Bug 1897605. Implement parsing of CSS 'anchor-scope'. r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D210874

devtools/server/actors/animation-type-longhand.js

@@ -10,6 +10,7 @@ exports.ANIMATION_TYPE_FOR_LONGHANDS = [
     "discrete",
     new Set([
       "anchor-name",
+      "anchor-scope",
       "align-content",
       "align-items",
       "align-self",

dom/base/use_counter_metrics.yaml

@@ -107,7 +107,7 @@ use.counter:
     send_in_pings:
       - use-counters
 
-# Total of 2303 use counter metrics (excludes denominators).
+# Total of 2305 use counter metrics (excludes denominators).
 # Total of 354 'page' use counters.
 use.counter.page:
   svgsvgelement_getelementbyid:
@@ -15541,7 +15541,7 @@ use.counter.deprecated_ops.doc:
     send_in_pings:
       - use-counters
 
-# Total of 698 'CSS (page)' use counters.
+# Total of 699 'CSS (page)' use counters.
 use.counter.css.page:
   css_align_content:
     type: counter
@@ -18603,6 +18603,23 @@ use.counter.css.page:
     send_in_pings:
       - use-counters
 
+  css_anchor_scope:
+    type: counter
+    description: >
+      Whether a page used the CSS property anchor-scope.
+      Compare against `use.counter.top_level_content_documents_destroyed`
+      to calculate the rate.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1852098
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1852098
+    notification_emails:
+      - dom-core@mozilla.com
+      - emilio@mozilla.com
+    expires: never
+    send_in_pings:
+      - use-counters
+
   css_animation_composition:
     type: counter
     description: >
@@ -27409,7 +27426,7 @@ use.counter.css.page:
     send_in_pings:
       - use-counters
 
-# Total of 698 'CSS (document)' use counters.
+# Total of 699 'CSS (document)' use counters.
 use.counter.css.doc:
   css_align_content:
     type: counter
@@ -30471,6 +30488,23 @@ use.counter.css.doc:
     send_in_pings:
       - use-counters
 
+  css_anchor_scope:
+    type: counter
+    description: >
+      Whether a document used the CSS property anchor-scope.
+      Compare against `use.counter.content_documents_destroyed`
+      to calculate the rate.
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1852098
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1852098
+    notification_emails:
+      - dom-core@mozilla.com
+      - emilio@mozilla.com
+    expires: never
+    send_in_pings:
+      - use-counters
+
   css_animation_composition:
     type: counter
     description: >

layout/style/ServoBindings.toml

@@ -621,6 +621,7 @@ cbindgen-types = [
     { gecko = "StyleBaselineSource", servo = "crate::values::computed::BaselineSource" },
     { gecko = "StyleAu", servo = "app_units::Au" },
     { gecko = "StyleAnchorName", servo = "crate::values::computed::position::AnchorName" },
+    { gecko = "StyleAnchorScope", servo = "crate::values::computed::position::AnchorScope" },
 ]
 
 mapped-generic-types = [

layout/style/nsStyleStruct.cpp

@@ -2093,7 +2093,8 @@ nsStyleDisplay::nsStyleDisplay()
       mBaselineSource(StyleBaselineSource::Auto),
       mWebkitLineClamp(0),
       mShapeMargin(LengthPercentage::Zero()),
-      mShapeOutside(StyleShapeOutside::None()) {
+      mShapeOutside(StyleShapeOutside::None()),
+      mAnchorScope(StyleAnchorScope::None()) {
   MOZ_COUNT_CTOR(nsStyleDisplay);
 }
 
@@ -2152,7 +2153,8 @@ nsStyleDisplay::nsStyleDisplay(const nsStyleDisplay& aSource)
       mShapeImageThreshold(aSource.mShapeImageThreshold),
       mShapeMargin(aSource.mShapeMargin),
       mShapeOutside(aSource.mShapeOutside),
-      mAnchorName(aSource.mAnchorName) {
+      mAnchorName(aSource.mAnchorName),
+      mAnchorScope(aSource.mAnchorScope) {
   MOZ_COUNT_CTOR(nsStyleDisplay);
 }
 
@@ -2524,7 +2526,8 @@ nsChangeHint nsStyleDisplay::CalcDifference(
                 mContainerType != aNewData.mContainerType ||
                 mContain != aNewData.mContain ||
                 mContainerName != aNewData.mContainerName ||
-                mAnchorName != aNewData.mAnchorName)) {
+                mAnchorName != aNewData.mAnchorName ||
+                mAnchorScope != aNewData.mAnchorScope)) {
     hint |= nsChangeHint_NeutralChange;
   }
 

layout/style/nsStyleStruct.h

@@ -1320,6 +1320,10 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleDisplay {
   // anchor positioned elements may reference.
   mozilla::StyleAnchorName mAnchorName;
 
+  // 'none', 'all', or a list of one or more `<dashed-ident>` identifiers that
+  // may identify anchor positioning anchor elements.
+  mozilla::StyleAnchorScope mAnchorScope;
+
   mozilla::Maybe<mozilla::WindowButtonType> GetWindowButtonType() const {
     if (MOZ_LIKELY(mDefaultAppearance == mozilla::StyleAppearance::None)) {
       return mozilla::Nothing();

layout/style/test/property_database.js

@@ -13312,6 +13312,31 @@ if (IsCSSPropertyPrefEnabled("layout.css.anchor-positioning.enabled")) {
       "--foo,",
     ],
   };
+
+  gCSSProperties["anchor-scope"] = {
+    domProp: "anchorScope",
+    inherited: false,
+    type: CSS_TYPE_LONGHAND,
+    initial_values: ["none"],
+    other_values: [
+      "all",
+      "--foo",
+      "--foo, --baz",
+      "--foo,--baz",
+      "--foo ,--baz",
+    ],
+    invalid_values: [
+      "all, --foo",
+      "--foo, all",
+      "--foo --bar",
+      "foo",
+      "none bar",
+      "none --baz",
+      "--foo bar",
+      ",--foo",
+      "--foo,",
+    ],
+  };
 }
 
 if (false) {

servo/components/style/properties/longhands/box.mako.rs

@@ -74,6 +74,19 @@ ${helpers.predefined_type(
     affects="",
 )}
 
+// Changes do not invalidate our element. We handle notify/invalidating
+// any affected descendants elsewhere.
+${helpers.predefined_type(
+    "anchor-scope",
+    "AnchorScope",
+    "computed::AnchorScope::none()",
+    engines="gecko",
+    animation_value_type="discrete",
+    gecko_pref="layout.css.anchor-positioning.enabled",
+    spec="https://drafts.csswg.org/css-anchor-position-1/#propdef-scope",
+    affects="",
+)}
+
 ${helpers.predefined_type(
     "float",
     "Float",

servo/components/style/values/computed/mod.rs

@@ -89,6 +89,7 @@ pub use self::outline::OutlineStyle;
 pub use self::page::{PageName, PageOrientation, PageSize, PageSizeOrientation, PaperSize};
 pub use self::percentage::{NonNegativePercentage, Percentage};
 pub use self::position::AnchorName;
+pub use self::position::AnchorScope;
 pub use self::position::AspectRatio;
 pub use self::position::{
     GridAutoFlow, GridTemplateAreas, MasonryAutoFlow, Position, PositionOrAuto, ZIndex,

servo/components/style/values/computed/position.rs

@@ -13,7 +13,7 @@ use crate::values::generics::position::Position as GenericPosition;
 use crate::values::generics::position::PositionComponent as GenericPositionComponent;
 use crate::values::generics::position::PositionOrAuto as GenericPositionOrAuto;
 use crate::values::generics::position::ZIndex as GenericZIndex;
-pub use crate::values::specified::position::{AnchorName, GridAutoFlow, GridTemplateAreas, MasonryAutoFlow};
+pub use crate::values::specified::position::{AnchorName, AnchorScope, GridAutoFlow, GridTemplateAreas, MasonryAutoFlow};
 use crate::Zero;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, ToCss};

servo/components/style/values/specified/mod.rs

@@ -82,6 +82,7 @@ pub use self::page::{PageName, PageOrientation, PageSize, PageSizeOrientation, P
 pub use self::percentage::{NonNegativePercentage, Percentage};
 pub use self::position::AspectRatio;
 pub use self::position::AnchorName;
+pub use self::position::AnchorScope;
 pub use self::position::{GridAutoFlow, GridTemplateAreas, Position, PositionOrAuto};
 pub use self::position::{MasonryAutoFlow, MasonryItemOrder, MasonryPlacement};
 pub use self::position::{PositionComponent, ZIndex};

servo/components/style/values/specified/position.rs

@@ -28,6 +28,7 @@ use std::collections::hash_map::Entry;
 use std::fmt::{self, Write};
 use style_traits::values::specified::AllowedNumericType;
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
+use style_traits::{KeywordsCollectFn, SpecifiedValueInfo};
 use style_traits::arc_slice::ArcSlice;
 
 /// The specified value of a CSS `<position>`
@@ -407,6 +408,94 @@ impl ToCss for AnchorName {
     }
 }
 
+/// https://drafts.csswg.org/css-anchor-position-1/#propdef-scope
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(u8)]
+pub enum AnchorScope {
+    /// `none`
+    None,
+    /// `all`
+    All,
+    /// `<dashed-ident>#`
+    Idents(#[ignore_malloc_size_of = "Arc"] crate::ArcSlice<DashedIdent>),
+}
+
+impl AnchorScope {
+    /// Return the `none` value.
+    pub fn none() -> Self {
+        Self::None
+    }
+
+    /// Returns whether this is the `none` value.
+    pub fn is_none(&self) -> bool {
+        *self == Self::None
+    }
+}
+
+impl Parse for AnchorScope {
+    fn parse<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        let location = input.current_source_location();
+        let first = input.expect_ident()?;
+        if first.eq_ignore_ascii_case("none") {
+            return Ok(Self::None);
+        }
+        if first.eq_ignore_ascii_case("all") {
+            return Ok(Self::All);
+        }
+        // Authors using more than a handful of anchored elements is likely
+        // uncommon, so we only pre-allocate for 8 on the stack here.
+        let mut idents: SmallVec<[DashedIdent; 8]> = smallvec![DashedIdent::from_ident(
+            location,
+            first,
+        )?];
+        while input.try_parse(|input| input.expect_comma()).is_ok() {
+            idents.push(DashedIdent::parse(context, input)?);
+        }
+        Ok(AnchorScope::Idents(ArcSlice::from_iter(idents.drain(..))))
+    }
+}
+
+impl ToCss for AnchorScope {
+    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: fmt::Write,
+    {
+       match *self {
+            Self::None => dest.write_str("none")?,
+            Self::All => dest.write_str("all")?,
+            Self::Idents(ref idents) => {
+                if let Some((ref first, rest)) = idents.split_first() {
+                    first.to_css(dest)?;
+                    for name in rest {
+                        dest.write_str(", ")?;
+                        name.to_css(dest)?;
+                    }
+                }
+            },
+        }
+        Ok(())
+    }
+}
+
+impl SpecifiedValueInfo for AnchorScope {
+    fn collect_completion_keywords(f: KeywordsCollectFn) {
+        // It would be nice if we could also list all the author defined dashed
+        // idents in the doc, but that's not practical.
+        f(&["none", "all"])
+    }
+}
+
 /// Represents a side, either horizontal or vertical, of a CSS position.
 pub trait Side {
     /// Returns the start side.

servo/ports/geckolib/cbindgen.toml

@@ -83,6 +83,7 @@ exclude = [
 ]
 include = [
   "AnchorName",
+  "AnchorScope",
   "AnimationTimeline",
   "AnimationIterationCount",
   "AnimationDirection",