csswg-drafts/css-transitions/use-cases.html at ce285b248ba2948eb78e137770de864c0b0c64c7 · w3c/csswg-drafts · GitHub

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
<html>
<title>Use cases for transitions/animations/effects</title>
<style>
body { margin: 1em }
table { border-collapse: collapse }
td, th { padding: 0.3em; border: thin solid black; vertical-align: top; text-align: left; min-width: 12em; }
.issue { color: red }
</style>


<h1>Use cases for transitions/animations/effects</h1>

<table>
<tr><th>Use case</th><th>Current drafts (<a href="http://dev.w3.org/csswg/css3-transitions/">transitions</a>, <a href="http://dev.w3.org/csswg/css3-animations/">animations</a>)<th>the <a href="#effect">'effect'</a> proposal</th><th>Tab's <a href="http://lists.w3.org/Archives/Public/www-style/2010Apr/0259.html">proposal</a><th>Brad's <a href="">proposal</a></th><th>Andrew's proposal <a href="http://lists.w3.org/Archives/Public/www-style/2010Apr/0264.html">[1]</a>, <a href="http://lists.w3.org/Archives/Public/www-style/2010Apr/0332.html">[2]</a></th><th>Use case</th>

<tr><td>1a: Change the color of an element from red to green when
the element is hovered. The change should occur over a period of 1
second. When the element is un-hovered, the reverse change should
occur.

<td>
<pre>
foo {
  color: red;
  transition: color 1s;
}
foo:hover {
  color: green;
}
</pre>

<td>
<pre>
foo {
  color: red;
  effect: change(color) 1s;
}
foo:hover {
  color: green;
}
</pre>


<td>
<pre>
foo {
  color: red;
  transition: color 1s;
}
foo:hover {
  color: green;
}
<pre>

<td>
<pre>
foo {
  color: red;
  transition: color 1s;
}
foo:hover {
  color: green;
}
</pre>

<td>
<pre>
foo {
  color red;
  animate: color 1s;
}
foo:hover {
  color: green;
}
</pre>

<td>1a: Change the color of an element from red to green when
the element is hovered. The change should occur over a period of 1
second. When the element is un-hovered, the reverse change should
occur.

<tr><td>1b: Same as 1a, but the reverse change should take 0.8 second.

<td>
<pre>
foo {
  color: red;
  transition: color 1s;
}
foo:hover {
  color: green;
  transition: color 0.8s;
}
</pre>

<td>
<pre>
foo {
  color: red;
  effect: change(color) 1s;
}
foo:hover {
  color: green;
  effect: change(color) 0.8s;
}
</pre>

<td>
<pre>
foo {
  color: red;
  transition: color 1s;
}
foo:hover {
  color: green;
  transition: color .8s;
}
</pre>

<td>
<pre>
foo {
  color: red;
  transition: color 1s;
}
foo:hover {
  color: green;
  transition: color 0.8s;
}
</pre>

<td>
<pre>
foo {
  color: red;
  animate: color 1s;
}
foo:hover {
  color: green;
  animate: color 0.8s;
}
</pre>


<td>1b: Same as 1a, but the reverse change should take 0.8 second.

<tr><td>2a: Play the 'bounce animation once for 1s when the element is hovered.

<td>
<pre>
foo:hover {
  animation: bounce 1s;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  effect: play(bounce) 1s;
}
@animation bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  play-in: bounce 1s;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  animation: bounce 1s;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  animate-in: "bounce" top 1s once;
}
@profile "bounce"
  0% 0px,
  33% -20px,
  66% 20px,
  100% 0px;
</pre>


<td>2a: Play the 'bounce animation once for 1s when the element is hovered.


<tr><td>2b: Same as 2a, but also play the animation when the element is un-hovered.

<td>not possible in CSS

<td>
<pre>
foo:hover {
  effect: play(bounce) 1s,
    on-exit play(bounce) 1s;
}

@animation bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  play-in: bounce 1s;
  play-out: bounce 1s;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>


<td>
<pre>
foo {
  position:static;
  transition: position 1s / bounce 1s;
}
foo:hover { position:relative; }

@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  animate: "bounce" top 1s once;
}
@profile "bounce"
  0% 0px,
  33% -20px,
  66% 20px,
  100% 0px;
</pre>

<td>2b: Same as 2a, but also play the animation when the element is un-hovered.

<tr><td>2c: Same as 2b, but play the animation in reverse when un-hovered.

<td>not possible

<td>
<pre>
foo:hover {
  effect: play(bounce) 1s,
    on-exit play(bounce) 1s reverse;
}
@animation bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  play-in: bounce 1s;
  play-out: bounce reversed 1s;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<p>(or whatever, I don't care how keyframes are reversed, as long as
they <em>can</em> be reversed)

<td>
<pre>
foo {
  position:static;
  transition: position 1s / bounce 1s alternate;
}
foo:hover {
  position:relative;
  transition-animation: bounce 1s;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
foo:hover {
  animate-in:  "bounce" top 1s once;
  animate-out: "reversed-bounce" top 1s once;
}
@profile "reversed-bounce"
  0% 0px,
  33% 20px,
  66% -20px,
  100% 0px;

@profile "bounce"
  0% 0px,
  33% -20px,
  66% 20px,
  100% 0px;
</pre>

<td>2c: Same as 2b, but play the animation in reverse when un-hovered.


<tr><td>3a: When an element's class changes from "one" to "two", move the element 500px rightwards and simultaneously play the 'bounce' animation 5 times for a total of 1s.

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  transition: left 1s;
}
.two {
  position: relative;
  left: 500px;
  animation: bounce 0.2s 5;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  effect: change(left) 1s;
}
.two {
  position: relative;
  left: 500px;
  effect: play(bounce) 0.2s 5;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  transition: left 1s;
}
.two {
  position: relative;
  left: 500px;
  play-in: bounce .2s 5;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  transition: left 1s;
}
.two {
  position: relative;
  left: 500px;
  animation: bounce 0.2s 5;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
}
.two {
  position: relative;
  left: 500px;
  animate-in: "bounce" top 0.2s 5,
              linear left 1s once;
}
@profile "bounce"
  0% 0px,
  33% -20px,
  66% 20px,
  100% 0px;

</pre>

<td>3a: When an element's class changes from "one" to "two", move the element 500px rightwards and simultaneously play the 'bounce' animation 5 times for a total of 1s.


<tr><td>3b: Same as 3a, but also play the 'bounce' animation when the class of the element is changed back from "two" to "one", while the element is moved back to its original position.

<td>
not possible in CSS
<td>
<pre>
.one {
  position: relative;
  left: 0px;
  effect: change(left) 1s;
}

.two {
  position: relative;
  left: 500px;
  effect: play(bounce) 10 0.1s,
    on-exit play(bounce);
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  transition: left 1s play(bounce .2s 5);
}

.two {
  position: relative;
  left: 500px;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  transition: left 1s / bounce .2s 5;
}
.two {
  position: relative;
  left: 500px;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
}
.two {
  position: relative;
  left: 500px;
  animate: "bounce" top 0.2s 5,
             linear left 1s once;
}
@profile "bounce"
  0% 0px,
  33% -20px,
  66% 20px,
  100% 0px;
</pre>

<td>3b: Same as 3a, but also play the 'bounce' animation when the class of the element is changed back from "two" to "one", while the element is moved back to its original position.

<tr><td>3c: Same as 3b, but play the 'sway' animation (which takes 2s to run) continously between the two 'bounce' animations.

<td>not possible in CSS
<td>
<pre>
.one {
  position: relative;
  left: 0px;
  change(left) 1s;
}

.two {
  position: relative;
  left: 500px;
  effect: play(bounce) 10 0.1s,
    play(sway) 2s 1s during,
    on-exit play(bounce);
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
@keyframes sway {
  from { left: 0; }
  33%  { left: -20px; }
  66%  { left: 20px; }
  to   { left: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  transition: left 1s play(bounce .2s 5);
}

.two {
  position: relative;
  left: 500px;
  play-during: sway 1s 1s;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<p>(Delay added to make it wait until the transition is done.)

<td>
<pre>
.one {
  position: relative;
  left: 0px;
  transition: left 1s / bounce .2s 5;
}
.two {
  position: relative;
  left: 500px;
  transition: left 1s / bounce .2s 5;
  animation: bounce 0.2s 5, sway 1s 1s infinite;
}
@keyframes bounce {
  from { top: 0; }
  33%  { top: -20px; }
  66%  { top: 20px; }
  to   { top: 0; }
}
</pre>

<td>
<pre>
.one {
  position: relative;
  left: 0px;
}
.two {
  position: relative;
  left: 500px;
  animate: "bounce" top 0.2s 5,
           linear left 1s once,
           "bounce" left 1s 1s infinite;
}
@profile "bounce"
  0% 0px,
  33% -20px,
  66% 20px,
  100% 0px;
</pre>


<td>3c: Same as 3b, but play the 'sway' animation (which takes 2s to run) continously between the two 'bounce' animations.
</table>

<h2 id=effect>The 'effect' property</h2>

<p>The 'effect' property accepts a comma-separated list of effects as
value. Each effect must contain on change() or play() function in
addition to optional other values. An effect is referred to as a
'change effect' or a 'play effect'.

<p>The change() function takes a property name as value. A change effect
indicates that the specified property should be monitored; whenever it
changes, the change effect will be shown. The length of the change,
the delay of the change, and the timing function of the change can be
specified. For example, this declaration specifies that the change
should take 1s, there should be a 0.2s delay for both changes, and the
'ease-in' timing function should be applied:

<pre>
   effect: change(left) 1s 0.2s ease-in;
</pre>

<p>The play() function takes the name of an animation as value.
Animations are specified in separate @animation constructs. Unlike
change effects, play effects are not triggered by value changes other
properties, but rather by value changes on the 'effect' property
itself. When an element is assigned a new value on 'effect' property,
the value is examined and any effects set to start immediately are
started, while effects with delays are scheduled to be started later.
Further, any effect marked to start 'on-exit' on the previous value is
started. For example, this rule specifies that the 'bounce' animation
should be played twice: when the 'effect' value is first set, and when
the 'effect' value is reset the animation is played in reverse:

<pre>
  a:hover {
    effect: play(bounce) 1s,
      on-exit play(bounce) 1s reverse;
  }
</pre>

<p>The 'on-exit' can be considered to be a delay equal to 0.

<p>The 'reverse' keyword is offered as an alternative to the proposed
'alternate' keyword.

<p>The 'during' keyword is offered as an alternative to the proposed
'infinite' keyword.

<p>Otherwise, the values are the same as in
the <a href="http://dev.w3.org/csswg/css3-transitions/">transitions</a>, <a href="http://dev.w3.org/csswg/css3-animations/">animations</a>
proposal.


</table>