style: Add page-size parsing to Servo

Differential Revision: https://phabricator.services.mozilla.com/D102360

components/style/values/generics/mod.rs

@@ -31,6 +31,7 @@ pub mod grid;
 pub mod image;
 pub mod length;
 pub mod motion;
+pub mod page;
 pub mod position;
 pub mod rect;
 pub mod size;
@@ -292,3 +293,5 @@ impl<L> ClipRectOrAuto<L> {
         matches!(*self, ClipRectOrAuto::Auto)
     }
 }
+
+pub use page::PageSize;

components/style/values/generics/page.rs

@@ -0,0 +1,114 @@
+/* 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/. */
+
+//! @page at-rule properties
+
+/// Page size names.
+///
+/// https://drafts.csswg.org/css-page-3/#typedef-page-size-page-size
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(u8)]
+pub enum PaperSize {
+    /// ISO A5 media
+    A5,
+    /// ISO A4 media
+    A4,
+    /// ISO A3 media
+    A3,
+    /// ISO B5 media
+    B5,
+    /// ISO B4 media
+    B4,
+    /// JIS B5 media
+    JisB5,
+    /// JIS B4 media
+    JisB4,
+    /// North American Letter size
+    Letter,
+    /// North American Legal size
+    Legal,
+    /// North American Ledger size
+    Ledger,
+}
+
+/// Paper orientation
+///
+/// https://drafts.csswg.org/css-page-3/#page-size-prop
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(u8)]
+pub enum Orientation {
+    /// Portrait orientation
+    Portrait,
+    /// Landscape orientation
+    Landscape,
+}
+
+/// Page size property
+///
+/// https://drafts.csswg.org/css-page-3/#page-size-prop
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C, u8)]
+pub enum PageSize<S> {
+    /// Page dimensions.
+    Size(S),
+    /// Paper size with no orientation.
+    PaperSize(PaperSize),
+    /// An orientation with no size.
+    Orientation(Orientation),
+    /// Paper size by name, with an orientation.
+    PaperSizeAndOrientation(PaperSize, Orientation),
+    /// `auto` value.
+    Auto,
+}
+
+impl<S> PageSize<S> {
+    /// `auto` value.
+    #[inline]
+    pub fn auto() -> Self {
+        PageSize::Auto
+    }
+
+    /// Whether this is the `auto` value.
+    #[inline]
+    pub fn is_auto(&self) -> bool {
+        matches!(*self, PageSize::Auto)
+    }
+}