### Fragments
Fragments are used to highlight individual elements on a slide. Every element with the class ```fragment``` will be stepped through before moving on to the next slide. Here's an example: http://lab.hakim.se/reveal-js/#/fragments

The default fragment style is to start out invisible and fade in. This style can be changed by appending a different class to the fragment:

```html

grow

shrink

roll-in

fade-out

visible only once

blue only once

highlight-red

highlight-green

highlight-blue

```

Multiple fragments can be applied to the same element sequentially by wrapping it, this will fade in the text on the first step and fade it back out on the second.

```html

I'll fade in, then out

```

The display order of fragments can be controlled using the ```data-fragment-index``` attribute.

```html

Appears last

Appears first

Appears second

```

### Fragment events

When a slide fragment is either shown or hidden reveal.js will dispatch an event.

Some libraries, like MathJax (see #505), get confused by the initially hidden fragment elements. Often times this can be fixed by calling their update or render function from this callback.

```javascript
Reveal.addEventListener( 'fragmentshown', function( event ) {
// event.fragment = the fragment DOM element
} );
Reveal.addEventListener( 'fragmenthidden', function( event ) {
// event.fragment = the fragment DOM element
} );
```

### Code syntax highlighting

By default, Reveal is configured with [highlight.js](http://softwaremaniacs.org/soft/highlight/en/) for code syntax highlighting. Below is an example with clojure code that will be syntax highlighted. When the `data-trim` attribute is present surrounding whitespace is automatically removed.

```html

(def lazy-fib

  (concat

   [0 1]

   ((fn rfib [a b]

        (lazy-cons (+ a b) (rfib b (+ a b)))) 0 1)))

	

```

### Slide number
If you would like to display the page number of the current slide you can do so using the ```slideNumber``` configuration value.

```javascript
Reveal.configure({ slideNumber: true });
```

### Overview mode

Press "Esc" or "o" keys to toggle the overview mode on and off. While you're in this mode, you can still navigate between slides,
as if you were at 1,000 feet above your presentation. The overview mode comes with a few API hooks:

```javascript
Reveal.addEventListener( 'overviewshown', function( event ) { /* ... */ } );
Reveal.addEventListener( 'overviewhidden', function( event ) { /* ... */ } );

// Toggle the overview mode programmatically
Reveal.toggleOverview();
```

### Fullscreen mode
Just press »F« on your keyboard to show your presentation in fullscreen mode. Press the »ESC« key to exit fullscreen mode.

### Embedded media
Embedded HTML5 ``/`` and YouTube iframes are automatically paused when you navigate away from a slide. This can be disabled by decorating your element with a `data-ignore` attribute.

Add `data-autoplay` to your media element if you want it to automatically start playing when the slide is shown:

```html

```

Additionally the framework automatically pushes two [post messages](https://developer.mozilla.org/en-US/docs/Web/API/Window.postMessage) to all iframes, ```slide:start``` when the slide containing the iframe is made visible and ```slide:stop``` when it is hidden.

### Stretching elements
Sometimes it's desirable to have an element, like an image or video, stretch to consume as much space as possible within a given slide. This can be done by adding the ```.stretch``` class to an element as seen below:

```html

This video will use up the remaining space on the slide

```

Limitations:
- Only direct descendants of a slide section can be stretched
- Only one descendant per slide section can be stretched

## PDF Export

Presentations can be exported to PDF via a special print stylesheet. This feature requires that you use [Google Chrome](http://google.com/chrome).
Here's an example of an exported presentation that's been uploaded to SlideShare: http://www.slideshare.net/hakimel/revealjs-13872948.

1. Open your presentation with [css/print/pdf.css](https://github.com/hakimel/reveal.js/blob/master/css/print/pdf.css) included on the page. The default index HTML lets you add *print-pdf* anywhere in the query to include the stylesheet, for example: [lab.hakim.se/reveal-js?print-pdf](http://lab.hakim.se/reveal-js?print-pdf).
2. Open the in-browser print dialog (CMD+P).
3. Change the **Destination** setting to **Save as PDF**.
4. Change the **Layout** to **Landscape**.
5. Change the **Margins** to **None**.
6. Click **Save**.


## Theming

The framework comes with a few different themes included:

- default: Gray background, white text, blue links
- beige: Beige background, dark text, brown links
- sky: Blue background, thin white text, blue links
- night: Black background, thick white text, orange links
- serif: Cappuccino background, gray text, brown links
- simple: White background, black text, blue links
- solarized: Cream-colored background, dark green text, blue links

Each theme is available as a separate stylesheet. To change theme you will need to replace **default** below with your desired theme name in index.html:

```html

```

If you want to add a theme of your own see the instructions here: [/css/theme/README.md](https://github.com/hakimel/reveal.js/blob/master/css/theme/README.md).

## Speaker Notes

reveal.js comes with a speaker notes plugin which can be used to present per-slide notes in a separate browser window. The notes window also gives you a preview of the next upcoming slide so it may be helpful even if you haven't written any notes. Press the 's' key on your keyboard to open the notes window.

Notes are defined by appending an `````` element to a slide as seen below. You can add the ```data-markdown``` attribute to the aside element if you prefer writing notes using Markdown.

When used locally, this feature requires that reveal.js [runs from a local web server](#full-setup).

```html

Some Slide

Oh hey, these are some notes. They'll be hidden in your presentation, but you can see them if you open the speaker notes window (hit 's' on your keyboard).

```

If you're using the external Markdown plugin, you can add notes with the help of a special delimiter:

```html

# Title
## Sub-title

Here is some content...

Note:
This will only display in the notes window.
```

## Server Side Speaker Notes

In some cases it can be desirable to run notes on a separate device from the one you're presenting on. The Node.js-based notes plugin lets you do this using the same note definitions as its client side counterpart. Include the required scripts by adding the following dependencies:

```javascript
Reveal.initialize({
...

dependencies: [
{ src: 'socket.io/socket.io.js', async: true },
{ src: 'plugin/notes-server/client.js', async: true }
]
});
```

Then:

1. Install [Node.js](http://nodejs.org/)
2. Run ```npm install```
3. Run ```node plugin/notes-server```

## Multiplexing

The multiplex plugin allows your audience to view the slides of the presentation you are controlling on their own phone, tablet or laptop. As the master presentation navigates the slides, all client presentations will update in real time. See a demo at [http://revealjs.jit.su/](http://revealjs.jit.su).

The multiplex plugin needs the following 3 things to operate:

1. Master presentation that has control
2. Client presentations that follow the master
3. Socket.io server to broadcast events from the master to the clients

More details:

#### Master presentation
Served from a static file server accessible (preferably) only to the presenter. This need only be on your (the presenter's) computer. (It's safer to run the master presentation from your own computer, so if the venue's Internet goes down it doesn't stop the show.) An example would be to execute the following commands in the directory of your master presentation:

1. ```npm install node-static```
2. ```static```

If you want to use the speaker notes plugin with your master presentation then make sure you have the speaker notes plugin configured correctly along with the configuration shown below, then execute ```node plugin/notes-server``` in the directory of your master presentation. The configuration below will cause it to connect to the socket.io server as a master, as well as launch your speaker-notes/static-file server.

You can then access your master presentation at ```http://localhost:1947```

Example configuration:
```javascript
Reveal.initialize({
// other options...

multiplex: {
// Example values. To generate your own, see the socket.io server instructions.
secret: '13652805320794272084', // Obtained from the socket.io server. Gives this (the master) control of the presentation
id: '1ea875674b17ca76', // Obtained from socket.io server
url: 'revealjs.jit.su:80' // Location of socket.io server
},

// Don't forget to add the dependencies
dependencies: [
{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.10/socket.io.min.js', async: true },
{ src: 'plugin/multiplex/master.js', async: true },

// and if you want speaker notes
{ src: 'plugin/notes-server/client.js', async: true }

// other dependencies...
]
});
```

#### Client presentation
Served from a publicly accessible static file server. Examples include: GitHub Pages, Amazon S3, Dreamhost, Akamai, etc. The more reliable, the better. Your audience can then access the client presentation via ```http://example.com/path/to/presentation/client/index.html```, with the configuration below causing them to connect to the socket.io server as clients.

Example configuration:
```javascript
Reveal.initialize({
// other options...

multiplex: {
// Example values. To generate your own, see the socket.io server instructions.
secret: null, // null so the clients do not have control of the master presentation
id: '1ea875674b17ca76', // id, obtained from socket.io server
url: 'revealjs.jit.su:80' // Location of socket.io server
},

// Don't forget to add the dependencies
dependencies: [
{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.10/socket.io.min.js', async: true },
{ src: 'plugin/multiplex/client.js', async: true }

// other dependencies...
]
});
```

#### Socket.io server
Server that receives the slideChanged events from the master presentation and broadcasts them out to the connected client presentations. This needs to be publicly accessible. You can run your own socket.io server with the commands:

1. ```npm install```
2. ```node plugin/multiplex```

Or you use the socket.io server at [http://revealjs.jit.su](http://revealjs.jit.su).

You'll need to generate a unique secret and token pair for your master and client presentations. To do so, visit ```http://example.com/token```, where ```http://example.com``` is the location of your socket.io server. Or if you're going to use the socket.io server at [http://revealjs.jit.su](http://revealjs.jit.su), visit [http://revealjs.jit.su/token](http://revealjs.jit.su/token).

You are very welcome to point your presentations at the Socket.io server running at [http://revealjs.jit.su](http://revealjs.jit.su), but availability and stability are not guaranteed. For anything mission critical I recommend you run your own server. It is simple to deploy to nodejitsu, heroku, your own environment, etc.

##### socket.io server as file static server

The socket.io server can play the role of static file server for your client presentation, as in the example at [http://revealjs.jit.su](http://revealjs.jit.su). (Open [http://revealjs.jit.su](http://revealjs.jit.su) in two browsers. Navigate through the slides on one, and the other will update to match.)

Example configuration:
```javascript
Reveal.initialize({
// other options...

multiplex: {
// Example values. To generate your own, see the socket.io server instructions.
secret: null, // null so the clients do not have control of the master presentation
id: '1ea875674b17ca76', // id, obtained from socket.io server
url: 'example.com:80' // Location of your socket.io server
},

// Don't forget to add the dependencies
dependencies: [
{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.10/socket.io.min.js', async: true },
{ src: 'plugin/multiplex/client.js', async: true }

// other dependencies...
]
```

It can also play the role of static file server for your master presentation and client presentations at the same time (as long as you don't want to use speaker notes). (Open [http://revealjs.jit.su](http://revealjs.jit.su) in two browsers. Navigate through the slides on one, and the other will update to match. Navigate through the slides on the second, and the first will update to match.) This is probably not desirable, because you don't want your audience to mess with your slides while you're presenting. ;)

Example configuration:
```javascript
Reveal.initialize({
// other options...

multiplex: {
// Example values. To generate your own, see the socket.io server instructions.
secret: '13652805320794272084', // Obtained from the socket.io server. Gives this (the master) control of the presentation
id: '1ea875674b17ca76', // Obtained from socket.io server
url: 'example.com:80' // Location of your socket.io server
},

// Don't forget to add the dependencies
dependencies: [
{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/0.9.10/socket.io.min.js', async: true },
{ src: 'plugin/multiplex/master.js', async: true },
{ src: 'plugin/multiplex/client.js', async: true }

// other dependencies...
]
});
```

## Leap Motion
The Leap Motion plugin lets you utilize your [Leap Motion](https://www.leapmotion.com/) device to control basic navigation of your presentation. The gestures currently supported are:

##### 1 to 2 fingers
Pointer — Point to anything on screen. Move your finger past the device to expand the pointer.

##### 1 hand + 3 or more fingers (left/right/up/down)
Navigate through your slides. See config options to invert movements.

##### 2 hands upwards
Toggle the overview mode. Do it a second time to exit the overview.

#### Config Options
You can edit the following options:

| Property | Default | Description
| ----------------- |:-----------------:| :-------------
| autoCenter | true | Center the pointer based on where you put your finger into the leap motions detection field.
| gestureDelay | 500 | How long to delay between gestures in milliseconds.
| naturalSwipe | true | Swipe as though you were touching a touch screen. Set to false to invert.
| pointerColor | #00aaff | The color of the pointer.
| pointerOpacity | 0.7 | The opacity of the pointer.
| pointerSize | 15 | The minimum height and width of the pointer.
| pointerTolerance | 120 | Bigger = slower pointer.

Example configuration:
```js
Reveal.initialize({

// other options...

leap: {
naturalSwipe : false, // Invert swipe gestures
pointerOpacity : 0.5, // Set pointer opacity to 0.5
pointerColor : '#d80000' // Red pointer
},

dependencies: [
{ src: 'plugin/leap/leap.js', async: true }
]

});
```

## MathJax

If you want to display math equations in your presentation you can easily do so by including this plugin. The plugin is a very thin wrapper around the [MathJax](http://www.mathjax.org/) library. To use it you'll need to include it as a reveal.js dependency, [find our more about dependencies here](#dependencies).

The plugin defaults to using [LaTeX](http://en.wikipedia.org/wiki/LaTeX) but that can be adjusted through the ```math``` configuration object. Note that MathJax is loaded from a remote server. If you want to use it offline you'll need to download a copy of the library and adjust the ```mathjax``` configuration value.

Below is an example of how the plugin can be configured. If you don't intend to change these values you do not need to include the ```math``` config object at all.

```js
Reveal.initialize({

// other options ...

math: {
mathjax: 'http://cdn.mathjax.org/mathjax/latest/MathJax.js',
config: 'TeX-AMS_HTML-full' // See http://docs.mathjax.org/en/latest/config-files.html
},

dependencies: [
{ src: 'plugin/math/math.js', async: true }
]

});
```

Read MathJax's documentation if you need [HTTPS delivery](http://docs.mathjax.org/en/latest/start.html#secure-access-to-the-cdn) or serving of [specific versions](http://docs.mathjax.org/en/latest/configuration.html#loading-mathjax-from-the-cdn) for stability.

## Installation

The **basic setup** is for authoring presentations only. The **full setup** gives you access to all reveal.js features and plugins such as speaker notes as well as the development tasks needed to make changes to the source.

### Basic setup

The core of reveal.js is very easy to install. You'll simply need to download a copy of this repository and open the index.html file directly in your browser.

1. Download the latest version of reveal.js from

2. Unzip and replace the example contents in index.html with your own

3. Open index.html in a browser to view it

### Full setup

Some reveal.js features, like external markdown and speaker notes, require that presentations run from a local web server. The following instructions will set up such a server as well as all of the development tasks needed to make edits to the reveal.js source code.

1. Install [Node.js](http://nodejs.org/)

2. Install [Grunt](http://gruntjs.com/getting-started#installing-the-cli)

4. Clone the reveal.js repository
```sh
$ git clone https://github.com/hakimel/reveal.js.git
```

5. Navigate to the reveal.js folder
```sh
$ cd reveal.js
```

6. Install dependencies
```sh
$ npm install
```

7. Serve the presentation and monitor source files for changes
```sh
$ grunt serve
```

8. Open to view your presentation

You can change the port by using `grunt serve --port 8001`.

### Folder Structure
- **css/** Core styles without which the project does not function
- **js/** Like above but for JavaScript
- **plugin/** Components that have been developed as extensions to reveal.js
- **lib/** All other third party assets (JavaScript, CSS, fonts)

### Contributing

Please keep the [issue tracker](http://github.com/hakimel/reveal.js/issues) limited to **bug reports**, **feature requests** and **pull requests**. If you are reporting a bug make sure to include information about which browser and operating system you are using as well as the necessary steps to reproduce the issue.

If you have personal support questions use [StackOverflow](http://stackoverflow.com/questions/tagged/reveal.js).

#### Pull requests

- Should follow the coding style of the file you work in, most importantly:
- Tabs to indent
- Single-quoted strings
- Should be made towards the **dev branch**
- Should be submitted from a feature/topic branch (not your master)
- Should not include the minified **reveal.min.js** file

## License

MIT licensed