forked from w3c/web-animations
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathfuture.html
1465 lines (1441 loc) · 59.5 KB
/
future.html
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
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html>
<!-- vim: set expandtab ts=2 sw=2 tw=80: -->
<html>
<head>
<title>Web Animations Future</title>
<meta charset="utf-8">
<script src="respec/respec.js" class="remove"></script>
<script
src="http://dev.w3.org/2009/dap/ReSpec.js/js/lang/sh_javascript.min.js"
class="remove"></script>
<script class="remove">
var respecConfig = {
// specification status (e.g. WD, LCWD, NOTE, etc.). If in doubt use
// ED.
specStatus: "unofficial",
// the specification's short name, as in
// http://www.w3.org/TR/short-name/
// shortName: "web-anim",
// if your specification has a subtitle that goes below the main
// formal title, define it here
// subtitle : "an excellent document",
// if you wish the publication date to be other than today, set this
// publishDate: "2009-08-06",
// if the specification's copyright date is a range of years, specify
// the start date here:
// copyrightStart: "2012"
// if there is a previously published draft, uncomment this and set
// its YYYY-MM-DD date and its maturity status
// previousPublishDate: "1977-03-15",
// previousMaturity: "WD",
// if there a publicly available Editor's Draft, this is the link
// edDraftURI:
// "https://dvcs.w3.org/hg/FXTF/raw-file/tip/web-anim/index.html",
// if this is a LCWD, uncomment and set the end of its review period
// lcEnd: "2009-08-05",
// if you want to have extra CSS, append them to this list
// it is recommended that the respec.css stylesheet be kept
extraCSS: ["respec/respec.css",
"web-animations.css"],
// Turning off inlineCSS for now since if extraCSS points to
// a relative URL your testing from a file URL the XHR will fail.
// Probably should turn this back on once this is hosted on a server
// somewhere.
inlineCSS: false,
// editors, add as many as you like
// only "name" is required
editors: [
{ name: "Web Animations editors" }
],
// authors, add as many as you like.
// This is optional, uncomment if you have authors as well as editors.
// only "name" is required. Same format as editors.
//authors: [
// { name: "Your Name", url: "http://example.org/",
// company: "Your Company", companyURL: "http://example.com/" },
//],
// XXX If we continue using ReSpec then we need to tweak it to support
// multiple working groups. It includes updating the patent section
// prose to say "groups" instead of "group" etc.
// name of the WG
wg: "CSS Working Group (part of the Style Activity) and the SVG " +
"Working Group (part of the Graphics Activity)",
// URI of the public WG page
// wgURI: "http://www.w3.org/Graphics/fx/",
// name (without the @w3c.org) of the public mailing to which comments
// are due
wgPublicList: "public-fx",
// URI of the patent status for this WG, for Rec-track documents
// !!!! IMPORTANT !!!!
// This is important for Rec-track documents, do not copy a patent URI
// from a random document unless you know what you're doing. If in
// doubt ask your friendly neighbourhood Team Contact.
wgPatentURI: "",
noIDLSorting: true,
noIDLIn: true
};
</script>
</head>
<body>
<section id='abstract'>
This is the abstract for your specification.
</section>
<section>
<h2>The <code>Timeline</code> interface</h2>
<dl title="partial interface Timeline" class="idl">
<dt>double? fromTimelineTime (double timelineTime,
TimedItem target)</dt>
<dd>
<p class="annotation">
This is basically supposed to be a method that answers the question,
"If the time of this timeline is A (<em>timelineTime</em>), what
will the local time be at timed item B (<em>target</em>)?"
</p>
<p>
Returns the corresponding time value for a given timed item,
<em>target</em>, for a time value relative to this timeline
using the following procedure.
</p>
<p class="todo">
All the following needs to be updated since it refers to time
sources etc.
</p>
<ol>
<li>Define the <dfn>parent time source</dfn> of time source A as
being the value of a <code>timeline</code> property on A if
such a property exists and refers to a <a>TimeSource</a>
object.</li>
<li>Define an <dfn>ancestor time source</dfn> of time source A as
any time source that appears in the chain of parent time
sources constructed starting with the <a>parent time
source</a> of A and continuing with each subsequent parent
up to and including a document time source or until there are
no further parent time sources.</li>
<li>Define a time source A as being <dfn>derived from another time
source</dfn> B if B is an <a>ancestor time source</a> of
A.</li>
<li>Determine <var>local document time</var> as follows:
<dl class="switch">
<dt>If <em>other</em> is not <a title="derived from another
time source">derived from</a> this document time source,</dt>
<dd>
<ol>
<li>
Let <var>remote document</var> be the document time
source that is an <a>ancestor time source</a> of
<em>other</em> if such a document time source exists.
</li>
<li>
If there is no such <var>remote document</var> raise
a <code>DOMException</code> of type
<code>HierarchyRequestError</code>.
</li>
<li>
Let <var>local document time</var> be the result of
calling <code>toDocumentTime(<em>documentTime</em>,
<var>remote document</var>)</code> on this object.
</li>
</ol>
</dd>
<dt>Otherwise,</dt>
<dd>
Let <var>local document time</var> be <em>documentTime</em>.
</dd>
</dl>
</li>
<li>
Calculate the <code>currentTime</code> of <em>other</em> by
following the steps described <span
class="todo">somewhere...</span>
</li>
</ol>
<p>
Exceptions:
</p>
<dl class="exceptions">
<dt>DOMException of type <code>HierarchyRequestError</code></dt>
<dd>
Raised if <em>other</em> does not have an <a>ancestor time
source</a> that is a document time source object.
</dd>
</dl>
<p class="issue">
Is this needed? And is the automatic cross-document time source
negotation required?
</p>
</dd>
</dl>
</section>
<section>
<h2>Scaling the time</h2>
<section>
<h3>The <code>TimingFunctionCallback</code> callback</h3>
<p>
In addition to the timing functions provided by Web Animations,
authors may also provide their own time scaling function.
The behavior of this function is defined by the
<a>TimingFunctionCallback</a> type below.
</p>
<div title="callback TimingFunctionCallback = double ()" class="idl">
<p>
A <a>TimingFunctionCallback</a> function has the same behavior as
defined for the <code>scaleTime</code> method on the
<a>TimingFunction</a> interface.
That is, it takes an input time fraction, applies some scaling
operation to it, and returns an output time fraction.
</p>
<p>
For the same input <code>time</code> and <code>item</code>, this
function MUST return the same output.
</p>
<p>
As a result, a user agent MAY cache the results returned by
a <a>TimingFunctionCallback</a> as an optimization.
Note, however, that if the <code>item</code> object is changed, this
consitutes different input to the function and hence the user agent
MUST NOT cache the results of the callback if the <code>item</code>
object changes.
Given the requirement that callback functions do not change
<code>item</code>, a user agent can expect that it is safe to cache
the output of a <a>TimingFunctionCallback</a> for at least the
duration of a sample.
</p>
<div class="issue">
<p>
Is it important to be able to differentiate between when the
scaling is being applied to an iteration as a whole or simply to
a segment of a keyframe animation?
</p>
<p>
I suspect it probably is and that that would consitute different
input to the function.
</p>
</div>
<dl class="parameters">
<dt>double time</dt>
<dd>
The input time fraction in the range [0.0, 1.0].
</dd>
<dt>TimedItem? item</dt>
<dd>
The <a>TimedItem</a> for which the scaling is being performed.
This object MUST NOT be modified.
</dd>
</dl>
</div>
<section>
<h4>Applying time manipulations</h4>
<p>Needs to be adjusted as follows:</p>
<ol>
<li>…</li>
<li>
Scale the time as follows:
<dl class="switch">
<dt>If <var>timing.timingFunction</var> is
a <a>TimingFunction</a> object,</dt>
<dd>
<p>
Let <var>scaled iteration time</var> be
<code>unscaled iteration time *
timing.timingFunction.scaleTime(<var>unscaled iteration
time</var> / <a>iteration duration</a>)))</code>.
</p>
</dd>
<dt>If <var>timing.timingFunction</var> is
a <a>TimingFunctionCallback</a> function,</dt>
<dd>
<p>
Let <var>scaled iteration time</var> be
<code>unscaled iteration time *
timing.timingFunction(<var>unscaled iteration
time</var> / <a>iteration duration</a>)))</code>.
</p>
<p>
If calling <code>timing.timingFunction</code>
results in an exception being thrown, let <var>scaled
iteration time</var> be <var>unscaled iteration time</var>.
</p>
<div class="todo">
<p>
Need to consider:
</p>
<ul>
<li>Is there any way to lock down the model during this
step? i.e. make everything read-only?
(Of course it's not fully possible, but can we do
enough that it's meaningful?)
Maybe implementations can just display something in
the console: "If you're changing stuff in a timing
function you're going to have a bad time"</li>
<li>Can we cache some values before calling to ensure that
at least this procedure will complete as
expected?</li>
<li>Need to define exactly when this procedure is
performed since both the timing and the number of
times it is called could produce different results if
the script has side effects.
For example, does querying
<code>TimedItem.iterationTime</code> result in the
script being executed every time?
<p>
Possibly could define things such that iteration time
is evaluated on each sample (need to define sampling)
and then only if <code>iterationTime</code> is
explicitly requested (i.e. no caching there)... what
about other operations that rely on iteration time
being up to date? what are they?
</p>
</li>
<li>At points where this is called we need to check the
state of the model after calling.</li>
<li>Do we need some disclaimer saying, "if the script has
side effects all bets are off"</li>
<li>Also need to be careful that the callback doesn't call
anything that triggers calculating the iteration time
(e.g. <code>TimedItem.iterationTime</code> should use
a cached value in that case)</li>
<li>I think script-defined timing functions might get
punted to v2</li>
</ul>
</div>
</dd>
<dt>Otherwise,</dt>
<dd>
Let <var>scaled iteration time</var> be <var>unscaled
iteration time</var>.
</dd>
</dl>
</li>
<li>…</li>
</ol>
</section>
</section>
</section>
<section>
<h2>Animation templates</h2>
<div class="informative">
<p>
It is sometimes necessary to apply the same animation effect to a series
of targets.
Animation templates provide a means for the same set of animation
properties to be applied repeatedly to a number of targets
whilst maintaining a link such that changes to the template are
reflected at each place where the template is applied.
</p>
<p>
In concrete terms, an <a>AnimationTemplate</a> object is used to create
multiple <a>Animation</a> objects each of which maintains a link back to
the template via its <code>template</code> property.
Such <a>Animation</a> objects are said to be <dfn>linked</dfn> to
a template.
</p>
<p>
The timing and animation parameters of <a>linked</a> animations cannot
be modified directly.
Rather, changes are made to the template which is then echoed to all
animations linked to the same template.
In order to modify the timing and animation parameters of
a <a>linked</a> animation directly, it must first be unlinked using the
<code>unlink</code> method.
</p>
<p>
Note that run-time properties of a <a>linked</a> animation such as its
<var>start time</var> and <var>time drift</var> can still be modified.
Only those properties attached to the <code>timing</code> and
<code>effect</code> properties of a <a>linked</a> <a>Animation</a>
object are read-only.
</p>
<p>
Unlinked animations can be linked to a template by:
</p>
<ul>
<li>assigning the <var>template</var> property to an
<a>AnimationTemplate</a> <span class="todo">(Is this right? Are we going
to do this?)</span>, or</li>
<li>calling <code>templatize</code> to create a new
<a>AnimationTemplate</a> with properties set to reflect the current
state of the <a>Animation</a> object on which it is called.</li>
</ul>
<p class="todo">
Provide some javascript sample here demonstrating?
</p>
</div> <!-- informative -->
<section>
<h3><a>Animation</a> interface members</h3>
<dl title="partial interface Animation" class="idl">
<dt>attribute AnimationTemplate? template</dt>
<dd>
<p>
For linked animations (see <a href="#animation-templates"
class="sectionRef"></a>), the <a>AnimationTemplate</a> object
from which this object derives its values.
For animations that are not linked to a template, this property is
<code>null</code>.
</p>
<p>
Setting this property has the following effect:
</p>
<ol>
<li>Let <var>new template</var> be the value to assign to the
<code>template</code> property.</li>
<li>If <var>new template</var> is <code>null</code>,
<ol>
<li>Call <code>unlink()</code>.</li>
</ol>
</li>
<li>Otherwise,
<ol>
<li>Set <code>timing</code> to <code><var>new
template</var>.timing.clone()</code>.</li>
<li>Set <code>effect</code> to <code><var>new
template</var>.effect.clone()</code>.</li>
<li>Set <code>template</code> to <code><var>new
template</var></code>.</li>
</ol>
</li>
</ol>
</dd>
<dt>AnimationTemplate templatize()</dt>
<dd>
<p>
If this object is not already linked to a template,
creates a new <a>AnimationTemplate</a> object based on this object
and links this object to it (see <a href="#animation-templates"
class="sectionRef"></a>).
</p>
<p class="feedbackWanted">
What is the more useful behavior? To always create a template?
Or to only create one if it doesn't already have one?
</p>
<p>
The effect is equivalent to the following steps:
</p>
<ol>
<li>Let <var>source</var> be the object on which
<code>templatize</code> is called.</li>
<li>If <code><var>source</var>.template</code> is not
<code>null</code>, return.</li>
<li>Create a new <a>AnimationTemplate</a> object,
<var>template</var>.</li>
<li>Set <code><var>template</var>.timing</code> to
<code><var>source</var>.timing.clone()</code>.</li>
<li>Set <code><var>template</var>.effect</code> to
<code><var>source</var>.effect.clone()</code>.</li>
<li>Set <code><var>source</var>.template</code> to
<var>template</var>.</li>
<li>Return <var>template</var>.</li>
</ol>
</dd>
<dt>AnimationTemplate? unlink()</dt>
<dd>
<p>
Makes this animation independent of the template with which it is
associated if any
(see <a href="#animation-templates" class="sectionRef"></a>)
</p>
<p>
After setting <code>template</code> to <code>null</code> the
previous value of <code>template</code> is returned.
</p>
<p>
The effect is equivalent to the following steps:
</p>
<ol>
<li>If <code>template</code> is <code>null</code>, return
<code>null</code>.</li>
<li>Let <var>old template</var> be <code>template</code>.</li>
<li>Set <code>timing</code> to
<code>template.timing.clone()</code>.</li>
<li>Set <code>effect</code> to
<code>template.effect.clone()</code>.</li>
<li>Set <code>template</code> to <code>null</code> (but do not
recursively call this function).</li>
<li>Return <var>old template</var>.</li>
</ol>
</dd>
</dl>
</dl>
</section>
<section>
<h3>The <code>AnimationTemplate</code> interface</h3>
<p>
<dl title="[Constructor] interface AnimationTemplate : TimedTemplate"
class="idl">
<dt>attribute (AnimationEffect or CustomAnimationEffect)
effect</dt> <dd>
The animation effect to apply.
</dd>
</dl>
</p>
</section>
<section>
<h3>The <code>TimedTemplate</code> interface</h3>
<p>
Both the timing of an <code>AnimationTemplate</code> and the methods
for creating an <code>Animation</code> from an
<code>AnimationTemplate</code> are specified on the
<code>TimedTemplate</code> since this behavior is shared with
animation groups (see <a href="#group-templates"
class="sectionRef"></a>).
</p>
<p class="todo">
Should we allow live lists to be passed in? i.e. selectors etc.?
</p>
<dl title="interface TimedTemplate" class="idl">
<dt>attribute Timing timing</dt>
<dd>
The timing parameters to use for generated timed items.
</dd>
<dt>TimedItem animate ()</dt>
<dd>
<p>
Creates an independent <code>TimedItem</code> and appends it
to <code>element.ownerDocument.animationTimeline</code>.
</p>
<p>
This allows the following sort of usage:
</p>
<pre class="example sh_javascript">
anim.animate(document.getElementById("a"));
</pre>
<p>
The specific steps for instantiating a
<code>TimedTemplate</code> depends on its concrete type and is
described in <a href="#instantiating-an-animationtemplate"
class="sectionRef"></a> and <a
href="#instantiating-an-animationgrouptemplate"
class="sectionRef"></a>.
</p>
<dl class="parameters">
<dt>AnimationTarget target</dt>
<dd>
The element or pseudo-element to be targetted.
</dd>
<dt>optional double startTime</dt>
<dd>
<p>
The start time for the generated animations
expressed in seconds in the iteration time space of the
<code>AnimationGroup</code> to which it is
appended (see <a href="#time-spaces" class="sectionRef"></a>).
</p>
<p>
If this parameter is not specified it will default to the
current iteration time of the
<code>AnimationGroup</code> to which it is
appended if it is not <code>null</code>, otherwise it will
default to zero.
</p>
</dd>
</dl>
</dd>
<dt>sequence<TimedItem> animate ()</dt>
<dd>
<p>
Creates a series of independent <code>TimedItem</code>
objects, one for each element in <code>target</code>.
As with <code>animate(AnimationTarget target, double
startTime)</code> each such <code>TimedItem</code> object is
appended to <code>element.ownerDocument.animationTimeline</code>.
</p>
<p>
This allows the following sort of usage:
</p>
<pre class="example sh_javascript">
anim.animate([document.getElementById("a"), document.getElementById("b")]);
anim.animate(document.querySelectorAll("div.warning"));
anim.animate(document.getElementsByTagName("button"));
anim.animate(document.getElementById("group").childNodes);
</pre>
<p>
The specific steps for instantiating a
<code>TimedTemplate</code> depends on its concrete type and is
described in <a href="#instantiating-an-animationtemplate"
class="sectionRef"></a> and <a
href="#instantiating-an-animationgrouptemplate"
class="sectionRef"></a>.
</p>
<dl class="parameters">
<dt>sequence<Node> targets</dt>
<dd>
An sequence of <code>Node</code>s to be animated.
Any nodes in the sequence that are not of type
<code>ELEMENT_NODE</code> will be ignored.
</dd>
<dt>optional double startTime</dt>
<dd>
As with <code>animate(AnimationTarget target, optional double
startTime)</code>.
</dd>
</dl>
</dd>
<dt>TimedItem animateWithParent ()</dt>
<dd>
<p>
Similar to <code>animate</code>, this method creates
independent <code>TimedItem</code> object(s) for the
elements in <code>target</code>.
However, the resulting items are appended to the given
<code>parentGroup</code>, if provided.
If <code>parentGroup</code> is <code>null</code>, the
<code>TimedItem</code> objects will not be added to any
group.
</p>
<dl class="parameters">
<dt>AnimationTarget target</dt>
<dd>
As with <code>animate</code>.
</dd>
<dt>AnimationGroup? parentGroup</dt>
<dd>
The animation group to which animations should be appended.
</dd>
<dt>optional double startTime</dt>
<dd>
<p>
The start time for the generated animations
expressed in seconds in the iteration time space of the
<code>AnimationGroup</code> to which it is
appended (see <a href="#time-spaces" class="sectionRef"></a>).
</p>
<p>
If this parameter is not specified it will default to the
current iteration time of <code>parentGroup</code>.
If <code>parentGroup</code> is <code>null</code>,
this parameter will default to zero.
</p>
</dd>
</dl>
</dd>
<dt>sequence<TimedItem> animateWithParent (
sequence<Node> targets,
AnimationGroup? parentGroup,
optional double startTime)</dt>
<dd>
As with <code>animateWithParent(AnimationTarget target,
AnimationGroup? parentGroup,
optional double startTime)</code> except
one <code>TimedItem</code> is created for each
<code>Node</code> in <code>target</code> that is of type
<code>ELEMENT_NODE</code>.
</dd>
<dt>TimedItem animateLive (AnimationTarget target,
optional double startTime)</dt>
<dd>
As with <code>animate</code> with the exception that the
<code>TimedItem</code> objects generated by this method are
live.
</dd>
<dt>sequence<TimedItem> animateLive (
sequence<Node> targets, optional double startTime)</dt>
<dd>
As with <code>animate</code> with the exception that the
<code>TimedItem</code> objects generated by this method are
live.
</dd>
<dt>TimedItem animateLiveWithParent
(AnimationTarget target, AnimationGroup? parentGroup,
optional double startTime)</dt>
<dd>
As with <code>animateWithParent</code> with the exception that the
animations generated by this method are live.
</dd>
<dt>sequence<TimedItem> animateLiveWithParent
(sequence<Node> targets, AnimationGroup? parentGroup,
optional double startTime)</dt>
<dd>
As with <code>animateWithParent</code> with the exception that the
animations generated by this method are live.
</dd>
</dl>
</section>
<section>
<h3>Instantiating an <code>AnimationTemplate</code></h3>
<p>
The procedure for instantiating an <code>AnimationTemplate</code>,
<var>template</var>, given a list of target elements and an optional
<var>parent group</var>, is as follows:
</p>
<ol>
<li>
Create an empty sequence of <code>Animation</code> objects.
</li>
<li>
For each <var>element</var> in the list of target elements:
<ol>
<li>
Create a new <code>Animation</code> object, <var>anim</var>.
</li>
<li>
Set the <code>timing</code> and <code>effect</code>
properties of <var>anim</var> to copies
<code>template.timing</code> and
<code>template.effect</code>.
</li>
<li>
If <var>parentGroup</var> is not specified, let
<var>parentGroup</var> be
<code><var>element</var>.ownerDocument.animationTimeline</code>.
</li>
<li>
Append <var>element</var> to <var>parentGroup</var>.
</li>
<li>
Append <var>element</var> to the sequence of
<code>Animation</code> objects.
</li>
</ol>
</li>
<li>
Return the sequence of <code>Animation</code> objects.
</li>
</ol>
</section>
<section>
<h3>Group templates</h3>
<p>
As with animations, templates can also be created for animation
groups.
</p>
<p class="todo">
Lots of questions here about how this should work.
</p>
</section>
<section>
<h3>The <code>AnimationGroupTemplate</code> interface</h3>
<p class="todo">
TBD
</p>
<dl title="interface AnimationGroupTemplate : TimedTemplate"
class="idl">
<dt>void clear ()</dt>
<dd>
Removes all child items from the group.
</dd>
<dt>getter TimedTemplate? (unsigned long index)</dt>
<dd>
Returns the template item at <code>index</code>.
If <code>index</code> is greater than or equal to
<code>length</code> returns <code>null</code>.
</dd>
<dt>setter TimedTemplate (unsigned long index,
TimedTemplate newItem)</dt>
<dd>
<p>
Replaces the item at <code>index</code> with
<code>newItem</code> by calling
<code>splice(index, 1, newItem)</code>.
</p>
<p>
Returns <code>newItem</code>.
</p>
<p>
The behavior of this method is identical to
the equivalent setter in <code>AnimationGroup</code>
except that DOMExceptions of type HierarchyRequestError are not
thrown.
</p>
</dd>
<dt>sequence<TimedTemplate> add (
TimedTemplate newItem, TimedTemplate... otherItems)</dt>
<dd>
<p>
Add <code>newItem</code> and each <code>otherItems</code> as the
last item(s) in the group by calling <code>splice(group.length, 0,
newItem, otherItem1, ... otherItemN)</code>.
</p>
<p>
Returns a sequence containing the added items:
<code>[newItem, otherItem1, ... otherItemN]</code>.
</p>
</dd>
<dt>sequence<TimedTemplate> remove (
long index, optional unsigned long count = 1)</dt>
<dd>
<p>
Removes the item(s) at <code>index</code> by calling
<code>splice(index, count)</code>.
</p>
<p>
Returns the removed items.
</p>
</dd>
<dt>
sequence<TimedTemplate> splice ()
</dt>
<dd>
<p>
Modifies the list of children of this group by first removing
<code>deleteCount</code> items from <code>start</code> followed by
adding <code>newItems</code> at the same point.
</p>
<p>
Returns a sequence of the items removed from group during the
removal step (regardless of whether these items were re-added
during the addition step).
</p>
<p>
As with <code>AnimationGroup.slice</code> the operation of
slice is based on <a
href="http://www.ecma-international.org/publications/files/ECMA-ST-ARCH/ECMA-262%205th%20edition%20December%202009.pdf#page=140">ECMAScript
5's Array.prototype.splice</a>.
</p>
<p>
The operation of this method is identical to that of
<code>AnimationGroup.slice</code> with the notable difference
that DOMExceptions of type HierarchyRequestError are not thrown
since there is no <code>AnimationGroupTemplate</code>
corresponding to a document timeline.
</p>
<dl class="parameters">
<dt>long start</dt>
<dd>
The index at which items should be removed and inserted.
Negative indices represent an offset from the end of the list of
items.
This value is clamped to the range [-<code>length</code>,
<code>length</code>].
</dd>
<dt>unsigned long deleteCount</dt>
<dd>
The number of items to remove from the group beginning at
<code>start</code>.
Negative values are clamped to zero, and all other values are
clamped such that
0 < <code>start</code> + <code>deleteCount</code> ≤
length.
</dd>
<dt>sequence<TimedTemplate> newItems</dt>
<dd>
The items to be added at <code>start</code>.
Each item, if it already has a parent group (including this
group), is first removed from its parent group before being
added to this group.
</dd>
</dl>
</dd>
<dt>
sequence<TimedTemplate> splice (long start,
unsigned long deleteCount, TimedTemplate... newItem)
</dt>
<dd>
An overload of <code>splice</code> to take a variadic list of items
rather than requiring a sequence.
The operation is identical to <code>splice(unsigned long start,
unsigned long deleteCount, sequence<TimedTemplate>
newItems)</code>.
</dd>
<dt>long indexOf (TimedTemplate item)</dt>
<dd>
Returns the index of <code>item</code> within the group.
If <code>item</code> is not in the group, returns <code>-1</code>.
</dd>
</dl>
</section>
<section>
<h3>The <code>ParGroupTemplate</code> interface</h3>
<p>
<a>ParGroup</a> objects can be created from <a>ParGroupTemplate</a>
objects.
</p>
<dl title="[Constructor] interface ParGroupTemplate
: AnimationGroupTemplate"
class="idl">
</dl>
</section>
<section>
<h3>The <code>SeqGroupTemplate</code> interface</h3>
<p>
<a>SeqGroup</a> objects can be created from <a>SeqGroupTemplate</a>
objects.
</p>
<dl title="[Constructor] interface SeqGroupTemplate
: AnimationGroupTemplate" class="idl">
</dl>
</section>
<section>
<h3>Instantiating an <code>AnimationGroupTemplate</code></h3>
<p class="todo">
TBD. This is probably all wrong.
</p>
<p>
The procedure for creating an <code>AnimationGroup</code> from
an <code>AnimationGroupTemplate</code>, <var>template</var>,
given a list of target elements, and optionally given a <var>parent
group</var> follows.
</p>
<p>
Note that <code>ParGroupTemplate</code> objects produce
<code>ParGroup</code> objects and likewise
<code>SeqGroupTemplate</code> objects produce <code>SeqGroup</code>
objects.
In the following description the <code>AnimationGroupTemplate</code>
and <code>AnimationGroup</code> types should be substituted with the
concrete types in use.
</p>
<ol>
<li>
Create an empty sequence to hold the generated
<code>AnimationGroup</code> objects.
</li>
<li>
For each <var>element</var> in the list of target elements:
<ol>
<li>
Create a new <code>AnimationGroup</code> object,
<var>group</var>.
</li>
<li>
Set the <code>timing</code> property of <var>group</var> to
a copy of <code>template.timing</code>.
</li>
<li>
For each <var>child</var> in <var>template</var>, call
<code><var>child</var>.animateWithParent(<var>element</var>,
<var>group</var>, <code>startTime</code>)</code> or
<code><var>child</var>.animateLiveWithParent(<var>element</var>,
<var>group</var>, <code>startTime</code>)</code> depending on
whether this procedure was invoked with <code>animate</code> or
<code>animateLive</code>.
</li>
<li>
If <var>parentGroup</var> is not specified, let
<var>parentGroup</var> be
<code><var>element</var>.ownerDocument.animationTimeline</code>.
</li>
<li>
Append <var>group</var> to <var>parentGroup</var>.
</li>
<li>
Append <var>group</var> to the sequence of
<code>AnimationGroup</code> objects.
</li>
</ol>
</li>
<li>
Return the sequence of <code>AnimationGroup</code> objects.
</li>
</ol>
</section>
</section>
<section>
<h2>Custom effects</h2>
<div class="annotation">
<p>
I think we want two types of custom effects.
Following is the general-purpose animate-anything kind of effect.
The other type, which is not defined here, is the one that can
participate in the animation sandwich just like any other.
</p>
<p>
This, second, native-like animation effect, would have the
following features:
</p>
<ul>
<li>Shares the same function signature as
<code><a>AnimationEffect</a>.sample</code></li>
<li>Gets passed the underlying value and passes out the animated
value.</li>
<li>Has a target attribute and is sorted against other
<a>AnimationEffect</a> objects (including platform
objects)</li>
<li>Can be added as a child of
a <a>GroupedAnimationEffect</a>.</li>
</ul>
<p>
That's a bit more difficult since you have to be careful that the
custom effect doesn't do anything naughty while you're in the
middle of compositing the animation sandwich.
I think we should postpone this until Web Animations 2.
</p>
</div>
</section>
<section>
<h2>Script interface</h2>
<section>
<h3>The <code>TimingFunction</code> interface</h3>
<p>
The <a title="timing function">timing functions</a> provided by Web
Animations share a common <a>TimingFunction</a> interface as defined
below.
</p>
<dl title="interface TimingFunction" class="idl">
<dt>double scaleTime()</dt>
<dd>
<p>
Takes an input time fraction in the range [0, 1] and applies some
transformation on the value to produce an output time fraction.
</p>
<dl class="parameters">
<dt>double time</dt> <!-- Oh yeah! -->
<dd>
The input time fraction.
</dd>
<dt>TimedItem? item</dt>
<dd>
<p>
The <a>TimedItem</a> for which the time scaling operation is
being performed.
</p>
<p>