On Fri, Nov 6, 2015 at 12:53 PM, Martin Robinson <mrobin...@igalia.com> wrote:
> By way of example: > > <div style="font-size: 100px; line-height: 50px;"> > <div style="background: pink; width: 50px; height: 50px; transform: > translateY(100px) translateX(50px);"></div> > <span style="background: blue; opacity: 0.99;">Line 1</span><br/> > <span style="background: green;">Line 2</span> > <div style="background: red; width: 50px; height: 50px; transform: > translateY(-40px) translateX(-10px);"></div> > </div> > > The two spans are inline, so normally "Line 1" would stack underneath > "Line 2" due to tree order. Since "Line 1" establishes a stacking > context (via the opacity style property), it stacks in tree order with > the divs (which also establish stacking contexts via their transform > style properties). The way I implement this is to always insert inline > stacking contexts into the positioned content section of the display list. > That's right. > The issue I'm having now is that I cannot figure out where or how this > behavior is described in the spec [1][2]. Both the divs and the first > span seem to be treated as "positioned descendants" as described in > Section E.2.8. > > I still plan to implement the same behavior as Gecko and Chrome, but I > would be very grateful is someone could help shed light on how this > relates to the spec. Thanks! > Yeah, it's not in Appendix E, though it probably should be. For 'opacity' this is described in the CSS3 Color spec: http://www.w3.org/TR/css3-color/#transparency > If an element with opacity less than 1 is not positioned, implementations > must paint the layer it creates, within its parent stacking context, at the > same stacking order that would be used if it were a positioned element with > ‘z-index: 0’ and ‘opacity: 1’. > All properties that induce a stacking context behave this way. Rob -- lbir ye,ea yer.tnietoehr rdn rdsme,anea lurpr edna e hnysnenh hhe uresyf toD selthor stor edna siewaoeodm or v sstvr esBa kbvted,t rdsme,aoreseoouoto o l euetiuruewFa kbn e hnystoivateweh uresyf tulsa rehr rdm or rnea lurpr .a war hsrer holsa rodvted,t nenh hneireseoouot.tniesiewaoeivatewt sstvr esn _______________________________________________ dev-servo mailing list dev-servo@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-servo
