angular.js/src/ng/anchorScroll.js
2012-12-19 21:14:09 +01:00

67 lines
2.2 KiB
JavaScript

/**
* @ngdoc function
* @name ng.$anchorScroll
* @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}.
*
* It also watches the `$location.hash()` and scroll whenever it changes to match any anchor.
* This can be disabled by calling `$anchorScrollProvider.disableAutoScrolling()`.
*/
function $AnchorScrollProvider() {
var autoScrollingEnabled = true;
this.disableAutoScrolling = function() {
autoScrollingEnabled = false;
};
this.$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);
}
// does not scroll when user clicks on anchor link that is currently on
// (no url change, no $location.hash() change), browser native does scroll
if (autoScrollingEnabled) {
$rootScope.$watch(function autoScrollWatch() {return $location.hash();},
function autoScrollWatchAction() {
$rootScope.$evalAsync(scroll);
});
}
return scroll;
}];
}