/*

html2canvas @VERSION@ <http://html2canvas.hertzen.com>

Copyright (c) 2011 Niklas von Hertzen. All rights reserved.

http://www.twitter.com/niklasvh

Released under MIT License

*/

html2canvas.Preload = function(element, opts){

var options = {

proxy: "http://html2canvas.appspot.com/",

timeout: 0 // no timeout

},

images = {

numLoaded: 0, // also failed are counted here

numFailed: 0,

numTotal: 0,

cleanupDone: false

},

pageOrigin,

methods,

i,

count = 0,

doc = element.ownerDocument,

domImages = doc.images, // TODO probably should limit it to images present in the element only

imgLen = domImages.length,

link = doc.createElement("a"),

timeoutTimer;

link.href = window.location.href;

pageOrigin = link.protocol + link.host;

opts = opts || {};

options = html2canvas.Util.Extend(opts, options);

element = element || doc.body;

function isSameOrigin(url){

link.href = url;

var origin = link.protocol + link.host;

return ":" === origin || (origin === pageOrigin);

}

function start(){

html2canvas.log("html2canvas: start: images: " + images.numLoaded + " / " + images.numTotal + " (failed: " + images.numFailed + ")");

if (!images.firstRun && images.numLoaded >= images.numTotal){

/*

this.log('Finished loading '+this.imagesLoaded+' images, Started parsing');

this.bodyOverflow = document.getElementsByTagName('body')[0].style.overflow;

document.getElementsByTagName('body')[0].style.overflow = "hidden";

*/

if (typeof options.complete === "function"){

options.complete(images);

}

html2canvas.log("Finished loading images: # " + images.numTotal + " (failed: " + images.numFailed + ")");

}

}

function proxyGetImage(url, img){

var callback_name,

scriptUrl = options.proxy,

script,

imgObj = images[url];

link.href = url;

url = link.href; // work around for pages with base href="" set - WARNING: this may change the url -> so access imgObj from images map before changing that url!

callback_name = 'html2canvas_' + count;

imgObj.callbackname = callback_name;

if (scriptUrl.indexOf("?") > -1) {

scriptUrl += "&";

} else {

scriptUrl += "?";

}

scriptUrl += 'url=' + encodeURIComponent(url) + '&callback=' + callback_name;

window[callback_name] = function(a){

if (a.substring(0,6) === "error:"){

imgObj.succeeded = false;

images.numLoaded++;

images.numFailed++;

start();

} else {

img.onload = function(){

imgObj.succeeded = true;

images.numLoaded++;

start();

};

img.src = a;

}

window[callback_name] = undefined; // to work with IE<9 // NOTE: that the undefined callback property-name still exists on the window object (for IE<9)

try {

delete window[callback_name]; // for all browser that support this

} catch(ex) {}

script.parentNode.removeChild(script);

script = null;

imgObj.callbackname = undefined;

};

count += 1;

script = doc.createElement("script");

script.setAttribute("src", scriptUrl);

script.setAttribute("type", "text/javascript");

imgObj.script = script;

window.document.body.appendChild(script);

/*

// enable xhr2 requests where available (no need for base64 / json)

$.ajax({

data:{

xhr2:false,

url:url

},

url: options.proxy,

dataType: "jsonp",

success: function(a){

if (a.substring(0,6) === "error:"){

images.splice(getIndex(images, url), 2);

start();

}else{

img.onload = function(){

imagesLoaded+=1;

start();

};

img.src = a;

}

},

error: function(){

images.splice(getIndex(images, url), 2);

start();

}

});

*/

}

function getImages (el) {

// if (!this.ignoreRe.test(el.nodeName)){

//

var contents = html2canvas.Util.Children(el),

i,

contentsLen = contents.length,

background_image,

src,

img,

elNodeType = false;

for (i = 0; i < contentsLen; i+=1 ){

// var ignRe = new RegExp("("+this.ignoreElements+")");

// if (!ignRe.test(element.nodeName)){

getImages(contents[i]);

// }

}

// }

try {

elNodeType = el.nodeType;

} catch (ex) {

elNodeType = false;

html2canvas.log("html2canvas: failed to access some element's nodeType - Exception: " + ex.message);

}

if (elNodeType === 1 || elNodeType === undefined){

background_image = html2canvas.Util.getCSS(el, 'backgroundImage');

if ( background_image && background_image !== "1" && background_image !== "none" ) {

// TODO add multi image background support

if (background_image.substring(0,7) === "-webkit" || background_image.substring(0,3) === "-o-" || background_image.substring(0,4) === "-moz") {

img = html2canvas.Generate.Gradient( background_image, html2canvas.Util.Bounds( el ) );

if ( img !== undefined ){

images[background_image] = { img: img, succeeded: true };

images.numTotal++;

images.numLoaded++;

start();

}

} else {

src = html2canvas.Util.backgroundImage(background_image.match(/data:image\/.*;base64,/i) ? background_image : background_image.split(",")[0]);

methods.loadImage(src);

}

/*

if (background_image && background_image !== "1" && background_image !== "none" && background_image.substring(0,7) !== "-webkit" && background_image.substring(0,3)!== "-o-" && background_image.substring(0,4) !== "-moz"){

// TODO add multi image background support

src = html2canvas.Util.backgroundImage(background_image.split(",")[0]);

methods.loadImage(src); */

}

}

}

methods = {

loadImage: function( src ) {

var img;

if ( src && images[src] === undefined ) {

if ( src.match(/data:image\/.*;base64,/i) ) {

//Base64 src

img = new Image();

img.src = src.replace(/url\(['"]{0,}|['"]{0,}\)$/ig, '');

images[src] = { img: img, succeeded: true };

images.numTotal++;

images.numLoaded++;

start();

}else if ( isSameOrigin( src ) ) {

img = new Image();

images[src] = { img: img };

images.numTotal++;

img.onload = function() {

images.numLoaded++;

images[src].succeeded = true;

start();

};

img.onerror = function() {

images.numLoaded++;

images.numFailed++;

images[src].succeeded = false;

start();

};

img.src = src;

}else if ( options.proxy ){

// console.log('b'+src);

img = new Image();

images[src] = { img: img };

images.numTotal++;

proxyGetImage( src, img );

}

}

},

cleanupDOM: function(cause) {

var img, src;

if (!images.cleanupDone) {

if (cause && typeof cause === "string") {

html2canvas.log("html2canvas: Cleanup because: " + cause);

} else {

html2canvas.log("html2canvas: Cleanup after timeout: " + options.timeout + " ms.");

}

for (src in images) {

if (images.hasOwnProperty(src)) {

img = images[src];

if (typeof img === "object" && img.callbackname && img.succeeded === undefined) {

// cancel proxy image request

window[img.callbackname] = undefined; // to work with IE<9 // NOTE: that the undefined callback property-name still exists on the window object (for IE<9)

try {

delete window[img.callbackname]; // for all browser that support this

} catch(ex) {}

if (img.script && img.script.parentNode) {

img.script.setAttribute("src", "about:blank"); // try to cancel running request

img.script.parentNode.removeChild(img.script);

}

images.numLoaded++;

images.numFailed++;

html2canvas.log("html2canvas: Cleaned up failed img: '" + src + "' Steps: " + images.numLoaded + " / " + images.numTotal);

}

}

}

// cancel any pending requests

if(window.stop !== undefined) {

window.stop();

} else if(document.execCommand !== undefined) {

document.execCommand("Stop", false);

}

if (document.close !== undefined) {

document.close();

}

images.cleanupDone = true;

if (!(cause && typeof cause === "string")) {

start();

}

}

},

renderingDone: function() {

if (timeoutTimer) {

window.clearTimeout(timeoutTimer);

}

}

};

if (options.timeout > 0) {

timeoutTimer = window.setTimeout(methods.cleanupDOM, options.timeout);

}

var startTime = (new Date()).getTime();

html2canvas.log('html2canvas: Preload starts: finding background-images');

images.firstRun = true;

getImages( element );

html2canvas.log('html2canvas: Preload: Finding images');

// load <img> images

for (i = 0; i < imgLen; i+=1){

methods.loadImage( domImages[i].getAttribute( "src" ) );

}

images.firstRun = false;

html2canvas.log('html2canvas: Preload: Done.');

if ( images.numTotal === images.numLoaded ) {

start();

}

return methods;

};