-
Notifications
You must be signed in to change notification settings - Fork 791
Expand file tree
/
Copy pathOverview.html
More file actions
871 lines (639 loc) · 57.2 KB
/
Overview.html
File metadata and controls
871 lines (639 loc) · 57.2 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
<!doctype html>
<html lang="en">
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<title>Web Animations CSS Integration</title>
<link href="../default.css" rel="stylesheet" type="text/css">
<link href="../csslogo.ico" rel="shortcut icon" type="image/x-icon">
<link href="https://www.w3.org/StyleSheets/TR/W3C-ED" rel="stylesheet" type="text/css">
</head>
<body class="h-entry">
<div class="head">
<p data-fill-with="logo"><a class="logo" href="http://www.w3.org/">
<img alt="W3C" height="48" src="https://www.w3.org/Icons/w3c_home" width="72">
</a>
</p>
<h1 class="p-name no-ref" id="title">Web Animations CSS Integration</h1>
<h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Editor’s Draft,
<time class="dt-updated" datetime="2015-01-15">15 January 2015</time></span></h2>
<div data-fill-with="spec-metadata">
<dl>
<dt>This version:</dt>
<dd><a class="u-url" href="none">none</a></dd>
<dt>Feedback:</dt>
<dd><span><a href="mailto:public-fx@w3.org?subject=%5Bweb-animations-css%5D%20feedback">public-fx@w3.org</a> with subject line “<kbd>[web-animations-css] <var>… message topic …</var></kbd>” (<a href="http://lists.w3.org/Archives/Public/public-fx/" rel="discussion">archives</a>)</span></dd>
<dt>Issue Tracking:</dt>
<dd><a href="#issues-index">Inline In Spec</a></dd>
<dt class="editor">Editor:</dt>
<dd class="editor">
<div class="p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:shans@google.com">Shane Stephens</a> (<span class="p-org org">Google</span>)</div>
</dd>
</dl>
</div>
<div data-fill-with="warning"></div>
<p class="copyright" data-fill-with="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 2014 <a href="http://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a href="http://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>, <a href="http://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>, <a href="http://www.keio.ac.jp/">Keio</a>, <a href="http://ev.buaa.edu.cn/">Beihang</a>), All Rights Reserved. W3C <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a> rules apply.
</p>
<hr title="Separator for header">
</div>
<h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
<div class="p-summary" data-fill-with="abstract">
<p>This specification defines mappings between <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-animations" title="CSS3-ANIMATIONS">[CSS3-ANIMATIONS]</a>, <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-transitions" title="CSS3-TRANSITIONS">[CSS3-TRANSITIONS]</a> and the <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-web-animations" title="WEB-ANIMATIONS">[WEB-ANIMATIONS]</a> model.</p>
</div>
<h2 class="no-num no-toc no-ref heading settled" id="status"><span class="content">Status of this document</span></h2>
<div data-fill-with="status">
<p>
This is a public copy of the editors' draft.
It is provided for discussion only and may change at any moment.
Its publication here does not imply endorsement of its contents by W3C.
Don’t cite this document other than as work in progress.
</p>
<p>
The contents of this draft are intended to be incorporated into Level 2
of both the CSS Animations and CSS Transitions specifications as these
specifications are drafted.
</p>
<p>
The (<a href="http://lists.w3.org/Archives/Public/public-fx/">archived</a>) public mailing list
<a href="mailto:public-fx@w3.org?Subject=%5Bweb-animations-css%5D%20PUT%20SUBJECT%20HERE">public-fx@w3.org</a>
(see <a href="http://www.w3.org/Mail/Request">instructions</a>)
is preferred for discussion of this specification.
When sending e-mail,
please put the text “web-animations-css” in the subject,
preferably like this:
“[web-animations-css] <em>…summary of comment…</em>”
</p>
<p>
This document was produced by the <a href="http://www.w3.org/Style/CSS/members">CSS Working Group</a>
(part of the <a href="http://www.w3.org/Style/">Style Activity</a>) and the <a href="http://www.w3.org/Graphics/SVG/WG/">SVG Working Group</a> (part of the
<a href="http://www.w3.org/Graphics/">Graphics Activity</a>).
</p>
<p>
This document was produced by groups operating under
the <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004 W3C Patent Policy</a>.
W3C maintains a <a href="http://www.w3.org/2004/01/pp-impl/32061/status" rel="disclosure">public list of any patent disclosures (CSS)</a>
and a <a href="http://www.w3.org/2004/01/pp-impl/19480/status" rel="disclosure">public list of any patent disclosures (SVG)</a>
made in connection with the deliverables of each group;
these pages also includes instructions for disclosing a patent.
An individual who has actual knowledge of a patent which the individual believes contains
<a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential Claim(s)</a>
must disclose the information in accordance with <a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section 6 of the W3C Patent Policy</a>.</p>
</div>
<div data-fill-with="at-risk"></div>
<h2 class="no-num no-toc no-ref heading settled" id="contents"><span class="content">Table of Contents</span></h2>
<div data-fill-with="table-of-contents" role="navigation">
<ul class="toc" role="directory">
<li><a href="#introduction"><span class="secno">1</span> <span class="content">Introduction</span></a></li>
<li><a href="#css-transitions"><span class="secno">2</span> <span class="content">CSS Transitions</span></a>
<ul class="toc">
<li><a href="#css-transitions-events"><span class="secno">2.1</span> <span class="content">CSS Transitions events</span></a></li>
</ul>
</li>
<li><a href="#css-animations"><span class="secno">3</span> <span class="content">CSS Animations</span></a>
<ul class="toc">
<li><a href="#the-csskeyframesmap-mapping"><span class="secno">3.1</span> <span class="content">The CSSKeyframesMap mapping</span></a>
<ul class="toc">
<li><a href="#the-csskeyframesmap-interface"><span class="secno">3.1.1</span> <span class="content">The CSSKeyframesMap interface</span></a></li>
<li><a href="#documentkeyframes"><span class="secno">3.1.2</span> <span class="content">Document.keyframes</span></a></li>
<li><a href="#conversion-of-css-keyframes"><span class="secno">3.1.3</span> <span class="content">Converting a CSS Keyframes rule into a
KeyframeEffect</span></a></li>
</ul>
</li>
<li><a href="#web-animations-instantiation"><span class="secno">3.2</span> <span class="content">Web Animations Instantiation</span></a></li>
<li><a href="#css-animations-events"><span class="secno">3.3</span> <span class="content">CSS Animations Events</span></a></li>
<li><a href="#instantiating-an-animating-effect"><span class="secno">3.4</span> <span class="content">Instantiating the animating effect
</span></a></li>
</ul>
</li>
<li><a href="#exposure-in-the-web-animations-api"><span class="secno">4</span> <span class="content">Exposure in the Web Animations API</span></a></li>
<li><a href="#conformance"><span class="secno"></span> <span class="content">
Conformance</span></a>
<ul class="toc">
<li><a href="#conventions"><span class="secno"></span> <span class="content">
Document conventions</span></a></li>
<li><a href="#conformance-classes"><span class="secno"></span> <span class="content">
Conformance classes</span></a></li>
<li><a href="#partial"><span class="secno"></span> <span class="content">
Partial implementations</span></a></li>
<li><a href="#experimental"><span class="secno"></span> <span class="content">
Experimental implementations</span></a></li>
<li><a href="#testing"><span class="secno"></span> <span class="content">
Non-experimental implementations</span></a></li>
</ul>
</li>
<li><a href="#references"><span class="secno"></span> <span class="content">References</span></a>
<ul class="toc">
<li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a></li>
<li><a href="#informative"><span class="secno"></span> <span class="content">Informative References</span></a></li>
</ul>
</li>
<li><a href="#index"><span class="secno"></span> <span class="content">Index</span></a></li>
<li><a href="#idl-index"><span class="secno"></span> <span class="content">IDL Index</span></a></li>
<li><a href="#issues-index"><span class="secno"></span> <span class="content">Issues Index</span></a></li>
</ul></div>
<main>
<h2 class="heading settled" data-level="1" id="introduction"><span class="secno">1. </span><span class="content">Introduction</span><a class="self-link" href="#introduction"></a></h2>
<p><a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-animations" title="CSS3-ANIMATIONS">[CSS3-ANIMATIONS]</a> and <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-transitions" title="CSS3-TRANSITIONS">[CSS3-TRANSITIONS]</a> provide models for defining
declarative animations via CSS. <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-svg12" title="SVG12">[SVG12]</a> provides a model for defining
declarative animations via SVG. However, the three specifications do not
define or present a unified animation model.</p>
<p>To solve this problem, the <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-web-animations" title="WEB-ANIMATIONS">[WEB-ANIMATIONS]</a> specification defines a
comprehensive animation model that is capable of supporting <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-animations" title="CSS3-ANIMATIONS">[CSS3-ANIMATIONS]</a>,
<a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-transitions" title="CSS3-TRANSITIONS">[CSS3-TRANSITIONS]</a> and <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-svg12" title="SVG12">[SVG12]</a>.</p>
<p>This document describes how <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-animations" title="CSS3-ANIMATIONS">[CSS3-ANIMATIONS]</a> and <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-css3-transitions" title="CSS3-TRANSITIONS">[CSS3-TRANSITIONS]</a> are
supported by the <a data-biblio-type="informative" data-link-type="biblio" href="#biblio-web-animations" title="WEB-ANIMATIONS">[WEB-ANIMATIONS]</a> model.</p>
<h2 class="heading settled" data-level="2" id="css-transitions"><span class="secno">2. </span><span class="content">CSS Transitions</span><a class="self-link" href="#css-transitions"></a></h2>
<div data-link-spec="css-transitions">
<p>For CSS Transitions, mappings into the Web Animations model are established
pairwise for a specific CSS property, the <dfn data-dfn-type="dfn" data-noexport="" id="transitioning-property">transitioning property<a class="self-link" href="#transitioning-property"></a></dfn>, on
a specific element, the <dfn data-dfn-type="dfn" data-noexport="" id="transitioning-element">transitioning element<a class="self-link" href="#transitioning-element"></a></dfn>.</p>
<p>When a CSS Transition is started for the <a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-property">transitioning property</a> of a
<a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-element">transitioning element</a>, an <a data-link-spec="css-transitions" data-link-type="dfn" href="#animation">Animation</a> is constructed and
associated with a <a data-link-spec="css-transitions" data-link-type="dfn" href="#player">Player</a> on the <a data-link-spec="css-transitions" data-link-type="dfn" href="#document-timeline">document timeline</a>, configured
with a <a data-link-spec="css-transitions" data-link-type="dfn" href="#custom-player-priority">custom player priority</a> which ensures that the <a data-link-spec="css-transitions" data-link-type="dfn" href="#player">Player</a> sorts
before <a data-link-spec="css-transitions" data-link-type="dfn" href="#player">Player</a>s created through the Web Animations API and those generated
for CSS Animations. The <a data-link-spec="css-transitions" data-link-type="dfn" href="#animation">Animation</a> is configured as follows:</p>
<ul>
<li>The <a data-link-spec="css-transitions" data-link-type="dfn" href="#target-element">target element</a> is set to the <a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-element">transitioning element</a>.
</li>
<li>The <a data-link-spec="css-transitions" data-link-type="dfn" href="#start-delay">start delay</a> is set to the current used value of the <a class="property" data-link-spec="css-transitions" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-transitions-1/#transition-delay">transition-delay</a>
property.
</li>
<li>The <a data-link-spec="css-transitions" data-link-type="dfn" href="#iteration-duration">iteration duration</a> is set to the current used value of the
<a class="property" data-link-spec="css-transitions" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-transitions-1/#transition-duration">transition-duration</a> property.
</li>
<li>The <a data-link-spec="css-transitions" data-link-type="dfn" href="#timing-function">timing function</a> is set to the current used value of the
<a class="property" data-link-spec="css-transitions" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-transitions-1/#transition-timing-function">transition-timing-function</a> property.
</li>
<li>The <a data-link-spec="css-transitions" data-link-type="dfn" href="#animation-effect">animation effect</a> is set to a <a data-link-spec="css-transitions" data-link-type="dfn" href="#keyframe-animation-effect">keyframe animation effect</a>
with two <a data-link-spec="css-transitions" data-link-type="dfn" href="#keyframes">keyframes</a> defined as follows:
<ul>
<li>The first keyframe references the <a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-property">transitioning property</a> with a
value set to the <a data-link-spec="css-transitions" data-link-type="dfn" href="http://dev.w3.org/csswg/css-transitions-1/#start-value">start value</a> of the transition.
</li>
<li>The second and final keyframe references the
<a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-property">transitioning property</a> with a value set to the <a data-link-spec="css-transitions" data-link-type="dfn" href="http://dev.w3.org/csswg/css-transitions-1/#end-value">end value</a> of
the transition.
</li>
</ul>
</li></ul>
<p class="note" role="note">Note, changes to the values of the <a class="property" data-link-spec="css-transitions" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-transitions-1/#transition-delay">transition-delay</a>, <a class="property" data-link-spec="css-transitions" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-transitions-1/#transition-duration">transition-duration</a>,
and <a class="property" data-link-spec="css-transitions" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-transitions-1/#transition-timing-function">transition-timing-function</a> have no effect on a transition once it has
started.</p>
<p>When a transition affecting the <a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-property">transitioning property</a> of a
<a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-element">transitioning element</a> is removed or interrupted the <a data-link-spec="css-transitions" data-link-type="dfn" href="#cancel">cancel</a>
method of the corresponding <a data-link-spec="css-transitions" data-link-type="dfn" href="#player">Player</a> is called.</p>
<p>When a transition affecting the <a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-property">transitioning property</a> of a
<a data-link-spec="css-transitions" data-link-type="dfn" href="#transitioning-element">transitioning element</a> is reversed the <a data-link-spec="css-transitions" data-link-type="dfn" href="#cancel">cancel</a>
method of the corresponding <a data-link-spec="css-transitions" data-link-type="dfn" href="#player">Player</a> is called and a new <a data-link-spec="css-transitions" data-link-type="dfn" href="#player">Player</a> is
generated as if the transition had just begun.</p>
<h3 class="heading settled" data-level="2.1" id="css-transitions-events"><span class="secno">2.1. </span><span class="content">CSS Transitions events</span><a class="self-link" href="#css-transitions-events"></a></h3>
The <a data-link-spec="css-transitions" data-link-type="dfn" href="http://dev.w3.org/csswg/css-transitions-1/#transitionend">transitionend</a> event is triggered to fire each time the
corresponding <a data-link-spec="css-transitions" data-link-type="dfn" href="#animation">Animation</a> enters the <a data-link-spec="css-transitions" data-link-type="dfn" href="#after-phase">after phase</a> during a
<a data-link-spec="css-transitions" data-link-type="dfn" href="#sample">sample</a>.
</div>
<h2 class="heading settled" data-level="3" id="css-animations"><span class="secno">3. </span><span class="content">CSS Animations</span><a class="self-link" href="#css-animations"></a></h2>
<h3 class="heading settled" data-level="3.1" id="the-csskeyframesmap-mapping"><span class="secno">3.1. </span><span class="content">The CSSKeyframesMap mapping</span><a class="self-link" href="#the-csskeyframesmap-mapping"></a></h3>
<p class="issue" id="issue-a495e9c5"><a class="self-link" href="#issue-a495e9c5"></a>This feature is at risk.</p>
<div data-link-spec="html5">
<pre class="idl" style="display:none">//FIXME: figure out the appropriate thing to do here and remove this!
interface <dfn class="idl-code" data-dfn-type="interface" data-export="" data-global-name="" id="string">String<a class="self-link" href="#string"></a></dfn> { };
</pre>
<pre class="idl">[MapClass(<a data-link-spec="html5" data-link-type="idl-name" href="#string">String</a>, <a data-link-spec="html5" data-link-type="idl-name" href="#animationeffect">AnimationEffect</a>)]
interface <a class="idl-code" data-global-name="" data-link-spec="html5" data-link-type="interface" href="#csskeyframesmap">CSSKeyframesMap</a> {
};
partial interface <a class="idl-code" data-global-name="" data-link-spec="html5" data-link-type="interface" href="https://html.spec.whatwg.org/#dom-document">Document</a> {
readonly attribute <a data-link-spec="html5" data-link-type="idl-name" href="#csskeyframesmap">CSSKeyframesMap</a> <a class="idl-code" data-global-name="Document<interface>/keyframes<attribute>" data-link-for="Document" data-link-spec="html5&q
1F85
uot; data-link-type="attribute" data-readonly="" data-type="CSSKeyframesMap " href="#dom-document-keyframes">keyframes</a>;
};
</pre>
</div>
<div data-link-spec="css-animations">
<h4 class="heading settled" data-level="3.1.1" id="the-csskeyframesmap-interface"><span class="secno">3.1.1. </span><span class="content">The CSSKeyframesMap interface</span><a class="self-link" href="#the-csskeyframesmap-interface"></a></h4>
<p>The <dfn class="idl-code" data-dfn-type="interface" data-export="" id="csskeyframesmap">CSSKeyframesMap<a class="self-link" href="#csskeyframesmap"></a></dfn> interface defines a map type that can
be used to store sequences of Keyframes indexed by Strings.</p>
<h4 class="heading settled" data-level="3.1.2" id="documentkeyframes"><span class="secno">3.1.2. </span><span class="content">Document.keyframes</span><a class="self-link" href="#documentkeyframes"></a></h4>
<p>The <dfn class="idl-code" data-dfn-for="Document" data-dfn-type="attribute" data-export="" id="dom-document-keyframes">keyframes<a class="self-link" href="#dom-document-keyframes"></a></dfn> attribute on the
<a class="idl-code" data-link-spec="html5" data-link-type="interface" href="https://html.spec.whatwg.org/#dom-document">Document</a> interface references a map of type
<a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#csskeyframesmap">CSSKeyframesMap</a>.</p>
<p class="note" role="note">Note: The <a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#csskeyframesmap">CSSKeyframesMap</a> enables animations created using the
Web Animations API to re-use the keyframe rules declared by CSS, and for
animations declared by CSS to act on <a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#animationeffect">AnimationEffect</a>s created
through the API.</p>
<p class="note" role="note">Note: The processing defined in this section does not alter the way in which
keyframes rules are selected when CSS animations are started, unless a name is
explicitly overridden by setting its value in the map.</p>
<p>When a new <a class="css" data-link-spec="css-animations" data-link-type="at-rule" href="http://dev.w3.org/csswg/css-animations-1/#at-ruledef-keyframes">@keyframes</a> rule name is encountered in a
style sheet, the action taken depends upon the current value stored against the
name in the <a class="idl-code" data-link-spec="css-animations" data-link-type="attribute" href="#dom-document-keyframes">keyframes</a> map.</p>
<dl>
<dt>If the current value has never been set, or has only been set due to
style changes:</dt>
<dd>
The keyframes defined by the <a class="css" data-link-spec="css-animations" data-link-type="at-rule" href="http://dev.w3.org/csswg/css-animations-1/#at-ruledef-keyframes">@keyframes</a> rule are
converted into a <a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#keyframeeffect">KeyframeEffect</a> (see
<a data-section="" href="#conversion-of-css-keyframes">§3.1.3 Converting a CSS Keyframes rule into a
KeyframeEffect</a>), then stored against the
name in the <a class="idl-code" data-link-spec="css-animations" data-link-type="attribute" href="#dom-document-keyframes">keyframes</a> map.
</dd>
<dt>Otherwise:
</dt>
<dd>
The rule is ignored.
</dd></dl>
<p class="issue" id="issue-1a6a93a1"><a class="self-link" href="#issue-1a6a93a1"></a>Should the KeyframeEffects generated by @keyframes rules be read-only?</p>
<p>When the used <a class="css" data-link-spec="css-animations" data-link-type="at-rule" href="http://dev.w3.org/csswg/css-animations-1/#at-ruledef-keyframes">@keyframes</a> rule associated with a
given name changes due to a change in a style sheet, the action taken depends
upon the current value stored against the name in the
<a class="idl-code" data-link-spec="css-animations" data-link-type="attribute" href="#dom-document-keyframes">keyframes</a> map.</p>
<dl>
<dt>If the current value has only been set due to style changes:
</dt>
<dd>
The keyframes defined by the new rule are converted into a
<a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#keyframeeffect">KeyframeEffect</a>
(see <a data-section="" href="#conversion-of-css-keyframes">§3.1.3 Converting a CSS Keyframes rule into a
KeyframeEffect</a>), then stored
against the name in the <a class="idl-code" data-link-spec="css-animations" data-link-type="attribute" href="#dom-document-keyframes">keyframes</a> map.
</dd>
<dt>Otherwise:
</dt>
<dd>The change is ignored.
</dd></dl>
<p>When the last <a class="css" data-link-spec="css-animations" data-link-type="at-rule" href="http://dev.w3.org/csswg/css-animations-1/#at-ruledef-keyframes">@keyframes</a> rule for a given name is
removed from a style sheet, the action taken depends upon the current value
stored against the name in the <a class="idl-code" data-link-spec="css-animations" data-link-type="attribute" href="#dom-document-keyframes">keyframes</a>
map.</p>
<dl>
<dt>If the current value has only been set due to style changes:
</dt>
<dd>
The value referenced by the <a class="css" data-link-spec="css-animations" data-link-type="at-rule" href="http://dev.w3.org/csswg/css-animations-1/#at-ruledef-keyframes">@keyframes</a> name is
cleared from the <a class="idl-code" data-link-spec="css-animations" data-link-type="attribute" href="#dom-document-keyframes">keyframes</a> map.
</dd>
<dt>Otherwise:
</dt>
<dd>The removal is ignored.
</dd></dl>
<h4 class="heading settled" data-level="3.1.3" id="conversion-of-css-keyframes"><span class="secno">3.1.3. </span><span class="content">Converting a CSS Keyframes rule into a
KeyframeEffect</span><a class="self-link" href="#conversion-of-css-keyframes"></a></h4>
<p>A CSS <a class="css" data-link-spec="css-animations" data-link-type="at-rule" href="http://dev.w3.org/csswg/css-animations-1/#at-ruledef-keyframes">@keyframes</a> rule <em>keyframes</em> is
c
AAB7
onverted into a <a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#keyframeeffect">KeyframeEffect</a> using the following process:</p>
<ol>
<li>Initialize an empty list <em>keyframeList</em>.
</li>
<li>For each <em>keyframe</em> in keyframes:
<ol>
<li>Create a new dictionary <em>newKeyframe</em>.
</li>
<li>Set <em>newKeyframe</em>’s <a data-link-spec="css-animations" data-link-type="dfn" href="#offset">offset</a> to the offset defined by
<em>keyframe</em>.
</li>
<li>If <em>keyframe</em> defines an <a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-timing-function">animation-timing-function</a>, set
<em>newKeyframe</em>’s <a data-link-spec="css-animations" data-link-type="dfn" href="#easing">easing</a> to the defined <a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-timing-function">animation-timing-function</a>.
</li>
<li>For each <em>property</em> defined in <em>keyframe</em>:
<ol>
<li>Set <em>newKeyframe[property]</em> to the value associated with that
property in <em>keyframe</em>
</li>
<li>Add <em>property</em> to referencedProperties.
</li></ol>
</li></ol>
</li>
<li>Add <em>newKeyframe</em> to <em>keyframeList</em>.
</li>
<li>Remove keyframes with duplicated offsets from <em>keyframeList</em>such that
only the last keyframe to specify a given offset remains.
</li>
<li>Construct a new <a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#keyframeeffect">KeyframeEffect</a>, providing
<em>keyframeList</em> as the frames parameter.
</li></ol>
</div>
<h3 class="heading settled" data-level="3.2" id="web-animations-instantiation"><span class="secno">3.2. </span><span class="content">Web Animations Instantiation</span><a class="self-link" href="#web-animations-instantiation"></a></h3>
<div data-link-spec="css-animations">
<p>For CSS Animations, mappings into the Web Animations model are established
pairwise between a specific <a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#animationeffect">AnimationEffect</a>, the
<dfn data-dfn-type="dfn" data-noexport="" id="animating-effect">animating effect<a class="self-link" href="#animating-effect"></a></dfn>, and a specific element, the
<dfn data-dfn-type="dfn" data-noexport="" id="animating-element">animating element<a class="self-link" href="#animating-element"></a></dfn>.</p>
<p>When a CSS Animation is to be started, the value of <a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-name">animation-name</a> is used
as an index into the <a data-link-spec="css-animations" data-link-type="dfn" href="#keyframes">keyframes</a> map, and the matching
<a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#animationeffect">AnimationEffect</a> (if any) is used to instantiate the
<a data-link-spec="css-animations" data-link-type="dfn" href="#animating-effect">animating effect</a> by following the procedure defined below
(see <a data-section="" href="#instantiating-an-animating-effect">§3.4 Instantiating the animating effect
</a>).</p>
<p>When a CSS Animation is started an <a data-link-spec="css-animations" data-link-type="dfn" href="#animation">Animation</a> is constructed and
associated with a <a data-link-spec="css-animations" data-link-type="dfn" href="#player">Player</a> on the <a data-link-spec="css-animations" data-link-type="dfn" href="#document-timeline">Document Timeline</a>. The animation
is configured as follows:</p>
<ul>
<li>The <a data-link-spec="css-animations" data-link-type="dfn" href="#target-element">target element</a> is set to the <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-element">animating element</a>.
</li>
<li>The <a data-link-spec="css-animations" data-link-type="dfn" href="#start-delay">start delay</a> is set to the current used value of the
<a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-delay">animation-delay</a> property for the <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-element">animating element</a>.
</li>
<li>The <a data-link-spec="css-animations" data-link-type="dfn" href="#iteration-duration">iteration duration</a> is set to the current used value of the
<a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-duration">animation-duration</a> property for the <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-element">animating element</a>.
</li>
<li>The <a data-link-spec="css-animations" data-link-type="dfn" href="#iteration-count">iteration count</a> is set to the current used value of the
<a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-iteration-count">animation-iteration-count</a> property for the <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-element">animating element</a>.
</li>
<li>The <a data-link-spec="css-animations" data-link-type="dfn" href="#direction">direction</a> is set to the current used value of the
<a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-direction">animation-direction</a> property for the <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-element">animating element</a>.
</li>
<li>The <a data-link-spec="css-animations" data-link-type="dfn" href="#fill-mode">fill mode</a> is set to the current used value of the
<a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-fill-mode">animation-fill-mode</a> property for the <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-element">animating element</a>.
</li>
<li>The <a data-link-spec="css-animations" data-link-type="dfn" href="#animation-effect">animation effect</a> is set to the <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-effect">animating effect</a>
</li></ul>
<p class="issue" id="issue-0f1dc13a"><a class="self-link" href="#issue-0f1dc13a"></a>Deal with animation-play-state</p>
<p class="issue" id="issue-66af4048"><a class="self-link" href="#issue-66af4048"></a>Explain where we need to cancel the Player for a css animation.</p>
<h3 class="heading settled" data-level="3.3" id="css-animations-events"><span class="secno">3.3. </span><span class="content">CSS Animations Events</span><a class="self-link" href="#css-animations-events"></a></h3>
<p>The <a class="idl-code" data-link-spec="css-animations" data-link-type="event" href="http://dev.w3.org/csswg/css-animations-1/#dom-animationevent-animationstart">animationstart</a> event is triggered to fire each time the
corresponding <a data-link-spec="css-animations" data-link-type="dfn" href="#animation">Animation</a> enters the <a data-link-spec="css-animations" data-link-type="dfn" href="#active-phase">active phase</a> or
<a data-link-spec="css-animations" data-link-type="dfn" href="#after-phase">after phase</a> during a <a data-link-spec="css-animations" data-link-type="dfn" href="#sample">sample</a>.</p>
<p>The <a class="idl-code" data-link-spec="css-animations" data-link-type="event" href="http://dev.w3.org/csswg/css-animations-1/#dom-animationevent-animationiteration">animationiteration</a> event is triggered to fire, on each <a data-link-spec="css-animations" data-link-type="dfn" href="#sample">sample</a>
where all of the following conditions are met:</p>
<ol>
<li>the corresponding <a data-link-spec="css-animations" data-link-type="dfn" href="#animation">Animation</a> is in the <a data-link-spec="css-animations" data-link-type="dfn" href="#active-phase">active phase</a>
</li>
<li>the corresponding <a data-link-spec="css-animations" data-link-type="dfn" href="#animation">Animation</a> was in the <a data-link-spec="css-animations" data-link-type="dfn" href="#active-phase">active phase</a> on the
last <a data-link-spec="css-animations" data-link-type="dfn" href="#sample">sample</a>
</li>
<li>the corresponding <a data-link-spec="css-animations" data-link-type="dfn" href="#animation">Animation</a> has a <a data-link-spec="css-animations" data-link-type="dfn" href="#current-iteration">current iteration</a> which is
different to the
<a data-link-spec="css-animations" data-link-type="dfn" href="#current-iteration">current iteration</a> of the last <a data-link-spec="css-animations" data-link-type="dfn" href="#sample">sample</a>.
</li></ol>
<p>The <a class="idl-code" data-link-spec="css-animations" data-link-type="event" href="http://dev.w3.org/csswg/css-animations-1/#dom-animationevent-animationend">animationend</a> event is triggered to fire each time the
corresponding <a data-link-spec="css-animations" data-link-type="dfn" href="#animation">Animation</a> enters the <a data-link-spec="css-animations" data-link-type="dfn" href="#after-phase">after phase</a> during a
<a data-link-spec="css-animations" data-link-type="dfn" href="#sample">sample</a>.</p>
<h3 class="heading settled" data-level="3.4" id="instantiating-an-animating-effect"><span class="secno">3.4. </span><span class="content">Instantiating the animating effect
</span><a class="self-link" href="#instantiating-an-animating-effect"></a></h3>
<p>The <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-effect">animating effect</a> is instantiated from an
<a class="idl-code" data-link-spec="css-animations" data-link-type="interface" href="#animationeffect">AnimationEffect</a> (the <em>reference effect</em>) stored in the
<a class="idl-code" data-link-spec="css-animations" data-link-type="attribute" href="#dom-document-keyframes">keyframes</a> attribute using the following process:</p>
<p class="issue" id="issue-2e72571b"><a class="self-link" href="#issue-2e72571b"></a>turn this into boring old specificese</p>
<dl>
<dt>If the <em>reference effect</em> is a KeyframeEffect which was converted
from a CSS <a class="css" data-link-spec="css-animations" data-link-type="at-rule" href="http://dev.w3.org/csswg/css-animations-1/#at-ruledef-keyframes">@keyframes</a> rule using the process
defined in <a data-section="" href="#conversion-of-css-keyframes">§3.1.3 Converting a CSS Keyframes rule into a
KeyframeEffect</a>:
</dt>
<dd>
<ol>
<li>The <em>result effect</em> is created as a clone of the
<em>reference effect</em>.
</li>
<li>Convert "add" keyframes at an offset of 0 and 1 by snapshotting
their referenced properties from the computed style of the
<a data-link-spec="css-animations" data-link-type="dfn" href="#animating-element">animating element</a>, then changing the keyframe to a "replace" keyframe.
</li>
<li>Set the <a data-link-spec="css-animations" data-link-type="dfn" href="#easing">easing</a> of all keyframes which do not have an <a data-link-spec="css-animations" data-link-type="dfn" href="#easing">easing</a>
to the value of <a class="property" data-link-spec="css-animations" data-link-type="propdesc" href="http://dev.w3.org/csswg/css-animations-1/#propdef-animation-timing-function">animation-timing-function</a>.
</li></ol>
</dd>
<dt>Otherwise
</dt>
<dd> The <a data-link-spec="css-animations" data-link-type="dfn" href="#animating-effect">animating effect</a> is the <em>reference effect</em>.
<h2 class="heading settled" data-level="4" id="exposure-in-the-web-animations-api"><span class="secno">4. </span><span class="content">Exposure in the Web Animations API</span><a class="self-link" href="#exposure-in-the-web-animations-api"></a></h2>
<p><a data-link-spec="css-animations" data-link-type="dfn" href="#player">Player</a>s generated by CSS Animations and CSS Transitions are accessible
via <a data-link-spec="css-animations" data-link-type="dfn" href="#getanimationplayers">getAnimationPlayers</a> with the restriction that <a data-link-spec="css-animations" data-link-type="dfn" href="#source">source</a> will
point to a read-only <a data-link-spec="css-animations" data-link-type="dfn" href="#timeditem">TimedItem</a> which disallows changes to its
<a data-link-spec="css-animations" data-link-type="dfn" href="#specified-timing">specified timing</a> and <a data-link-spec="css-animations" data-link-type="dfn" href="#effect">effect</a>.</p>
<p class="note" role="note">Note: The <a data-link-spec="css-animations" data-link-type="dfn" href="#player">Player</a> remains fully functional. The <a data-link-spec="css-animations" data-link-type="dfn" href="#source">source</a>,
<a data-link-spec="css-animations" data-link-type="dfn" href="#playbackrate">playbackRate</a>, <a data-link-spec="css-animations" data-link-type="dfn" href="#currenttime">currentTime</a>, startTime and play control methods will
be live and function as normal.</p>
</dd></dl></div>
<div style="display:none">
REMOVE ME: Definitions that should be resolved by Web Animations
<p><dfn data-dfn-type="dfn" data-noexport="" id="animation">animation<a class="self-link" href="#animation"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="player">player<a class="self-link" href="#player"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="document-timeline">document timeline<a class="self-link" href="#document-timeline"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="target-element">target element<a class="self-link" href="#target-element"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="start-delay">start delay<a class="self-link" href="#start-delay"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="iteration-duration">iteration duration<a class="self-link" href="#iteration-duration"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="timing-function">timing function<a class="self-link" href="#timing-function"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="animation-effect">animation effect<a class="self-link" href="#animation-effect"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="keyframe-animation-effect">keyframe animation effect<a class="self-link" href="#keyframe-animation-effect"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="keyframes">keyframes<a class="self-link" href="#keyframes"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="after-phase">after phase<a class="self-link" href="#after-phase"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="custom-player-priority">custom player priority<a class="self-link" href="#custom-player-priority"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="cancel">cancel<a class="self-link" href="#cancel"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="getanimationplayers">getanimationplayers<a class="self-link" href="#getanimationplayers"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="timeditem">TimedItem<a class="self-link" href="#timeditem"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="source">source<a class="self-link" href="#source"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="specified-timing">specified timing<a class="self-link" href="#specified-timing"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="effect">effect<a class="self-link" href="#effect"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="playbackrate">playbackRate<a class="self-link" href="#playbackrate"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="currenttime">currentTime<a class="self-link" href="#currenttime"></a></dfn>
<dfn class="idl-code" data-dfn-type="interface" data-export="" id="keyframeeffect">keyframeEffect<a class="self-link" href="#keyframeeffect"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="offset">offset<a class="self-link" href="#offset"></a></dfn>
<dfn class="idl-code" data-dfn-type="interface" data-export="" id="animationeffect">animationEffect<a class="self-link" href="#animationeffect"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="sample">sample<a class="self-link" href="#sample"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="easing">easing<a class="self-link" href="#easing"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="iteration-count">iteration count<a class="self-link" href="#iteration-count"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="direction">direction<a class="self-link" href="#direction"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="fill-mode">fill mode<a class="self-link" href="#fill-mode"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="current-iteration">current iteration<a class="self-link" href="#current-iteration"></a></dfn>
<dfn data-dfn-type="dfn" data-noexport="" id="active-phase">active phase<a class="self-link" href="#active-phase"></a></dfn></p>
</div>
</main>
<h2 class="no-ref no-num heading settled" id="conformance"><span class="content">
Conformance</span><a class="self-link" href="#conformance"></a></h2>
<h3 class="no-ref heading settled" id="conventions"><span class="content">
Document conventions</span><a class="self-link" href="#conventions"></a></h3>
<p>Conformance requirements are expressed with a combination of
descriptive assertions and RFC 2119 terminology. The key words "MUST",
"MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT",
"RECOMMENDED", "MAY", and "OPTIONAL" in the normative parts of this
document are to be interpreted as described in RFC 2119.
However, for readability, these words do not appear in all uppercase
letters in this specification.
</p>
<p>All of the text of this specification is normative except sections
explicitly marked as non-normative, examples, and notes. <a data-biblio-type="normative" data-link-type="biblio" href="#biblio-rfc2119" title="RFC2119">[RFC2119]</a></p>
<p>Examples in this specification are introduced with the words "for example"
or are set apart from the normative text with <code>class="example"</code>,
like this:
</p>
<div class="example">
<p>This is an example of an informative example.</p>
</div>
<p>Informative notes begin with the word "Note" and are set apart from the
normative text with <code>class="note"</code>, like this:
</p>
<p class="note" role="note">Note, this is an informative note.</p>
<p>Advisements are normative sections styled to evoke special attention and are
set apart from other normative text with <code><strong class="advisement"></code>, like
this:
<strong class="advisement">
UAs MUST provide an accessible alternative.
</strong>
</p>
<h3 class="no-ref heading settled" id="conformance-classes"><span class="content">
Conformance classes</span><a class="self-link" href="#conformance-classes"></a></h3>
<p>Conformance to this specification
is defined for three conformance classes:
</p>
<dl>
<dt>style sheet
</dt>
<dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#style-sheet">CSS
style sheet</a>.
</dd>
<dt>renderer
</dt>
<dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
that interprets the semantics of a style sheet and renders
documents that use them.
</dd>
<dt>authoring tool
</dt>
<dd>A <a href="http://www.w3.org/TR/CSS21/conform.html#user-agent">UA</a>
that writes a style sheet.
</dd>
</dl>
<p>A style sheet is conformant to this specification
if all of its statements that use syntax defined in this module are valid
according to the generic CSS grammar and the individual grammars of each
feature defined in this module.
</p>
<p>A renderer is conformant to this specification
if, in addition to interpreting the style sheet as defined by the
appropriate specifications, it supports all the features defined
by this specification by parsing them correctly
and rendering the document accordingly. However, the inability of a
UA to correctly render a document due to limitations of the device
does not make the UA non-conformant. (For example, a UA is not
required to render color on a monochrome monitor.)
</p>
<p>An authoring tool is conformant to this specification
if it writes style sheets that are syntactically correct according to the
generic CSS grammar and the individual grammars of each feature in
this module, and meet all other conformance requirements of style sheets
as described in this module.
</p>
<h3 class="no-ref heading settled" id="partial"><span class="content">
Partial implementations</span><a class="self-link" href="#partial"></a></h3>
<p>So that authors can exploit the forward-compatible parsing rules to
assign fallback values, CSS renderers <strong>must</strong>
treat as invalid (and <a href="http://www.w3.org/TR/CSS21/conform.html#ignore">ignore
as appropriate</a>) any at-rules, properties, property values, keywords,
and other syntactic constructs for which they have no usable level of
support. In particular, user agents <strong>must not</strong> selectively
ignore unsupported component values and honor supported values in a single
multi-value property declaration: if any value is considered invalid
(as unsupported values must be), CSS requires that the entire declaration
be ignored.</p>
<h3 class="no-ref heading settled" id="experimental"><span class="content">
Experimental implementations</span><a class="self-link" href="#experimental"></a></h3>
<p>To avoid clashes with future CSS features, the CSS2.1 specification
reserves a <a href="http://www.w3.org/TR/CSS21/syndata.html#vendor-keywords">prefixed
syntax</a> for proprietary and experimental extensions to CSS.
</p>
<p>Prior to a specification reaching the Candidate Recommendation stage
in the W3C process, all implementations of a CSS feature are considered
experimental. The CSS Working Group recommends that implementations
use a vendor-prefixed syntax for such features, including those in
W3C Working Drafts. This avoids incompatibilities with future changes
in the draft.
</p>
<h3 class="no-ref heading settled" id="testing"><span class="content">
Non-experimental implementations</span><a class="self-link" href="#testing"></a></h3>
<p>Once a specification reaches the Candidate Recommendation stage,
non-experimental implementations are possible, and implementors should
release an unprefixed implementation of any CR-level feature they
can demonstrate to be correctly implemented according to spec.
</p>
<p>To establish and maintain the interoperability of CSS across
implementations, the CSS Working Group requests that non-experimental
CSS renderers submit an implementation report (and, if necessary, the
testcases used for that implementation report) to the W3C before
releasing an unprefixed implementation of any CSS features. Testcases
submitted to W3C are subject to review and correction by the CSS
Working Group.
</p>
<p>Further information on submitting testcases and implementation reports
can be found from on the CSS Working Group’s website at
<a href="http://www.w3.org/Style/CSS/Test/">http://www.w3.org/Style/CSS/Test/</a>.
Questions should be directed to the
<a href="http://lists.w3.org/Archives/Public/public-css-testsuite">public-css-testsuite@w3.org</a>
mailing list.
</p>
<h2 class="no-num heading settled" id="references"><span class="content">References</span><a class="self-link" href="#references"></a></h2>
<h3 class="no-num heading settled" id="normative"><span class="content">Normative References</span><a class="self-link" href="#normative"></a></h3>
<dl>
<dt id="biblio-rfc2119" title="rfc2119"><a class="self-link" href="#biblio-rfc2119"></a>[rfc2119]</dt>
<dd>S. Bradner. <a href="https://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>. March 1997. Best Current Practice. URL: <a href="https://tools.ietf.org/html/rfc2119">https://tools.ietf.org/html/rfc2119</a></dd>
</dl>
<h3 class="no-num heading settled" id="informative"><span class="content">Informative References</span><a class="self-link" href="#informative"></a></h3>
<dl>
<dt id="biblio-svg12" title="SVG12"><a class="self-link" href="#biblio-svg12"></a>[SVG12]</dt>
<dd>Dean Jackson; Craig Northway. <a href="http://www.w3.org/TR/SVG12">Scalable Vector Graphics (SVG) Full 1.2 Specification</a>. 13 April 2005. WD. URL: <a href="http://www.w3.org/TR/SVG12">http://www.w3.org/TR/SVG12</a></dd>
<dt id="biblio-css3-animations" title="css3-animations"><a class="self-link" href="#biblio-css3-animations"></a>[css3-animations]</dt>
<dd>Dean Jackson; et al. <a href="http://www.w3.org/TR/css3-animations/">CSS Animations</a>. 19 February 2013. WD. URL: <a href="http://www.w3.org/TR/css3-animations/">http://www.w3.org/TR/css3-animations/</a></dd>
<dt id="biblio-css3-transitions" title="css3-transitions"><a class="self-link" href="#biblio-css3-transitions"></a>[css3-transitions]</dt>
<dd>Dean Jackson; et al. <a href="http://www.w3.org/TR/css3-transitions/">CSS Transitions</a>. 19 November 2013. WD. URL: <a href="http://www.w3.org/TR/css3-transitions/">http://www.w3.org/TR/css3-transitions/</a></dd>
<dt id="biblio-web-animations" title="web-animations"><a class="self-link" href="#biblio-web-animations"></a>[web-animations]</dt>
<dd>Brian Birtles; et al. <a href="http://www.w3.org/TR/web-animations/">Web Animations 1.0</a>. 5 June 2014. WD. URL: <a href="http://www.w3.org/TR/web-animations/">http://www.w3.org/TR/web-animations/</a></dd>
</dl>
<h2 class="no-num heading settled" id="index"><span class="content">Index</span><a class="self-link" href="#index"></a></h2>
<ul class="indexlist">
<li>active phase, <a href="#active-phase" title="section 3.2">3.2</a></li>
<li>after phase, <a href="#after-phase" title="section 3.2">3.2</a></li>
<li>animating effect, <a href="#animating-effect" title="section 3.2">3.2</a></li>
<li>animating element, <a href="#animating-element" title="section 3.2">3.2</a></li>
<li>animation, <a href="#animation" title="section 3.2">3.2</a></li>
<li>animationEffect, <a href="#animationeffect" title="section 3.2">3.2</a></li>
<li>animation effect, <a href="#animation-effect" title="section 3.2">3.2</a></li>
<li>cancel, <a href="#cancel" title="section 3.2">3.2</a></li>
<li>CSSKeyframesMap, <a href="#csskeyframesmap" title="section 3.1.1">3.1.1</a></li>
<li>current iteration, <a href="#current-iteration" title="section 3.2">3.2</a></li>
<li>currentTime, <a href="#currenttime" title="section 3.2">3.2</a></li>
<li>custom player priority, <a href="#custom-player-priority" title="section 3.2">3.2</a></li>
<li>direction, <a href="#direction" title="section 3.2">3.2</a></li>
<li>document timeline, <a href="#document-timeline" title="section 3.2">3.2</a></li>
<li>easing, <a href="#easing" title="section 3.2">3.2</a></li>
<li>effect, <a href="#effect" title="section 3.2">3.2</a></li>
<li>fill mode, <a href="#fill-mode" title="section 3.2">3.2</a></li>
<li>getanimationplayers, <a href="#getanimationplayers" title="section 3.2">3.2</a></li>
<li>iteration count, <a href="#iteration-count" title="section 3.2">3.2</a></li>
<li>iteration duration, <a href="#iteration-duration" title="section 3.2">3.2</a></li>
<li>keyframe animation effect, <a href="#keyframe-animation-effect" title="section 3.2">3.2</a></li>
<li>keyframeEffect, <a href="#keyframeeffect" title="section 3.2">3.2</a></li>
<li>keyframes
<ul>
<li>attribute for Document, <a href="#dom-document-keyframes" title="section 3.1.2">3.1.2</a></li>
<li>definition of, <a href="#keyframes" title="section 3.2">3.2</a></li>
</ul>
</li>
<li>offset, <a href="#offset" title="section 3.2">3.2</a></li>
<li>playbackRate, <a href="#playbackrate" title="section 3.2">3.2</a></li>
<li>player, <a href="#player" title="section 3.2">3.2</a></li>
<li>sample, <a href="#sample" title="section 3.2">3.2</a></li>
<li>source, <a href="#source" title="section 3.2">3.2</a></li>
<li>specified timing, <a href="#specified-timing" title="section 3.2">3.2</a></li>
<li>start delay, <a href="#start-delay" title="section 3.2">3.2</a></li>
<li>String, <a href="#string" title="section 3.1">3.1</a></li>
<li>target element, <a href="#target-element" title="section 3.2">3.2</a></li>
<li>TimedItem, <a href="#timeditem" title="section 3.2">3.2</a></li>
<li>timing function, <a href="#timing-function" title="section 3.2">3.2</a></li>
<li>transitioning element, <a href="#transitioning-element" title="section 2">2</a></li>
<li>transitioning property, <a href="#transitioning-property" title="section 2">2</a></li>
</ul>
<h2 class="no-num heading settled" id="idl-index"><span class="content">IDL Index</span><a class="self-link" href="#idl-index"></a></h2>
<pre class="idl">//FIXME: figure out the appropriate thing to do here and remove this!
interface <a data-dfn-type="interface" data-export="" data-global-name="" href="#string">String</a> { };
[MapClass(<a data-link-spec="html5" data-link-type="idl-name" href="#string">String</a>, <a data-link-spec="html5" data-link-type="idl-name" href="#animationeffect">AnimationEffect</a>)]
interface <a class="idl-code" data-global-name="" data-link-spec="html5" data-link-type="interface" href="#csskeyframesmap">CSSKeyframesMap</a> {
};
partial interface <a class="idl-code" data-global-name="" data-link-spec="html5" data-link-type="interface" href="https://html.spec.whatwg.org/#dom-document">Document</a> {
readonly attribute <a data-link-spec="html5" data-link-type="idl-name" href="#csskeyframesmap">CSSKeyframesMap</a> <a class="idl-code" data-global-name="Document<interface>/keyframes<attribute>" data-link-for="Document" data-link-spec="html5" data-link-type="attribute" data-readonly="" data-type="CSSKeyframesMap " href="#dom-document-keyframes">keyframes</a>;
};
</pre>
<h2 class="no-num heading settled" id="issues-index"><span class="content">Issues Index</span><a class="self-link" href="#issues-index"></a></h2>
<div style="counter-reset:issue">
<div class="issue">This feature is at risk.<a href="#issue-a495e9c5"> ↵ </a></div>
<div class="issue">Should the KeyframeEffects generated by @keyframes rules be read-only?<a href="#issue-1a6a93a1"> ↵ </a></div>
<div class="issue">Deal with animation-play-state<a href="#issue-0f1dc13a"> ↵ </a></div>
<div class="issue">Explain where we need to cancel the Player for a css animation.<a href="#issue-66af4048"> ↵ </a></div>
<div class="issue">turn this into boring old specificese<a href="#issue-2e72571b"> ↵ </a></div>
</div></body>
</html>