/**
 * @ngdoc module
 * @name material.components.showHide
 */

// Add additional handlers to ng-show and ng-hide that notify directives
// contained within that they should recompute their size.
// These run in addition to Angular's built-in ng-hide and ng-show directives.
angular.module('material.components.showHide', [
  'material.core'
])
  .directive('ngShow', createDirective('ngShow', true))
  .directive('ngHide', createDirective('ngHide', false));


function createDirective(name, targetValue) {
  return ['$mdUtil', '$window', function($mdUtil, $window) {
    return {
      restrict: 'A',
      multiElement: true,
      link: function($scope, $element, $attr) {
        var unregister = $scope.$on('$md-resize-enable', function() {
          unregister();

          var node = $element[0];
          var cachedTransitionStyles = node.nodeType === $window.Node.ELEMENT_NODE ?
            $window.getComputedStyle(node) : {};

          $scope.$watch($attr[name], function(value) {
            if (!!value === targetValue) {
              $mdUtil.nextTick(function() {
                $scope.$broadcast('$md-resize');
              });

              var opts = {
                cachedTransitionStyles: cachedTransitionStyles
              };

              $mdUtil.dom.animator.waitTransitionEnd($element, opts).then(function() {
                $scope.$broadcast('$md-resize');
              });
            }
          });
        });
      }
    };
  }];
}
