stylo: Move font-size stuff to values::*::font

components/style/values/computed/font.rs

@@ -0,0 +1,61 @@
+/* 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 font properties
+
+use app_units::Au;
+use std::fmt;
+use style_traits::ToCss;
+use values::computed::NonNegativeLength;
+use values::specified::font as specified;
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
+#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
+/// The computed value of font-size
+pub struct FontSize {
+    /// The size.
+    pub size: NonNegativeLength,
+    /// If derived from a keyword, the keyword and additional transformations applied to it
+    pub info: Option<KeywordInfo>,
+}
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
+#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
+#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
+/// Additional information for keyword-derived font sizes.
+pub struct KeywordInfo {
+    /// The keyword used
+    pub kw: specified::KeywordSize,
+    /// A factor to be multiplied by the computed size of the keyword
+    pub factor: f32,
+    /// An additional Au offset to add to the kw*factor in the case of calcs
+    pub offset: NonNegativeLength,
+}
+
+impl KeywordInfo {
+    /// Given a parent keyword info (self), apply an additional factor/offset to it
+    pub fn compose(self, factor: f32, offset: NonNegativeLength) -> Self {
+        KeywordInfo {
+            kw: self.kw,
+            factor: self.factor * factor,
+            offset: self.offset.scale_by(factor) + offset,
+        }
+    }
+}
+
+impl FontSize {
+    /// The actual computed font size.
+    pub fn size(self) -> Au {
+        self.size.into()
+    }
+}
+
+impl ToCss for FontSize {
+    fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
+        self.size.to_css(dest)
+    }
+}