| (function ($) { | |
| var selectors = []; var check_binded = false; var check_lock = false; var defaults = { interval: 250, force_process: false } | |
| var $window = $(window); var $prior_appeared; function process() { | |
| check_lock = false; for (var index = 0; index < selectors.length; index++) { | |
| var $appeared = $(selectors[index]).filter(function () { return $(this).is(':appeared'); }); $appeared.trigger('appear', [$appeared]); if ($prior_appeared) { var $disappeared = $prior_appeared.not($appeared); $disappeared.trigger('disappear', [$disappeared]); } | |
| $prior_appeared = $appeared; | |
| } | |
| } | |
| $.expr[':']['appeared'] = function (element) { | |
| var $element = $(element); if (!$element.is(':visible')) { return false; } | |
| var window_left = $window.scrollLeft(); var window_top = $window.scrollTop(); var offset = $element.offset(); var left = offset.left; var top = offset.top; if (top + $element.height() >= window_top && top - ($element.data('appear-top-offset') || 0) <= window_top + $window.height() && left + $element.width() >= window_left && left - ($element.data('appear-left-offset') || 0) <= window_left + $window.width()) { return true; } else { return false; } | |
| } | |
| $.fn.extend({ | |
| appear: function (options) { | |
| var opts = $.extend({}, defaults, options || {}); var selector = this.selector || this; if (!check_binded) { | |
| var on_check = function () { | |
| if (check_lock) { return; } | |
| check_lock = true; setTimeout(process, opts.interval); | |
| }; $(window).scroll(on_check).resize(on_check); check_binded = true; | |
| } | |
| if (opts.force_process) { setTimeout(process, opts.interval); } | |
| selectors.push(selector); return $(selector); | |
| } | |
| }); $.extend({ force_appear: function () { if (check_binded) { process(); return true; }; return false; } }); | |
| })(jQuery); |