jquery.lazyload.js
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(function($) {
$.fn.lazyload = function(options) {
var settings = {
threshold: 0,
failurelimit: 0,
event: "scroll",
effect: "show",
container: window
};
if (options) {
$.extend(settings, options)
}
var elements = this;
if ("scroll" == settings.event) {
$(settings.container).bind("scroll",
function(event) {
var counter = 0;
elements.each(function() {
if (!$.belowthefold(this, settings) && !$.rightoffold(this, settings)) {
$(this).trigger("appear")
} else {
if (counter++>settings.failurelimit) {
return false
}
}
});
var temp = $.grep(elements,
function(element) {
return ! element.loaded
});
elements = $(temp)
})
}
return this.each(function() {
var self = this;
// $(self).attr("original", $(self).attr("src"));
if ("scroll" != settings.event || $.belowthefold(self, settings) || $.rightoffold(self, settings)) {
if (settings.placeholder) {
$(self).attr("src", settings.placeholder)
} else {
$(self).removeAttr("src")
}
self.loaded = false
} else {
$(self).attr("src", $(self).attr("original"));
self.loaded = true
}
$(self).one("appear",
function() {
if (!this.loaded) {
$("<img />").bind("load",
function() {
$(self).hide().attr("src", $(self).attr("original"))[settings.effect](settings.effectspeed);
self.loaded = true
}).attr("src", $(self).attr("original"))
}
});
if ("scroll" != settings.event) {
$(self).bind(settings.event,
function(event) {
if (!self.loaded) {
$(self).trigger("appear")
}
})
}
})
};
$.belowthefold = function(element, settings) {
if (settings.container === undefined || settings.container === window) {
var fold = $(window).height() + $(window).scrollTop()
} else {
var fold = $(settings.container).offset().top + $(settings.container).height()
}
return fold <= $(element).offset().top - settings.threshold
};
$.rightoffold = function(element, settings) {
if (settings.container === undefined || settings.container === window) {
var fold = $(window).width() + $(window).scrollLeft()
} else {
var fold = $(settings.container).offset().left + $(settings.container).width()
}
return fold <= $(element).offset().left - settings.threshold
};
$.extend($.expr[':'], {
"below-the-fold": "$.belowthefold(a, {threshold : 0, container: window})",
"above-the-fold": "!$.belowthefold(a, {threshold : 0, container: window})",
"right-of-fold": "$.rightoffold(a, {threshold : 0, container: window})",
"left-of-fold": "!$.rightoffold(a, {threshold : 0, container: window})"
})
})(jQuery);