mirror of
https://github.com/niklasvh/html2canvas.git
synced 2023-08-10 21:13:10 +03:00
329 lines
9.6 KiB
JavaScript
329 lines
9.6 KiB
JavaScript
_html2canvas.Preload = function( options ) {
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var images = {
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numLoaded: 0, // also failed are counted here
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numFailed: 0,
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numTotal: 0,
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cleanupDone: false
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},
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pageOrigin,
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methods,
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i,
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count = 0,
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element = options.elements[0] || document.body,
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doc = element.ownerDocument,
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domImages = doc.images, // TODO probably should limit it to images present in the element only
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imgLen = domImages.length,
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link = doc.createElement("a"),
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supportCORS = (function( img ){
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return (img.crossOrigin !== undefined);
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})(new Image()),
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timeoutTimer;
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link.href = window.location.href;
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pageOrigin = link.protocol + link.host;
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function isSameOrigin(url){
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link.href = url;
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link.href = link.href; // YES, BELIEVE IT OR NOT, that is required for IE9 - http://jsfiddle.net/niklasvh/2e48b/
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var origin = link.protocol + link.host;
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return (origin === pageOrigin);
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}
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function start(){
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h2clog("html2canvas: start: images: " + images.numLoaded + " / " + images.numTotal + " (failed: " + images.numFailed + ")");
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if (!images.firstRun && images.numLoaded >= images.numTotal){
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h2clog("Finished loading images: # " + images.numTotal + " (failed: " + images.numFailed + ")");
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if (typeof options.complete === "function"){
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options.complete(images);
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}
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}
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}
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// TODO modify proxy to serve images with CORS enabled, where available
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function proxyGetImage(url, img, imageObj){
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var callback_name,
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scriptUrl = options.proxy,
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script;
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link.href = url;
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url = link.href; // work around for pages with base href="" set - WARNING: this may change the url
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callback_name = 'html2canvas_' + (count++);
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imageObj.callbackname = callback_name;
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if (scriptUrl.indexOf("?") > -1) {
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scriptUrl += "&";
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} else {
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scriptUrl += "?";
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}
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scriptUrl += 'url=' + encodeURIComponent(url) + '&callback=' + callback_name;
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script = doc.createElement("script");
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window[callback_name] = function(a){
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if (a.substring(0,6) === "error:"){
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imageObj.succeeded = false;
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images.numLoaded++;
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images.numFailed++;
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start();
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} else {
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setImageLoadHandlers(img, imageObj);
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img.src = a;
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}
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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)
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try {
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delete window[callback_name]; // for all browser that support this
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} catch(ex) {}
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script.parentNode.removeChild(script);
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script = null;
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delete imageObj.script;
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delete imageObj.callbackname;
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};
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script.setAttribute("type", "text/javascript");
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script.setAttribute("src", scriptUrl);
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imageObj.script = script;
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window.document.body.appendChild(script);
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}
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function getImages (el) {
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var contents = _html2canvas.Util.Children(el),
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i,
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background_image,
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src,
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img,
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elNodeType = false;
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// Firefox fails with permission denied on pages with iframes
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try {
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var contentsLen = contents.length;
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for (i = 0; i < contentsLen; i+=1 ){
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getImages(contents[i]);
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}
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}
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catch( e ) {}
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try {
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elNodeType = el.nodeType;
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} catch (ex) {
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elNodeType = false;
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h2clog("html2canvas: failed to access some element's nodeType - Exception: " + ex.message);
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}
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if (elNodeType === 1 || elNodeType === undefined){
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// opera throws exception on external-content.html
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try {
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background_image = _html2canvas.Util.getCSS(el, 'backgroundImage');
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}catch(e) {
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h2clog("html2canvas: failed to get background-image - Exception: " + e.message);
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}
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if ( background_image && background_image !== "1" && background_image !== "none" ) {
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// TODO add multi image background support
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if (/^(-webkit|-o|-moz|-ms|linear)-/.test( background_image )) {
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img = _html2canvas.Generate.Gradient( background_image, _html2canvas.Util.Bounds( el ) );
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if ( img !== undefined ){
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images[background_image] = {
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img: img,
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succeeded: true
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};
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images.numTotal++;
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images.numLoaded++;
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start();
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}
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} else {
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src = _html2canvas.Util.backgroundImage(background_image.match(/data:image\/.*;base64,/i) ? background_image : background_image.split(",")[0]);
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methods.loadImage(src);
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}
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}
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}
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}
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function setImageLoadHandlers(img, imageObj) {
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img.onload = function() {
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if ( imageObj.timer !== undefined ) {
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// CORS succeeded
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window.clearTimeout( imageObj.timer );
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}
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images.numLoaded++;
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imageObj.succeeded = true;
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img.onerror = img.onload = null;
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start();
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};
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img.onerror = function() {
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if (img.crossOrigin === "anonymous") {
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// CORS failed
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window.clearTimeout( imageObj.timer );
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// let's try with proxy instead
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if ( options.proxy ) {
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var src = img.src;
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img = new Image();
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imageObj.img = img;
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img.src = src;
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proxyGetImage( img.src, img, imageObj );
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return;
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}
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}
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images.numLoaded++;
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images.numFailed++;
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imageObj.succeeded = false;
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img.onerror = img.onload = null;
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start();
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};
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// TODO Opera has no load/error event for SVG images
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// Opera ninja onload's cached images
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/*
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window.setTimeout(function(){
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if ( img.width !== 0 && imageObj.succeeded === undefined ) {
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img.onload();
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}
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}, 100); // needs a reflow for base64 encoded images? interestingly timeout of 0 doesn't work but 1 does.
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*/
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}
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methods = {
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loadImage: function( src ) {
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var img, imageObj;
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if ( src && images[src] === undefined ) {
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img = new Image();
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if ( src.match(/data:image\/.*;base64,/i) ) {
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img.src = src.replace(/url\(['"]{0,}|['"]{0,}\)$/ig, '');
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imageObj = images[src] = {
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img: img
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};
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images.numTotal++;
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setImageLoadHandlers(img, imageObj);
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} else if ( isSameOrigin( src ) || options.allowTaint === true ) {
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imageObj = images[src] = {
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img: img
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};
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images.numTotal++;
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setImageLoadHandlers(img, imageObj);
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img.src = src;
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} else if ( supportCORS && !options.allowTaint && options.useCORS ) {
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// attempt to load with CORS
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img.crossOrigin = "anonymous";
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imageObj = images[src] = {
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img: img
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};
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images.numTotal++;
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setImageLoadHandlers(img, imageObj);
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img.src = src;
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// work around for https://bugs.webkit.org/show_bug.cgi?id=80028
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img.customComplete = function () {
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if (!this.img.complete) {
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this.timer = window.setTimeout(this.img.customComplete, 100);
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} else {
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this.img.onerror();
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}
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}.bind(imageObj);
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img.customComplete();
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} else if ( options.proxy ) {
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imageObj = images[src] = {
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img: img
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};
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images.numTotal++;
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proxyGetImage( src, img, imageObj );
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}
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}
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},
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cleanupDOM: function(cause) {
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var img, src;
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if (!images.cleanupDone) {
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if (cause && typeof cause === "string") {
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h2clog("html2canvas: Cleanup because: " + cause);
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} else {
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h2clog("html2canvas: Cleanup after timeout: " + options.timeout + " ms.");
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}
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for (src in images) {
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if (images.hasOwnProperty(src)) {
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img = images[src];
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if (typeof img === "object" && img.callbackname && img.succeeded === undefined) {
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// cancel proxy image request
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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)
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try {
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delete window[img.callbackname]; // for all browser that support this
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} catch(ex) {}
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if (img.script && img.script.parentNode) {
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img.script.setAttribute("src", "about:blank"); // try to cancel running request
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img.script.parentNode.removeChild(img.script);
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}
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images.numLoaded++;
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images.numFailed++;
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h2clog("html2canvas: Cleaned up failed img: '" + src + "' Steps: " + images.numLoaded + " / " + images.numTotal);
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}
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}
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}
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// cancel any pending requests
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if(window.stop !== undefined) {
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window.stop();
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} else if(document.execCommand !== undefined) {
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document.execCommand("Stop", false);
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}
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if (document.close !== undefined) {
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document.close();
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}
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images.cleanupDone = true;
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if (!(cause && typeof cause === "string")) {
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start();
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}
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}
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},
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renderingDone: function() {
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if (timeoutTimer) {
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window.clearTimeout(timeoutTimer);
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}
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}
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};
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if (options.timeout > 0) {
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timeoutTimer = window.setTimeout(methods.cleanupDOM, options.timeout);
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}
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h2clog('html2canvas: Preload starts: finding background-images');
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images.firstRun = true;
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getImages( element );
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h2clog('html2canvas: Preload: Finding images');
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// load <img> images
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for (i = 0; i < imgLen; i+=1){
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methods.loadImage( domImages[i].getAttribute( "src" ) );
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}
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images.firstRun = false;
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h2clog('html2canvas: Preload: Done.');
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if ( images.numTotal === images.numLoaded ) {
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start();
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}
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return methods;
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}; |