https://www.anonimagiocatori.it/sito/wp-content/plugins/organic-cu…/jquery.backgroundbrightness.js?ver=6.8.11

1/*
2 *  backgroundBrightness.js
3 *
4 *  Copyright 2016, Jesse Lee & Organic Themes w/ snippets from ColourBrightness.js
5 *  Released under the WTFPL license
6 *  https://organicthemes.com
7 *
8 *  Version: 1.0
9 */
10
11(function ($) {
12
13    "use strict";
14
15    $.fn.extend({
16
17      backgroundBrightness: function (contentSelectors, threshold) {
18
19      // RGB Brightness Threshold
20      var threshold = 160;
21
22      // Background Object
23      var el = $(this);
24
25      // Content Targets
26      if ( ! contentSelectors ) {
27        contentSelectors = false;
28      } else if ( !( contentSelectors.constructor === Array) ) {
29        contentSelectors = [contentSelectors];
30      }
31
32      //Loop Through all Items
33      $.each(el, function(key, value){
34
35        //Initialize
36        var r,g,b,brightness;
37
38        //Get Background Styles for element
39        var bgStyles = getBackgroundStyles( $(value) );
40        var colour = bgStyles.bgColor;
41        var image = bgStyles.bgImage;
42        var targetedElement = bgStyles.targetedElement;
43
44        // If bg image found, calculate luminosity of image
45        if ( image ) {
46          getBackgroundImageLuminosity( targetedElement, contentSelectors, threshold);
47        }
48        // If no bg image, calculate bg color brightness
49        else if ( colour ) {
50          if (colour.match(/^rgb/)) {
51            colour = colour.match(/rgba?\(([^)]+)\)/)[1];
52            colour = colour.split(/ *, */).map(Number);
53            r = colour[0];
54            g = colour[1];
55            b = colour[2];
56          } else if ("#" === colour[0] && 7 === colour.length) {
57            r = parseInt(colour.slice(1, 3), 16);
58            g = parseInt(colour.slice(3, 5), 16);
59            b = parseInt(colour.slice(5, 7), 16);
60          } else if ("#" === colour[0] && 4 === colour.length) {
61            r = parseInt(colour[1] + colour[1], 16);
62            g = parseInt(colour[2] + colour[2], 16);
63            b = parseInt(colour[3] + colour[3], 16);
64          }
65
66          brightness = (r * 299 + g * 587 + b * 114) / 1000;
67
68          if (brightness < threshold) {
69            // white text
70            targetedElement.removeClass("ocw-bg-light").addClass("ocw-bg-dark");
71          } else {
72            // black text
73            targetedElement.removeClass("ocw-bg-dark").addClass("ocw-bg-light");
74          }
75
76        }
77
78      });
79
80      function getBackgroundImageLuminosity(el, contentSelectors, threshold ) {
81
82        var bg = el.css("backgroundImage");
83        bg = bg.replace(/^url\(['"]?/, "").replace(/['"]?\)$/, "");
84
85        getImageLightness( bg, el ,function(brightness,el){
86
87          // Set classes to add and to remove
88          if (brightness < threshold) {
89            var addClass = "ocw-bg-dark";
90            var removeClass = "ocw-bg-light";
91          } else {
92            var addClass = "ocw-bg-light";
93            var removeClass = "ocw-bg-dark";
94          }
95
96          // Add and remove classes
97          // If applying to self
98          if (!contentSelectors ){
99            if ( !el.hasClass("ocw-bg-img") ) el.addClass("ocw-bg-img");
100            el.removeClass(removeClass);
101            el.addClass(addClass);
102          }
103          // If applying to custom selectors
104          else {
105            contentSelectors.forEach(function(contentSelector){
106              if ( !$(contentSelector).hasClass("ocw-bg-img") ) $(contentSelector).addClass("ocw-bg-img");
107              $(contentSelector).removeClass(removeClass);
108              $(contentSelector).addClass(addClass);
109            });
110          }
111
112          }); // End getImageLightness(){}
113
114      } // End getBackgroundImageLuminosity(){}
115
116      function getImageLightness(imageSrc, imgObject, callback) {
117        var img = document.createElement("img");
118        img.crossOrigin = "Anonymous";
119        img.src = imageSrc;
120        img.style.display = "none";
121        // document.body.appendChild(img); // Adds HTML img tag in footer twice
122
123        var colorSum = 0;
124
125        img.onload = function() {
126          // create canvas
127          var canvas = document.createElement( "canvas" );
128          canvas.width = this.width;
129          canvas.height = this.height;
130
131          var ctx = canvas.getContext( "2d" );
132          ctx.drawImage(this,0,0);
133
134          var imageData = ctx.getImageData( 0, 0, canvas.width, canvas.height );
135          var data = imageData.data;
136          var r,g,b,avg;
137
138          for ( var x = 0, len = data.length; x < len; x += 4 ) {
139            r = data[x];
140            g = data[x + 1];
141            b = data[x + 2];
142
143            avg = Math.floor( (r + g + b) / 3 );
144            colorSum += avg;
145          }
146
147          var brightness = Math.floor(colorSum / (this.width * this.height));
148          callback(brightness, imgObject);
149        }
150      } // End getImageLightness(){}
151
152      /* ======== ColourBrightness Addons =========*/
153

154      function getBackgroundStyles(el) {
155        var bgColor = false;
156        var bgImage = false;
157        while(el[0].tagName.toLowerCase() !== "html") {
158          bgColor = ( ! el.css("backgroundColor") || el.css("backgroundColor") === "rgba(0, 0, 0, 0)" || el.css("backgroundColor") === "transparent" ) ? false : el.css("backgroundColor");
159          bgImage = ( ! el.css("backgroundImage") || el.css("backgroundImage") === "" || el.css("backgroundImage") === "none" ) ? false : el.css("backgroundImage");
160          if ( bgColor || bgImage ) {
161            break;
162          }
163          el = el.parent();
164        }
165        return { bgColor: bgColor, bgImage: bgImage, targetedElement: el };
166      }
167
168    } // End backgroundBrightness(){}
169
170  })
171
172})( jQuery );