Initial commit

wp-content/themes/evisa/assets/js/appear.js

@@ -0,0 +1,120 @@
+(function($) {
+    var selectors = [];
+
+    var checkBinded = false;
+    var checkLock = false;
+    var defaults = {
+        interval: 250,
+        force_process: false
+    };
+    var $window = $(window);
+
+    var $priorAppeared = [];
+
+    function isAppeared() {
+        return $(this).is(':appeared');
+    }
+
+    function isNotTriggered() {
+        return !$(this).data('_appear_triggered');
+    }
+
+    function process() {
+        checkLock = false;
+
+        for (var index = 0, selectorsLength = selectors.length; index < selectorsLength; index++) {
+            var $appeared = $(selectors[index]).filter(isAppeared);
+
+            $appeared
+                .filter(isNotTriggered)
+                .data('_appear_triggered', true)
+                .trigger('appear', [$appeared]);
+
+            if ($priorAppeared[index]) {
+                var $disappeared = $priorAppeared[index].not($appeared);
+                $disappeared
+                    .data('_appear_triggered', false)
+                    .trigger('disappear', [$disappeared]);
+            }
+            $priorAppeared[index] = $appeared;
+        }
+    }
+
+    function addSelector(selector) {
+        selectors.push(selector);
+        $priorAppeared.push();
+    }
+
+    // ":appeared" custom filter
+    $.expr.pseudos.appeared = $.expr.createPseudo(function(_arg) {
+        return function(element) {
+            var $element = $(element);
+
+            if (!$element.is(':visible')) {
+                return false;
+            }
+
+            var windowLeft = $window.scrollLeft();
+            var windowTop = $window.scrollTop();
+            var offset = $element.offset();
+            var left = offset.left;
+            var top = offset.top;
+
+            if (top + $element.height() >= windowTop &&
+                top - ($element.data('appear-top-offset') || 0) <= windowTop + $window.height() &&
+                left + $element.width() >= windowLeft &&
+                left - ($element.data('appear-left-offset') || 0) <= windowLeft + $window.width()) {
+                return true;
+            }
+            return false;
+        };
+    });
+
+    $.fn.extend({
+        // watching for element's appearance in browser viewport
+        appear: function(selector, options) {
+            $.appear(this, options);
+            return this;
+        }
+    });
+
+    $.extend({
+        appear: function(selector, options) {
+            var opts = $.extend({}, defaults, options || {});
+
+            if (!checkBinded) {
+                var onCheck = function() {
+                    if (checkLock) {
+                        return;
+                    }
+                    checkLock = true;
+
+                    setTimeout(process, opts.interval);
+                };
+
+                $(window).scroll(onCheck).resize(onCheck);
+                checkBinded = true;
+            }
+
+            if (opts.force_process) {
+                setTimeout(process, opts.interval);
+            }
+
+            addSelector(selector);
+        },
+        // force elements's appearance check
+        force_appear: function() {
+            if (checkBinded) {
+                process();
+                return true;
+            }
+            return false;
+        }
+    });
+}(function() {
+    if (typeof module !== 'undefined') {
+        // Node
+        return require('jquery');
+    }
+    return jQuery;
+}()));