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Bootstrap/docs/assets/js/holder.js

501 lines
14 KiB
JavaScript

/*
Holder - 2.2 - client side image placeholders
(c) 2012-2013 Ivan Malopinsky / http://imsky.co
Provided under the MIT License.
Commercial use requires attribution.
*/
var Holder = Holder || {};
(function (app, win) {
var preempted = false,
fallback = false,
canvas = document.createElement('canvas');
var dpr = 1, bsr = 1;
var resizable_images = [];
if (!canvas.getContext) {
fallback = true;
} else {
if (canvas.toDataURL("image/png")
.indexOf("data:image/png") < 0) {
//Android doesn't support data URI
fallback = true;
} else {
var ctx = canvas.getContext("2d");
}
}
if(!fallback){
dpr = window.devicePixelRatio || 1,
bsr = ctx.webkitBackingStorePixelRatio || ctx.mozBackingStorePixelRatio || ctx.msBackingStorePixelRatio || ctx.oBackingStorePixelRatio || ctx.backingStorePixelRatio || 1;
}
var ratio = dpr / bsr;
var settings = {
domain: "holder.js",
images: "img",
bgnodes: ".holderjs",
themes: {
"gray": {
background: "#eee",
foreground: "#aaa",
size: 12
},
"social": {
background: "#3a5a97",
foreground: "#fff",
size: 12
},
"industrial": {
background: "#434A52",
foreground: "#C2F200",
size: 12
},
"sky": {
background: "#0D8FDB",
foreground: "#fff",
size: 12
},
"vine": {
background: "#39DBAC",
foreground: "#1E292C",
size: 12
},
"lava": {
background: "#F8591A",
foreground: "#1C2846",
size: 12
}
},
stylesheet: ""
};
app.flags = {
dimensions: {
regex: /^(\d+)x(\d+)$/,
output: function (val) {
var exec = this.regex.exec(val);
return {
width: +exec[1],
height: +exec[2]
}
}
},
fluid: {
regex: /^([0-9%]+)x([0-9%]+)$/,
output: function (val) {
var exec = this.regex.exec(val);
return {
width: exec[1],
height: exec[2]
}
}
},
colors: {
regex: /#([0-9a-f]{3,})\:#([0-9a-f]{3,})/i,
output: function (val) {
var exec = this.regex.exec(val);
return {
size: settings.themes.gray.size,
foreground: "#" + exec[2],
background: "#" + exec[1]
}
}
},
text: {
regex: /text\:(.*)/,
output: function (val) {
return this.regex.exec(val)[1];
}
},
font: {
regex: /font\:(.*)/,
output: function (val) {
return this.regex.exec(val)[1];
}
},
auto: {
regex: /^auto$/
},
textmode: {
regex: /textmode\:(.*)/,
output: function(val){
return this.regex.exec(val)[1];
}
}
}
//getElementsByClassName polyfill
document.getElementsByClassName||(document.getElementsByClassName=function(e){var t=document,n,r,i,s=[];if(t.querySelectorAll)return t.querySelectorAll("."+e);if(t.evaluate){r=".//*[contains(concat(' ', @class, ' '), ' "+e+" ')]",n=t.evaluate(r,t,null,0,null);while(i=n.iterateNext())s.push(i)}else{n=t.getElementsByTagName("*"),r=new RegExp("(^|\\s)"+e+"(\\s|$)");for(i=0;i<n.length;i++)r.test(n[i].className)&&s.push(n[i])}return s})
//getComputedStyle polyfill
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})
//http://javascript.nwbox.com/ContentLoaded by Diego Perini with modifications
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)}}
//https://gist.github.com/991057 by Jed Schmidt with modifications
function selector(a){
a=a.match(/^(\W)?(.*)/);var b=document["getElement"+(a[1]?a[1]=="#"?"ById":"sByClassName":"sByTagName")](a[2]);
var ret=[]; b!==null&&(b.length?ret=b:b.length===0?ret=b:ret=[b]); return ret;
}
//shallow object property extend
function extend(a,b){
var c={};
for(var i in a){
if(a.hasOwnProperty(i)){
c[i]=a[i];
}
}
for(var i in b){
if(b.hasOwnProperty(i)){
c[i]=b[i];
}
}
return c
}
//hasOwnProperty polyfill
if (!Object.prototype.hasOwnProperty)
/*jshint -W001, -W103 */
Object.prototype.hasOwnProperty = function(prop) {
var proto = this.__proto__ || this.constructor.prototype;
return (prop in this) && (!(prop in proto) || proto[prop] !== this[prop]);
}
/*jshint +W001, +W103 */
function text_size(width, height, template) {
height = parseInt(height, 10);
width = parseInt(width, 10);
var bigSide = Math.max(height, width)
var smallSide = Math.min(height, width)
var scale = 1 / 12;
var newHeight = Math.min(smallSide * 0.75, 0.75 * bigSide * scale);
return {
height: Math.round(Math.max(template.size, newHeight))
}
}
function draw(args) {
var ctx = args.ctx;
var dimensions = args.dimensions;
var template = args.template;
var ratio = args.ratio;
var holder = args.holder;
var literal = holder.textmode == "literal";
var exact = holder.textmode == "exact";
var ts = text_size(dimensions.width, dimensions.height, template);
var text_height = ts.height;
var width = dimensions.width * ratio,
height = dimensions.height * ratio;
var font = template.font ? template.font : "sans-serif";
canvas.width = width;
canvas.height = height;
ctx.textAlign = "center";
ctx.textBaseline = "middle";
ctx.fillStyle = template.background;
ctx.fillRect(0, 0, width, height);
ctx.fillStyle = template.foreground;
ctx.font = "bold " + text_height + "px " + font;
var text = template.text ? template.text : (Math.floor(dimensions.width) + "x" + Math.floor(dimensions.height));
if (literal) {
var dimensions = holder.dimensions;
text = dimensions.width + "x" + dimensions.height;
}
else if(exact && holder.exact_dimensions){
var dimensions = holder.exact_dimensions;
text = (Math.floor(dimensions.width) + "x" + Math.floor(dimensions.height));
}
var text_width = ctx.measureText(text).width;
if (text_width / width >= 0.75) {
text_height = Math.floor(text_height * 0.75 * (width / text_width));
}
//Resetting font size if necessary
ctx.font = "bold " + (text_height * ratio) + "px " + font;
ctx.fillText(text, (width / 2), (height / 2), width);
return canvas.toDataURL("image/png");
}
function render(mode, el, holder, src) {
var dimensions = holder.dimensions,
theme = holder.theme,
text = holder.text ? decodeURIComponent(holder.text) : holder.text;
var dimensions_caption = dimensions.width + "x" + dimensions.height;
theme = (text ? extend(theme, {
text: text
}) : theme);
theme = (holder.font ? extend(theme, {
font: holder.font
}) : theme);
el.setAttribute("data-src", src);
holder.theme = theme;
el.holder_data = holder;
if (mode == "image") {
el.setAttribute("alt", text ? text : theme.text ? theme.text + " [" + dimensions_caption + "]" : dimensions_caption);
if (fallback || !holder.auto) {
el.style.width = dimensions.width + "px";
el.style.height = dimensions.height + "px";
}
if (fallback) {
el.style.backgroundColor = theme.background;
} else {
el.setAttribute("src", draw({ctx: ctx, dimensions: dimensions, template: theme, ratio:ratio, holder: holder}));
if(holder.textmode && holder.textmode == "exact"){
resizable_images.push(el);
resizable_update(el);
}
}
} else if (mode == "background") {
if (!fallback) {
el.style.backgroundImage = "url(" + draw({ctx:ctx, dimensions: dimensions, template: theme, ratio: ratio, holder: holder}) + ")";
el.style.backgroundSize = dimensions.width + "px " + dimensions.height + "px";
}
} else if (mode == "fluid") {
el.setAttribute("alt", text ? text : theme.text ? theme.text + " [" + dimensions_caption + "]" : dimensions_caption);
if (dimensions.height.slice(-1) == "%") {
el.style.height = dimensions.height
} else {
el.style.height = dimensions.height + "px"
}
if (dimensions.width.slice(-1) == "%") {
el.style.width = dimensions.width
} else {
el.style.width = dimensions.width + "px"
}
if (el.style.display == "inline" || el.style.display === "" || el.style.display == "none") {
el.style.display = "block";
}
if (fallback) {
el.style.backgroundColor = theme.background;
} else {
resizable_images.push(el);
resizable_update(el);
}
}
}
function dimension_check(el, callback) {
var dimensions = {
height: el.clientHeight,
width: el.clientWidth
};
if (!dimensions.height && !dimensions.width) {
if (el.hasAttribute("data-holder-invisible")) {
throw new Error("Holder: placeholder is not visible");
} else {
el.setAttribute("data-holder-invisible", true)
setTimeout(function () {
callback.call(this, el)
}, 1)
return null;
}
} else {
el.removeAttribute("data-holder-invisible")
}
return dimensions;
}
function resizable_update(element) {
var images;
if (element.nodeType == null) {
images = resizable_images;
} else {
images = [element]
}
for (var i in images) {
if (!images.hasOwnProperty(i)) {
continue;
}
var el = images[i]
if (el.holder_data) {
var holder = el.holder_data;
var dimensions = dimension_check(el, resizable_update)
if(dimensions){
if(holder.fluid){
el.setAttribute("src", draw({
ctx: ctx,
dimensions: dimensions,
template: holder.theme,
ratio: ratio,
holder: holder
}))
}
if(holder.textmode && holder.textmode == "exact"){
holder.exact_dimensions = dimensions;
el.setAttribute("src", draw({
ctx: ctx,
dimensions: holder.dimensions,
template: holder.theme,
ratio: ratio,
holder: holder
}))
}
}
}
}
}
function parse_flags(flags, options) {
var ret = {
theme: extend(settings.themes.gray, {})
};
var render = false;
for (sl = flags.length, j = 0; j < sl; j++) {
var flag = flags[j];
if (app.flags.dimensions.match(flag)) {
render = true;
ret.dimensions = app.flags.dimensions.output(flag);
} else if (app.flags.fluid.match(flag)) {
render = true;
ret.dimensions = app.flags.fluid.output(flag);
ret.fluid = true;
} else if (app.flags.textmode.match(flag)) {
ret.textmode = app.flags.textmode.output(flag)
} else if (app.flags.colors.match(flag)) {
ret.theme = app.flags.colors.output(flag);
} else if (options.themes[flag]) {
//If a theme is specified, it will override custom colors
if(options.themes.hasOwnProperty(flag)){
ret.theme = extend(options.themes[flag], {});
}
} else if (app.flags.font.match(flag)) {
ret.font = app.flags.font.output(flag);
} else if (app.flags.auto.match(flag)) {
ret.auto = true;
} else if (app.flags.text.match(flag)) {
ret.text = app.flags.text.output(flag);
}
}
return render ? ret : false;
}
for (var flag in app.flags) {
if (!app.flags.hasOwnProperty(flag)) continue;
app.flags[flag].match = function (val) {
return val.match(this.regex)
}
}
app.add_theme = function (name, theme) {
name != null && theme != null && (settings.themes[name] = theme);
return app;
};
app.add_image = function (src, el) {
var node = selector(el);
if (node.length) {
for (var i = 0, l = node.length; i < l; i++) {
var img = document.createElement("img")
img.setAttribute("data-src", src);
node[i].appendChild(img);
}
}
return app;
};
app.run = function (o) {
preempted = true;
var options = extend(settings, o),
images = [],
imageNodes = [],
bgnodes = [];
if (typeof (options.images) == "string") {
imageNodes = selector(options.images);
} else if (window.NodeList && options.images instanceof window.NodeList) {
imageNodes = options.images;
} else if (window.Node && options.images instanceof window.Node) {
imageNodes = [options.images];
}
if (typeof (options.bgnodes) == "string") {
bgnodes = selector(options.bgnodes);
} else if (window.NodeList && options.elements instanceof window.NodeList) {
bgnodes = options.bgnodes;
} else if (window.Node && options.bgnodes instanceof window.Node) {
bgnodes = [options.bgnodes];
}
for (i = 0, l = imageNodes.length; i < l; i++) images.push(imageNodes[i]);
var holdercss = document.getElementById("holderjs-style");
if (!holdercss) {
holdercss = document.createElement("style");
holdercss.setAttribute("id", "holderjs-style");
holdercss.type = "text/css";
document.getElementsByTagName("head")[0].appendChild(holdercss);
}
if (!options.nocss) {
if (holdercss.styleSheet) {
holdercss.styleSheet.cssText += options.stylesheet;
} else {
holdercss.appendChild(document.createTextNode(options.stylesheet));
}
}
var cssregex = new RegExp(options.domain + "\/(.*?)\"?\\)");
for (var l = bgnodes.length, i = 0; i < l; i++) {
var src = window.getComputedStyle(bgnodes[i], null)
.getPropertyValue("background-image");
var flags = src.match(cssregex);
var bgsrc = bgnodes[i].getAttribute("data-background-src");
if (flags) {
var holder = parse_flags(flags[1].split("/"), options);
if (holder) {
render("background", bgnodes[i], holder, src);
}
} else if (bgsrc != null) {
var holder = parse_flags(bgsrc.substr(bgsrc.lastIndexOf(options.domain) + options.domain.length + 1)
.split("/"), options);
if (holder) {
render("background", bgnodes[i], holder, src);
}
}
}
for (l = images.length, i = 0; i < l; i++) {
var attr_data_src, attr_src;
attr_src = attr_data_src = src = null;
try {
attr_src = images[i].getAttribute("src");
attr_datasrc = images[i].getAttribute("data-src");
} catch (e) {}
if (attr_datasrc == null && !! attr_src && attr_src.indexOf(options.domain) >= 0) {
src = attr_src;
} else if ( !! attr_datasrc && attr_datasrc.indexOf(options.domain) >= 0) {
src = attr_datasrc;
}
if (src) {
var holder = parse_flags(src.substr(src.lastIndexOf(options.domain) + options.domain.length + 1)
.split("/"), options);
if (holder) {
if (holder.fluid) {
render("fluid", images[i], holder, src)
} else {
render("image", images[i], holder, src);
}
}
}
}
return app;
};
contentLoaded(win, function () {
if (window.addEventListener) {
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);