On Mon, Aug 21, 2023 at 4:23 PM kalyani Shinde <kalyani.mutualf...@gmail.com> wrote:
> Hi Team, > > I have recently started working with chromium/blink, so quite new to this > code. > I wanted to understand where and how css pseudo elements(e.g > webkit-scrollbar) are handled while applying style to any element. These > elements are not treated as PseudoElement when we do "GetPseudoElement" on > StyleResolveState which finally applies to any element. > Simple question here is to know how to identify this particular style > change(state <StyleResolverState>) is defined for Css PseudoElement. > > Thanks in advance. > In short, Blink first detects the presence of pseudo element style when matching rules for the originating element. If all but the pseudo element part of the selector matches, we mark the element as having pseudo element style: https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/css/element_rule_collector.cc;l=1057;drc=d708cc843536cc344f0f7679a978634cc14d6153;bpv=1;bpt=1 For tree-abiding pseudo elements that generate a PseudoElement, such elements are then generated from Element::UpdatePseudoElement(), ultimately checking the flag that was set when computing the originating element's style: https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/style/computed_style.h;l=2474;drc=d708cc843536cc344f0f7679a978634cc14d6153 For scrollbars, CustomScrollbar is created based on the HasPseudoElementStyle() here: https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/paint/paint_layer_scrollable_area.cc;l=2780?q=MakeGarbageCollected%3CCustomScrollbar%3E&ss=chromium%2Fchromium%2Fsrc And the styling for the various scrollbar parts is computed here: https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/renderer/core/layout/custom_scrollbar.cc;l=134-162;drc=d708cc843536cc344f0f7679a978634cc14d6153;bpv=1;bpt=1?q=CustomScrollbar::&ss=chromium%2Fchromium%2Fsrc Hope that helps. -- Rune Lillesveen -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACuPfeQiu3X%2BVgZbDZF-6iRDrrzt6KAE1iMpwyFOk%2Bhtm%3DooUQ%40mail.gmail.com.
