501 lines
14 KiB
JavaScript
501 lines
14 KiB
JavaScript
/*
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Holder - 2.2 - client side image placeholders
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(c) 2012-2013 Ivan Malopinsky / http://imsky.co
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Provided under the MIT License.
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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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var dpr = 1, bsr = 1;
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var resizable_images = [];
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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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if(!fallback){
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dpr = window.devicePixelRatio || 1,
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bsr = ctx.webkitBackingStorePixelRatio || ctx.mozBackingStorePixelRatio || ctx.msBackingStorePixelRatio || ctx.oBackingStorePixelRatio || ctx.backingStorePixelRatio || 1;
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}
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var ratio = dpr / bsr;
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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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"sky": {
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background: "#0D8FDB",
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foreground: "#fff",
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size: 12
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},
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"vine": {
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background: "#39DBAC",
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foreground: "#1E292C",
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size: 12
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},
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"lava": {
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background: "#F8591A",
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foreground: "#1C2846",
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size: 12
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}
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},
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stylesheet: ""
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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$/
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},
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textmode: {
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regex: /textmode\:(.*)/,
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output: function(val){
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return this.regex.exec(val)[1];
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}
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}
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}
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//getElementsByClassName polyfill
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document.getElementsByClassName||(document.getElementsByClassName=function(e){var t=document,n,r,i,s=[];if(t.querySelectorAll)return t.querySelectorAll("."+e);if(t.evaluate){r=".//*[contains(concat(' ', @class, ' '), ' "+e+" ')]",n=t.evaluate(r,t,null,0,null);while(i=n.iterateNext())s.push(i)}else{n=t.getElementsByTagName("*"),r=new RegExp("(^|\\s)"+e+"(\\s|$)");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){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){
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var c={};
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for(var i in a){
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if(a.hasOwnProperty(i)){
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c[i]=a[i];
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}
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}
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for(var i in b){
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if(b.hasOwnProperty(i)){
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c[i]=b[i];
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}
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}
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return c
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}
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//hasOwnProperty polyfill
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if (!Object.prototype.hasOwnProperty)
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/*jshint -W001, -W103 */
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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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/*jshint +W001, +W103 */
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function text_size(width, height, template) {
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height = parseInt(height, 10);
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width = parseInt(width, 10);
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var bigSide = Math.max(height, width)
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var smallSide = Math.min(height, width)
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var scale = 1 / 12;
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var newHeight = Math.min(smallSide * 0.75, 0.75 * bigSide * scale);
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return {
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height: Math.round(Math.max(template.size, newHeight))
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}
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}
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function draw(args) {
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var ctx = args.ctx;
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var dimensions = args.dimensions;
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var template = args.template;
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var ratio = args.ratio;
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var holder = args.holder;
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var literal = holder.textmode == "literal";
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var exact = holder.textmode == "exact";
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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,
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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 : (Math.floor(dimensions.width) + "x" + Math.floor(dimensions.height));
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if (literal) {
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var dimensions = holder.dimensions;
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text = dimensions.width + "x" + dimensions.height;
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}
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else if(exact && holder.exact_dimensions){
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var dimensions = holder.exact_dimensions;
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text = (Math.floor(dimensions.width) + "x" + Math.floor(dimensions.height));
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}
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var text_width = ctx.measureText(text).width;
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if (text_width / width >= 0.75) {
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text_height = Math.floor(text_height * 0.75 * (width / text_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, {
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text: text
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}) : theme);
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theme = (holder.font ? extend(theme, {
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font: holder.font
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}) : theme);
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el.setAttribute("data-src", src);
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holder.theme = theme;
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el.holder_data = holder;
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if (mode == "image") {
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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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} else {
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el.setAttribute("src", draw({ctx: ctx, dimensions: dimensions, template: theme, ratio:ratio, holder: holder}));
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if(holder.textmode && holder.textmode == "exact"){
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resizable_images.push(el);
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resizable_update(el);
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}
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}
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} else if (mode == "background") {
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if (!fallback) {
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el.style.backgroundImage = "url(" + draw({ctx:ctx, dimensions: dimensions, template: theme, ratio: ratio, holder: holder}) + ")";
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el.style.backgroundSize = dimensions.width + "px " + dimensions.height + "px";
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}
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} else if (mode == "fluid") {
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el.setAttribute("alt", text ? text : theme.text ? theme.text + " [" + dimensions_caption + "]" : dimensions_caption);
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if (dimensions.height.slice(-1) == "%") {
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el.style.height = dimensions.height
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} else {
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el.style.height = dimensions.height + "px"
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}
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if (dimensions.width.slice(-1) == "%") {
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el.style.width = dimensions.width
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} else {
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el.style.width = dimensions.width + "px"
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}
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if (el.style.display == "inline" || el.style.display === "" || el.style.display == "none") {
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el.style.display = "block";
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}
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if (fallback) {
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el.style.backgroundColor = theme.background;
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} else {
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resizable_images.push(el);
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resizable_update(el);
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}
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}
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}
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function dimension_check(el, callback) {
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var dimensions = {
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height: el.clientHeight,
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width: el.clientWidth
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};
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if (!dimensions.height && !dimensions.width) {
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if (el.hasAttribute("data-holder-invisible")) {
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throw new Error("Holder: placeholder is not visible");
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} else {
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el.setAttribute("data-holder-invisible", true)
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setTimeout(function () {
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callback.call(this, el)
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}, 1)
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return null;
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}
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} else {
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el.removeAttribute("data-holder-invisible")
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}
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return dimensions;
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}
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function resizable_update(element) {
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var images;
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if (element.nodeType == null) {
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images = resizable_images;
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} else {
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images = [element]
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}
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for (var i in images) {
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if (!images.hasOwnProperty(i)) {
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continue;
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}
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var el = images[i]
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if (el.holder_data) {
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var holder = el.holder_data;
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var dimensions = dimension_check(el, resizable_update)
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if(dimensions){
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if(holder.fluid){
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el.setAttribute("src", draw({
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ctx: ctx,
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dimensions: dimensions,
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template: holder.theme,
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ratio: ratio,
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holder: holder
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}))
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}
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if(holder.textmode && holder.textmode == "exact"){
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holder.exact_dimensions = dimensions;
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el.setAttribute("src", draw({
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ctx: ctx,
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dimensions: holder.dimensions,
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template: holder.theme,
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ratio: ratio,
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holder: holder
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}))
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}
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}
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}
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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: extend(settings.themes.gray, {})
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};
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var 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.textmode.match(flag)) {
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ret.textmode = app.flags.textmode.output(flag)
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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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if(options.themes.hasOwnProperty(flag)){
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ret.theme = extend(options.themes[flag], {});
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}
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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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} else if (app.flags.auto.match(flag)) {
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ret.auto = true;
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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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}
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}
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return render ? ret : false;
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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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preempted = true;
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var options = extend(settings, o),
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images = [],
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imageNodes = [],
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bgnodes = [];
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if (typeof (options.images) == "string") {
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imageNodes = selector(options.images);
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} else if (window.NodeList && options.images instanceof window.NodeList) {
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imageNodes = options.images;
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} else if (window.Node && options.images instanceof window.Node) {
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imageNodes = [options.images];
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}
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if (typeof (options.bgnodes) == "string") {
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bgnodes = selector(options.bgnodes);
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} else if (window.NodeList && options.elements instanceof window.NodeList) {
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bgnodes = options.bgnodes;
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} else if (window.Node && options.bgnodes instanceof window.Node) {
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bgnodes = [options.bgnodes];
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}
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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 (!options.nocss) {
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if (holdercss.styleSheet) {
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holdercss.styleSheet.cssText += options.stylesheet;
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} else {
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holdercss.appendChild(document.createTextNode(options.stylesheet));
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}
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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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var bgsrc = bgnodes[i].getAttribute("data-background-src");
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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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} else if (bgsrc != null) {
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var holder = parse_flags(bgsrc.substr(bgsrc.lastIndexOf(options.domain) + options.domain.length + 1)
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.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 (l = images.length, i = 0; i < l; i++) {
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var attr_data_src, attr_src;
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attr_src = attr_data_src = src = null;
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try {
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attr_src = images[i].getAttribute("src");
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attr_datasrc = images[i].getAttribute("data-src");
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} catch (e) {}
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if (attr_datasrc == null && !! attr_src && attr_src.indexOf(options.domain) >= 0) {
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src = attr_src;
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} else if ( !! attr_datasrc && attr_datasrc.indexOf(options.domain) >= 0) {
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src = attr_datasrc;
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}
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if (src) {
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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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render("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", resizable_update, false);
|
|
window.addEventListener("orientationchange", resizable_update, false);
|
|
} else {
|
|
window.attachEvent("onresize", resizable_update)
|
|
}
|
|
preempted || app.run();
|
|
});
|
|
if (typeof define === "function" && define.amd) {
|
|
define([], function () {
|
|
return app;
|
|
});
|
|
}
|
|
|
|
})(Holder, window);
|