script: Move CSS DOM interfaces to script/dom/css/ (#40241)

Moves interfaces defined by the CSS spec to the `script/dom/css/` module
from `script/dom/`.

Testing: Just a refactor shouldn't need any testing
Fixes: Partially #38901

Signed-off-by: WaterWhisperer <waterwhisperer24@qq.com>

components/script/dom/css/css.rs

@@ -0,0 +1,117 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use cssparser::{Parser, ParserInput, serialize_identifier};
+use dom_struct::dom_struct;
+use layout_api::{PropertyRegistration, RegisterPropertyError};
+use script_bindings::codegen::GenericBindings::CSSBinding::PropertyDefinition;
+use style::context::QuirksMode;
+use style::parser::ParserContext;
+use style::stylesheets::supports_rule::{Declaration, parse_condition_or_declaration};
+use style::stylesheets::{CssRuleType, Origin, UrlExtraData};
+use style_traits::ParsingMode;
+
+use crate::dom::bindings::codegen::Bindings::CSSBinding::CSSMethods;
+use crate::dom::bindings::codegen::Bindings::WindowBinding::Window_Binding::WindowMethods;
+use crate::dom::bindings::error::{Error, Fallible};
+use crate::dom::bindings::reflector::Reflector;
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::str::DOMString;
+use crate::dom::window::Window;
+use crate::dom::worklet::Worklet;
+
+#[dom_struct]
+#[allow(clippy::upper_case_acronyms)]
+pub(crate) struct CSS {
+    reflector_: Reflector,
+}
+
+impl CSSMethods<crate::DomTypeHolder> for CSS {
+    /// <https://drafts.csswg.org/cssom/#the-css.escape()-method>
+    fn Escape(_: &Window, ident: DOMString) -> Fallible<DOMString> {
+        let mut escaped = String::new();
+        serialize_identifier(&ident.str(), &mut escaped).unwrap();
+        Ok(DOMString::from(escaped))
+    }
+
+    /// <https://drafts.csswg.org/css-conditional/#dom-css-supports>
+    fn Supports(win: &Window, property: DOMString, value: DOMString) -> bool {
+        let mut decl = String::new();
+        serialize_identifier(&property.str(), &mut decl).unwrap();
+        decl.push_str(": ");
+        decl.push_str(&value.str());
+        let decl = Declaration(decl);
+        let url_data = UrlExtraData(win.Document().url().get_arc());
+        let context = ParserContext::new(
+            Origin::Author,
+            &url_data,
+            Some(CssRuleType::Style),
+            ParsingMode::DEFAULT,
+            QuirksMode::NoQuirks,
+            /* namespaces = */ Default::default(),
+            None,
+            None,
+        );
+        decl.eval(&context)
+    }
+
+    /// <https://drafts.csswg.org/css-conditional/#dom-css-supports>
+    fn Supports_(win: &Window, condition: DOMString) -> bool {
+        let condition = condition.str();
+        let mut input = ParserInput::new(&condition);
+        let mut input = Parser::new(&mut input);
+        let cond = match parse_condition_or_declaration(&mut input) {
+            Ok(c) => c,
+            Err(..) => return false,
+        };
+
+        let url_data = UrlExtraData(win.Document().url().get_arc());
+        let context = ParserContext::new(
+            Origin::Author,
+            &url_data,
+            Some(CssRuleType::Style),
+            ParsingMode::DEFAULT,
+            QuirksMode::NoQuirks,
+            /* namespaces = */ Default::default(),
+            None,
+            None,
+        );
+        cond.eval(&context)
+    }
+
+    /// <https://drafts.css-houdini.org/css-paint-api-1/#paint-worklet>
+    fn PaintWorklet(win: &Window) -> DomRoot<Worklet> {
+        win.paint_worklet()
+    }
+
+    /// <https://drafts.css-houdini.org/css-properties-values-api/#the-registerproperty-function>
+    fn RegisterProperty(window: &Window, property_definition: &PropertyDefinition) -> Fallible<()> {
+        let property_registration = PropertyRegistration {
+            name: property_definition.name.str().to_owned(),
+            inherits: property_definition.inherits,
+            url_data: UrlExtraData(window.get_url().get_arc()),
+            initial_value: property_definition
+                .initialValue
+                .as_ref()
+                .map(|value| value.str().to_owned()),
+            syntax: property_definition.syntax.str().to_owned(),
+        };
+
+        window
+            .layout_mut()
+            .register_custom_property(property_registration)
+            .map_err(|error| match error {
+                RegisterPropertyError::InvalidName |
+                RegisterPropertyError::InvalidSyntax |
+                RegisterPropertyError::InvalidInitialValue |
+                RegisterPropertyError::NoInitialValue |
+                RegisterPropertyError::InitialValueNotComputationallyIndependent => {
+                    Error::Syntax(None)
+                },
+                RegisterPropertyError::AlreadyRegistered => Error::InvalidModification,
+            })?;
+
+        Ok(())
+    }
+}