1 files changed, 70 insertions, 0 deletions
diff --git a/components/script/stylesheet_set.rs b/components/script/stylesheet_set.rs
new file mode 100644
index 00000000000..ddb2f608e57
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+++ b/components/script/stylesheet_set.rs
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+/* 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 style::media_queries::Device;
+use style::shared_lock::SharedRwLockReadGuard;
+use style::stylesheet_set::{AuthorStylesheetSet, DocumentStylesheetSet};
+use style::stylesheets::StylesheetInDocument;
+
+/// Functionality common to DocumentStylesheetSet and AuthorStylesheetSet.
+pub enum StylesheetSetRef<'a, S>
+where
+    S: StylesheetInDocument + PartialEq + 'static,
+{
+    /// Author stylesheet set.
+    Author(&'a mut AuthorStylesheetSet<S>),
+    /// Document stylesheet set.
+    Document(&'a mut DocumentStylesheetSet<S>),
+}
+
+impl<'a, S> StylesheetSetRef<'a, S>
+where
+    S: StylesheetInDocument + PartialEq + 'static,
+{
+    /// Appends a new stylesheet to the current set.
+    ///
+    /// No device implies not computing invalidations.
+    pub fn append_stylesheet(
+        &mut self,
+        device: Option<&Device>,
+        sheet: S,
+        guard: &SharedRwLockReadGuard,
+    ) {
+        match self {
+            StylesheetSetRef::Author(set) => set.append_stylesheet(device, sheet, guard),
+            StylesheetSetRef::Document(set) => set.append_stylesheet(device, sheet, guard),
+        }
+    }
+
+    /// Insert a given stylesheet before another stylesheet in the document.
+    pub fn insert_stylesheet_before(
+        &mut self,
+        device: Option<&Device>,
+        sheet: S,
+        before_sheet: S,
+        guard: &SharedRwLockReadGuard,
+    ) {
+        match self {
+            StylesheetSetRef::Author(set) => {
+                set.insert_stylesheet_before(device, sheet, before_sheet, guard)
+            },
+            StylesheetSetRef::Document(set) => {
+                set.insert_stylesheet_before(device, sheet, before_sheet, guard)
+            },
+        }
+    }
+
+    /// Remove a given stylesheet from the set.
+    pub fn remove_stylesheet(
+        &mut self,
+        device: Option<&Device>,
+        sheet: S,
+        guard: &SharedRwLockReadGuard,
+    ) {
+        match self {
+            StylesheetSetRef::Author(set) => set.remove_stylesheet(device, sheet, guard),
+            StylesheetSetRef::Document(set) => set.remove_stylesheet(device, sheet, guard),
+        }
+    }
+}