import speakerViewHTML from './speaker-view.html';
import marked from 'marked';
/**
* 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
*/
const Plugin = () => {
let popup = null;
let deck;
function openNotes() {
if (popup && !popup.closed) {
popup.focus();
return;
}
popup = window.open( 'about:blank', 'reveal.js - Notes', 'width=1100,height=700' );
popup.marked = marked;
popup.document.write( speakerViewHTML );
if( !popup ) {
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
let connectInterval = setInterval( function() {
popup.postMessage( JSON.stringify( {
namespace: 'reveal-notes',
type: 'connect',
url: window.location.protocol + '//' + window.location.host + window.location.pathname + window.location.search,
state: deck.getState()
} ), '*' );
}, 500 );
window.addEventListener( 'message', function( event ) {
let 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 ) {
let result = deck[methodName].apply( deck, methodArguments );
popup.postMessage( JSON.stringify( {
namespace: 'reveal-notes',
type: 'return',
result: result,
callId: callId
} ), '*' );
}
/**
* Posts the current slide data to the notes window
*/
function post( event ) {
let slideElement = deck.getCurrentSlide(),
notesElement = slideElement.querySelector( 'aside.notes' ),
fragmentElement = slideElement.querySelector( '.current-fragment' );
let messageData = {
namespace: 'reveal-notes',
type: 'state',
notes: '',
markdown: false,
whitespace: 'normal',
state: deck.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 ) {
let 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';
}
popup.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
deck.on( 'slidechanged', post );
deck.on( 'fragmentshown', post );
deck.on( 'fragmenthidden', post );
deck.on( 'overviewhidden', post );
deck.on( 'overviewshown', post );
deck.on( 'paused', post );
deck.on( 'resumed', post );
// Post the initial state
post();
}
connect();
}
return {
id: 'notes',
init: function( reveal ) {
deck = reveal;
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
deck.addKeyBinding({keyCode: 83, key: 'S', description: 'Speaker notes view'}, function() {
openNotes();
} );
}
},
open: openNotes
};
};
export default Plugin;
