y + this.arcScaleY_ * p.radius), ' ',
  
                           mr(p.xStart), ',', mr(p.yStart), ' ',
  
                           mr(p.xEnd), ',', mr(p.yEnd));
  
              break;
  
          }
  
    
  
    
  
          // TODO: Following is broken for curves due to
  
          //       move to proper paths.
  
    
  
          // Figure out dimensions so we can do gradient fills
  
          // properly
  
          if (p) {
  
            if (min.x == null || p.x < min.x) {
  
              min.x = p.x;
  
            }
  
            if (max.x == null || p.x > max.x) {
  
              max.x = p.x;
  
            }
  
            if (min.y == null || p.y < min.y) {
  
              min.y = p.y;
  
            }
  
            if (max.y == null || p.y > max.y) {
  
              max.y = p.y;
  
            }
  
          }
  
        }
  
        lineStr.push(' ">');
  
    
  
        if (!aFill) {
  
          appendStroke(this, lineStr);
  
        } else {
  
          appendFill(this, lineStr, min, max);
  
        }
  
    
  
        lineStr.push('</g_vml_:shape>');
  
    
  
        this.element_.insertAdjacentHTML('beforeEnd', lineStr.join(''));
  
      }
  
    };
  
  
  
    function appendStroke(ctx, lineStr) {
  
      var a = processStyle(ctx.strokeStyle);
  
      var color = a.color;
  
      var opacity = a.alpha * ctx.globalAlpha;
  
      var lineWidth = ctx.lineScale_ * ctx.lineWidth;
  
  
  
      // VML cannot correctly render a line if the width is less than 1px.
  
      // In that case, we dilute the color to make the line look thinner.
  
      if (lineWidth < 1) {
  
        opacity *= lineWidth;
  
      }
  
  
  
      lineStr.push(
  
        '<g_vml_:stroke',
  
        ' opacity="', opacity, '"',
  
        ' joinstyle="', ctx.lineJoin, '"',
  
        ' miterlimit="', ctx.miterLimit, '"',
  
        ' endcap="', processLineCap(ctx.lineCap), '"',
  
        ' weight="', lineWidth, 'px"',
  
        ' color="', color, '" />'
  
      );
  
    }
  
  
  
    function appendFill(ctx, lineStr, min, max) {
  
      var fillStyle = ctx.fillStyle;
  
      var arcScaleX = ctx.arcScaleX_;
  
      var arcScaleY = ctx.arcScaleY_;
  
      var width = max.x - min.x;
  
      var height = max.y - min.y;
  
      if (fillStyle instanceof CanvasGradient_) {
  
        // TODO: Gradients transformed with the transformation matrix.
  
        var angle = 0;
  
        var focus = {x: 0, y: 0};
  
  
  
        // additional offset
  
        var shift = 0;
  
        // scale factor for offset
  
        var expansion = 1;
  
  
  
        if (fillStyle.type_ == 'gradient') {
  
          var x0 = fillStyle.x0_ / arcScaleX;
  
          var y0 = fillStyle.y0_ / arcScaleY;
  
          var x1 = fillStyle.x1_ / arcScaleX;
  
          var y1 = fillStyle.y1_ / arcScaleY;
  
          var p0 = getCoords(ctx, x0, y0);
  
          var p1 = getCoords(ctx, x1, y1);
  
          var dx = p1.x - p0.x;
  
          var dy = p1.y - p0.y;
  
          angle = Math.atan2(dx, dy) * 180 / Math.PI;
  
  
  
          // The angle should be a non-negative number.
  
          if (angle < 0) {
  
            angle += 360;
  
          }
  
  
  
          // Very small angles produce an unexpected result because they are
  
          // converted to a scientific notation string.
  
          if (angle < 1e-6) {
  
            angle = 0;
  
          }
  
        } else {
  
          var p0 = getCoords(ctx, fillStyle.x0_, fillStyle.y0_);
  
          focus = {
  
            x: (p0.x - min.x) / width,
  
            y: (p0.y - min.y) / height
  
          };
  
  
  
          width  /= arcScaleX * Z;
  
          height /= arcScaleY * Z;
  
          var dimension = m.max(width, height);
  
          shift = 2 * fillStyle.r0_ / dimension;
  
          expansion = 2 * fillStyle.r1_ / dimension - shift;
  
        }
  
  
  
        // We need to sort the color stops in ascending order by offset,
  
        // otherwise IE won't interpret it correctly.
  
        var stops = fillStyle.colors_;
  
        stops.sort(function(cs1, cs2) {
  
          return cs1.offset - cs2.offset;
  
        });
  
  
  
        var length = stops.length;
  
        var color1 = stops[0].color;
  
        var color2 = stops[length - 1].color;
  
        var opacity1 = stops[0].alpha * ctx.globalAlpha;
  
        var opacity2 = stops[length - 1].alpha * ctx.globalAlpha;
  
  
  
        var colors = [];
  
        for (var i = 0; i < length; i++) {
  
          var stop = stops[i];
  
          colors.push(stop.offset * expansion + shift + ' ' + stop.color);
  
        }
  
  
  
        // When colors attribute is used, the meanings of opacity and o:opacity2
  
        // are reversed.
  
        lineStr.push('<g_vml_:fill type="', fillStyle.type_, '"',
  
                     ' method="none" focus="100%"',
  
                     ' color="', color1, '"',
  
                     ' color2="', color2, '"',
  
                     ' colors="', colors.join(','), '"',
  
                     ' opacity="', opacity2, '"',
  
                     ' g_o_:opacity2="', opacity1, '"',
  
                     ' angle="', angle, '"',
  
                     ' focusposition="', focus.x, ',', focus.y, '" />');
  
      } else if (fillStyle instanceof CanvasPattern_) {
  
        if (width && height) {
  
          var deltaLeft = -min.x;
  
          var deltaTop = -min.y;
  
          lineStr.push('<g_vml_:fill',
  
                       ' position="',
  
                       deltaLeft / width * arcScaleX * arcScaleX, ',',
  
                       deltaTop / height * arcScaleY * arcScaleY, '"',
  
                       ' type="tile"',
  
                       // TODO: Figure out the correct size to fit the scale.
  
                       //' size="', w, 'px ', h, 'px"',
  
                       ' src="', fillStyle.src_, '" />');
  
         }
  
      } else {
  
        var a = processStyle(ctx.fillStyle);
  
        var color = a.color;
  
        var opacity = a.alpha * ctx.globalAlpha;
  
        lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity,
  
                     '" />');
  
      }
  
    }
  
  
  
    contextPrototype.fill = function() {
  
      this.stroke(true);
  
    };
  
  
  
    contextPrototype.closePath = function() {
  
      this.currentPath_.push({type: 'close'});
  
    };
  
  
  
    function getCoords(ctx, aX, aY) {
  
      var m = ctx.m_;
  
      return {
  
        x: Z * (aX * m[0][0] + aY * m[1][0] + m[2][0]) - Z2,
  
        y: Z * (aX * m[0][1] + aY * m[1][1] + m[2][1]) - Z2
  
      };
  
    }
  
      contextPrototype.save = function() {
  
      var o = {};
  
      copyState(this, o);
  
      this.aStack_.push(o);
  
      this.mStack_.push(this.m_);
  
      this.m_ = matrixMultiply(createMatrixIdentity(), this.m_);
  
    };
  
  
  
    contextPrototype.restore = function() {
  
      if (this.aStack_.length) {
  
        copyState(this.aStack_.pop(), this);
  
        this.m_ = this.mStack_.pop();
  
      }
  
    };
  
  
  
    function matrixIsFinite(m) {
  
      return isFinite(m[0][0]) && isFinite(m[0][1]) &&
  
          isFinite(m[1][0]) && isFinite(m[1][1]) &&
  
          isFinite(m[2][0]) && isFinite(m[2][1]);
  
    }
  
  
  
    function setM(ctx, m, updateLineScale) {
  
      if (!matrixIsFinite(m)) {
  
        return;
  
      }
  
      ctx.m_ = m;
  
  
  
      if (updateLineScale) {
  
        // Get the line scale.
  
        // Determinant of this.m_ means how much the area is enlarged by the
  
        // transformation. So its square root can be used as a scale factor
  
        // for width.
  
        var det = m[0][0] * m[1][1] - m[0][1] * m[1][0];
  
        ctx.lineScale_ = sqrt(abs(det));
  
      }
  
    }
  
  
  
    contextPrototype.translate = function(aX, aY) {
  
      var m1 = [
  
        [1,  0,  0],
  
        [0,  1,  0],
  
        [aX, aY, 1]
  
      ];
  
  
  
      setM(this, matrixMultiply(m1, this.m_), false);
  
    };
  
  
  
    contextPrototype.rotate = function(aRot) {
  
      var c = mc(aRot);
  
      var s = ms(aRot);
  
  
  
      var m1 = [
  
        [c,  s, 0],
  
        [-s, c, 0],
  
        [0,  0, 1]
  
      ];
  
  
  
      setM(this, matrixMultiply(m1, this.m_), false);
  
    };
  
  
  
    contextPrototype.scale = function(aX, aY) {
  
      this.arcScaleX_ *= aX;
  
      this.arcScaleY_ *= aY;
  
      var m1 = [
  
        [aX, 0,  0],
  
        [0,  aY, 0],
  
        [0,  0,  1]
  
      ];
  
  
  
      setM(this, matrixMultiply(m1, this.m_), true);
  
    };
  
  
  
    contextPrototype.transform = function(m11, m12, m21, m22, dx, dy) {
  
      var m1 = [
  
        [m11, m12, 0],
  
        [m21, m22, 0],
  
        [dx,  dy,  1]
  
      ];
  
  
  
      setM(this, matrixMultiply(m1, this.m_), true);
  
    };
  
  
  
    contextPrototype.setTransform = function(m11, m12, m21, m22, dx, dy) {
  
      var m = [
  
        [m11, m12, 0],
  
        [m21, m22, 0],
  
        [dx,  dy,  1]
  
      ];
  
  
  
      setM(this, m, true);
  
    };
  
  
  
    /**
  
     * The text drawing function.
  
     * The maxWidth argument isn't taken in account, since no browser supports
  
     * it yet.
  
     */
  
    contextPrototype.drawText_ = function(text, x, y, maxWidth, stroke) {
  
      var m = this.m_,
  
          delta = 1000,
  
          left = 0,
  
          right = delta,
  
          offset = {x: 0, y: 0},
  
          lineStr = [];
  
  
  
      var fontStyle = getComputedStyle(processFontStyle(this.font),
  
                                       this.element_);
  
  
  
      var fontStyleString = buildStyle(fontStyle);
  
  
  
      var elementStyle = this.element_.currentStyle;
  
      var textAlign = this.textAlign.toLowerCase();
  
      switch (textAlign) {
  
        case 'left':
  
        case 'center':
  
        case 'right':
  
          break;
  
        case 'end':
  
          textAlign = elementStyle.direction == 'ltr' ? 'right' : 'left';
  
          break;
  
        case 'start':
  
          textAlign = elementStyle.direction == 'rtl' ? 'right' : 'left';
  
          break;
  
        default:
  
          textAlign = 'left';
  
      }
  
  
  
      // 1.75 is an arbitrary number, as there is no info about the text baseline
  
      switch (this.textBaseline) {
  
        case 'hanging':
  
        case 'top':
  
          offset.y = fontStyle.size / 1.75;
  
          break;
  
        case 'middle':
  
          break;
  
        default:
  
        case null:
  
        case 'alphabetic':
  
        case 'ideographic':
  
        case 'bottom':
  
          offset.y = -fontStyle.size / 2.25;
  
          break;
  
      }
  
  
  
      switch(textAlign) {
  
        case 'right':
  
          left = delta;
  
          right = 0.05;
  
          break;
  
        case 'center':
  
          left = right = delta / 2;
  
          break;
  
      }
  
  
  
      var d = getCoords(this, x + offset.x, y + offset.y);
  
  
  
      lineStr.push('<g_vml_:line from="', -left ,' 0" to="', right ,' 0.05" ',
  
                   ' coordsize="100 100" coordorigin="0 0"',
  
                   ' filled="', !stroke, '" stroked="', !!stroke,
  
                   '" style="position:absolute;width:1px;height:1px;">');
  
  
  
      if (stroke) {
  
        appendStroke(this, lineStr);
  
      } else {
  
        // TODO: Fix the min and max params.
  
        appendFill(this, lineStr, {x: -left, y: 0},
  
                   {x: right, y: fontStyle.size});
  
      }
  
  
  
      var skewM = m[0][0].toFixed(3) + ',' + m[1][0].toFixed(3) + ',' +
  
                  m[0][1].toFixed(3) + ',' + m[1][1].toFixed(3) + ',0,0';
  
  
  
      var skewOffset = mr(d.x / Z) + ',' + mr(d.y / Z);
  
  
  
      lineStr.push('<g_vml_:skew on="t" matrix="', skewM ,'" ',
  
                   ' offset="', skewOffset, '" origin="', left ,' 0" />',
  
                   '<g_vml_:path textpathok="true" />',
  
                   '<g_vml_:textpath on="true" string="',
  
                   encodeHtmlAttribute(text),
  
                   '" style="v-text-align:', textAlign,
  
                   ';font:', encodeHtmlAttribute(fontStyleString),
  
                   '" /></g_vml_:line>');
  
  
  
      this.element_.insertAdjacentHTML('beforeEnd', lineStr.join(''));
  
    };
  
  
  
    contextPrototype.fillText = function(text, x, y, maxWidth) {
  
      this.drawText_(text, x, y, maxWidth, false);
  
    };
  
  
  
    contextPrototype.strokeText = function(text, x, y, maxWidth) {
  
      this.drawText_(text, x, y, maxWidth, true);
  
    };
  
  
  
    contextPrototype.measureText = function(text) {
  
      if (!this.textMeasureEl_) {
  
        var s = '<span style="position:absolute;' +
  
            'top:-20000px;left:0;padding:0;margin:0;border:none;' +
  
            'white-space:pre;"></span>';
  
        this.element_.insertAdjacentHTML('beforeEnd', s);
  
        this.textMeasureEl_ = this.element_.lastChild;
  
      }
  
      var doc = this.element_.ownerDocument;
  
      this.textMeasureEl_.innerHTML = '';
  
      this.textMeasureEl_.style.font = this.font;
  
      // Don't use innerHTML or innerText because they allow markup/whitespace.
  
      this.textMeasureEl_.appendChild(doc.createTextNode(text));
  
      return {width: this.textMeasureEl_.offsetWidth};
  
    };
  
  
  
    /******** STUBS ********/
  
    contextPrototype.clip = function() {
  
      // TODO: Implement
  
    };
  
  
  
    contextPrototype.arcTo = function() {
  
      // TODO: Implement
  
    };
  
  
  
    contextPrototype.createPattern = function(image, repetition) {
  
      return new CanvasPattern_(image, repetition);
  
    };
  
  
  
    // Gradient / Pattern Stubs
  
    function CanvasGradient_(aType) {
  
      this.type_ = aType;
  
      this.x0_ = 0;
  
      this.y0_ = 0;
  
      this.r0_ = 0;
  
      this.x1_ = 0;
  
      this.y1_ = 0;
  
      this.r1_ = 0;
  
      this.colors_ = [];
  
    }
  
  
  
    CanvasGradient_.prototype.addColorStop = function(aOffset, aColor) {
  
      aColor = processStyle(aColor);
  
      this.colors_.push({offset: aOffset,
  
                         color: aColor.color,
  
                         alpha: aColor.alpha});
  
    };
  
  
  
    function CanvasPattern_(image, repetition) {
  
      assertImageIsValid(image);
  
      switch (repetition) {
  
        case 'repeat':
  
        case null:
  
        case '':
  
          this.repetition_ = 'repeat';
  
          break;
  
        case 'repeat-x':
  
        case 'repeat-y':
  
        case 'no-repeat':
  
          this.repetition_ = repetition;
  
          break;
  
        default:
  
          throwException('SYNTAX_ERR');
  
      }
  
  
  
      this.src_ = image.src;
  
      this.width_ = image.width;
  
      this.height_ = image.height;
  
    }
  
  
  
    function throwException(s) {
  
      throw new DOMException_(s);
  
    }
  
  
  
    function assertImageIsValid(img) {
  
      if (!img || img.nodeType != 1 || img.tagName != 'IMG') {
  
        throwException('TYPE_MISMATCH_ERR');
  
      }
  
      if (img.readyState != 'complete') {
  
        throwException('INVALID_STATE_ERR');
  
      }
  
    }
  
  
  
    function DOMException_(s) {
  
      this.code = this[s];
  
      this.message = s +': DOM Exception ' + this.code;
  
    }
  
    var p = DOMException_.prototype = new Error;
  
    p.INDEX_SIZE_ERR = 1;
  
    p.DOMSTRING_SIZE_ERR = 2;
  
    p.HIERARCHY_REQUEST_ERR = 3;
  
    p.WRONG_DOCUMENT_ERR = 4;
  
    p.INVALID_CHARACTER_ERR = 5;
  
    p.NO_DATA_ALLOWED_ERR = 6;
  
    p.NO_MODIFICATION_ALLOWED_ERR = 7;
  
    p.NOT_FOUND_ERR = 8;
  
    p.NOT_SUPPORTED_ERR = 9;
  
    p.INUSE_ATTRIBUTE_ERR = 10;
  
    p.INVALID_STATE_ERR = 11;
  
    p.SYNTAX_ERR = 12;
  
    p.INVALID_MODIFICATION_ERR = 13;
  
    p.NAMESPACE_ERR = 14;
  
    p.INVALID_ACCESS_ERR = 15;
  
    p.VALIDATION_ERR = 16;
  
    p.TYPE_MISMATCH_ERR = 17;
  
  
  
    // set up externs
  
    G_vmlCanvasManager = G_vmlCanvasManager_;
  
    CanvasRenderingContext2D = CanvasRenderingContext2D_;
  
    CanvasGradient = CanvasGradient_;
  
    CanvasPattern = CanvasPattern_;
  
    DOMException = DOMException_;
  
  })();
  
  
  
  } // if
  
  