gistfile1.js

$scope.getWidth = function() {
      return $(window).width();
  };
  $scope.$watch($scope.getWidth, function(newValue, oldValue) {
      $scope.window_width = newValue;
  });
  window.onresize = function(){
    $scope.$apply(function() {
      if($scope.window_width < 768) {
        $rootScope.showMap = false;
      } else {
        $rootScope.showMap = true;
      }
    });
  }