1 files changed, 85 insertions, 0 deletions
diff --git a/servo/components/style/gecko/values.rs b/servo/components/style/gecko/values.rs
new file mode 100644
index 0000000000..a755556e85
--- /dev/null
+++ b/servo/components/style/gecko/values.rs
@@ -0,0 +1,85 @@
+/* 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/. */
+
+#![allow(unsafe_code)]
+
+//! Different kind of helpers to interact with Gecko values.
+
+use crate::counter_style::{Symbol, Symbols};
+use crate::gecko_bindings::bindings;
+use crate::gecko_bindings::structs::CounterStylePtr;
+use crate::values::generics::CounterStyle;
+use crate::values::Either;
+use crate::Atom;
+use app_units::Au;
+use cssparser::RGBA;
+use std::cmp::max;
+
+/// Convert a given RGBA value to `nscolor`.
+pub fn convert_rgba_to_nscolor(rgba: &RGBA) -> u32 {
+    ((rgba.alpha as u32) << 24) |
+        ((rgba.blue as u32) << 16) |
+        ((rgba.green as u32) << 8) |
+        (rgba.red as u32)
+}
+
+/// Convert a given `nscolor` to a Servo RGBA value.
+pub fn convert_nscolor_to_rgba(color: u32) -> RGBA {
+    RGBA::new(
+        (color & 0xff) as u8,
+        (color >> 8 & 0xff) as u8,
+        (color >> 16 & 0xff) as u8,
+        (color >> 24 & 0xff) as u8,
+    )
+}
+
+/// Round `width` down to the nearest device pixel, but any non-zero value that
+/// would round down to zero is clamped to 1 device pixel.  Used for storing
+/// computed values of border-*-width and outline-width.
+#[inline]
+pub fn round_border_to_device_pixels(width: Au, au_per_device_px: Au) -> Au {
+    if width == Au(0) {
+        Au(0)
+    } else {
+        max(
+            au_per_device_px,
+            Au(width.0 / au_per_device_px.0 * au_per_device_px.0),
+        )
+    }
+}
+
+impl CounterStyle {
+    /// Convert this counter style to a Gecko CounterStylePtr.
+    #[inline]
+    pub fn to_gecko_value(&self, gecko_value: &mut CounterStylePtr) {
+        unsafe { bindings::Gecko_CounterStyle_ToPtr(self, gecko_value) }
+    }
+
+    /// Convert Gecko CounterStylePtr to CounterStyle or String.
+    pub fn from_gecko_value(gecko_value: &CounterStylePtr) -> Either<Self, String> {
+        use crate::values::CustomIdent;
+
+        let name = unsafe { bindings::Gecko_CounterStyle_GetName(gecko_value) };
+        if !name.is_null() {
+            let name = unsafe { Atom::from_raw(name) };
+            debug_assert_ne!(name, atom!("none"));
+            Either::First(CounterStyle::Name(CustomIdent(name)))
+        } else {
+            let anonymous =
+                unsafe { bindings::Gecko_CounterStyle_GetAnonymous(gecko_value).as_ref() }.unwrap();
+            let symbols = &anonymous.mSymbols;
+            if anonymous.mSingleString {
+                debug_assert_eq!(symbols.len(), 1);
+                Either::Second(symbols[0].to_string())
+            } else {
+                let symbol_type = anonymous.mSymbolsType;
+                let symbols = symbols
+                    .iter()
+                    .map(|gecko_symbol| Symbol::String(gecko_symbol.to_string().into()))
+                    .collect();
+                Either::First(CounterStyle::Symbols(symbol_type, Symbols(symbols)))
+            }
+        }
+    }
+}