https://motuca.sp.gov.br/js/scroll.js

1/*
2                       _ _ _____                      _   _
3                      | | |  __ \                    | | (_)
4    ___  ___ _ __ ___ | | | |__) |_____   _____  __ _| |  _ ___
5   / __|/ __| '__/ _ \| | |  _  // _ \ \ / / _ \/ _` | | | / __|
6   \__ \ (__| | | (_) | | | | \ \  __/\ V /  __/ (_| | |_| \__ \
7   |___/\___|_|  \___/|_|_|_|  \_\___| \_/ \___|\__,_|_(_) |___/
8                                                        _/ |
9                                                       |__/
10
11    "Declarative on-scroll reveal animations."
12
13/*=============================================================================
14
15    scrollReveal.js is inspired by cbpScroller.js, © 2014, Codrops.
16
17    Licensed under the MIT license.
18    https://www.opensource.org/licenses/mit-license.php
19
20    scrollReveal.js, © 2014 https://twitter.com/julianlloyd
21
22=============================================================================*/
23
24;(function (window) {
25
26  'use strict';
27
28  var docElem = window.document.documentElement;
29
30  function getViewportH () {
31    var client = docElem['clientHeight'],
32      inner = window['innerHeight'];
33
34    return (client < inner) ? inner : client;
35  }
36
37  function getOffset (el) {
38    var offsetTop = 0,
39        offsetLeft = 0;
40
41    do {
42      if (!isNaN(el.offsetTop)) {
43        offsetTop += el.offsetTop;
44      }
45      if (!isNaN(el.offsetLeft)) {
46        offsetLeft += el.offsetLeft;
47      }
48    } while (el = el.offsetParent)
49
50    return {
51      top: offsetTop,
52      left: offsetLeft
53    }
54  }
55
56  function isElementInViewport (el, h) {
57    var scrolled = window.pageYOffset,
58        viewed = scrolled + getViewportH(),
59        elH = el.offsetHeight,
60        elTop = getOffset(el).top,
61        elBottom = elTop + elH,
62        h = h || 0;
63
64    return (elTop + elH * h) <= viewed && (elBottom) >= scrolled;
65  }
66
67  function extend (a, b) {
68    for (var key in b) {
69      if (b.hasOwnProperty(key)) {
70        a[key] = b[key];
71      }
72    }
73    return a;
74  }
75
76
77  function scrollReveal(options) {
78      this.options = extend(this.defaults, options);
79      this._init();
80  }
81
82
83
84  scrollReveal.prototype = {
85    defaults: {
86      axis: 'y',
87      distance: '25px',
88      duration: '0.66s',
89      delay: '0s',
90
91  //  if 0, the element is considered in the viewport as soon as it enters
92  //  if 1, the element is considered in the viewport when it's fully visible
93      viewportFactor: 0.33
94    },
95
96    /*=============================================================================*/
97
98    _init: function () {
99
100      var self = this;
101
102      this.elems = Array.prototype.slice.call(docElem.querySelectorAll('[data-scrollReveal]'));
103      this.scrolled = false;
104
105  //  Initialize all scrollreveals, triggering all
106  //  reveals on visible elements.
107      this.elems.forEach(function (el, i) {
108        self.animate(el);
109      });
110
111      var scrollHandler = function () {
112        if (!self.scrolled) {
113          self.scrolled = true;
114          setTimeout(function () {
115            self._scrollPage();
116          }, 60);
117        }
118      };
119
120      var resizeHandler = function () {
121        function delayed() {
122          self._scrollPage();
123          self.resizeTimeout = null;
124        }
125        if (self.resizeTimeout) {
126          clearTimeout(self.resizeTimeout);
127        }
128        self.resizeTimeout = setTimeout(delayed, 200);
129      };
130
131      window.addEventListener('scroll', scrollHandler, false);
132      window.addEventListener('resize', resizeHandler, false);
133    },
134
135    /*=============================================================================*/
136
137    _scrollPage: function () {
138        var self = this;
139
140        this.elems.forEach(function (el, i) {
141            if (isElementInViewport(el, self.options.viewportFactor)) {
142                self.animate(el);
143            }
144        });
145        this.scrolled = false;
146    },
147
148    /*=============================================================================*/
149
150    parseLanguage: function (el) {
151
152  //  Splits on a sequence of one or more commas, periods or spaces.
153      var words = el.getAttribute('data-scrollreveal').split(/[, ]+/),
154          enterFrom,
155          parsed = {};
156
157      function filter (words) {
158        var ret = [],
159
160            blacklist = [
161              "from",
162              "the",
163              "and",
164              "then",
165              "but"
166            ];
167
168        words.forEach(function (word, i) {
169          if (blacklist.indexOf(word) > -1) {
170            return;
171          }

172          ret.push(word);
173        });
174
175        return ret;
176      }
177
178      words = filter(words);
179
180      words.forEach(function (word, i) {
181
182        switch (word) {
183          case "enter":
184            enterFrom = words[i + 1];
185
186            if (enterFrom == "top" || enterFrom == "bottom") {
187              parsed.axis = "y";
188            }
189
190            if (enterFrom == "left" || enterFrom == "right") {
191              parsed.axis = "x";
192            }
193
194            return;
195
196          case "after":
197            parsed.delay = words[i + 1];
198            return;
199
200          case "wait":
201            parsed.delay = words[i + 1];
202            return;
203
204          case "move":
205            parsed.distance = words[i + 1];
206            return;
207
208          case "over":
209            parsed.duration = words[i + 1];
210            return;
211
212          case "trigger":
213            parsed.eventName = words[i + 1];
214            return;
215
216          default:
217        //  Unrecognizable words; do nothing.
218            return;
219        }
220      });
221
222  //  After all values are parsed, let’s make sure our our
223  //  pixel distance is negative for top and left entrances.
224  //
225  //  ie. "move 25px from top" starts at 'top: -25px' in CSS.
226
227      if (enterFrom == "top" || enterFrom == "left") {
228
229        if (!typeof parsed.distance == "undefined") {
230          parsed.distance = "-" + parsed.distance;
231        }
232
233        else {
234          parsed.distance = "-" + this.options.distance;
235        }
236
237      }
238
239      return parsed;
240    },
241
242    /*=============================================================================*/
243
244    genCSS: function (el, axis) {
245      var parsed = this.parseLanguage(el);
246
247      var dist   = parsed.distance || this.options.distance,
248          dur    = parsed.duration || this.options.duration,
249          delay  = parsed.delay    || this.options.delay,
250          axis   = parsed.axis     || this.options.axis;
251
252      var transition = "-webkit-transition: all " + dur + " ease " + delay + ";" +
253                          "-moz-transition: all " + dur + " ease " + delay + ";" +
254                            "-o-transition: all " + dur + " ease " + delay + ";" +
255                               "transition: all " + dur + " ease " + delay + ";";
256
257      var initial = "-webkit-transform: translate" + axis + "(" + dist + ");" +
258                       "-moz-transform: translate" + axis + "(" + dist + ");" +
259                            "transform: translate" + axis + "(" + dist + ");" +
260                              "opacity: 0;";
261
262      var target = "-webkit-transform: translate" + axis + "(0);" +
263                      "-moz-transform: translate" + axis + "(0);" +
264                           "transform: translate" + axis + "(0);" +
265                             "opacity: 1;";
266      return {
267        transition: transition,
268        initial: initial,
269        target: target,
270        totalDuration: ((parseFloat(dur) + parseFloat(delay)) * 1000)
271      };
272    },
273
274    /*=============================================================================*/
275
276    animate: function (el) {
277      var css = this.genCSS(el);
278
279      if (!el.getAttribute('data-sr-init')) {
280        el.setAttribute('style', css.initial);
281        el.setAttribute('data-sr-init', true);
282      }
283
284      if (el.getAttribute('data-sr-complete')) {
285        return;
286      }
287
288      if (isElementInViewport(el, this.options.viewportFactor)) {
289        el.setAttribute('style', css.target + css.transition);
290
291        setTimeout(function () {
292          el.removeAttribute('style');
293          el.setAttribute('data-sr-complete', true);
294        }, css.totalDuration);
295      }
296
297    }
298  }; // end scrollReveal.prototype
299
300  document.addEventListener("DOMContentLoaded", function (evt) {
301    window.scrollReveal = new scrollReveal();
302  });
303
304})(window);