messing with scrolling in angularjs

scrolling angular

    $rootScope.scrollLevel = {
        'one': false,
        'two': false,
    };
    $rootScope.scrollY = window.pageYOffset;
    $rootScope.scrollingDown = false;
    $rootScope.scrollingUp = false
    window.onscroll = function () {
        if($rootScope.scrollY>window.pageYOffset){
            $rootScope.scrollingDown = false;
            $rootScope.scrollingUp = true;
        };
        if($rootScope.scrollY<window.pageYOffset){
            $rootScope.scrollingDown = true;
            $rootScope.scrollingUp = false;
        };
        $rootScope.scrollY = window.pageYOffset;
        // any $scope variable updates
        if($rootScope.scrollY<=64) {
            $rootScope.scrollLevel.one=false;
        };
        if($rootScope.scrollY>64) {
            $rootScope.scrollLevel.one=true;
        };
        if($rootScope.scrollY>128) {
            $rootScope.scrollLevel.two=true;
        };
        if($rootScope.scrollY<=128) {
            $rootScope.scrollLevel.two=false;
        };
        $scope.$digest();
    };
    $scope.$on('$destroy', function() {
        window.onscroll = null;
    });