16020 2007-11-16 14:25:23 -0800 A transition of width: auto to a fixed width computes auto as zero. 2017-06-15 00:23:08 -0700 1 1 1 Unclassified WebKit CSS 528+ (Nightly build) All All RESOLVED WONTFIX InRadar P2 Normal --- 46590 1 timothy webkit-unassigned arv bdakin bosselmann cedricv chriscoyier dglazkov dino farukates felixcca humaknlght hyatt jarred jcraig joe jonathon jscinoz kimmo.t.kinnunen lamargoddard mathias mihaip mjs mkozakewich rboucher rik samtsai simon.fraser s+webkit webkit webmaster oldest_to_newest 61420 0 timothy 2007-11-16 14:25:23 -0800 A transition of width: auto to a fixed width computes auto as zero. See attached test case. 61421 1 17321 timothy 2007-11-16 14:25:46 -0800 Created attachment 17321 Testcase 64232 2 hyatt 2007-12-14 18:31:11 -0800 This is tricky, since animation happens on RenderStyles, so a layout would actually be required in order to determine what the auto width value at the destination is going to be. 71282 3 jcraig 2008-02-20 13:15:10 -0800 Adding Radar I filed a while back. <rdar://problem/5639997> transition fails when animating between different size units (e.g. px and %) 71285 4 19236 jcraig 2008-02-20 13:19:01 -0800 Created attachment 19236 Test case from related Radar, includes both % and auto widths. Adding test case from related Radar, includes both % and auto widths. 78913 5 mitz 2008-04-25 08:40:06 -0700 *** Bug 18726 has been marked as a duplicate of this bug. *** 105097 6 simon.fraser 2009-01-09 17:44:21 -0800 <rdar://problem/5639997> 111467 7 simon.fraser 2009-02-27 10:29:14 -0800 Comment from Dave Hyatt on the w3-style list: This is right. In WebKit, we transition on the computed value of a property (not the specified value or used value). Note that there have been requests to transition on the used value instead, the most obvious example being wanting to transition from, e.g., width:100% to width:50px. If you transition on the computed value, then it's impossible to run an animation from width:auto to width:50px or from width:50% to width:80px, etc. The problem with transitioning on the used value, though, is it can change when your style hasn't.... if you resize a window that contains a width:auto or width:100% block for example. Obviously you don't want to run a transition in that case. My own preference would be (for simplicity) to just stick with transitioning on the computed value and to just say "Tough" to people who want to animate width this way, but maybe others disagree. We continue to get bugs in WebKit from confused people trying to animate auto widths to fixed values (or percents to fixed values) and not understanding why it doesn't work. 167110 8 mkozakewich 2009-11-29 15:03:26 -0800 *** Bug 31957 has been marked as a duplicate of this bug. *** 178379 9 mjs 2010-01-07 14:13:47 -0800 How about we animate on the used value but only when the computed value changes? 178395 10 farukates 2010-01-07 14:53:11 -0800 Isn't the computed value internally kept as a pixel value no matter what the unit is? Wouldn't that mean that a change from width:80px to width:auto could do a non-transitioned lookup to see what pixel value "auto" currently computes to, and transition to that? I'm probably not understanding it, but it seems weird that every Javascript library in the world that does this has it figured out, but a hardware accelerated implementation can't? 182824 11 s+webkit 2010-01-20 08:58:29 -0800 > My own preference would be (for simplicity) to just stick with transitioning on the computed value and to just say "Tough" to people who want to animate width this way, but maybe others disagree. Many use cases for CSS transitions and animations include starting and ending at a computed value — showing and hiding content is a huge one. Also, treating computed values as zero is never going to be the right behavior. If this isn't going to be fixed, then trying to animate a computed property should kill the animation entirely. 182838 12 farukates 2010-01-20 09:45:47 -0800 I think not fixing this bug would be a grave mistake; this is the #1 use case for animation libraries used on the Web today, and thus, the #1 use case for the CSS Transitions implementation. And it is broken in CSS Transitions. 285739 13 simon.fraser 2010-09-27 14:17:09 -0700 Dave Hyatt and I talked about how we might fix this. We'd have to do a layout at the start of the animation to compute the end state, but this might not work in some cases. 315797 14 simon.fraser 2010-12-01 12:08:20 -0800 *** Bug 35816 has been marked as a duplicate of this bug. *** 332882 15 simon.fraser 2011-01-11 20:13:01 -0800 *** Bug 52245 has been marked as a duplicate of this bug. *** 357165 16 simon.fraser 2011-02-24 10:59:12 -0800 *** Bug 55137 has been marked as a duplicate of this bug. *** 393672 17 samtsai 2011-04-27 11:15:48 -0700 Has there been any progress on this bug? Or are there alternate solutions that we could work towards? 441791 18 simon.fraser 2011-07-25 12:16:03 -0700 *** Bug 65067 has been marked as a duplicate of this bug. *** 921806 19 me 2013-08-27 20:12:20 -0700 *** Bug 113871 has been marked as a duplicate of this bug. *** 1189590 20 simon.fraser 2016-05-02 18:00:48 -0700 The CSS WG has resolved that transitions don't run to/from auto values. 1287750 21 joe 2017-03-14 12:59:03 -0700 This resolution is very frustrating. 1287751 22 joe 2017-03-14 12:59:57 -0700 The web keeps disappointing. Are you browser devs really okay with that? 1287770 23 simon.fraser 2017-03-14 13:35:42 -0700 (In reply to comment #22) > The web keeps disappointing. Are you browser devs really okay with that? Please bring this up on www-style if you think it's important. 17321 2007-11-16 14:25:46 -0800 2007-11-16 14:25:46 -0800 Testcase test-width.html text/html 271 timothy PHN0eWxlPgouYmFzZSB7Cglib3JkZXI6IDFweCBzb2xpZCByZWQ7Cgktd2Via2l0LXRyYW5zaXRp b246IHdpZHRoIDFzIGVhc2UtaW4tb3V0Owp9Cgoub25lIHsKCXdpZHRoOiBhdXRvOwp9CgoudHdv IHsKCXdpZHRoOiAyMDBweDsKfQo8L3N0eWxlPgo8ZGl2IGNsYXNzPSJiYXNlIG9uZSIgb25jbGlj az0idGhpcy5jbGFzc05hbWUgPSAnYmFzZSB0d28nIj5DbGljayBtZS4gVGhpcyBib3ggc2hvdWxk IHNocmluayB0byAyMDBweCwgbm90IGdyb3cgZnJvbSAwcHguPC9kaXY+Cg== 19236 2008-02-20 13:19:01 -0800 2008-02-20 13:19:01 -0800 Test case from related Radar, includes both % and auto widths. 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