réalise/_static/plugin/notes/speaker-view.html (view raw)
1<!--
2 NOTE: You need to build the notes plugin after making changes to this file.
3-->
4<html lang="en">
5 <head>
6 <meta charset="utf-8">
7
8 <title>reveal.js - Speaker View</title>
9
10 <style>
11 body {
12 font-family: Helvetica;
13 font-size: 18px;
14 }
15
16 #current-slide,
17 #upcoming-slide,
18 #speaker-controls {
19 padding: 6px;
20 box-sizing: border-box;
21 -moz-box-sizing: border-box;
22 }
23
24 #current-slide iframe,
25 #upcoming-slide iframe {
26 width: 100%;
27 height: 100%;
28 border: 1px solid #ddd;
29 }
30
31 #current-slide .label,
32 #upcoming-slide .label {
33 position: absolute;
34 top: 10px;
35 left: 10px;
36 z-index: 2;
37 }
38
39 #connection-status {
40 position: absolute;
41 top: 0;
42 left: 0;
43 width: 100%;
44 height: 100%;
45 z-index: 20;
46 padding: 30% 20% 20% 20%;
47 font-size: 18px;
48 color: #222;
49 background: #fff;
50 text-align: center;
51 box-sizing: border-box;
52 line-height: 1.4;
53 }
54
55 .overlay-element {
56 height: 34px;
57 line-height: 34px;
58 padding: 0 10px;
59 text-shadow: none;
60 background: rgba( 220, 220, 220, 0.8 );
61 color: #222;
62 font-size: 14px;
63 }
64
65 .overlay-element.interactive:hover {
66 background: rgba( 220, 220, 220, 1 );
67 }
68
69 #current-slide {
70 position: absolute;
71 width: 60%;
72 height: 100%;
73 top: 0;
74 left: 0;
75 padding-right: 0;
76 }
77
78 #upcoming-slide {
79 position: absolute;
80 width: 40%;
81 height: 40%;
82 right: 0;
83 top: 0;
84 }
85
86 /* Speaker controls */
87 #speaker-controls {
88 position: absolute;
89 top: 40%;
90 right: 0;
91 width: 40%;
92 height: 60%;
93 overflow: auto;
94 font-size: 18px;
95 }
96
97 .speaker-controls-time.hidden,
98 .speaker-controls-notes.hidden {
99 display: none;
100 }
101
102 .speaker-controls-time .label,
103 .speaker-controls-pace .label,
104 .speaker-controls-notes .label {
105 text-transform: uppercase;
106 font-weight: normal;
107 font-size: 0.66em;
108 color: #666;
109 margin: 0;
110 }
111
112 .speaker-controls-time, .speaker-controls-pace {
113 border-bottom: 1px solid rgba( 200, 200, 200, 0.5 );
114 margin-bottom: 10px;
115 padding: 10px 16px;
116 padding-bottom: 20px;
117 cursor: pointer;
118 }
119
120 .speaker-controls-time .reset-button {
121 opacity: 0;
122 float: right;
123 color: #666;
124 text-decoration: none;
125 }
126 .speaker-controls-time:hover .reset-button {
127 opacity: 1;
128 }
129
130 .speaker-controls-time .timer,
131 .speaker-controls-time .clock {
132 width: 50%;
133 }
134
135 .speaker-controls-time .timer,
136 .speaker-controls-time .clock,
137 .speaker-controls-time .pacing .hours-value,
138 .speaker-controls-time .pacing .minutes-value,
139 .speaker-controls-time .pacing .seconds-value {
140 font-size: 1.9em;
141 }
142
143 .speaker-controls-time .timer {
144 float: left;
145 }
146
147 .speaker-controls-time .clock {
148 float: right;
149 text-align: right;
150 }
151
152 .speaker-controls-time span.mute {
153 opacity: 0.3;
154 }
155
156 .speaker-controls-time .pacing-title {
157 margin-top: 5px;
158 }
159
160 .speaker-controls-time .pacing.ahead {
161 color: blue;
162 }
163
164 .speaker-controls-time .pacing.on-track {
165 color: green;
166 }
167
168 .speaker-controls-time .pacing.behind {
169 color: red;
170 }
171
172 .speaker-controls-notes {
173 padding: 10px 16px;
174 }
175
176 .speaker-controls-notes .value {
177 margin-top: 5px;
178 line-height: 1.4;
179 font-size: 1.2em;
180 }
181
182 /* Layout selector */
183 #speaker-layout {
184 position: absolute;
185 top: 10px;
186 right: 10px;
187 color: #222;
188 z-index: 10;
189 }
190 #speaker-layout select {
191 position: absolute;
192 width: 100%;
193 height: 100%;
194 top: 0;
195 left: 0;
196 border: 0;
197 box-shadow: 0;
198 cursor: pointer;
199 opacity: 0;
200
201 font-size: 1em;
202 background-color: transparent;
203
204 -moz-appearance: none;
205 -webkit-appearance: none;
206 -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
207 }
208
209 #speaker-layout select:focus {
210 outline: none;
211 box-shadow: none;
212 }
213
214 .clear {
215 clear: both;
216 }
217
218 /* Speaker layout: Wide */
219 body[data-speaker-layout="wide"] #current-slide,
220 body[data-speaker-layout="wide"] #upcoming-slide {
221 width: 50%;
222 height: 45%;
223 padding: 6px;
224 }
225
226 body[data-speaker-layout="wide"] #current-slide {
227 top: 0;
228 left: 0;
229 }
230
231 body[data-speaker-layout="wide"] #upcoming-slide {
232 top: 0;
233 left: 50%;
234 }
235
236 body[data-speaker-layout="wide"] #speaker-controls {
237 top: 45%;
238 left: 0;
239 width: 100%;
240 height: 50%;
241 font-size: 1.25em;
242 }
243
244 /* Speaker layout: Tall */
245 body[data-speaker-layout="tall"] #current-slide,
246 body[data-speaker-layout="tall"] #upcoming-slide {
247 width: 45%;
248 height: 50%;
249 padding: 6px;
250 }
251
252 body[data-speaker-layout="tall"] #current-slide {
253 top: 0;
254 left: 0;
255 }
256
257 body[data-speaker-layout="tall"] #upcoming-slide {
258 top: 50%;
259 left: 0;
260 }
261
262 body[data-speaker-layout="tall"] #speaker-controls {
263 padding-top: 40px;
264 top: 0;
265 left: 45%;
266 width: 55%;
267 height: 100%;
268 font-size: 1.25em;
269 }
270
271 /* Speaker layout: Notes only */
272 body[data-speaker-layout="notes-only"] #current-slide,
273 body[data-speaker-layout="notes-only"] #upcoming-slide {
274 display: none;
275 }
276
277 body[data-speaker-layout="notes-only"] #speaker-controls {
278 padding-top: 40px;
279 top: 0;
280 left: 0;
281 width: 100%;
282 height: 100%;
283 font-size: 1.25em;
284 }
285
286 @media screen and (max-width: 1080px) {
287 body[data-speaker-layout="default"] #speaker-controls {
288 font-size: 16px;
289 }
290 }
291
292 @media screen and (max-width: 900px) {
293 body[data-speaker-layout="default"] #speaker-controls {
294 font-size: 14px;
295 }
296 }
297
298 @media screen and (max-width: 800px) {
299 body[data-speaker-layout="default"] #speaker-controls {
300 font-size: 12px;
301 }
302 }
303
304 </style>
305 </head>
306
307 <body>
308
309 <div id="connection-status">Loading speaker view...</div>
310
311 <div id="current-slide"></div>
312 <div id="upcoming-slide"><span class="overlay-element label">Upcoming</span></div>
313 <div id="speaker-controls">
314 <div class="speaker-controls-time">
315 <h4 class="label">Time <span class="reset-button">Click to Reset</span></h4>
316 <div class="clock">
317 <span class="clock-value">0:00 AM</span>
318 </div>
319 <div class="timer">
320 <span class="hours-value">00</span><span class="minutes-value">:00</span><span class="seconds-value">:00</span>
321 </div>
322 <div class="clear"></div>
323
324 <h4 class="label pacing-title" style="display: none">Pacing – Time to finish current slide</h4>
325 <div class="pacing" style="display: none">
326 <span class="hours-value">00</span><span class="minutes-value">:00</span><span class="seconds-value">:00</span>
327 </div>
328 </div>
329
330 <div class="speaker-controls-notes hidden">
331 <h4 class="label">Notes</h4>
332 <div class="value"></div>
333 </div>
334 </div>
335 <div id="speaker-layout" class="overlay-element interactive">
336 <span class="speaker-layout-label"></span>
337 <select class="speaker-layout-dropdown"></select>
338 </div>
339
340 <script>
341
342 (function() {
343
344 var notes,
345 notesValue,
346 currentState,
347 currentSlide,
348 upcomingSlide,
349 layoutLabel,
350 layoutDropdown,
351 pendingCalls = {},
352 lastRevealApiCallId = 0,
353 connected = false
354
355 var connectionStatus = document.querySelector( '#connection-status' );
356
357 var SPEAKER_LAYOUTS = {
358 'default': 'Default',
359 'wide': 'Wide',
360 'tall': 'Tall',
361 'notes-only': 'Notes only'
362 };
363
364 setupLayout();
365
366 let openerOrigin;
367
368 try {
369 openerOrigin = window.opener.location.origin;
370 }
371 catch ( error ) { console.warn( error ) }
372
373 // In order to prevent XSS, the speaker view will only run if its
374 // opener has the same origin as itself
375 if( window.location.origin !== openerOrigin ) {
376 connectionStatus.innerHTML = 'Cross origin error.<br>The speaker window can only be opened from the same origin.';
377 return;
378 }
379
380 var connectionTimeout = setTimeout( function() {
381 connectionStatus.innerHTML = 'Error connecting to main window.<br>Please try closing and reopening the speaker view.';
382 }, 5000 );
383
384 window.addEventListener( 'message', function( event ) {
385
386 clearTimeout( connectionTimeout );
387 connectionStatus.style.display = 'none';
388
389 var data = JSON.parse( event.data );
390
391 // The overview mode is only useful to the reveal.js instance
392 // where navigation occurs so we don't sync it
393 if( data.state ) delete data.state.overview;
394
395 // Messages sent by the notes plugin inside of the main window
396 if( data && data.namespace === 'reveal-notes' ) {
397 if( data.type === 'connect' ) {
398 handleConnectMessage( data );
399 }
400 else if( data.type === 'state' ) {
401 handleStateMessage( data );
402 }
403 else if( data.type === 'return' ) {
404 pendingCalls[data.callId](data.result);
405 delete pendingCalls[data.callId];
406 }
407 }
408 // Messages sent by the reveal.js inside of the current slide preview
409 else if( data && data.namespace === 'reveal' ) {
410 if( /ready/.test( data.eventName ) ) {
411 // Send a message back to notify that the handshake is complete
412 window.opener.postMessage( JSON.stringify({ namespace: 'reveal-notes', type: 'connected'} ), '*' );
413 }
414 else if( /slidechanged|fragmentshown|fragmenthidden|paused|resumed/.test( data.eventName ) && currentState !== JSON.stringify( data.state ) ) {
415
416 dispatchStateToMainWindow( data.state );
417
418 }
419 }
420
421 } );
422
423 /**
424 * Updates the presentation in the main window to match the state
425 * of the presentation in the notes window.
426 */
427 const dispatchStateToMainWindow = debounce(( state ) => {
428 window.opener.postMessage( JSON.stringify({ method: 'setState', args: [ state ]} ), '*' );
429 }, 500);
430
431 /**
432 * Asynchronously calls the Reveal.js API of the main frame.
433 */
434 function callRevealApi( methodName, methodArguments, callback ) {
435
436 var callId = ++lastRevealApiCallId;
437 pendingCalls[callId] = callback;
438 window.opener.postMessage( JSON.stringify( {
439 namespace: 'reveal-notes',
440 type: 'call',
441 callId: callId,
442 methodName: methodName,
443 arguments: methodArguments
444 } ), '*' );
445
446 }
447
448 /**
449 * Called when the main window is trying to establish a
450 * connection.
451 */
452 function handleConnectMessage( data ) {
453
454 if( connected === false ) {
455 connected = true;
456
457 setupIframes( data );
458 setupKeyboard();
459 setupNotes();
460 setupTimer();
461 setupHeartbeat();
462 }
463
464 }
465
466 /**
467 * Called when the main window sends an updated state.
468 */
469 function handleStateMessage( data ) {
470
471 // Store the most recently set state to avoid circular loops
472 // applying the same state
473 currentState = JSON.stringify( data.state );
474
475 // No need for updating the notes in case of fragment changes
476 if ( data.notes ) {
477 notes.classList.remove( 'hidden' );
478 notesValue.style.whiteSpace = data.whitespace;
479 if( data.markdown ) {
480 notesValue.innerHTML = marked( data.notes );
481 }
482 else {
483 notesValue.innerHTML = data.notes;
484 }
485 }
486 else {
487 notes.classList.add( 'hidden' );
488 }
489
490 // Update the note slides
491 currentSlide.contentWindow.postMessage( JSON.stringify({ method: 'setState', args: [ data.state ] }), '*' );
492 upcomingSlide.contentWindow.postMessage( JSON.stringify({ method: 'setState', args: [ data.state ] }), '*' );
493 upcomingSlide.contentWindow.postMessage( JSON.stringify({ method: 'next' }), '*' );
494
495 }
496
497 // Limit to max one state update per X ms
498 handleStateMessage = debounce( handleStateMessage, 200 );
499
500 /**
501 * Forward keyboard events to the current slide window.
502 * This enables keyboard events to work even if focus
503 * isn't set on the current slide iframe.
504 *
505 * Block F5 default handling, it reloads and disconnects
506 * the speaker notes window.
507 */
508 function setupKeyboard() {
509
510 document.addEventListener( 'keydown', function( event ) {
511 if( event.keyCode === 116 || ( event.metaKey && event.keyCode === 82 ) ) {
512 event.preventDefault();
513 return false;
514 }
515 currentSlide.contentWindow.postMessage( JSON.stringify({ method: 'triggerKey', args: [ event.keyCode ] }), '*' );
516 } );
517
518 }
519
520 /**
521 * Creates the preview iframes.
522 */
523 function setupIframes( data ) {
524
525 var params = [
526 'receiver',
527 'progress=false',
528 'history=false',
529 'transition=none',
530 'autoSlide=0',
531 'backgroundTransition=none'
532 ].join( '&' );
533
534 var urlSeparator = /\?/.test(data.url) ? '&' : '?';
535 var hash = '#/' + data.state.indexh + '/' + data.state.indexv;
536 var currentURL = data.url + urlSeparator + params + '&postMessageEvents=true' + hash;
537 var upcomingURL = data.url + urlSeparator + params + '&controls=false' + hash;
538
539 currentSlide = document.createElement( 'iframe' );
540 currentSlide.setAttribute( 'width', 1280 );
541 currentSlide.setAttribute( 'height', 1024 );
542 currentSlide.setAttribute( 'src', currentURL );
543 document.querySelector( '#current-slide' ).appendChild( currentSlide );
544
545 upcomingSlide = document.createElement( 'iframe' );
546 upcomingSlide.setAttribute( 'width', 640 );
547 upcomingSlide.setAttribute( 'height', 512 );
548 upcomingSlide.setAttribute( 'src', upcomingURL );
549 document.querySelector( '#upcoming-slide' ).appendChild( upcomingSlide );
550
551 }
552
553 /**
554 * Setup the notes UI.
555 */
556 function setupNotes() {
557
558 notes = document.querySelector( '.speaker-controls-notes' );
559 notesValue = document.querySelector( '.speaker-controls-notes .value' );
560
561 }
562
563 /**
564 * We send out a heartbeat at all times to ensure we can
565 * reconnect with the main presentation window after reloads.
566 */
567 function setupHeartbeat() {
568
569 setInterval( () => {
570 window.opener.postMessage( JSON.stringify({ namespace: 'reveal-notes', type: 'heartbeat'} ), '*' );
571 }, 1000 );
572
573 }
574
575 function getTimings( callback ) {
576
577 callRevealApi( 'getSlidesAttributes', [], function ( slideAttributes ) {
578 callRevealApi( 'getConfig', [], function ( config ) {
579 var totalTime = config.totalTime;
580 var minTimePerSlide = config.minimumTimePerSlide || 0;
581 var defaultTiming = config.defaultTiming;
582 if ((defaultTiming == null) && (totalTime == null)) {
583 callback(null);
584 return;
585 }
586 // Setting totalTime overrides defaultTiming
587 if (totalTime) {
588 defaultTiming = 0;
589 }
590 var timings = [];
591 for ( var i in slideAttributes ) {
592 var slide = slideAttributes[ i ];
593 var timing = defaultTiming;
594 if( slide.hasOwnProperty( 'data-timing' )) {
595 var t = slide[ 'data-timing' ];
596 timing = parseInt(t);
597 if( isNaN(timing) ) {
598 console.warn("Could not parse timing '" + t + "' of slide " + i + "; using default of " + defaultTiming);
599 timing = defaultTiming;
600 }
601 }
602 timings.push(timing);
603 }
604 if ( totalTime ) {
605 // After we've allocated time to individual slides, we summarize it and
606 // subtract it from the total time
607 var remainingTime = totalTime - timings.reduce( function(a, b) { return a + b; }, 0 );
608 // The remaining time is divided by the number of slides that have 0 seconds
609 // allocated at the moment, giving the average time-per-slide on the remaining slides
610 var remainingSlides = (timings.filter( function(x) { return x == 0 }) ).length
611 var timePerSlide = Math.round( remainingTime / remainingSlides, 0 )
612 // And now we replace every zero-value timing with that average
613 timings = timings.map( function(x) { return (x==0 ? timePerSlide : x) } );
614 }
615 var slidesUnderMinimum = timings.filter( function(x) { return (x < minTimePerSlide) } ).length
616 if ( slidesUnderMinimum ) {
617 message = "The pacing time for " + slidesUnderMinimum + " slide(s) is under the configured minimum of " + minTimePerSlide + " seconds. Check the data-timing attribute on individual slides, or consider increasing the totalTime or minimumTimePerSlide configuration options (or removing some slides).";
618 alert(message);
619 }
620 callback( timings );
621 } );
622 } );
623
624 }
625
626 /**
627 * Return the number of seconds allocated for presenting
628 * all slides up to and including this one.
629 */
630 function getTimeAllocated( timings, callback ) {
631
632 callRevealApi( 'getSlidePastCount', [], function ( currentSlide ) {
633 var allocated = 0;
634 for (var i in timings.slice(0, currentSlide + 1)) {
635 allocated += timings[i];
636 }
637 callback( allocated );
638 } );
639
640 }
641
642 /**
643 * Create the timer and clock and start updating them
644 * at an interval.
645 */
646 function setupTimer() {
647
648 var start = new Date(),
649 timeEl = document.querySelector( '.speaker-controls-time' ),
650 clockEl = timeEl.querySelector( '.clock-value' ),
651 hoursEl = timeEl.querySelector( '.hours-value' ),
652 minutesEl = timeEl.querySelector( '.minutes-value' ),
653 secondsEl = timeEl.querySelector( '.seconds-value' ),
654 pacingTitleEl = timeEl.querySelector( '.pacing-title' ),
655 pacingEl = timeEl.querySelector( '.pacing' ),
656 pacingHoursEl = pacingEl.querySelector( '.hours-value' ),
657 pacingMinutesEl = pacingEl.querySelector( '.minutes-value' ),
658 pacingSecondsEl = pacingEl.querySelector( '.seconds-value' );
659
660 var timings = null;
661 getTimings( function ( _timings ) {
662
663 timings = _timings;
664 if (_timings !== null) {
665 pacingTitleEl.style.removeProperty('display');
666 pacingEl.style.removeProperty('display');
667 }
668
669 // Update once directly
670 _updateTimer();
671
672 // Then update every second
673 setInterval( _updateTimer, 1000 );
674
675 } );
676
677
678 function _resetTimer() {
679
680 if (timings == null) {
681 start = new Date();
682 _updateTimer();
683 }
684 else {
685 // Reset timer to beginning of current slide
686 getTimeAllocated( timings, function ( slideEndTimingSeconds ) {
687 var slideEndTiming = slideEndTimingSeconds * 1000;
688 callRevealApi( 'getSlidePastCount', [], function ( currentSlide ) {
689 var currentSlideTiming = timings[currentSlide] * 1000;
690 var previousSlidesTiming = slideEndTiming - currentSlideTiming;
691 var now = new Date();
692 start = new Date(now.getTime() - previousSlidesTiming);
693 _updateTimer();
694 } );
695 } );
696 }
697
698 }
699
700 timeEl.addEventListener( 'click', function() {
701 _resetTimer();
702 return false;
703 } );
704
705 function _displayTime( hrEl, minEl, secEl, time) {
706
707 var sign = Math.sign(time) == -1 ? "-" : "";
708 time = Math.abs(Math.round(time / 1000));
709 var seconds = time % 60;
710 var minutes = Math.floor( time / 60 ) % 60 ;
711 var hours = Math.floor( time / ( 60 * 60 )) ;
712 hrEl.innerHTML = sign + zeroPadInteger( hours );
713 if (hours == 0) {
714 hrEl.classList.add( 'mute' );
715 }
716 else {
717 hrEl.classList.remove( 'mute' );
718 }
719 minEl.innerHTML = ':' + zeroPadInteger( minutes );
720 if (hours == 0 && minutes == 0) {
721 minEl.classList.add( 'mute' );
722 }
723 else {
724 minEl.classList.remove( 'mute' );
725 }
726 secEl.innerHTML = ':' + zeroPadInteger( seconds );
727 }
728
729 function _updateTimer() {
730
731 var diff, hours, minutes, seconds,
732 now = new Date();
733
734 diff = now.getTime() - start.getTime();
735
736 clockEl.innerHTML = now.toLocaleTimeString( 'en-US', { hour12: true, hour: '2-digit', minute:'2-digit' } );
737 _displayTime( hoursEl, minutesEl, secondsEl, diff );
738 if (timings !== null) {
739 _updatePacing(diff);
740 }
741
742 }
743
744 function _updatePacing(diff) {
745
746 getTimeAllocated( timings, function ( slideEndTimingSeconds ) {
747 var slideEndTiming = slideEndTimingSeconds * 1000;
748
749 callRevealApi( 'getSlidePastCount', [], function ( currentSlide ) {
750 var currentSlideTiming = timings[currentSlide] * 1000;
751 var timeLeftCurrentSlide = slideEndTiming - diff;
752 if (timeLeftCurrentSlide < 0) {
753 pacingEl.className = 'pacing behind';
754 }
755 else if (timeLeftCurrentSlide < currentSlideTiming) {
756 pacingEl.className = 'pacing on-track';
757 }
758 else {
759 pacingEl.className = 'pacing ahead';
760 }
761 _displayTime( pacingHoursEl, pacingMinutesEl, pacingSecondsEl, timeLeftCurrentSlide );
762 } );
763 } );
764 }
765
766 }
767
768 /**
769 * Sets up the speaker view layout and layout selector.
770 */
771 function setupLayout() {
772
773 layoutDropdown = document.querySelector( '.speaker-layout-dropdown' );
774 layoutLabel = document.querySelector( '.speaker-layout-label' );
775
776 // Render the list of available layouts
777 for( var id in SPEAKER_LAYOUTS ) {
778 var option = document.createElement( 'option' );
779 option.setAttribute( 'value', id );
780 option.textContent = SPEAKER_LAYOUTS[ id ];
781 layoutDropdown.appendChild( option );
782 }
783
784 // Monitor the dropdown for changes
785 layoutDropdown.addEventListener( 'change', function( event ) {
786
787 setLayout( layoutDropdown.value );
788
789 }, false );
790
791 // Restore any currently persisted layout
792 setLayout( getLayout() );
793
794 }
795
796 /**
797 * Sets a new speaker view layout. The layout is persisted
798 * in local storage.
799 */
800 function setLayout( value ) {
801
802 var title = SPEAKER_LAYOUTS[ value ];
803
804 layoutLabel.innerHTML = 'Layout' + ( title ? ( ': ' + title ) : '' );
805 layoutDropdown.value = value;
806
807 document.body.setAttribute( 'data-speaker-layout', value );
808
809 // Persist locally
810 if( supportsLocalStorage() ) {
811 window.localStorage.setItem( 'reveal-speaker-layout', value );
812 }
813
814 }
815
816 /**
817 * Returns the ID of the most recently set speaker layout
818 * or our default layout if none has been set.
819 */
820 function getLayout() {
821
822 if( supportsLocalStorage() ) {
823 var layout = window.localStorage.getItem( 'reveal-speaker-layout' );
824 if( layout ) {
825 return layout;
826 }
827 }
828
829 // Default to the first record in the layouts hash
830 for( var id in SPEAKER_LAYOUTS ) {
831 return id;
832 }
833
834 }
835
836 function supportsLocalStorage() {
837
838 try {
839 localStorage.setItem('test', 'test');
840 localStorage.removeItem('test');
841 return true;
842 }
843 catch( e ) {
844 return false;
845 }
846
847 }
848
849 function zeroPadInteger( num ) {
850
851 var str = '00' + parseInt( num );
852 return str.substring( str.length - 2 );
853
854 }
855
856 /**
857 * Limits the frequency at which a function can be called.
858 */
859 function debounce( fn, ms ) {
860
861 var lastTime = 0,
862 timeout;
863
864 return function() {
865
866 var args = arguments;
867 var context = this;
868
869 clearTimeout( timeout );
870
871 var timeSinceLastCall = Date.now() - lastTime;
872 if( timeSinceLastCall > ms ) {
873 fn.apply( context, args );
874 lastTime = Date.now();
875 }
876 else {
877 timeout = setTimeout( function() {
878 fn.apply( context, args );
879 lastTime = Date.now();
880 }, ms - timeSinceLastCall );
881 }
882
883 }
884
885 }
886
887 })();
888
889 </script>
890 </body>
891</html>