style: implement -moz-inert CSS property.

-moz-inert CSS property reflects inert subtrees concept and can be used to implement HTML:dialog element and HTML:inert attribute

Differential Revision: https://phabricator.services.mozilla.com/D81701

components/style/element_state.rs

@@ -145,6 +145,9 @@ bitflags! {
         ///
         /// https://html.spec.whatwg.org/multipage/#centered-alignment
         const IN_MODAL_DIALOG_STATE = 1 << 53;
+
+        /// https://html.spec.whatwg.org/multipage/interaction.html#inert-subtrees
+        const IN_MOZINERT_STATE = 1 << 54;
     }
 }
 

components/style/gecko/non_ts_pseudo_class_list.rs

@@ -48,6 +48,7 @@ macro_rules! apply_non_ts_list {
                 ("-moz-drag-over", MozDragOver, IN_DRAGOVER_STATE, _),
                 ("target", Target, IN_TARGET_STATE, _),
                 ("indeterminate", Indeterminate, IN_INDETERMINATE_STATE, _),
+                ("-moz-inert", MozInert, IN_MOZINERT_STATE, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS),
                 ("-moz-devtools-highlighted", MozDevtoolsHighlighted, IN_DEVTOOLS_HIGHLIGHTED_STATE, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS),
                 ("-moz-styleeditor-transitioning", MozStyleeditorTransitioning, IN_STYLEEDITOR_TRANSITIONING_STATE, PSEUDO_CLASS_ENABLED_IN_UA_SHEETS),
                 ("fullscreen", Fullscreen, IN_FULLSCREEN_STATE, _),

components/style/gecko/wrapper.rs

@@ -2022,6 +2022,7 @@ impl<'le> ::selectors::Element for GeckoElement<'le> {
             NonTSPseudoClass::Checked |
             NonTSPseudoClass::Fullscreen |
             NonTSPseudoClass::Indeterminate |
+            NonTSPseudoClass::MozInert |
             NonTSPseudoClass::PlaceholderShown |
             NonTSPseudoClass::Target |
             NonTSPseudoClass::Valid |

components/style/properties/longhands/inherited_ui.mako.rs

@@ -29,6 +29,17 @@ ${helpers.single_keyword(
     gecko_enum_prefix="StylePointerEvents",
 )}
 
+${helpers.single_keyword(
+    "-moz-inert",
+    "none inert",
+    engines="gecko",
+    gecko_ffi_name="mInert",
+    gecko_enum_prefix="StyleInert",
+    animation_value_type="discrete",
+    enabled_in="ua",
+    spec="Nonstandard (https://html.spec.whatwg.org/multipage/interaction.html#inert-subtrees)",
+)}
+
 ${helpers.single_keyword(
     "-moz-user-input",
     "auto none",

components/style/servo/selector_parser.rs

@@ -349,6 +349,7 @@ impl ToCss for NonTSPseudoClass {
             Fullscreen => ":fullscreen",
             Hover => ":hover",
             Indeterminate => ":indeterminate",
+            MozInert => ":-moz-inert",
             Link => ":link",
             PlaceholderShown => ":placeholder-shown",
             ReadWrite => ":read-write",
@@ -438,6 +439,7 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
             "fullscreen" => Fullscreen,
             "hover" => Hover,
             "indeterminate" => Indeterminate,
+            "-moz-inert" => MozInert,
             "link" => Link,
             "placeholder-shown" => PlaceholderShown,
             "read-write" => ReadWrite,

components/style/style_adjuster.rs

@@ -153,6 +153,56 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         }
     }
 
+    /// https://html.spec.whatwg.org/multipage/interaction.html#inert-subtrees
+    ///
+    ///    If -moz-inert is applied then add:
+    ///        -moz-user-focus: none;
+    ///        -moz-user-input: none;
+    ///        -moz-user-modify: read-only;
+    ///        user-select: none;
+    ///        pointer-events: none;
+    ///        cursor: default;
+    fn adjust_for_inert(&mut self) {
+        use properties::longhands::_moz_inert::computed_value::T as Inert;
+        use properties::longhands::_moz_user_focus::computed_value::T as UserFocus;
+        use properties::longhands::_moz_user_input::computed_value::T as UserInput;
+        use properties::longhands::_moz_user_modify::computed_value::T as UserModify;
+        use properties::longhands::pointer_events::computed_value::T as PointerEvents;
+        use properties::longhands::cursor::computed_value::T as Cursor;
+        use crate::values::specified::ui::CursorKind;
+        use crate::values::specified::ui::UserSelect;
+
+        let needs_update = {
+            let ui = self.style.get_inherited_ui();
+            if ui.clone__moz_inert() == Inert::None {
+                return;
+            }
+
+            ui.clone__moz_user_focus() != UserFocus::None ||
+                ui.clone__moz_user_input() != UserInput::None ||
+                ui.clone__moz_user_modify() != UserModify::ReadOnly ||
+                ui.clone_pointer_events() != PointerEvents::None ||
+                ui.clone_cursor().keyword != CursorKind::Default ||
+                ui.clone_cursor().images != Default::default()
+        };
+
+        if needs_update {
+            let ui = self.style.mutate_inherited_ui();
+            ui.set__moz_user_focus(UserFocus::None);
+            ui.set__moz_user_input(UserInput::None);
+            ui.set__moz_user_modify(UserModify::ReadOnly);
+            ui.set_pointer_events(PointerEvents::None);
+            ui.set_cursor(Cursor {
+                images: Default::default(),
+                keyword: CursorKind::Default,
+            });
+        }
+
+        if self.style.get_ui().clone_user_select() != UserSelect::None {
+            self.style.mutate_ui().set_user_select(UserSelect::None);
+        }
+    }
+
     /// Whether we should skip any item-based display property blockification on
     /// this element.
     fn skip_item_display_fixup<E>(&self, element: Option<E>) -> bool
@@ -855,6 +905,7 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         #[cfg(feature = "gecko")]
         {
             self.adjust_for_appearance(element);
+            self.adjust_for_inert();
         }
         self.set_bits();
     }