firefox/servo/components/style/values/generics/mod.rs

/* 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/. */

//! Generic types that share their serialization implementations
//! for both specified and computed values.

use crate::Zero;
use std::ops::Add;

pub mod animation;
pub mod background;
pub mod basic_shape;
pub mod border;
#[path = "box.rs"]
pub mod box_;
pub mod calc;
pub mod color;
pub mod column;
pub mod counters;
pub mod easing;
pub mod effects;
pub mod flex;
pub mod font;
pub mod grid;
pub mod image;
pub mod length;
pub mod motion;
pub mod page;
pub mod position;
pub mod ratio;
pub mod rect;
pub mod size;
pub mod svg;
pub mod text;
pub mod transform;
pub mod ui;
pub mod url;

/// A wrapper of Non-negative values.
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    Deserialize,
    Hash,
    MallocSizeOf,
    PartialEq,
    PartialOrd,
    SpecifiedValueInfo,
    Serialize,
    ToAnimatedZero,
    ToComputedValue,
    ToCss,
    ToResolvedValue,
    ToShmem,
)]
#[repr(transparent)]
pub struct NonNegative<T>(pub T);

impl<T: Add<Output = T>> Add<NonNegative<T>> for NonNegative<T> {
    type Output = Self;

    fn add(self, other: Self) -> Self {
        NonNegative(self.0 + other.0)
    }
}

impl<T: Zero> Zero for NonNegative<T> {
    fn is_zero(&self) -> bool {
        self.0.is_zero()
    }

    fn zero() -> Self {
        NonNegative(T::zero())
    }
}

/// A wrapper of greater-than-or-equal-to-one values.
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    MallocSizeOf,
    PartialEq,
    PartialOrd,
    SpecifiedValueInfo,
    ToAnimatedZero,
    ToComputedValue,
    ToCss,
    ToResolvedValue,
    ToShmem,
)]
#[repr(transparent)]
pub struct GreaterThanOrEqualToOne<T>(pub T);

/// A wrapper of values between zero and one.
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    Hash,
    MallocSizeOf,
    PartialEq,
    PartialOrd,
    SpecifiedValueInfo,
    ToAnimatedZero,
    ToComputedValue,
    ToCss,
    ToResolvedValue,
    ToShmem,
)]
#[repr(transparent)]
pub struct ZeroToOne<T>(pub T);

/// A clip rect for clip and image-region
#[allow(missing_docs)]
#[derive(
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    MallocSizeOf,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToAnimatedZero,
    ToComputedValue,
    ToCss,
    ToResolvedValue,
    ToShmem,
)]
#[css(function = "rect", comma)]
#[repr(C)]
pub struct GenericClipRect<LengthOrAuto> {
    pub top: LengthOrAuto,
    pub right: LengthOrAuto,
    pub bottom: LengthOrAuto,
    pub left: LengthOrAuto,
}

pub use self::GenericClipRect as ClipRect;

/// Either a clip-rect or `auto`.
#[allow(missing_docs)]
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    MallocSizeOf,
    Parse,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToAnimatedZero,
    ToComputedValue,
    ToCss,
    ToResolvedValue,
    ToShmem,
)]
#[repr(C, u8)]
pub enum GenericClipRectOrAuto<R> {
    Auto,
    Rect(R),
}

pub use self::GenericClipRectOrAuto as ClipRectOrAuto;

impl<L> ClipRectOrAuto<L> {
    /// Returns the `auto` value.
    #[inline]
    pub fn auto() -> Self {
        ClipRectOrAuto::Auto
    }

    /// Returns whether this value is the `auto` value.
    #[inline]
    pub fn is_auto(&self) -> bool {
        matches!(*self, ClipRectOrAuto::Auto)
    }
}

pub use page::PageSize;

pub use text::NumberOrAuto;

/// An optional value, much like `Option<T>`, but with a defined struct layout
/// to be able to use it from C++ as well.
///
/// Note that this is relatively inefficient, struct-layout-wise, as you have
/// one byte for the tag, but padding to the alignment of T. If you have
/// multiple optional values and care about struct compactness, you might be
/// better off "coalescing" the combinations into a parent enum. But that
/// shouldn't matter for most use cases.
#[allow(missing_docs)]
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    MallocSizeOf,
    Parse,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToAnimatedZero,
    ToComputedValue,
    ToCss,
    ToResolvedValue,
    ToShmem,
    Serialize,
    Deserialize,
)]
#[repr(C, u8)]
pub enum Optional<T> {
    #[css(skip)]
    None,
    Some(T),
}

impl<T> Optional<T> {
    /// Returns whether this value is present.
    pub fn is_some(&self) -> bool {
        matches!(*self, Self::Some(..))
    }

    /// Returns whether this value is not present.
    pub fn is_none(&self) -> bool {
        matches!(*self, Self::None)
    }

    /// Turns this Optional<> into a regular rust Option<>.
    pub fn into_rust(self) -> Option<T> {
        match self {
            Self::Some(v) => Some(v),
            Self::None => None,
        }
    }

    /// Return a reference to the containing value, if any, as a plain rust
    /// Option<>.
    pub fn as_ref(&self) -> Option<&T> {
        match *self {
            Self::Some(ref v) => Some(v),
            Self::None => None,
        }
    }

    /// Return a mutable reference to the containing value, if any, as a plain
    /// rust Option<>.
    pub fn as_mut(&mut self) -> Option<&mut T> {
        match *self {
            Self::Some(ref mut v) => Some(v),
            Self::None => None,
        }
    }
}

impl<T> From<Option<T>> for Optional<T> {
    fn from(rust: Option<T>) -> Self {
        match rust {
            Some(t) => Self::Some(t),
            None => Self::None,
        }
    }
}