style/values/computed/
box.rs

1/* This Source Code Form is subject to the terms of the Mozilla Public
2 * License, v. 2.0. If a copy of the MPL was not distributed with this
3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
4
5//! Computed types for box properties.
6
7use crate::values::animated::{Animate, Procedure, ToAnimatedValue};
8use crate::values::computed::length::{LengthPercentage, NonNegativeLength};
9use crate::values::computed::{Context, Integer, Number, ToComputedValue};
10use crate::values::generics::box_::{
11    GenericContainIntrinsicSize, GenericLineClamp, GenericPerspective, GenericVerticalAlign,
12};
13use crate::values::specified::box_ as specified;
14use std::fmt;
15use style_traits::{CssWriter, ToCss};
16
17pub use crate::values::specified::box_::{
18    Appearance, BaselineSource, BreakBetween, BreakWithin, Clear, Contain, ContainerName,
19    ContainerType, ContentVisibility, Display, Float, Overflow, OverflowAnchor, OverflowClipBox,
20    OverscrollBehavior, PositionProperty, ScrollSnapAlign, ScrollSnapAxis, ScrollSnapStop,
21    ScrollSnapStrictness, ScrollSnapType, ScrollbarGutter, TouchAction, WillChange,
22    WritingModeProperty,
23};
24
25/// A computed value for the `vertical-align` property.
26pub type VerticalAlign = GenericVerticalAlign<LengthPercentage>;
27
28/// A computed value for the `contain-intrinsic-size` property.
29pub type ContainIntrinsicSize = GenericContainIntrinsicSize<NonNegativeLength>;
30
31impl ContainIntrinsicSize {
32    /// Converts contain-intrinsic-size to auto style.
33    pub fn add_auto_if_needed(&self) -> Option<Self> {
34        Some(match *self {
35            Self::None => Self::AutoNone,
36            Self::Length(ref l) => Self::AutoLength(*l),
37            Self::AutoNone | Self::AutoLength(..) => return None,
38        })
39    }
40}
41
42/// A computed value for the `line-clamp` property.
43pub type LineClamp = GenericLineClamp<Integer>;
44
45impl Animate for LineClamp {
46    #[inline]
47    fn animate(&self, other: &Self, procedure: Procedure) -> Result<Self, ()> {
48        if self.is_none() != other.is_none() {
49            return Err(());
50        }
51        if self.is_none() {
52            return Ok(Self::none());
53        }
54        Ok(Self(self.0.animate(&other.0, procedure)?.max(1)))
55    }
56}
57
58/// A computed value for the `perspective` property.
59pub type Perspective = GenericPerspective<NonNegativeLength>;
60
61/// A computed value for the `resize` property.
62#[allow(missing_docs)]
63#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
64#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Parse, PartialEq, ToCss, ToResolvedValue)]
65#[repr(u8)]
66pub enum Resize {
67    None,
68    Both,
69    Horizontal,
70    Vertical,
71}
72
73impl ToComputedValue for specified::Resize {
74    type ComputedValue = Resize;
75
76    #[inline]
77    fn to_computed_value(&self, context: &Context) -> Resize {
78        let is_vertical = context.style().writing_mode.is_vertical();
79        match self {
80            specified::Resize::Inline => {
81                context
82                    .rule_cache_conditions
83                    .borrow_mut()
84                    .set_writing_mode_dependency(context.builder.writing_mode);
85                if is_vertical {
86                    Resize::Vertical
87                } else {
88                    Resize::Horizontal
89                }
90            },
91            specified::Resize::Block => {
92                context
93                    .rule_cache_conditions
94                    .borrow_mut()
95                    .set_writing_mode_dependency(context.builder.writing_mode);
96                if is_vertical {
97                    Resize::Horizontal
98                } else {
99                    Resize::Vertical
100                }
101            },
102            specified::Resize::None => Resize::None,
103            specified::Resize::Both => Resize::Both,
104            specified::Resize::Horizontal => Resize::Horizontal,
105            specified::Resize::Vertical => Resize::Vertical,
106        }
107    }
108
109    #[inline]
110    fn from_computed_value(computed: &Resize) -> specified::Resize {
111        match computed {
112            Resize::None => specified::Resize::None,
113            Resize::Both => specified::Resize::Both,
114            Resize::Horizontal => specified::Resize::Horizontal,
115            Resize::Vertical => specified::Resize::Vertical,
116        }
117    }
118}
119
120/// The computed `zoom` property value.
121#[derive(
122    Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToResolvedValue,
123)]
124#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
125#[repr(C)]
126pub struct Zoom(f32);
127
128impl ToComputedValue for specified::Zoom {
129    type ComputedValue = Zoom;
130
131    #[inline]
132    fn to_computed_value(&self, _: &Context) -> Self::ComputedValue {
133        let n = match *self {
134            Self::Normal => return Zoom::ONE,
135            Self::Document => return Zoom::DOCUMENT,
136            Self::Value(ref n) => n.0.to_number().get(),
137        };
138        if n == 0.0 {
139            // For legacy reasons, zoom: 0 (and 0%) computes to 1. ¯\_(ツ)_/¯
140            return Zoom::ONE;
141        }
142        Zoom(n)
143    }
144
145    #[inline]
146    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
147        Self::new_number(computed.value())
148    }
149}
150
151impl ToCss for Zoom {
152    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
153    where
154        W: fmt::Write,
155    {
156        use std::fmt::Write;
157        if *self == Self::DOCUMENT {
158            return dest.write_str("document");
159        }
160        self.value().to_css(dest)
161    }
162}
163
164impl ToAnimatedValue for Zoom {
165    type AnimatedValue = Number;
166
167    #[inline]
168    fn to_animated_value(self, _: &crate::values::animated::Context) -> Self::AnimatedValue {
169        self.value()
170    }
171
172    #[inline]
173    fn from_animated_value(animated: Self::AnimatedValue) -> Self {
174        Zoom(animated.max(0.0))
175    }
176}
177
178impl Zoom {
179    /// The value 1. This is by far the most common value.
180    pub const ONE: Zoom = Zoom(1.0);
181
182    /// The `document` value. This can appear in the computed zoom property value, but not in the
183    /// `effective_zoom` field.
184    pub const DOCUMENT: Zoom = Zoom(0.0);
185
186    /// Returns whether we're the number 1.
187    #[inline]
188    pub fn is_one(self) -> bool {
189        self == Self::ONE
190    }
191
192    /// Returns whether we're the `document` keyword.
193    #[inline]
194    pub fn is_document(self) -> bool {
195        self == Self::DOCUMENT
196    }
197
198    /// Returns the inverse of our value.
199    #[inline]
200    pub fn inverted(&self) -> Option<Self> {
201        if self.0 == 0.0 {
202            return None;
203        }
204        Some(Self(1. / self.0))
205    }
206
207    /// Returns the value as a float.
208    #[inline]
209    pub fn value(&self) -> f32 {
210        self.0
211    }
212
213    /// Computes the effective zoom for a given new zoom value in rhs.
214    pub fn compute_effective(self, specified: Self) -> Self {
215        if specified == Self::DOCUMENT {
216            return Self::ONE;
217        }
218        if self == Self::ONE {
219            return specified;
220        }
221        if specified == Self::ONE {
222            return self;
223        }
224        Zoom(self.0 * specified.0)
225    }
226
227    /// Returns the zoomed value.
228    #[inline]
229    pub fn zoom(self, value: f32) -> f32 {
230        if self == Self::ONE {
231            return value;
232        }
233        value * self.value()
234    }
235
236    /// Returns the un-zoomed value.
237    #[inline]
238    pub fn unzoom(self, value: f32) -> f32 {
239        // Avoid division by zero if our effective zoom computation ends up being zero.
240        if self == Self::ONE || self.0 == 0.0 {
241            return value;
242        }
243        value / self.value()
244    }
245}
style/values/computed/box.rs

style/values/computed/
box.rs
