hugo-academic/wowchemy/static/js/vendor/reveal.js/plugin/notes/notes.js

/**
 * Handles opening of and synchronization with the reveal.js
 * notes window.
 *
 * Handshake process:
 * 1. This window posts 'connect' to notes window
 *    - Includes URL of presentation to show
 * 2. Notes window responds with 'connected' when it is available
 * 3. This window proceeds to send the current presentation state
 *    to the notes window
 */
var RevealNotes = (function () {
  var notesPopup = null;

  function openNotes(notesFilePath) {
    if (notesPopup && !notesPopup.closed) {
      notesPopup.focus();
      return;
    }

    if (!notesFilePath) {
      var jsFileLocation = document.querySelector('script[src$="notes.js"]').src; // this js file path
      jsFileLocation = jsFileLocation.replace(/notes\.js(\?.*)?$/, ''); // the js folder path
      notesFilePath = jsFileLocation + 'notes.html';
    }

    notesPopup = window.open(notesFilePath, 'reveal.js - Notes', 'width=1100,height=700');

    if (!notesPopup) {
      alert('Speaker view popup failed to open. Please make sure popups are allowed and reopen the speaker view.');
      return;
    }

    /**
     * Connect to the notes window through a postmessage handshake.
     * Using postmessage enables us to work in situations where the
     * origins differ, such as a presentation being opened from the
     * file system.
     */
    function connect() {
      // Keep trying to connect until we get a 'connected' message back
      var connectInterval = setInterval(function () {
        notesPopup.postMessage(
          JSON.stringify({
            namespace: 'reveal-notes',
            type: 'connect',
            url:
              window.location.protocol +
              '//' +
              window.location.host +
              window.location.pathname +
              window.location.search,
            state: Reveal.getState(),
          }),
          '*',
        );
      }, 500);

      window.addEventListener('message', function (event) {
        var data = JSON.parse(event.data);
        if (data && data.namespace === 'reveal-notes' && data.type === 'connected') {
          clearInterval(connectInterval);
          onConnected();
        }
        if (data && data.namespace === 'reveal-notes' && data.type === 'call') {
          callRevealApi(data.methodName, data.arguments, data.callId);
        }
      });
    }

    /**
     * Calls the specified Reveal.js method with the provided argument
     * and then pushes the result to the notes frame.
     */
    function callRevealApi(methodName, methodArguments, callId) {
      var result = Reveal[methodName].apply(Reveal, methodArguments);
      notesPopup.postMessage(
        JSON.stringify({
          namespace: 'reveal-notes',
          type: 'return',
          result: result,
          callId: callId,
        }),
        '*',
      );
    }

    /**
     * Posts the current slide data to the notes window
     */
    function post(event) {
      var slideElement = Reveal.getCurrentSlide(),
        notesElement = slideElement.querySelector('aside.notes'),
        fragmentElement = slideElement.querySelector('.current-fragment');

      var messageData = {
        namespace: 'reveal-notes',
        type: 'state',
        notes: '',
        markdown: false,
        whitespace: 'normal',
        state: Reveal.getState(),
      };

      // Look for notes defined in a slide attribute
      if (slideElement.hasAttribute('data-notes')) {
        messageData.notes = slideElement.getAttribute('data-notes');
        messageData.whitespace = 'pre-wrap';
      }

      // Look for notes defined in a fragment
      if (fragmentElement) {
        var fragmentNotes = fragmentElement.querySelector('aside.notes');
        if (fragmentNotes) {
          notesElement = fragmentNotes;
        } else if (fragmentElement.hasAttribute('data-notes')) {
          messageData.notes = fragmentElement.getAttribute('data-notes');
          messageData.whitespace = 'pre-wrap';

          // In case there are slide notes
          notesElement = null;
        }
      }

      // Look for notes defined in an aside element
      if (notesElement) {
        messageData.notes = notesElement.innerHTML;
        messageData.markdown = typeof notesElement.getAttribute('data-markdown') === 'string';
      }

      notesPopup.postMessage(JSON.stringify(messageData), '*');
    }

    /**
     * Called once we have established a connection to the notes
     * window.
     */
    function onConnected() {
      // Monitor events that trigger a change in state
      Reveal.addEventListener('slidechanged', post);
      Reveal.addEventListener('fragmentshown', post);
      Reveal.addEventListener('fragmenthidden', post);
      Reveal.addEventListener('overviewhidden', post);
      Reveal.addEventListener('overviewshown', post);
      Reveal.addEventListener('paused', post);
      Reveal.addEventListener('resumed', post);

      // Post the initial state
      post();
    }

    connect();
  }

  return {
    init: function () {
      if (!/receiver/i.test(window.location.search)) {
        // If the there's a 'notes' query set, open directly
        if (window.location.search.match(/(\?|\&)notes/gi) !== null) {
          openNotes();
        }

        // Open the notes when the 's' key is hit
        Reveal.addKeyBinding({keyCode: 83, key: 'S', description: 'Speaker notes view'}, function () {
          openNotes();
        });
      }
    },

    open: openNotes,
  };
})();

Reveal.registerPlugin('notes', RevealNotes);