401 lines
12 KiB
JavaScript
401 lines
12 KiB
JavaScript
/*
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Holder - 1.9 - client side image placeholders
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(c) 2012-2013 Ivan Malopinsky / http://imsky.co
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Provided under the Apache 2.0 License: http://www.apache.org/licenses/LICENSE-2.0
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Commercial use requires attribution.
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*/
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var Holder = Holder || {};
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(function (app, win) {
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var preempted = false,
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fallback = false,
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canvas = document.createElement('canvas');
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//getElementsByClassName polyfill
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document.getElementsByClassName||(document.getElementsByClassName=function(e){var t=document,n,r,i,s=[];if(t.querySelectorAll)return t.querySelectorAll("."+e);if(t.evaluate){r=".//*[contains(concat(' ', @class, ' '), ' "+e+" ')]",n=t.evaluate(r,t,null,0,null);while(i=n.iterateNext())s.push(i)}else{n=t.getElementsByTagName("*"),r=new RegExp("(^|\\s)"+e+"(\\s|$)");for(i=0;i<n.length;i++)r.test(n[i].className)&&s.push(n[i])}return s})
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//getComputedStyle polyfill
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window.getComputedStyle||(window.getComputedStyle=function(e,t){return this.el=e,this.getPropertyValue=function(t){var n=/(\-([a-z]){1})/g;return t=="float"&&(t="styleFloat"),n.test(t)&&(t=t.replace(n,function(){return arguments[2].toUpperCase()})),e.currentStyle[t]?e.currentStyle[t]:null},this})
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//http://javascript.nwbox.com/ContentLoaded by Diego Perini with modifications
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function contentLoaded(n,t){var l="complete",s="readystatechange",u=!1,h=u,c=!0,i=n.document,a=i.documentElement,e=i.addEventListener?"addEventListener":"attachEvent",v=i.addEventListener?"removeEventListener":"detachEvent",f=i.addEventListener?"":"on",r=function(e){(e.type!=s||i.readyState==l)&&((e.type=="load"?n:i)[v](f+e.type,r,u),!h&&(h=!0)&&t.call(n,null))},o=function(){try{a.doScroll("left")}catch(n){setTimeout(o,50);return}r("poll")};if(i.readyState==l)t.call(n,"lazy");else{if(i.createEventObject&&a.doScroll){try{c=!n.frameElement}catch(y){}c&&o()}i[e](f+"DOMContentLoaded",r,u),i[e](f+s,r,u),n[e](f+"load",r,u)}};
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//https://gist.github.com/991057 by Jed Schmidt with modifications
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function selector(a){
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a=a.match(/^(\W)?(.*)/);var b=document["getElement"+(a[1]?a[1]=="#"?"ById":"sByClassName":"sByTagName")](a[2]);
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var ret=[]; b!=null&&(b.length?ret=b:b.length==0?ret=b:ret=[b]); return ret;
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}
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//shallow object property extend
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function extend(a,b){var c={};for(var d in a)c[d]=a[d];for(var e in b)c[e]=b[e];return c}
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//hasOwnProperty polyfill
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if (!Object.prototype.hasOwnProperty)
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Object.prototype.hasOwnProperty = function(prop) {
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var proto = this.__proto__ || this.constructor.prototype;
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return (prop in this) && (!(prop in proto) || proto[prop] !== this[prop]);
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}
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function text_size(width, height, template) {
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var dimension_arr = [height, width].sort();
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var maxFactor = Math.round(dimension_arr[1] / 16),
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minFactor = Math.round(dimension_arr[0] / 16);
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var text_height = Math.max(template.size, maxFactor);
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return {
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height: text_height
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}
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}
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function draw(ctx, dimensions, template, ratio) {
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var ts = text_size(dimensions.width, dimensions.height, template);
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var text_height = ts.height;
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var width = dimensions.width * ratio, height = dimensions.height * ratio;
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var font = template.font ? template.font : "sans-serif";
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canvas.width = width;
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canvas.height = height;
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ctx.textAlign = "center";
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ctx.textBaseline = "middle";
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ctx.fillStyle = template.background;
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ctx.fillRect(0, 0, width, height);
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ctx.fillStyle = template.foreground;
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ctx.font = "bold " + text_height + "px "+font;
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var text = template.text ? template.text : (dimensions.width + "x" + dimensions.height);
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if (ctx.measureText(text).width / width > 1) {
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text_height = template.size / (ctx.measureText(text).width / width);
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}
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//Resetting font size if necessary
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ctx.font = "bold " + (text_height * ratio) + "px "+font;
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ctx.fillText(text, (width / 2), (height / 2), width);
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return canvas.toDataURL("image/png");
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}
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function render(mode, el, holder, src) {
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var dimensions = holder.dimensions,
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theme = holder.theme,
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text = holder.text ? decodeURIComponent(holder.text) : holder.text;
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var dimensions_caption = dimensions.width + "x" + dimensions.height;
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theme = (text ? extend(theme, { text: text }) : theme);
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theme = (holder.font ? extend(theme, {font: holder.font}) : theme);
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var ratio = 1;
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if(window.devicePixelRatio && window.devicePixelRatio > 1){
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ratio = window.devicePixelRatio;
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}
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if (mode == "image") {
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el.setAttribute("data-src", src);
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el.setAttribute("alt", text ? text : theme.text ? theme.text + " [" + dimensions_caption + "]" : dimensions_caption);
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if(fallback || !holder.auto){
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el.style.width = dimensions.width + "px";
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el.style.height = dimensions.height + "px";
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}
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if (fallback) {
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el.style.backgroundColor = theme.background;
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}
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else{
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el.setAttribute("src", draw(ctx, dimensions, theme, ratio));
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}
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} else {
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if (!fallback) {
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el.style.backgroundImage = "url(" + draw(ctx, dimensions, theme, ratio) + ")";
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el.style.backgroundSize = dimensions.width+"px "+dimensions.height+"px";
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}
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}
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};
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function fluid(el, holder, src) {
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var dimensions = holder.dimensions,
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theme = holder.theme,
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text = holder.text;
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var dimensions_caption = dimensions.width + "x" + dimensions.height;
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theme = (text ? extend(theme, {
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text: text
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}) : theme);
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var fluid = document.createElement("div");
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fluid.style.backgroundColor = theme.background;
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fluid.style.color = theme.foreground;
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fluid.className = el.className + " holderjs-fluid";
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fluid.style.width = holder.dimensions.width + (holder.dimensions.width.indexOf("%")>0?"":"px");
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fluid.style.height = holder.dimensions.height + (holder.dimensions.height.indexOf("%")>0?"":"px");
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fluid.id = el.id;
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el.style.width=0;
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el.style.height=0;
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if (theme.text) {
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fluid.appendChild(document.createTextNode(theme.text))
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} else {
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fluid.appendChild(document.createTextNode(dimensions_caption))
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fluid_images.push(fluid);
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setTimeout(fluid_update, 0);
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}
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el.parentNode.insertBefore(fluid, el.nextSibling)
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if(window.jQuery){
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jQuery(function($){
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$(el).on("load", function(){
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el.style.width = fluid.style.width;
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el.style.height = fluid.style.height;
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$(el).show();
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$(fluid).remove();
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});
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})
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}
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}
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function fluid_update() {
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for (i in fluid_images) {
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if(!fluid_images.hasOwnProperty(i)) continue;
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var el = fluid_images[i],
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label = el.firstChild;
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el.style.lineHeight = el.offsetHeight+"px";
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label.data = el.offsetWidth + "x" + el.offsetHeight;
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}
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}
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function parse_flags(flags, options) {
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var ret = {
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theme: settings.themes.gray
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}, render = false;
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for (sl = flags.length, j = 0; j < sl; j++) {
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var flag = flags[j];
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if (app.flags.dimensions.match(flag)) {
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render = true;
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ret.dimensions = app.flags.dimensions.output(flag);
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} else if (app.flags.fluid.match(flag)) {
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render = true;
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ret.dimensions = app.flags.fluid.output(flag);
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ret.fluid = true;
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} else if (app.flags.colors.match(flag)) {
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ret.theme = app.flags.colors.output(flag);
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} else if (options.themes[flag]) {
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//If a theme is specified, it will override custom colors
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ret.theme = options.themes[flag];
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} else if (app.flags.text.match(flag)) {
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ret.text = app.flags.text.output(flag);
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} else if(app.flags.font.match(flag)){
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ret.font = app.flags.font.output(flag);
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}
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else if(app.flags.auto.match(flag)){
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ret.auto = true;
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}
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}
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return render ? ret : false;
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};
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if (!canvas.getContext) {
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fallback = true;
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} else {
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if (canvas.toDataURL("image/png")
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.indexOf("data:image/png") < 0) {
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//Android doesn't support data URI
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fallback = true;
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} else {
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var ctx = canvas.getContext("2d");
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}
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}
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var fluid_images = [];
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var settings = {
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domain: "holder.js",
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images: "img",
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bgnodes: ".holderjs",
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themes: {
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"gray": {
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background: "#eee",
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foreground: "#aaa",
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size: 12
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},
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"social": {
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background: "#3a5a97",
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foreground: "#fff",
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size: 12
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},
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"industrial": {
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background: "#434A52",
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foreground: "#C2F200",
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size: 12
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}
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},
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stylesheet: ".holderjs-fluid {font-size:16px;font-weight:bold;text-align:center;font-family:sans-serif;margin:0}"
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};
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app.flags = {
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dimensions: {
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regex: /^(\d+)x(\d+)$/,
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output: function (val) {
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var exec = this.regex.exec(val);
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return {
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width: +exec[1],
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height: +exec[2]
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}
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}
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},
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fluid: {
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regex: /^([0-9%]+)x([0-9%]+)$/,
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output: function (val) {
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var exec = this.regex.exec(val);
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return {
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width: exec[1],
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height: exec[2]
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}
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}
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},
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colors: {
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regex: /#([0-9a-f]{3,})\:#([0-9a-f]{3,})/i,
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output: function (val) {
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var exec = this.regex.exec(val);
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return {
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size: settings.themes.gray.size,
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foreground: "#" + exec[2],
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background: "#" + exec[1]
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}
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}
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},
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text: {
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regex: /text\:(.*)/,
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output: function (val) {
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return this.regex.exec(val)[1];
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}
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},
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font: {
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regex: /font\:(.*)/,
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output: function(val){
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return this.regex.exec(val)[1];
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}
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},
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auto: {
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regex: /^auto$/
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}
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}
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for (var flag in app.flags) {
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if(!app.flags.hasOwnProperty(flag)) continue;
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app.flags[flag].match = function (val) {
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return val.match(this.regex)
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}
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}
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app.add_theme = function (name, theme) {
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name != null && theme != null && (settings.themes[name] = theme);
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return app;
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};
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app.add_image = function (src, el) {
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var node = selector(el);
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if (node.length) {
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for (var i = 0, l = node.length; i < l; i++) {
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var img = document.createElement("img")
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img.setAttribute("data-src", src);
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node[i].appendChild(img);
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}
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}
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return app;
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};
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app.run = function (o) {
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var options = extend(settings, o), images = [];
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if(options.images instanceof window.NodeList){
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imageNodes = options.images;
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}
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else if(options.images instanceof window.Node){
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imageNodes = [options.images];
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}
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else{
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imageNodes = selector(options.images);
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}
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if(options.elements instanceof window.NodeList){
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bgnodes = options.bgnodes;
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}
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else if(options.bgnodes instanceof window.Node){
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bgnodes = [options.bgnodes];
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}
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else{
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bgnodes = selector(options.bgnodes);
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}
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preempted = true;
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for (i = 0, l = imageNodes.length; i < l; i++) images.push(imageNodes[i]);
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var holdercss = document.getElementById("holderjs-style");
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if(!holdercss){
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holdercss = document.createElement("style");
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holdercss.setAttribute("id", "holderjs-style");
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holdercss.type = "text/css";
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document.getElementsByTagName("head")[0].appendChild(holdercss);
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}
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if(holdercss.styleSheet){
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holdercss.styleSheet += options.stylesheet;
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}
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else{
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holdercss.textContent+= options.stylesheet;
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}
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var cssregex = new RegExp(options.domain + "\/(.*?)\"?\\)");
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for (var l = bgnodes.length, i = 0; i < l; i++) {
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var src = window.getComputedStyle(bgnodes[i], null)
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.getPropertyValue("background-image");
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var flags = src.match(cssregex);
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if (flags) {
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var holder = parse_flags(flags[1].split("/"), options);
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if (holder) {
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render("background", bgnodes[i], holder, src);
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}
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}
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}
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for (var l = images.length, i = 0; i < l; i++) {
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var src = images[i].getAttribute("src") || images[i].getAttribute("data-src");
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if (src != null && src.indexOf(options.domain) >= 0) {
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var holder = parse_flags(src.substr(src.lastIndexOf(options.domain) + options.domain.length + 1)
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.split("/"), options);
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if (holder) {
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if (holder.fluid) {
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fluid(images[i], holder, src);
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} else {
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render("image", images[i], holder, src);
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}
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}
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}
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}
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return app;
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};
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contentLoaded(win, function () {
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if (window.addEventListener) {
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window.addEventListener("resize", fluid_update, false);
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window.addEventListener("orientationchange", fluid_update, false);
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} else {
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window.attachEvent("onresize", fluid_update)
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}
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preempted || app.run();
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});
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if ( typeof define === "function" && define.amd ) {
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define( "Holder", [], function () { return app; } );
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}
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})(Holder, window); |