/\*\*

- @ngdoc module
- @name ng.animate
- @description
-
- The `ng.animate` module provides support for CSS-based animations (keyframes and transitions) as well as JavaScript-based animations via
- callback hooks. Animations are not enabled by default, however, by including `ng.animate` the animation hooks are enabled for an AngularTS app.
-
- ## Usage
- Simply put, there are two ways to make use of animations when ng.animate is used: by using **CSS** and **JavaScript**. The former works purely based
- using CSS (by using matching CSS selectors/styles) and the latter triggers animations that are registered via `module.animation()`. For
- both CSS and JS animations the sole requirement is to have a matching `CSS class` that exists both in the registered animation and within
- the HTML element that the animation will be triggered on.
-
- ## Directive Support
- The following directives are "animation aware":
-
- | Directive | Supported Animations |
- |-------------------------------------------------------------------------------|---------------------------------------------------------------------------|
- | {@link ng.directive:form#animations form / ngForm} | add and remove ({@link ng.directive:form#css-classes various classes}) |
- | {@link ng.animate.directive:ng.animateSwap#animations ng.animateSwap} | enter and leave |
- | {@link ng.directive:ngClass#animations ngClass / class&#125;&#8203;&#125;} | add and remove |
- | {@link ng.directive:ngClassEven#animations ngClassEven} | add and remove |
- | {@link ng.directive:ngClassOdd#animations ngClassOdd} | add and remove |
- | {@link ng.directive:ngHide#animations ngHide} | add and remove (the `ng-hide` class) |
- | {@link ng.directive:ngIf#animations ngIf} | enter and leave |
- | {@link ng.directive:ngInclude#animations ngInclude} | enter and leave |
- | {@link module:ngMessages#animations ngMessage / ngMessageExp} | enter and leave |
- | {@link module:ngMessages#animations ngMessages} | add and remove (the `ng-active`/`ng-inactive` classes) |
- | {@link ng.directive:ngModel#animations ngModel} | add and remove ({@link ng.directive:ngModel#css-classes various classes}) |
- | {@link ng.directive:ngRepeat#animations ngRepeat} | enter, leave, and move |
- | {@link ng.directive:ngShow#animations ngShow} | add and remove (the `ng-hide` class) |
- | {@link ng.directive:ngSwitch#animations ngSwitch} | enter and leave |
- | {@link ngRoute.directive:ngView#animations ngView} | enter and leave |
-
- (More information can be found by visiting the documentation associated with each directive.)
-
- For a full breakdown of the steps involved during each animation event, refer to the
- {@link ng.$animate `$animate` API docs}.
-
- ## CSS-based Animations
-
- CSS-based animations with ng.animate are unique since they require no JavaScript code at all. By using a CSS class that we reference between our HTML
- and CSS code we can create an animation that will be picked up by AngularTS when an underlying directive performs an operation.
-
- The example below shows how an `enter` animation can be made possible on an element using `ng-if`:
-
- ```html

  ```

- <div ng-if="bool" class="fade">
- Fade me in out
- </div>
- <button ng-click="bool=true">Fade In!</button>
- <button ng-click="bool=false">Fade Out!</button>
- ```

  ```

-
- Notice the CSS class **fade**? We can now create the CSS transition code that references this class:
-
- ```css

  ```

- /\* The starting CSS styles for the enter animation \*/
- .fade.ng-enter {
- transition:0.5s linear all;
- opacity:0;
- }
-
- /\* The finishing CSS styles for the enter animation \*/
- .fade.ng-enter.ng-enter-active {
- opacity:1;
- }
- ```

  ```

-
- The key thing to remember here is that, depending on the animation event (which each of the directives above trigger depending on what's going on) two
- generated CSS classes will be applied to the element; in the example above we have `.ng-enter` and `.ng-enter-active`. For CSS transitions, the transition
- code **must** be defined within the starting CSS class (in this case `.ng-enter`). The destination class is what the transition will animate towards.
-
- If for example we wanted to create animations for `leave` and `move` (ngRepeat triggers move) then we can do so using the same CSS naming conventions:
-
- ```css

  ```

- /\* now the element will fade out before it is removed from the DOM \*/
- .fade.ng-leave {
- transition:0.5s linear all;
- opacity:1;
- }
- .fade.ng-leave.ng-leave-active {
- opacity:0;
- }
- ```

  ```

-
- We can also make use of **CSS Keyframes** by referencing the keyframe animation within the starting CSS class:
-
- ```css

  ```

- /\* there is no need to define anything inside of the destination
- CSS class since the keyframe will take charge of the animation \*/
- .fade.ng-leave {
- animation: my_fade_animation 0.5s linear;
- -webkit-animation: my_fade_animation 0.5s linear;
- }
-
- @keyframes my_fade_animation {
- from { opacity:1; }
- to { opacity:0; }
- }
-
- @-webkit-keyframes my_fade_animation {
- from { opacity:1; }
- to { opacity:0; }
- }
- ```

  ```

-
- Feel free also mix transitions and keyframes together as well as any other CSS classes on the same element.
-
- ### CSS Class-based Animations
-
- Class-based animations (animations that are triggered via `ngClass`, `ngShow`, `ngHide` and some other directives) have a slightly different
- naming convention. Class-based animations are basic enough that a standard transition or keyframe can be referenced on the class being added
- and removed.
-
- For example if we wanted to do a CSS animation for `ngHide` then we place an animation on the `.ng-hide` CSS class:
-
- ```html

  ```

- <div ng-show="bool" class="fade">
- Show and hide me
- </div>
- <button ng-click="bool=!bool">Toggle</button>
-
- <style>
- .fade.ng-hide {
- transition:0.5s linear all;
- opacity:0;
- }
- </style>
- ```

  ```

-
- All that is going on here with ngShow/ngHide behind the scenes is the `.ng-hide` class is added/removed (when the hidden state is valid). Since
- ngShow and ngHide are animation aware then we can match up a transition and ng.animate handles the rest.
-
- In addition the addition and removal of the CSS class, ng.animate also provides two helper methods that we can use to further decorate the animation
- with CSS styles.
-
- ```html

  ```

- <div ng-class="{on:onOff}" class="highlight">
- Highlight this box
- </div>
- <button ng-click="onOff=!onOff">Toggle</button>
-
- <style>
- .highlight {
- transition:0.5s linear all;
- }
- .highlight.on-add {
- background:white;
- }
- .highlight.on {
- background:yellow;
- }
- .highlight.on-remove {
- background:black;
- }
- </style>
- ```

  ```

-
- We can also make use of CSS keyframes by placing them within the CSS classes.
-
-
- ### CSS Staggering Animations
- A Staggering animation is a collection of animations that are issued with a slight delay in between each successive operation resulting in a
- curtain-like effect. The ng.animate module (versions >=1.2) supports staggering animations and the stagger effect can be
- performed by creating a **ng-EVENT-stagger** CSS class and attaching that class to the base CSS class used for
- the animation. The style property expected within the stagger class can either be a **transition-delay** or an
- **animation-delay** property (or both if your animation contains both transitions and keyframe animations).
-
- ```css

  ```

- .my-animation.ng-enter {
- /\* standard transition code \*/
- transition: 1s linear all;
- opacity:0;
- }
- .my-animation.ng-enter-stagger {
- /\* this will have a 100ms delay between each successive leave animation \*/
- transition-delay: 0.1s;
-
- /\* As of 1.4.4, this must always be set: it signals ng.animate
-     to not accidentally inherit a delay property from another CSS class &#42;/
- transition-duration: 0s;
-
- /\* if you are using animations instead of transitions you should configure as follows:
-     animation-delay: 0.1s;
-     animation-duration: 0s; &#42;/
- }
- .my-animation.ng-enter.ng-enter-active {
- /\* standard transition styles \*/
- opacity:1;
- }
- ```

  ```

-
- Staggering animations work by default in ngRepeat (so long as the CSS class is defined). Outside of ngRepeat, to use staggering animations
- on your own, they can be triggered by firing multiple calls to the same event on $animate. However, the restrictions surrounding this
- are that each of the elements must have the same CSS className value as well as the same parent element. A stagger operation
- will also be reset if one or more animation frames have passed since the multiple calls to `$animate` were fired.
-
- The following code will issue the **ng-leave-stagger** event on the element provided:
-
- ```js

  ```

- let kids = parent.children();
-
- $animate.leave(kids[0]); //stagger index=0
- $animate.leave(kids[1]); //stagger index=1
- $animate.leave(kids[2]); //stagger index=2
- $animate.leave(kids[3]); //stagger index=3
- $animate.leave(kids[4]); //stagger index=4
-
- window.requestAnimationFrame(function() {
- //stagger has reset itself
- $animate.leave(kids[5]); //stagger index=0
- $animate.leave(kids[6]); //stagger index=1
-
- ;
- });
- ```

  ```

-
- Stagger animations are currently only supported within CSS-defined animations.
-
- ### The `ng-animate` CSS class
-
- When ng.animate is animating an element it will apply the `ng-animate` CSS class to the element for the duration of the animation.
- This is a temporary CSS class and it will be removed once the animation is over (for both JavaScript and CSS-based animations).
-
- Therefore, animations can be applied to an element using this temporary class directly via CSS.
-
- ```css

  ```

- .zipper.ng-animate {
- transition:0.5s linear all;
- }
- .zipper.ng-enter {
- opacity:0;
- }
- .zipper.ng-enter.ng-enter-active {
- opacity:1;
- }
- .zipper.ng-leave {
- opacity:1;
- }
- .zipper.ng-leave.ng-leave-active {
- opacity:0;
- }
- ```

  ```

-
- (Note that the `ng-animate` CSS class is reserved and it cannot be applied on an element directly since ng.animate will always remove
- the CSS class once an animation has completed.)
-
-
- ### The `ng-[event]-prepare` class
-
- This is a special class that can be used to prevent unwanted flickering / flash of content before
- the actual animation starts. The class is added as soon as an animation is initialized, but removed
- before the actual animation starts (after waiting for a $digest).
- It is also only added for _structural_ animations (`enter`, `move`, and `leave`).
-
- In practice, flickering can appear when nesting elements with structural animations such as `ngIf`
- into elements that have class-based animations such as `ngClass`.
-
- ```html

  ```

- <div ng-class="{red: myProp}">
- <div ng-class="{blue: myProp}">
-     <div class="message" ng-if="myProp"></div>
- </div>
- </div>
- ```

  ```

-
- It is possible that during the `enter` animation, the `.message` div will be briefly visible before it starts animating.
- In that case, you can add styles to the CSS that make sure the element stays hidden before the animation starts:
-
- ```css

  ```

- .message.ng-enter-prepare {
- opacity: 0;
- }
- ```

  ```

-
- ### Animating between value changes
-
- Sometimes you need to animate between different expression states, whose values
- don't necessary need to be known or referenced in CSS styles.
- Unless possible with another {@link ng.animate#directive-support "animation aware" directive},
- that specific use case can always be covered with {@link ng.animate.directive:ng.animateSwap} as
- can be seen in {@link ng.animate.directive:ng.animateSwap#examples this example}.
-
- Note that {@link ng.animate.directive:ng.animateSwap} is a _structural directive_, which means it
- creates a new instance of the element (including any other/child directives it may have) and
- links it to a new scope every time _swap_ happens. In some cases this might not be desirable
- (e.g. for performance reasons, or when you wish to retain internal state on the original
- element instance).
-
- ## JavaScript-based Animations
-
- ng.animate also allows for animations to be consumed by JavaScript code. The approach is similar to CSS-based animations (where there is a shared
- CSS class that is referenced in our HTML code) but in addition we need to register the JavaScript animation on the module. By making use of the
- `module.animation()` module function we can register the animation.
-
- Let's see an example of a enter/leave animation using `ngRepeat`:
-
- ```html

  ```

- <div ng-repeat="item in items" class="slide">
- {{ item }}
- </div>
- ```

  ```

-
- See the **slide** CSS class? Let's use that class to define an animation that we'll structure in our module code by using `module.animation`:
-
- ```js

  ```

- myModule.animation('.slide', [function() {
- return {
-     // make note that other events (like addClass/removeClass)
-     // have different function input parameters
-     enter: function(element, doneFn) {
-       jQuery(element).fadeIn(1000, doneFn);
-
-       // remember to call doneFn so that AngularTS
-       // knows that the animation has concluded
-     },
-
-     move: function(element, doneFn) {
-       jQuery(element).fadeIn(1000, doneFn);
-     },
-
-     leave: function(element, doneFn) {
-       jQuery(element).fadeOut(1000, doneFn);
-     }
- }
- }]);
- ```

  ```

-
- The nice thing about JS-based animations is that we can inject other services and make use of advanced animation libraries such as
- greensock.js and velocity.js.
-
- If our animation code class-based (meaning that something like `ngClass`, `ngHide` and `ngShow` triggers it) then we can still define
- our animations inside of the same registered animation, however, the function input arguments are a bit different:
-
- ```html

  ```

- <div ng-class="color" class="colorful">
- this box is moody
- </div>
- <button ng-click="color='red'">Change to red</button>
- <button ng-click="color='blue'">Change to blue</button>
- <button ng-click="color='green'">Change to green</button>
- ```

  ```

-
- ```js

  ```

- myModule.animation('.colorful', [function() {
- return {
-     addClass: function(element, className, doneFn) {
-       // do some cool animation and call the doneFn
-     },
-     removeClass: function(element, className, doneFn) {
-       // do some cool animation and call the doneFn
-     },
-     setClass: function(element, addedClass, removedClass, doneFn) {
-       // do some cool animation and call the doneFn
-     }
- }
- }]);
- ```

  ```

-
- ## CSS + JS Animations Together
-
- AngularTS 1.4 and higher has taken steps to make the amalgamation of CSS and JS animations more flexible. However, unlike earlier versions of AngularTS,
- defining CSS and JS animations to work off of the same CSS class will not work anymore. Therefore the example below will only result in \*\*JS animations taking
- charge of the animation\*\*:
-
- ```html

  ```

- <div ng-if="bool" class="slide">
- Slide in and out
- </div>
- ```

  ```

-
- ```js

  ```

- myModule.animation('.slide', [function() {
- return {
-     enter: function(element, doneFn) {
-       jQuery(element).slideIn(1000, doneFn);
-     }
- }
- }]);
- ```

  ```

-
- ```css

  ```

- .slide.ng-enter {
- transition:0.5s linear all;
- transform:translateY(-100px);
- }
- .slide.ng-enter.ng-enter-active {
- transform:translateY(0);
- }
- ```

  ```

-
- Does this mean that CSS and JS animations cannot be used together? Do JS-based animations always have higher priority? We can make up for the
- lack of CSS animations by using the `$animateCss` service to trigger our own tweaked-out, CSS-based animations directly from
- our own JS-based animation code:
-
- ```js

  ```

- myModule.animation('.slide', ['$animateCss', function($animateCss) {
- return {
-     enter: function(element) {
-        // this will trigger `.slide.ng-enter` and `.slide.ng-enter-active`.
-       return $animateCss(element, {
-         event: 'enter',
-         structural: true
-       });
-     }
- }
- }]);
- ```

  ```

-
- The nice thing here is that we can save bandwidth by sticking to our CSS-based animation code and we don't need to rely on a 3rd-party animation framework.
-
- The `$animateCss` service is very powerful since we can feed in all kinds of extra properties that will be evaluated and fed into a CSS transition or
- keyframe animation. For example if we wanted to animate the height of an element while adding and removing classes then we can do so by providing that
- data into `$animateCss` directly:
-
- ```js

  ```

- myModule.animation('.slide', ['$animateCss', function($animateCss) {
- return {
-     enter: function(element) {
-       return $animateCss(element, {
-         event: 'enter',
-         structural: true,
-         addClass: 'maroon-setting',
-         from: { height:0 },
-         to: { height: 200 }
-       });
-     }
- }
- }]);
- ```

  ```

-
- Now we can fill in the rest via our transition CSS code:
-
- ```css

  ```

- /\* the transition tells ng.animate to make the animation happen \*/
- .slide.ng-enter { transition:0.5s linear all; }
-
- /\* this extra CSS class will be absorbed into the transition
- since the $animateCss code is adding the class \*/
- .maroon-setting { background:red; }
- ```

  ```

-
- And `$animateCss` will figure out the rest. Just make sure to have the `done()` callback fire the `doneFn` function to signal when the animation is over.
-
- To learn more about what's possible be sure to visit the {@link ng.animate.$animateCss $animateCss service}.
-
- ## Animation Anchoring (via `ng-animate-ref`)
-
- ng.animate in AngularTS 1.4 comes packed with the ability to cross-animate elements between
- structural areas of an application (like views) by pairing up elements using an attribute
- called `ng-animate-ref`.
-
- Let's say for example we have two views that are managed by `ng-view` and we want to show
- that there is a relationship between two components situated in within these views. By using the
- `ng-animate-ref` attribute we can identify that the two components are paired together and we
- can then attach an animation, which is triggered when the view changes.
-
- Say for example we have the following template code:
-
- ```html

  ```

- <!-- index.html -->
- <div ng-view class="view-animation">
- </div>
-
- <!-- home.html -->
- <a href="#/banner-page">
- <img src="./banner.jpg" class="banner" ng-animate-ref="banner">
- </a>
-
- <!-- banner-page.html -->
- <img src="./banner.jpg" class="banner" ng-animate-ref="banner">
- ```

  ```

-
- Now, when the view changes (once the link is clicked), ng.animate will examine the
- HTML contents to see if there is a match reference between any components in the view
- that is leaving and the view that is entering. It will scan both the view which is being
- removed (leave) and inserted (enter) to see if there are any paired DOM elements that
- contain a matching ref value.
-
- The two images match since they share the same ref value. ng.animate will now create a
- transport element (which is a clone of the first image element) and it will then attempt
- to animate to the position of the second image element in the next view. For the animation to
- work a special CSS class called `ng-anchor` will be added to the transported element.
-
- We can now attach a transition onto the `.banner.ng-anchor` CSS class and then
- ng.animate will handle the entire transition for us as well as the addition and removal of
- any changes of CSS classes between the elements:
-
- ```css

  ```

- .banner.ng-anchor {
- /\* this animation will last for 1 second since there are
-          two phases to the animation (an `in` and an `out` phase) &#42;/
- transition:0.5s linear all;
- }
- ```

  ```

-
- We also **must** include animations for the views that are being entered and removed
- (otherwise anchoring wouldn't be possible since the new view would be inserted right away).
-
- ```css

  ```

- .view-animation.ng-enter, .view-animation.ng-leave {
- transition:0.5s linear all;
- position:fixed;
- left:0;
- top:0;
- width:100%;
- }
- .view-animation.ng-enter {
- transform:translateX(100%);
- }
- .view-animation.ng-leave,
- .view-animation.ng-enter.ng-enter-active {
- transform:translateX(0%);
- }
- .view-animation.ng-leave.ng-leave-active {
- transform:translateX(-100%);
- }
- ```

  ```

-
- Now we can jump back to the anchor animation. When the animation happens, there are two stages that occur:
- an `out` and an `in` stage. The `out` stage happens first and that is when the element is animated away
- from its origin. Once that animation is over then the `in` stage occurs which animates the
- element to its destination. The reason why there are two animations is to give enough time
- for the enter animation on the new element to be ready.
-
- The example above sets up a transition for both the in and out phases, but we can also target the out or
- in phases directly via `ng-anchor-out` and `ng-anchor-in`.
-
- ```css

  ```

- .banner.ng-anchor-out {
- transition: 0.5s linear all;
-
- /\* the scale will be applied during the out animation,
-          but will be animated away when the in animation runs &#42;/
- transform: scale(1.2);
- }
-
- .banner.ng-anchor-in {
- transition: 1s linear all;
- }
- ```

  ```

-
-
-
-
- ### Anchoring Demo
- <example module="anchoringExample"
           name="anchoringExample"
           id="anchoringExample"
           deps="angular-animate.js;angular-route.js"
           animations="true">
  <file name="index.html">
  <a href="#!/">Home</a>
  <hr />
  <div class="view-container">
  <div ng-view class="view"></div>
  </div>
  </file>
  <file name="script.js">
  angular.module('anchoringExample', ['ng.animate', 'ngRoute'])
  .config(['$routeProvider', function($routeProvider) {
  $routeProvider.when('/', {
  templateUrl: 'home.html',
  controller: 'HomeController as home'
  });
  $routeProvider.when('/profile/:id', {
  templateUrl: 'profile.html',
  controller: 'ProfileController as profile'
  });
  }])
  .run(['$rootScope', function($rootScope) {
  $rootScope.records = [
            { id: 1, title: 'Miss Beulah Roob' },
            { id: 2, title: 'Trent Morissette' },
            { id: 3, title: 'Miss Ava Pouros' },
            { id: 4, title: 'Rod Pouros' },
            { id: 5, title: 'Abdul Rice' },
            { id: 6, title: 'Laurie Rutherford Sr.' },
            { id: 7, title: 'Nakia McLaughlin' },
            { id: 8, title: 'Jordon Blanda DVM' },
            { id: 9, title: 'Rhoda Hand' },
            { id: 10, title: 'Alexandrea Sauer' }
          ];
        }])
        .controller('HomeController', [function() {
          //empty
        }])
        .controller('ProfileController', ['$rootScope', '$routeParams',
            function ProfileController($rootScope, $routeParams) {
          let index = parseInt($routeParams.id, 10);
  let record = $rootScope.records[index - 1];

          this.title = record.title;
          this.id = record.id;
        }]);

    </file>
    <file name="home.html">
      <h2>Welcome to the home page</h1>
      <p>Please click on an element</p>
      <a class="record"
         ng-href="#!/profile/{{ record.id }}"
         ng-animate-ref="{{ record.id }}"
         ng-repeat="record in records">
        {{ record.title }}
      </a>
    </file>
    <file name="profile.html">
      <div class="profile record" ng-animate-ref="{{ profile.id }}">
        {{ profile.title }}
      </div>
    </file>
    <file name="animations.css">
      .record {
        display:block;
        font-size:20px;
      }
      .profile {
        background:black;
        color:white;
        font-size:100px;
      }
      .view-container {
        position:relative;
      }
      .view-container > .view.ng-animate {
        position:absolute;
        top:0;
        left:0;
        width:100%;
        min-height:500px;
      }
      .view.ng-enter, .view.ng-leave,
      .record.ng-anchor {
        transition:0.5s linear all;
      }
      .view.ng-enter {
        transform:translateX(100%);
      }
      .view.ng-enter.ng-enter-active, .view.ng-leave {
        transform:translateX(0%);
      }
      .view.ng-leave.ng-leave-active {
        transform:translateX(-100%);
      }
      .record.ng-anchor-out {
        background:red;
      }
    </file>
  </example>

-
- ### How is the element transported?
-
- When an anchor animation occurs, ng.animate will clone the starting element and position it exactly where the starting
- element is located on screen via absolute positioning. The cloned element will be placed inside of the root element
- of the application (where ng-app was defined) and all of the CSS classes of the starting element will be applied. The
- element will then animate into the `out` and `in` animations and will eventually reach the coordinates and match
- the dimensions of the destination element. During the entire animation a CSS class of `.ng-animate-shim` will be applied
- to both the starting and destination elements in order to hide them from being visible (the CSS styling for the class
- is: `visibility:hidden`). Once the anchor reaches its destination then it will be removed and the destination element
- will become visible since the shim class will be removed.
-
- ### How is the morphing handled?
-
- CSS Anchoring relies on transitions and keyframes and the internal code is intelligent enough to figure out
- what CSS classes differ between the starting element and the destination element. These different CSS classes
- will be added/removed on the anchor element and a transition will be applied (the transition that is provided
- in the anchor class). Long story short, ng.animate will figure out what classes to add and remove which will
- make the transition of the element as smooth and automatic as possible. Be sure to use simple CSS classes that
- do not rely on DOM nesting structure so that the anchor element appears the same as the starting element (since
- the cloned element is placed inside of root element which is likely close to the body element).
-
- Note that if the root element is on the `<html>` element then the cloned node will be placed inside of body.
-
-
- ## Using $animate in your directive code
-
- So far we've explored how to feed in animations into an AngularTS application, but how do we trigger animations within our own directives in our application?
- By injecting the `$animate` service into our directive code, we can trigger structural and class-based hooks which can then be consumed by animations. Let's
- imagine we have a greeting box that shows and hides itself when the data changes
-
- ```html

  ```

- <greeting-box active="onOrOff">Hi there</greeting-box>
- ```

  ```

-
- ```js

  ```

- ngModule.directive('greetingBox', ['$animate', function($animate) {
- return function(scope, element, attrs) {
-     attrs.$observe('active', function(value) {
-       value ? $animate.addClass(element, 'on') : $animate.removeClass(element, 'on');
-     });
- });
- }]);
- ```

  ```

-
- Now the `on` CSS class is added and removed on the greeting box component. Now if we add a CSS class on top of the greeting box element
- in our HTML code then we can trigger a CSS or JS animation to happen.
-
- ```css

  ```

- /\* normally we would create a CSS class to reference on the element \*/
- greeting-box.on { transition:0.5s linear all; background:green; color:white; }
- ```

  ```

-
- The `$animate` service contains a variety of other methods like `enter`, `leave`, `animate` and `setClass`. To learn more about what's
- possible be sure to visit the {@link ng.$animate $animate service API page}.
-
-
- ## Callbacks and Promises
-
- When `$animate` is called it returns a promise that can be used to capture when the animation has ended. Therefore if we were to trigger
- an animation (within our directive code) then we can continue performing directive and scope related activities after the animation has
- ended by chaining onto the returned promise that animation method returns.
-
- ```js

  ```

- // somewhere within the depths of the directive
- $animate.enter(element, parent).then(function() {
- //the animation has completed
- });
- ```

  ```

-
- (Note that earlier versions of AngularTS prior to v1.4 required the promise code to be wrapped using `$scope.$apply(...)`. This is not the case
- anymore.)
-
- In addition to the animation promise, we can also make use of animation-related callbacks within our directives and controller code by registering
- an event listener using the `$animate` service. Let's say for example that an animation was triggered on our view
- routing controller to hook into that:
-
- ```js

  ```

- ngModule.controller('HomePageController', ['$animate', function($animate) {
- $animate.on('enter', ngViewElement, function(element) {
-     // the animation for this route has completed
- }]);
- }])
- ```

  ```

-
- (Note that you will need to trigger a digest within the callback to get AngularTS to notice any scope-related changes.)
  \*/

/\*\*

- @ngdoc service
- @name $animate
- @kind object
-
- @description
- The ng.animate `$animate` service documentation is the same for the core `$animate` service.
-
- Click here {@link ng.$animate to learn more about animations with `$animate`}.
  \*/
