#+Title: Introduction to Org-Reveal
#+Author: Yujie Wen
#+Email: yjwen.ty@gmail.com

#+OPTIONS: reveal_center:nil reveal_progress:t reveal_history:nil reveal_control:t reveal_mathjax:t
#+REVEAL_TRANS: cube
#+REVEAL_THEME: moon
#+REVEAL_HLEVEL: 2

* Reveal.js and Org-Reveal

  - *Reveal.js* is a tool for creating good-looking HTML presentations,
    authored by [[hakim.se][Hakim El Hattab]]. \\
    For an example of reveal.js presentation, click [[http://lab.hakim.se/reveal-js/#/][here]].
  - *Org-Reveal* exports your [[orgmode.org][Org]] documents to reveal.js
    presentations.\\
    With Org-reveal, you can create beautiful presentations with 3D
    effects from simple but powerful Org contents.

* Requirements and Installation

  - Reveal.js.
  - Latest org-mode.
  - ox-reveal.el.
  - And, of course, emacs.

** Obtain Reveal.js

   Download Reveal.js packages from [[https://github.com/hakimel/reveal.js/][here]].

   Extract Reveal.js folders from the downloaded zip file.

** Obtain org-mode

   *Note*: Org-reveal relies on the Org-mode 8.0 export frame work.
   Pre-packaged org-mode may be out-of-date.

   If not sure, use the freshest development codes from git repository.
#+BEGIN_SRC sh 
$ git clone git://orgmode.org/org-mode.git
#+END_SRC

    Follow the [[http://orgmode.org/worg/dev/org-build-system.html][online instruction]] to build and install Org-mode.

** Obtain Org-reveal

   Download latest Org-reveal package from [[https://github.com/yjwen/org-reveal][the Org-reveal GitHub page]].

   Or clone the GitHub repository:
#+BEGIN_SRC sh
$ git clone https://github.com/yjwen/org-reveal.git
#+END_SRC

   Copy =ox-reveal.el= to the Org-mode installation directory.

   Add the following statement to your =.emacs= file.
#+BEGIN_SRC lisp 
(require 'ox-reveal)
#+END_SRC

* Configuration

** Set the location of Reveal.js

   Org-reveal must know where Reveal.js is on your computer before
   exporting Org contents.

   The default location is =./reveal.js=, relative to the Org file.

   Change variable =org-reveal-root= 's value will change the location
   globally. For example, add the following statement to your .emacs
   file:
#+BEGIN_SRC lisp 
(setq org-reveal-root "d:/reveal.js")
#+END_SRC

   By setting option =REVEAL_ROOT=, the location is only affected
   within the Org file.

#+BEGIN_SRC org 
,#+REVEAL_ROOT: d:/reveal.js
#+END_SRC

** First Try

   To wake-up Org-reveal now, type "M-x load-library", then type
   "ox-reveal".

   Now you can export this manual into Reveal.js presentation by
   typing "C-c C-e R R".

   Open the generated "Readme.html" in your browser and enjoy the
   cool slides.

** The HLevel

   Org-reveal maps each heading and its contents to one Reveal.js
   slides. Since Reveal.js arranges slides into a 2-dimentional matrix,
   Org-reveal use a *HLevel* value to decide map headings to hozirontal
   or vertical slides.

   * Headings of level less or equal to HLevel are mapped to hozirontal
     slides.
   * Headings of deeper levels are mapped to vertical slides.
     
   HLevel's default value is 1, means only level 1 headings are arranged
   horizontally, deeper headings are mapped to vertical slides below its
   parent level 1 heading.

*** HLevel's Affects on Slides Layout

    Assume we have a simple Org file as below:
#+BEGIN_SRC org 
,* H1
,* H2
,** H2.1
,*** H2.1.1
,* H3
#+END_SRC

    If HLevel is 1, the default value, headings H2.1 and H2.1.1 will
    be mapping to vertical slides below the slides of heading H2.

    [[./images/hlevel.png]]

    If HLevel is changed to 2, slide of heading H2.1 will be changed
    to the main hozirontal queue, and slide of heading H2.1.1 will be
    a vertical slide below it.

    [[./images/hlevel2.png]]

*** Configure HLevel's Value

    * Change variable =org-reveal-hlevel='s value to set HLevel globally.\\
      For example, add the following statement to your =.emacs= file.
#+BEGIN_SRC lisp 
(setq org-reveal-hlevel 2)
#+END_SRC

    * Setting Org files local HLevel to option =REVEAL_HLEVEL=.
#+BEGIN_SRC org 
,#+REVEAL_HLEVEL 2
#+END_SRC

** Select Theme and Transition

    Themes and transition styles are set globally throughout the whole
    file by setting options =REVEAL_THEME= and =REVEAL_TRANS=.

    For an example, please check the heading part of this document.

    Available themes can be found in "css/theme/" in the reveal.js directory.

    Available transitions are: default|cube|page|concave|zoom|linear|fade|none.

** Fragmented Contents

    Make contents fragmented (show up one-by-one) by setting option =ATTR_REVEAL= with
    property ":frag frag-style", as illustrated below.
    
#+ATTR_REVEAL: :frag roll-in
    Paragraphs can be fragmented.

#+ATTR_REVEAL: :frag roll-in
    Items can be fragmented, too.

    Availabe fragment styles are:
#+ATTR_REVEAL: :frag grow
    * grow
#+ATTR_REVEAL: :frag shrink
    * shrink
#+ATTR_REVEAL: :frag roll-in
    * roll-in
#+ATTR_REVEAL: :frag fade-out
    * fade-out
#+ATTR_REVEAL: :frag highlight-red
    * highlight-red
#+ATTR_REVEAL: :frag highlight-green
    * highlight-green
#+ATTR_REVEAL: :frag highlight-blue
    * highlight-blue

** Data State
   :PROPERTIES:
   :reveal_data_state: alert
   :END:

   Set property =reveal_data_state= to headings to change this slide's
   display style, as illustrated above.

   Availabe data states are: alert|blackout|soothe.

** Plug-ins

   Reveal.js provides several plug-in functions.

   - reveal-control : Show/hide browsing control pad.
   - reveal-progress : Show/hide progress bar.
   - reveal-history : Enable/disable slide history track.
   - reveal-center : Enable/disable slide centering.
     
*** Configure Plug-ins

    Each plug-ins can be set on/off by adding =#+OPTIONS= tags or
    settinng custom variables.

    - =#+OPTIONS= tags:\\
      =reveal_control=, =reveal_progress=, =reveal_history=,
      =reveal_center=
    - Custom variables:\\
      =org-reveal-control=, =org-reveal-progress=,
      =org-reveal-history=, =org-reveal-center=

    For an example, please refer to the heading part of this document.

** Source Codes

   Org-reveal use Org-Babel to highlight source codes.

   Codes copied from [[http://www.haskell.org/haskellwiki/The_Fibonacci_sequence][Haskell Wiki]].
#+BEGIN_SRC haskell

  fibs = 0 : 1 : next fibs
         where next (a : t@(b:_)) = (a+b) : next t
#+END_SRC

   If you saw odd indentation, please set variable =org-html-indent=
   to =nil= and export again.

** MathJax

   ${n! \over k!(n-k)!} = {n \choose k}$

   LateX equation are renderred in native HTML5 contents.

   *IMPORTANT*: Displaying equations requires internet connection to
   [[mathjax.org]] or local MathJax installation.

   *IMPORTANT 2*: MathJax is disabled by default to reduce internet
   traffic. Set =#+OPTIONS= tag =reveal_mathjax= or variable
   =org-reveal-mathjax= to true to enable it. For local MathJax
   installation, set option =REVEAL_MATH_JAX_URL= to pointing to the
   installation location.
   
* Thanks

  Courtesy to:

#+ATTR_REVEAL: :frag roll-in
  The powerful Org-mode, 
#+ATTR_REVEAL: :frag roll-in
  the impressive Reveal.js
#+ATTR_REVEAL: :frag roll-in
  and the precise MathJax