Move image-orientation property outside of mako

Fixes https://github.com/servo/servo/issues/19765

components/style/values/computed/inherited_box.rs

@@ -0,0 +1,75 @@
+/* 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 http://mozilla.org/MPL/2.0/. */
+
+//! Computed values for inherited box
+
+use std::fmt;
+use style_traits::ToCss;
+use values::specified::Angle;
+
+/// An angle rounded and normalized per https://drafts.csswg.org/css-images/#propdef-image-orientation
+#[allow(missing_docs)]
+#[derive(Clone, Copy, Debug, Eq, MallocSizeOf, PartialEq)]
+pub enum Orientation {
+    Angle0 = 0,
+    Angle90,
+    Angle180,
+    Angle270,
+}
+
+impl Orientation {
+    /// Get the actual angle that this orientation value represents.
+    pub fn angle(&self) -> Angle {
+        match *self {
+            Orientation::Angle0 => Angle::from_degrees(0.0, false),
+            Orientation::Angle90 => Angle::from_degrees(90.0, false),
+            Orientation::Angle180 => Angle::from_degrees(180.0, false),
+            Orientation::Angle270 => Angle::from_degrees(270.0, false),
+        }
+    }
+}
+
+impl ToCss for Orientation {
+    fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
+        // Should agree with Angle::to_css.
+        match *self {
+            Orientation::Angle0 => dest.write_str("0deg"),
+            Orientation::Angle90 => dest.write_str("90deg"),
+            Orientation::Angle180 => dest.write_str("180deg"),
+            Orientation::Angle270 => dest.write_str("270deg"),
+        }
+    }
+}
+
+/// https://drafts.csswg.org/css-images/#propdef-image-orientation
+#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq)]
+pub enum ImageOrientation {
+    /// 'from-image'
+    FromImage,
+
+    /// '<angle>' | '<angle>? flip'
+    AngleWithFlipped(Orientation, bool),
+}
+
+impl ImageOrientation {
+    #[allow(missing_docs)]
+    pub fn zero() -> Self {
+        ImageOrientation::AngleWithFlipped(Orientation::Angle0, false)
+    }
+}
+
+impl ToCss for ImageOrientation {
+    fn to_css<W: fmt::Write>(&self, dest: &mut W) -> fmt::Result {
+        match *self {
+            ImageOrientation::FromImage => dest.write_str("from-image"),
+            ImageOrientation::AngleWithFlipped(angle, flipped) => {
+                angle.to_css(dest)?;
+                if flipped {
+                    dest.write_str(" flip")?;
+                }
+                Ok(())
+            },
+        }
+    }
+}