style/values/computed/
length.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//! `<length>` computed values, and related ones.
6
7use super::{Number, ToComputedValue};
8use crate::derives::*;
9use crate::logical_geometry::PhysicalSide;
10use crate::typed_om::{NumericValue, ToTyped, TypedValue, UnitValue};
11use crate::values::animated::{Context as AnimatedContext, ToAnimatedValue};
12use crate::values::computed::position::TryTacticAdjustment;
13use crate::values::computed::{NonNegativeNumber, Percentage, Zoom};
14use crate::values::generics::length::{
15    GenericLengthOrNumber, GenericLengthPercentageOrNormal, GenericMaxSize, GenericSize,
16};
17#[cfg(feature = "gecko")]
18use crate::values::generics::position::TreeScoped;
19use crate::values::generics::NonNegative;
20use crate::values::generics::{length as generics, ClampToNonNegative};
21use crate::values::resolved::{Context as ResolvedContext, ToResolvedValue};
22use crate::values::CSSFloat;
23#[cfg(feature = "gecko")]
24use crate::values::DashedIdent;
25use crate::Zero;
26use app_units::Au;
27use std::fmt::{self, Write};
28use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, Sub, SubAssign};
29use style_traits::{CSSPixel, CssString, CssWriter, ToCss};
30use thin_vec::ThinVec;
31
32pub use super::image::Image;
33pub use super::length_percentage::{LengthPercentage, NonNegativeLengthPercentage};
34pub use crate::values::specified::url::UrlOrNone;
35pub use crate::values::specified::{Angle, BorderStyle, Time};
36
37/// Some boilerplate to share between negative and non-negative
38/// length-percentage or auto.
39macro_rules! computed_length_percentage_or_auto {
40    ($inner:ty) => {
41        /// Returns the used value.
42        #[inline]
43        pub fn to_used_value(&self, percentage_basis: Au) -> Option<Au> {
44            match *self {
45                Self::Auto => None,
46                Self::LengthPercentage(ref lp) => Some(lp.to_used_value(percentage_basis)),
47            }
48        }
49    };
50}
51
52/// A computed type for `<length-percentage> | auto`.
53pub type LengthPercentageOrAuto = generics::GenericLengthPercentageOrAuto<LengthPercentage>;
54
55impl LengthPercentageOrAuto {
56    /// Clamps the value to a non-negative value.
57    pub fn clamp_to_non_negative(self) -> Self {
58        use crate::values::generics::length::LengthPercentageOrAuto::*;
59        match self {
60            LengthPercentage(l) => LengthPercentage(l.clamp_to_non_negative()),
61            Auto => Auto,
62        }
63    }
64
65    /// Convert to have a borrow inside the enum
66    pub fn as_ref(&self) -> generics::GenericLengthPercentageOrAuto<&LengthPercentage> {
67        use crate::values::generics::length::LengthPercentageOrAuto::*;
68        match *self {
69            LengthPercentage(ref lp) => LengthPercentage(lp),
70            Auto => Auto,
71        }
72    }
73
74    computed_length_percentage_or_auto!(LengthPercentage);
75}
76
77impl generics::GenericLengthPercentageOrAuto<&LengthPercentage> {
78    /// Resolves the percentage.
79    #[inline]
80    pub fn percentage_relative_to(&self, basis: Length) -> LengthOrAuto {
81        use crate::values::generics::length::LengthPercentageOrAuto::*;
82        match self {
83            LengthPercentage(length_percentage) => {
84                LengthPercentage(length_percentage.percentage_relative_to(basis))
85            },
86            Auto => Auto,
87        }
88    }
89
90    /// Maybe resolves the percentage.
91    #[inline]
92    pub fn maybe_percentage_relative_to(&self, basis: Option<Length>) -> LengthOrAuto {
93        use crate::values::generics::length::LengthPercentageOrAuto::*;
94        match self {
95            LengthPercentage(length_percentage) => length_percentage
96                .maybe_percentage_relative_to(basis)
97                .map_or(Auto, LengthPercentage),
98            Auto => Auto,
99        }
100    }
101}
102
103/// A wrapper of LengthPercentageOrAuto, whose value must be >= 0.
104pub type NonNegativeLengthPercentageOrAuto =
105    generics::GenericLengthPercentageOrAuto<NonNegativeLengthPercentage>;
106
107impl NonNegativeLengthPercentageOrAuto {
108    computed_length_percentage_or_auto!(NonNegativeLengthPercentage);
109}
110
111/// The computed `<length>` value.
112#[derive(
113    Animate,
114    Clone,
115    ComputeSquaredDistance,
116    Copy,
117    Deserialize,
118    MallocSizeOf,
119    PartialEq,
120    PartialOrd,
121    Serialize,
122    ToAnimatedZero,
123    ToComputedValue,
124    ToShmem,
125)]
126#[repr(C)]
127pub struct CSSPixelLength(CSSFloat);
128
129impl ToResolvedValue for CSSPixelLength {
130    type ResolvedValue = Self;
131
132    fn to_resolved_value(self, context: &ResolvedContext) -> Self::ResolvedValue {
133        Self(context.style.effective_zoom.unzoom(self.0))
134    }
135
136    #[inline]
137    fn from_resolved_value(value: Self::ResolvedValue) -> Self {
138        value
139    }
140}
141
142impl ToAnimatedValue for CSSPixelLength {
143    type AnimatedValue = Self;
144
145    fn to_animated_value(self, context: &AnimatedContext) -> Self::AnimatedValue {
146        Self(context.style.effective_zoom.unzoom(self.0))
147    }
148
149    #[inline]
150    fn from_animated_value(value: Self::AnimatedValue) -> Self {
151        value
152    }
153}
154
155impl fmt::Debug for CSSPixelLength {
156    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
157        self.0.fmt(f)?;
158        f.write_str(" px")
159    }
160}
161
162impl CSSPixelLength {
163    /// Return a new CSSPixelLength.
164    #[inline]
165    pub fn new(px: CSSFloat) -> Self {
166        CSSPixelLength(px)
167    }
168
169    /// Returns a normalized (NaN turned to zero) version of this length.
170    #[inline]
171    pub fn normalized(self) -> Self {
172        Self::new(crate::values::normalize(self.0))
173    }
174
175    /// Returns a finite (normalized and clamped to float min and max) version of this length.
176    #[inline]
177    pub fn finite(self) -> Self {
178        Self::new(crate::values::normalize(self.0).min(f32::MAX).max(f32::MIN))
179    }
180
181    /// Scale the length by a given amount.
182    #[inline]
183    pub fn scale_by(self, scale: CSSFloat) -> Self {
184        CSSPixelLength(self.0 * scale)
185    }
186
187    /// Return the containing pixel value.
188    #[inline]
189    pub fn px(self) -> CSSFloat {
190        self.0
191    }
192
193    /// Zooms a particular length.
194    #[inline]
195    pub fn zoom(self, zoom: Zoom) -> Self {
196        Self::new(zoom.zoom(self.px()))
197    }
198
199    /// Return the length with app_unit i32 type.
200    #[inline]
201    pub fn to_i32_au(self) -> i32 {
202        Au::from(self).0
203    }
204
205    /// Return the absolute value of this length.
206    #[inline]
207    pub fn abs(self) -> Self {
208        CSSPixelLength::new(self.0.abs())
209    }
210
211    /// Return the clamped value of this length.
212    #[inline]
213    pub fn clamp_to_non_negative(self) -> Self {
214        CSSPixelLength::new(self.0.max(0.))
215    }
216
217    /// Returns the minimum between `self` and `other`.
218    #[inline]
219    pub fn min(self, other: Self) -> Self {
220        CSSPixelLength::new(self.0.min(other.0))
221    }
222
223    /// Returns the maximum between `self` and `other`.
224    #[inline]
225    pub fn max(self, other: Self) -> Self {
226        CSSPixelLength::new(self.0.max(other.0))
227    }
228
229    /// Sets `self` to the maximum between `self` and `other`.
230    #[inline]
231    pub fn max_assign(&mut self, other: Self) {
232        *self = self.max(other);
233    }
234
235    /// Clamp the value to a lower bound and an optional upper bound.
236    ///
237    /// Can be used for example with `min-width` and `max-width`.
238    #[inline]
239    pub fn clamp_between_extremums(self, min_size: Self, max_size: Option<Self>) -> Self {
240        self.clamp_below_max(max_size).max(min_size)
241    }
242
243    /// Clamp the value to an optional upper bound.
244    ///
245    /// Can be used for example with `max-width`.
246    #[inline]
247    pub fn clamp_below_max(self, max_size: Option<Self>) -> Self {
248        match max_size {
249            None => self,
250            Some(max_size) => self.min(max_size),
251        }
252    }
253}
254
255impl num_traits::Zero for CSSPixelLength {
256    fn zero() -> Self {
257        CSSPixelLength::new(0.)
258    }
259
260    fn is_zero(&self) -> bool {
261        self.px() == 0.
262    }
263}
264
265impl ToCss for CSSPixelLength {
266    #[inline]
267    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
268    where
269        W: Write,
270    {
271        self.0.to_css(dest)?;
272        dest.write_str("px")
273    }
274}
275
276impl ToTyped for CSSPixelLength {
277    fn to_typed(&self, dest: &mut ThinVec<TypedValue>) -> Result<(), ()> {
278        dest.push(TypedValue::Numeric(NumericValue::Unit(UnitValue {
279            value: self.0 as f32,
280            unit: CssString::from("px"),
281        })));
282        Ok(())
283    }
284}
285
286impl std::iter::Sum for CSSPixelLength {
287    fn sum<I: Iterator<Item = Self>>(iter: I) -> Self {
288        iter.fold(Length::zero(), Add::add)
289    }
290}
291
292impl Add for CSSPixelLength {
293    type Output = Self;
294
295    #[inline]
296    fn add(self, other: Self) -> Self {
297        Self::new(self.px() + other.px())
298    }
299}
300
301impl AddAssign for CSSPixelLength {
302    #[inline]
303    fn add_assign(&mut self, other: Self) {
304        self.0 += other.0;
305    }
306}
307
308impl Div for CSSPixelLength {
309    type Output = CSSFloat;
310
311    #[inline]
312    fn div(self, other: Self) -> CSSFloat {
313        self.px() / other.px()
314    }
315}
316
317impl Div<CSSFloat> for CSSPixelLength {
318    type Output = Self;
319
320    #[inline]
321    fn div(self, other: CSSFloat) -> Self {
322        Self::new(self.px() / other)
323    }
324}
325
326impl MulAssign<CSSFloat> for CSSPixelLength {
327    #[inline]
328    fn mul_assign(&mut self, other: CSSFloat) {
329        self.0 *= other;
330    }
331}
332
333impl Mul<CSSFloat> for CSSPixelLength {
334    type Output = Self;
335
336    #[inline]
337    fn mul(self, other: CSSFloat) -> Self {
338        Self::new(self.px() * other)
339    }
340}
341
342impl Neg for CSSPixelLength {
343    type Output = Self;
344
345    #[inline]
346    fn neg(self) -> Self {
347        CSSPixelLength::new(-self.0)
348    }
349}
350
351impl Sub for CSSPixelLength {
352    type Output = Self;
353
354    #[inline]
355    fn sub(self, other: Self) -> Self {
356        Self::new(self.px() - other.px())
357    }
358}
359
360impl SubAssign for CSSPixelLength {
361    #[inline]
362    fn sub_assign(&mut self, other: Self) {
363        self.0 -= other.0;
364    }
365}
366
367impl From<CSSPixelLength> for Au {
368    #[inline]
369    fn from(len: CSSPixelLength) -> Self {
370        Au::from_f32_px(len.0)
371    }
372}
373
374impl From<Au> for CSSPixelLength {
375    #[inline]
376    fn from(len: Au) -> Self {
377        CSSPixelLength::new(len.to_f32_px())
378    }
379}
380
381impl From<CSSPixelLength> for euclid::Length<CSSFloat, CSSPixel> {
382    #[inline]
383    fn from(length: CSSPixelLength) -> Self {
384        Self::new(length.0)
385    }
386}
387
388/// An alias of computed `<length>` value.
389pub type Length = CSSPixelLength;
390
391/// Either a computed `<length>` or the `auto` keyword.
392pub type LengthOrAuto = generics::GenericLengthPercentageOrAuto<Length>;
393
394/// Either a non-negative `<length>` or the `auto` keyword.
395pub type NonNegativeLengthOrAuto = generics::GenericLengthPercentageOrAuto<NonNegativeLength>;
396
397/// Either a computed `<length>` or a `<number>` value.
398pub type LengthOrNumber = GenericLengthOrNumber<Length, Number>;
399
400/// A wrapper of Length, whose value must be >= 0.
401pub type NonNegativeLength = NonNegative<Length>;
402
403impl ClampToNonNegative for Length {
404    fn clamp_to_non_negative(self) -> Self {
405        Self::new(self.px().max(0.))
406    }
407}
408
409impl NonNegativeLength {
410    /// Create a NonNegativeLength.
411    #[inline]
412    pub fn new(px: CSSFloat) -> Self {
413        NonNegative(Length::new(px.max(0.)))
414    }
415
416    /// Return the pixel value of |NonNegativeLength|.
417    #[inline]
418    pub fn px(&self) -> CSSFloat {
419        self.0.px()
420    }
421
422    #[inline]
423    /// Ensures it is non negative
424    pub fn clamp(self) -> Self {
425        if (self.0).0 < 0. {
426            Self::zero()
427        } else {
428            self
429        }
430    }
431}
432
433impl From<Length> for NonNegativeLength {
434    #[inline]
435    fn from(len: Length) -> Self {
436        NonNegative(len)
437    }
438}
439
440impl From<Au> for NonNegativeLength {
441    #[inline]
442    fn from(au: Au) -> Self {
443        NonNegative(au.into())
444    }
445}
446
447impl From<NonNegativeLength> for Au {
448    #[inline]
449    fn from(non_negative_len: NonNegativeLength) -> Self {
450        Au::from(non_negative_len.0)
451    }
452}
453
454/// Either a computed NonNegativeLengthPercentage or the `normal` keyword.
455pub type NonNegativeLengthPercentageOrNormal =
456    GenericLengthPercentageOrNormal<NonNegativeLengthPercentage>;
457
458/// Either a non-negative `<length>` or a `<number>`.
459pub type NonNegativeLengthOrNumber = GenericLengthOrNumber<NonNegativeLength, NonNegativeNumber>;
460
461/// A computed value for `min-width`, `min-height`, `width` or `height` property.
462pub type Size = GenericSize<NonNegativeLengthPercentage>;
463
464/// A computed value for `max-width` or `max-height` property.
465pub type MaxSize = GenericMaxSize<NonNegativeLengthPercentage>;
466
467#[cfg(feature = "gecko")]
468use crate::{
469    gecko_bindings::structs::AnchorPosResolutionParams, logical_geometry::PhysicalAxis,
470    values::generics::length::AnchorSizeKeyword,
471};
472
473/// Resolve the anchor function with the given resolver. Returns `Err()` if no anchor is found.
474/// `prop_axis`, axis of the property (e.g. `margin-left` -> Horizontal axis), is used if the
475/// anchor size keyword is not specified.
476#[cfg(feature = "gecko")]
477pub fn resolve_anchor_size(
478    anchor_name: &TreeScoped<DashedIdent>,
479    prop_axis: PhysicalAxis,
480    anchor_size_keyword: AnchorSizeKeyword,
481    params: &AnchorPosResolutionParams,
482) -> Result<Length, ()> {
483    use crate::gecko_bindings::structs::Gecko_GetAnchorPosSize;
484
485    let mut offset = Length::zero();
486    let valid = unsafe {
487        Gecko_GetAnchorPosSize(
488            params,
489            anchor_name.value.0.as_ptr(),
490            &anchor_name.scope,
491            prop_axis as u8,
492            anchor_size_keyword as u8,
493            &mut offset,
494        )
495    };
496
497    if !valid {
498        return Err(());
499    }
500
501    Ok(offset)
502}
503
504/// A computed type for `margin` properties.
505pub type Margin = generics::GenericMargin<LengthPercentage>;
506
507impl TryTacticAdjustment for MaxSize {
508    fn try_tactic_adjustment(&mut self, old_side: PhysicalSide, new_side: PhysicalSide) {
509        debug_assert!(
510            old_side.orthogonal_to(new_side),
511            "Sizes should only change axes"
512        );
513        match self {
514            Self::FitContentFunction(lp)
515            | Self::LengthPercentage(lp)
516            | Self::AnchorContainingCalcFunction(lp) => {
517                lp.try_tactic_adjustment(old_side, new_side);
518            },
519            Self::AnchorSizeFunction(s) => s.try_tactic_adjustment(old_side, new_side),
520            Self::None
521            | Self::MaxContent
522            | Self::MinContent
523            | Self::FitContent
524            | Self::WebkitFillAvailable
525            | Self::Stretch => {},
526            #[cfg(feature = "gecko")]
527            Self::MozAvailable => {},
528        }
529    }
530}
531
532impl TryTacticAdjustment for Size {
533    fn try_tactic_adjustment(&mut self, old_side: PhysicalSide, new_side: PhysicalSide) {
534        debug_assert!(
535            old_side.orthogonal_to(new_side),
536            "Sizes should only change axes"
537        );
538        match self {
539            Self::FitContentFunction(lp)
540            | Self::LengthPercentage(lp)
541            | Self::AnchorContainingCalcFunction(lp) => {
542                lp.try_tactic_adjustment(old_side, new_side);
543            },
544            Self::AnchorSizeFunction(s) => s.try_tactic_adjustment(old_side, new_side),
545            Self::Auto
546            | Self::MaxContent
547            | Self::MinContent
548            | Self::FitContent
549            | Self::WebkitFillAvailable
550            | Self::Stretch => {},
551            #[cfg(feature = "gecko")]
552            Self::MozAvailable => {},
553        }
554    }
555}
556
557impl TryTacticAdjustment for Percentage {
558    fn try_tactic_adjustment(&mut self, old_side: PhysicalSide, new_side: PhysicalSide) {
559        if old_side.parallel_to(new_side) {
560            self.0 = 1.0 - self.0;
561        }
562    }
563}
564
565impl TryTacticAdjustment for Margin {
566    fn try_tactic_adjustment(&mut self, old_side: PhysicalSide, new_side: PhysicalSide) {
567        match self {
568            Self::Auto => {},
569            Self::LengthPercentage(lp) | Self::AnchorContainingCalcFunction(lp) => {
570                lp.try_tactic_adjustment(old_side, new_side)
571            },
572            Self::AnchorSizeFunction(anchor) => anchor.try_tactic_adjustment(old_side, new_side),
573        }
574    }
575}
style/values/computed/length.rs

style/values/computed/
length.rs
