Zmiana nazwy project -> platforma.

[redakcja.git] / platforma / static / js / lib / jquery.lazyload.js

diff --git a/platforma/static/js/lib/jquery.lazyload.js b/platforma/static/js/lib/jquery.lazyload.js
new file mode 100755 (executable)
index 0000000..c15167b
--- /dev/null
+++ b/platforma/static/js/lib/jquery.lazyload.js
@@ -0,0 +1,52 @@
+(function($) {
+    jQuery.fn.lazyload = function(pattern, options) {
+        var settings = {
+            threshold: 0,
+            scrollThreshold: 300,
+            placeholder: 'loading...',
+            checkInterval: 2000
+        };
+        
+        if (options) {
+            $.extend(settings, options);
+        }
+        
+        var container = this;
+        container.data('lazyload:lastCheckedScrollTop', -10000);
+        
+        function aboveViewport(container, element, threshold) {
+            return $(container).offset().top >= $(element).offset().top + $(element).height() + threshold;
+        }
+        
+        function belowViewport(container, element, threshold) {
+            return $(container).offset().top + $(container).height() + threshold <= $(element).offset().top;
+        }
+        
+        function checkScroll() {
+            if (container.data('lazyload:lastCheckedScrollTop') == undefined) {
+                return;
+            }
+            if (Math.abs(container.scrollTop() - container.data('lazyload:lastCheckedScrollTop')) > settings.scrollThreshold) {
+                container.data('lazyload:lastCheckedScrollTop', container.scrollTop());
+                
+                $(pattern, container).each(function() {
+                    if (aboveViewport(container, this, settings.threshold)
+                        || belowViewport(container, this, settings.threshold)) {
+                        $(this).html(settings.placeholder);
+                    } else {
+                        $(this).html('');
+                        var self = this;
+                        $('<img src="' + $(this).attr('src') + '" width="' + $(this).width() + '" />').load(function() {
+                            if ($(this).height() > $(self).height()) {
+                                $(self).height($(this).height());
+                            }
+                        }).appendTo(this);
+                    }
+                })
+            }
+            setTimeout(checkScroll, settings.checkInterval);
+        }
+        
+        checkScroll();
+    };
+})(jQuery);