|
| 1 | +/*! |
| 2 | + * Retina.js v1.3.0 |
| 3 | + * |
| 4 | + * Copyright 2014 Imulus, LLC |
| 5 | + * Released under the MIT license |
| 6 | + * |
| 7 | + * Retina.js is an open source script that makes it easy to serve |
| 8 | + * high-resolution images to devices with retina displays. |
| 9 | + */ |
| 10 | + |
| 11 | +(function() { |
| 12 | + var root = (typeof exports === 'undefined' ? window : exports); |
| 13 | + var config = { |
| 14 | + // An option to choose a suffix for 2x images |
| 15 | + retinaImageSuffix : '@2x', |
| 16 | + |
| 17 | + // Ensure Content-Type is an image before trying to load @2x image |
| 18 | + // https://github.com/imulus/retinajs/pull/45) |
| 19 | + check_mime_type: true, |
| 20 | + |
| 21 | + // Resize high-resolution images to original image's pixel dimensions |
| 22 | + // https://github.com/imulus/retinajs/issues/8 |
| 23 | + force_original_dimensions: true |
| 24 | + }; |
| 25 | + |
| 26 | + function Retina() {} |
| 27 | + |
| 28 | + root.Retina = Retina; |
| 29 | + |
| 30 | + Retina.configure = function(options) { |
| 31 | + if (options === null) { |
| 32 | + options = {}; |
| 33 | + } |
| 34 | + |
| 35 | + for (var prop in options) { |
| 36 | + if (options.hasOwnProperty(prop)) { |
| 37 | + config[prop] = options[prop]; |
| 38 | + } |
| 39 | + } |
| 40 | + }; |
| 41 | + |
| 42 | + Retina.init = function(context) { |
| 43 | + if (context === null) { |
| 44 | + context = root; |
| 45 | + } |
| 46 | + |
| 47 | + var existing_onload = context.onload || function(){}; |
| 48 | + |
| 49 | + context.onload = function() { |
| 50 | + var images = document.getElementsByTagName('img'), retinaImages = [], i, image; |
| 51 | + for (i = 0; i < images.length; i += 1) { |
| 52 | + image = images[i]; |
| 53 | + if (!!!image.getAttributeNode('data-no-retina')) { |
| 54 | + retinaImages.push(new RetinaImage(image)); |
| 55 | + } |
| 56 | + } |
| 57 | + existing_onload(); |
| 58 | + }; |
| 59 | + }; |
| 60 | + |
| 61 | + Retina.isRetina = function(){ |
| 62 | + var mediaQuery = '(-webkit-min-device-pixel-ratio: 1.5), (min--moz-device-pixel-ratio: 1.5), (-o-min-device-pixel-ratio: 3/2), (min-resolution: 1.5dppx)'; |
| 63 | + |
| 64 | + if (root.devicePixelRatio > 1) { |
| 65 | + return true; |
| 66 | + } |
| 67 | + |
| 68 | + if (root.matchMedia && root.matchMedia(mediaQuery).matches) { |
| 69 | + return true; |
| 70 | + } |
| 71 | + |
| 72 | + return false; |
| 73 | + }; |
| 74 | + |
| 75 | + |
| 76 | + var regexMatch = /\.\w+$/; |
| 77 | + function suffixReplace (match) { |
| 78 | + return config.retinaImageSuffix + match; |
| 79 | + } |
| 80 | + |
| 81 | + function RetinaImagePath(path, at_2x_path) { |
| 82 | + this.path = path || ''; |
| 83 | + if (typeof at_2x_path !== 'undefined' && at_2x_path !== null) { |
| 84 | + this.at_2x_path = at_2x_path; |
| 85 | + this.perform_check = false; |
| 86 | + } else { |
| 87 | + if (undefined !== document.createElement) { |
| 88 | + var locationObject = document.createElement('a'); |
| 89 | + locationObject.href = this.path; |
| 90 | + locationObject.pathname = locationObject.pathname.replace(regexMatch, suffixReplace); |
| 91 | + this.at_2x_path = locationObject.href; |
| 92 | + } else { |
| 93 | + var parts = this.path.split('?'); |
| 94 | + parts[0] = parts[0].replace(regexMatch, suffixReplace); |
| 95 | + this.at_2x_path = parts.join('?'); |
| 96 | + } |
| 97 | + this.perform_check = true; |
| 98 | + } |
| 99 | + } |
| 100 | + |
| 101 | + root.RetinaImagePath = RetinaImagePath; |
| 102 | + |
| 103 | + RetinaImagePath.confirmed_paths = []; |
| 104 | + |
| 105 | + RetinaImagePath.prototype.is_external = function() { |
| 106 | + return !!(this.path.match(/^https?\:/i) && !this.path.match('//' + document.domain) ); |
| 107 | + }; |
| 108 | + |
| 109 | + RetinaImagePath.prototype.check_2x_variant = function(callback) { |
| 110 | + var http, that = this; |
| 111 | + if (this.is_external()) { |
| 112 | + return callback(false); |
| 113 | + } else if (!this.perform_check && typeof this.at_2x_path !== 'undefined' && this.at_2x_path !== null) { |
| 114 | + return callback(true); |
| 115 | + } else if (this.at_2x_path in RetinaImagePath.confirmed_paths) { |
| 116 | + return callback(true); |
| 117 | + } else { |
| 118 | + http = new XMLHttpRequest(); |
| 119 | + http.open('HEAD', this.at_2x_path); |
| 120 | + http.onreadystatechange = function() { |
| 121 | + if (http.readyState !== 4) { |
| 122 | + return callback(false); |
| 123 | + } |
| 124 | + |
| 125 | + if (http.status >= 200 && http.status <= 399) { |
| 126 | + if (config.check_mime_type) { |
| 127 | + var type = http.getResponseHeader('Content-Type'); |
| 128 | + if (type === null || !type.match(/^image/i)) { |
| 129 | + return callback(false); |
| 130 | + } |
| 131 | + } |
| 132 | + |
| 133 | + RetinaImagePath.confirmed_paths.push(that.at_2x_path); |
| 134 | + return callback(true); |
| 135 | + } else { |
| 136 | + return callback(false); |
| 137 | + } |
| 138 | + }; |
| 139 | + http.send(); |
| 140 | + } |
| 141 | + }; |
| 142 | + |
| 143 | + |
| 144 | + function RetinaImage(el) { |
| 145 | + this.el = el; |
| 146 | + this.path = new RetinaImagePath(this.el.getAttribute('src'), this.el.getAttribute('data-at2x')); |
| 147 | + var that = this; |
| 148 | + this.path.check_2x_variant(function(hasVariant) { |
| 149 | + if (hasVariant) { |
| 150 | + that.swap(); |
| 151 | + } |
| 152 | + }); |
| 153 | + } |
| 154 | + |
| 155 | + root.RetinaImage = RetinaImage; |
| 156 | + |
| 157 | + RetinaImage.prototype.swap = function(path) { |
| 158 | + if (typeof path === 'undefined') { |
| 159 | + path = this.path.at_2x_path; |
| 160 | + } |
| 161 | + |
| 162 | + var that = this; |
| 163 | + function load() { |
| 164 | + if (! that.el.complete) { |
| 165 | + setTimeout(load, 5); |
| 166 | + } else { |
| 167 | + if (config.force_original_dimensions) { |
| 168 | + that.el.setAttribute('width', that.el.offsetWidth); |
| 169 | + that.el.setAttribute('height', that.el.offsetHeight); |
| 170 | + } |
| 171 | + |
| 172 | + that.el.setAttribute('src', path); |
| 173 | + } |
| 174 | + } |
| 175 | + load(); |
| 176 | + }; |
| 177 | + |
| 178 | + |
| 179 | + if (Retina.isRetina()) { |
| 180 | + Retina.init(root); |
| 181 | + } |
| 182 | +})(); |
0 commit comments