mirror of https://github.com/kidoman/embd
82 lines
1.9 KiB
JavaScript
82 lines
1.9 KiB
JavaScript
/**
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* Gumby Retina
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*/
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!function($) {
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'use strict';
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function Retina($el) {
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Gumby.debug('Initializing Retina', $el);
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this.$el = $el;
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this.imageSrc = this.$el.attr('src');
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this.retinaSrc = this.fetchRetinaImage();
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this.$retinaImg = $(new Image());
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var scope = this;
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// image src not valid
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if(!this.retinaSrc) {
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return false;
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}
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// load retina image
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this.$retinaImg.attr('src', this.retinaSrc).load(function() {
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scope.retinaImageLoaded();
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}).error(function() {
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Gumby.error('Couln\'t load retina image: '+scope.retinaSrc);
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});
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}
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// fetch retina src by appending '@2x' to image string before extension
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Retina.prototype.fetchRetinaImage = function() {
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var imgSrc = this.imageSrc,
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index = this.imageSrc.search(/(\.|\/)(gif|jpe?g|png)$/i);
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// image src is not valid
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if(index < 0) {
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return false;
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}
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// return retina src
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return imgSrc.substr(0, index) + '@2x' + imgSrc.substr(index, imgSrc.length);
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};
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// once retina image loaded swap original src
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Retina.prototype.retinaImageLoaded = function() {
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Gumby.debug('Swapping image for retina version', this.$el);
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Gumby.debug('Triggering onRetina event', this.$el);
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this.$el.attr('src', this.$retinaImg.attr('src')).trigger('gumby.onRetina');
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};
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// add initialisation
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Gumby.addInitalisation('retina', function() {
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// this module is for retina devices only
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if(!window.devicePixelRatio || window.devicePixelRatio <= 1) {
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return;
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}
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$('img[data-retina],img[gumby-retina],img[retina]').each(function() {
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var $this = $(this);
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// this element has already been initialized
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if($this.data('isRetina')) {
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return true;
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}
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// mark element as initialized
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$this.data('isRetina', true);
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new Retina($this);
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});
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});
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// register UI module
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Gumby.UIModule({
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module: 'retina',
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events: ['onRetina'],
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init: function() {
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Gumby.initialize('retina');
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}
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});
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}(jQuery);
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