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File: excanvas.js
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Description: javascript lib (only for IE)
Class: cDWF
Render workflow diagrams in HTML or Flash
Author: By
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Date: 11 years ago
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// 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 are not implemented. // * 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. // * 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; /** * 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))); }; } var G_vmlCanvasManager_ = { init: function(opt_doc) { if (/MSIE/.test(navigator.userAgent) && !window.opera) { 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) { // create xmlns if (!doc.namespaces['g_vml_']) { doc.namespaces.add('g_vml_', 'urn:schemas-microsoft-com:vml', '#default#VML'); } if (!doc.namespaces['g_o_']) { doc.namespaces.add('g_o_', 'urn:schemas-microsoft-com:office:office', '#default#VML'); } // 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}' + 'g_vml_\\:*{behavior:url(#default#VML)}' + 'g_o_\\:*{behavior:url(#default#VML)}'; } // 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; // 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.style.width = el.attributes.width.nodeValue + 'px'; el.getContext().clearRect(); break; case 'height': el.style.height = el.attributes.height.nodeValue + 'px'; el.getContext().clearRect(); 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 dec2hex = []; for (var i = 0; i < 16; i++) { for (var j = 0; j < 16; j++) { dec2hex[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.arcScaleX_ = o1.arcScaleX_; o2.arcScaleY_ = o1.arcScaleY_; o2.lineScale_ = o1.lineScale_; } function processStyle(styleString) { var str, alpha = 1; styleString = String(styleString); if (styleString.substring(0, 3) == 'rgb') { var start = styleString.indexOf('(', 3); var end = styleString.indexOf(')', start + 1); var guts = styleString.substring(start + 1, end).split(','); str = '#'; for (var i = 0; i < 3; i++) { str += dec2hex[Number(guts[i])]; } if (guts.length == 4 && styleString.substr(3, 1) == 'a') { alpha = guts[3]; } } else { str = styleString; } return {color: str, alpha: alpha}; } function processLineCap(lineCap) { switch (lineCap) { case 'butt': return 'flat'; case 'round': return 'round'; case 'square': default: return 'square'; } } /** * This class implements CanvasRenderingContext2D interface as described by * the WHATWG. * @param {HTMLElement} surfaceElement The element that the 2D context should * be associated with */ function CanvasRenderingContext2D_(surfaceElement) { 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.canvas = surfaceElement; var el = surfaceElement.ownerDocument.createElement('div'); el.style.width = surfaceElement.clientWidth + 'px'; el.style.height = surfaceElement.clientHeight + 'px'; el.style.overflow = 'hidden'; el.style.position = 'absolute'; surfaceElement.appendChild(el); this.element_ = el; this.arcScaleX_ = 1; this.arcScaleY_ = 1; this.lineScale_ = 1; } var contextPrototype = CanvasRenderingContext2D_.prototype; contextPrototype.clearRect = function() { 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 = this.getCoords_(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 = this.getCoords_(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 = this.getCoords_(aX, aY); var cp1 = this.getCoords_(aCP1x, aCP1y); var cp2 = this.getCoords_(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 = this.getCoords_(aCPx, aCPy); var p = this.getCoords_(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 = this.getCoords_(aX, aY); var pStart = this.getCoords_(xStart, yStart); var pEnd = this.getCoords_(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 = this.getCoords_(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]) { 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 = this.getCoords_(dx + dw, dy); var c3 = this.getCoords_(dx, dy + dh); var c4 = this.getCoords_(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 lineStr = []; var lineOpen = false; var a = processStyle(aFill ? this.fillStyle : this.strokeStyle); var color = a.color; var opacity = a.alpha * this.globalAlpha; var W = 10; var H = 10; 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; var min = {x: null, y: null}; var max = {x: null, y: null}; for (var i = 0; i < this.currentPath_.length; i++) { 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) { var lineWidth = this.lineScale_ * this.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="', this.lineJoin, '"', ' miterlimit="', this.miterLimit, '"', ' endcap="', processLineCap(this.lineCap), '"', ' weight="', lineWidth, 'px"', ' color="', color, '" />' ); } else if (typeof this.fillStyle == 'object') { var fillStyle = this.fillStyle; 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_ / this.arcScaleX_; var y0 = fillStyle.y0_ / this.arcScaleY_; var x1 = fillStyle.x1_ / this.arcScaleX_; var y1 = fillStyle.y1_ / this.arcScaleY_; var p0 = this.getCoords_(x0, y0); var p1 = this.getCoords_(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 = this.getCoords_(fillStyle.x0_, fillStyle.y0_); var width = max.x - min.x; var height = max.y - min.y; focus = { x: (p0.x - min.x) / width, y: (p0.y - min.y) / height }; width /= this.arcScaleX_ * Z; height /= this.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 * this.globalAlpha; var opacity2 = stops[length - 1].alpha * this.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 { lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity, '" />'); } lineStr.push('</g_vml_:shape>'); this.element_.insertAdjacentHTML('beforeEnd', lineStr.join('')); }; contextPrototype.fill = function() { this.stroke(true); } contextPrototype.closePath = function() { this.currentPath_.push({type: 'close'}); }; /** * @private */ contextPrototype.getCoords_ = function(aX, aY) { var m = this.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() { copyState(this.aStack_.pop(), this); this.m_ = this.mStack_.pop(); }; function matrixIsFinite(m) { for (var j = 0; j < 3; j++) { for (var k = 0; k < 2; k++) { if (!isFinite(m[j][k]) || isNaN(m[j][k])) { return false; } } } return true; } 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); }; /******** STUBS ********/ contextPrototype.clip = function() { // TODO: Implement }; contextPrototype.arcTo = function() { // TODO: Implement }; contextPrototype.createPattern = function() { return new CanvasPattern_; }; // 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_() {} // set up externs G_vmlCanvasManager = G_vmlCanvasManager_; CanvasRenderingContext2D = CanvasRenderingContext2D_; CanvasGradient = CanvasGradient_; CanvasPattern = CanvasPattern_; })(); } // if