1 files changed, 67 insertions, 0 deletions
diff --git a/src/service/autoScroll.js b/src/service/autoScroll.js
new file mode 100644
index 00000000..7b5b28e4
--- /dev/null
+++ b/src/service/autoScroll.js
@@ -0,0 +1,67 @@
+/**
+ * @ngdoc function
+ * @name angular.module.ng.$autoScroll
+ * @requires $window
+ * @requires $location
+ * @requires $rootScope
+ *
+ * @description
+ * When called, it checks current value of `$location.hash()` and scroll to related element,
+ * according to rules specified in
+ * {@link http://dev.w3.org/html5/spec/Overview.html#the-indicated-part-of-the-document Html5 spec}.
+ *
+ * If `$location` uses `hashbang` url (running in `hashbang` mode or `html5` mode on browser without
+ * history API support), `$autoScroll` watches the `$location.hash()` and scroll whenever it
+ * changes.
+ *
+ * You can disable `$autoScroll` service by calling `disable()` on `$autoScrollProvider`.
+ * Note: disabling is only possible before the service is instantiated !
+ */
+function $AutoScrollProvider() {
+
+  this.disable = function() {
+    this.$get = function() {return noop;};
+  };
+
+  this.$get = ['$window', '$location', '$rootScope', function($window, $location, $rootScope) {
+    var document = $window.document;
+
+    // helper function to get first anchor from a NodeList
+    // can't use filter.filter, as it accepts only instances of Array
+    // and IE can't convert NodeList to an array using [].slice
+    // TODO(vojta): use filter if we change it to accept lists as well
+    function getFirstAnchor(list) {
+      var result = null;
+      forEach(list, function(element) {
+        if (!result && lowercase(element.nodeName) === 'a') result = element;
+      });
+      return result;
+    }
+
+    function scroll() {
+      var hash = $location.hash(), elm;
+
+      // empty hash, scroll to the top of the page
+      if (!hash) $window.scrollTo(0, 0);
+
+      // element with given id
+      else if ((elm = document.getElementById(hash))) elm.scrollIntoView();
+
+      // first anchor with given name :-D
+      else if ((elm = getFirstAnchor(document.getElementsByName(hash)))) elm.scrollIntoView();
+
+      // no element and hash == 'top', scroll to the top of the page
+      else if (hash === 'top') $window.scrollTo(0, 0);
+    }
+
+    // scroll whenever hash changes (with hashbang url, regular urls are handled by browser)
+    if ($location instanceof LocationHashbangUrl) {
+      $rootScope.$watch(function() {return $location.hash();}, function() {
+        $rootScope.$evalAsync(scroll);
+      });
+    }
+
+    return scroll;
+  }];
+}
+