taffy/
style_helpers.rs

Help
1//! Helper functions which it make it easier to create instances of types in the `style` and `geometry` modules.
2use crate::{
3    geometry::{Line, Point, Rect, Size},
4    style::LengthPercentage,
5};
6
7#[cfg(feature = "grid")]
8use crate::{
9    geometry::MinMax,
10    style::{
11        GridTrackRepetition, MaxTrackSizingFunction, MinTrackSizingFunction, NonRepeatedTrackSizingFunction,
12        TrackSizingFunction,
13    },
14    util::sys::Vec,
15};
16#[cfg(feature = "grid")]
17use core::fmt::Debug;
18
19/// Returns an auto-repeated track definition
20#[cfg(feature = "grid")]
21pub fn repeat<Input>(repetition_kind: Input, track_list: Vec<NonRepeatedTrackSizingFunction>) -> TrackSizingFunction
22where
23    Input: TryInto<GridTrackRepetition>,
24    <Input as TryInto<GridTrackRepetition>>::Error: Debug,
25{
26    TrackSizingFunction::Repeat(repetition_kind.try_into().unwrap(), track_list)
27}
28
29#[cfg(feature = "grid")]
30#[cfg(test)]
31mod repeat_fn_tests {
32    use super::repeat;
33    use crate::style::{GridTrackRepetition, NonRepeatedTrackSizingFunction, TrackSizingFunction};
34
35    const TEST_VEC: Vec<NonRepeatedTrackSizingFunction> = Vec::new();
36
37    #[test]
38    fn test_repeat_u16() {
39        assert_eq!(repeat(123, TEST_VEC), TrackSizingFunction::Repeat(GridTrackRepetition::Count(123), TEST_VEC));
40    }
41
42    #[test]
43    fn test_repeat_auto_fit_str() {
44        assert_eq!(repeat("auto-fit", TEST_VEC), TrackSizingFunction::Repeat(GridTrackRepetition::AutoFit, TEST_VEC));
45    }
46
47    #[test]
48    fn test_repeat_auto_fill_str() {
49        assert_eq!(repeat("auto-fill", TEST_VEC), TrackSizingFunction::Repeat(GridTrackRepetition::AutoFill, TEST_VEC));
50    }
51}
52
53#[cfg(feature = "grid")]
54/// Returns a grid template containing `count` evenly sized tracks
55pub fn evenly_sized_tracks(count: u16) -> Vec<TrackSizingFunction> {
56    use crate::util::sys::new_vec_with_capacity;
57    let mut repeated_tracks = new_vec_with_capacity(1);
58    repeated_tracks.push(flex(1.0));
59    let mut tracks = new_vec_with_capacity(1);
60    tracks.push(repeat(count, repeated_tracks));
61    tracks
62}
63
64/// Specifies a grid line to place a grid item between in CSS Grid Line coordinates:
65///  - Positive indicies count upwards from the start (top or left) of the explicit grid
66///  - Negative indicies count downwards from the end (bottom or right) of the explicit grid
67///  - ZERO IS INVALID index, and will be treated as a GridPlacement::Auto.
68pub fn line<T: TaffyGridLine>(index: i16) -> T {
69    T::from_line_index(index)
70}
71/// Trait to abstract over grid line values
72pub trait TaffyGridLine {
73    /// Converts an i16 into Self
74    fn from_line_index(index: i16) -> Self;
75}
76
77/// Returns a GridPlacement::Span
78pub fn span<T: TaffyGridSpan>(span: u16) -> T {
79    T::from_span(span)
80}
81/// Trait to abstract over grid span values
82pub trait TaffyGridSpan {
83    /// Converts an iu6 into Self
84    fn from_span(span: u16) -> Self;
85}
86
87/// Returns a MinMax with min value of min and max value of max
88#[cfg(feature = "grid")]
89pub fn minmax<Output>(min: MinTrackSizingFunction, max: MaxTrackSizingFunction) -> Output
90where
91    Output: From<MinMax<MinTrackSizingFunction, MaxTrackSizingFunction>>,
92{
93    MinMax { min, max }.into()
94}
95
96/// Shorthand for minmax(0, Nfr). Probably what you want if you want exactly evenly sized tracks.
97#[cfg(feature = "grid")]
98pub fn flex<Input, Output>(flex_fraction: Input) -> Output
99where
100    Input: Into<f32> + Copy,
101    Output: From<MinMax<MinTrackSizingFunction, MaxTrackSizingFunction>>,
102{
103    MinMax { min: zero(), max: fr(flex_fraction.into()) }.into()
104}
105
106/// Returns the zero value for that type
107pub const fn zero<T: TaffyZero>() -> T {
108    T::ZERO
109}
110
111/// Trait to abstract over zero values
112pub trait TaffyZero {
113    /// The zero value for type implementing TaffyZero
114    const ZERO: Self;
115}
116impl TaffyZero for f32 {
117    const ZERO: f32 = 0.0;
118}
119impl<T: TaffyZero> TaffyZero for Option<T> {
120    const ZERO: Option<T> = Some(T::ZERO);
121}
122impl<T: TaffyZero> TaffyZero for Point<T> {
123    const ZERO: Point<T> = Point { x: T::ZERO, y: T::ZERO };
124}
125impl<T: TaffyZero> Point<T> {
126    /// Returns a Point where both the x and y values are the zero value of the contained type
127    /// (e.g. 0.0, Some(0.0), or Dimension::Length(0.0))
128    pub const fn zero() -> Self {
129        zero::<Self>()
130    }
131}
132impl<T: TaffyZero> TaffyZero for Line<T> {
133    const ZERO: Line<T> = Line { start: T::ZERO, end: T::ZERO };
134}
135impl<T: TaffyZero> Line<T> {
136    /// Returns a Line where both the start and end values are the zero value of the contained type
137    /// (e.g. 0.0, Some(0.0), or Dimension::Length(0.0))
138    pub const fn zero() -> Self {
139        zero::<Self>()
140    }
141}
142impl<T: TaffyZero> TaffyZero for Size<T> {
143    const ZERO: Size<T> = Size { width: T::ZERO, height: T::ZERO };
144}
145impl<T: TaffyZero> Size<T> {
146    /// Returns a Size where both the width and height values are the zero value of the contained type
147    /// (e.g. 0.0, Some(0.0), or Dimension::Length(0.0))
148    pub const fn zero() -> Self {
149        zero::<Self>()
150    }
151}
152impl<T: TaffyZero> TaffyZero for Rect<T> {
153    const ZERO: Rect<T> = Rect { left: T::ZERO, right: T::ZERO, top: T::ZERO, bottom: T::ZERO };
154}
155impl<T: TaffyZero> Rect<T> {
156    /// Returns a Rect where the left, right, top, and bottom values are all the zero value of the contained type
157    /// (e.g. 0.0, Some(0.0), or Dimension::Length(0.0))
158    pub const fn zero() -> Self {
159        zero::<Self>()
160    }
161}
162
163/// Returns the auto value for that type
164pub const fn auto<T: TaffyAuto>() -> T {
165    T::AUTO
166}
167
168/// Trait to abstract over auto values
169pub trait TaffyAuto {
170    /// The auto value for type implementing TaffyAuto
171    const AUTO: Self;
172}
173impl<T: TaffyAuto> TaffyAuto for Option<T> {
174    const AUTO: Option<T> = Some(T::AUTO);
175}
176impl<T: TaffyAuto> TaffyAuto for Point<T> {
177    const AUTO: Point<T> = Point { x: T::AUTO, y: T::AUTO };
178}
179impl<T: TaffyAuto> Point<T> {
180    /// Returns a Point where both the x and y values are the auto value of the contained type
181    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
182    pub const fn auto() -> Self {
183        auto::<Self>()
184    }
185}
186impl<T: TaffyAuto> TaffyAuto for Line<T> {
187    const AUTO: Line<T> = Line { start: T::AUTO, end: T::AUTO };
188}
189impl<T: TaffyAuto> Line<T> {
190    /// Returns a Line where both the start and end values are the auto value of the contained type
191    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
192    pub const fn auto() -> Self {
193        auto::<Self>()
194    }
195}
196impl<T: TaffyAuto> TaffyAuto for Size<T> {
197    const AUTO: Size<T> = Size { width: T::AUTO, height: T::AUTO };
198}
199impl<T: TaffyAuto> Size<T> {
200    /// Returns a Size where both the width and height values are the auto value of the contained type
201    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
202    pub const fn auto() -> Self {
203        auto::<Self>()
204    }
205}
206impl<T: TaffyAuto> TaffyAuto for Rect<T> {
207    const AUTO: Rect<T> = Rect { left: T::AUTO, right: T::AUTO, top: T::AUTO, bottom: T::AUTO };
208}
209impl<T: TaffyAuto> Rect<T> {
210    /// Returns a Rect where the left, right, top, and bottom values are all the auto value of the contained type
211    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
212    pub const fn auto() -> Self {
213        auto::<Self>()
214    }
215}
216
217/// Returns the auto value for that type
218pub const fn min_content<T: TaffyMinContent>() -> T {
219    T::MIN_CONTENT
220}
221
222/// Trait to abstract over min_content values
223pub trait TaffyMinContent {
224    /// The min_content value for type implementing TaffyZero
225    const MIN_CONTENT: Self;
226}
227impl<T: TaffyMinContent> TaffyMinContent for Option<T> {
228    const MIN_CONTENT: Option<T> = Some(T::MIN_CONTENT);
229}
230impl<T: TaffyMinContent> TaffyMinContent for Point<T> {
231    const MIN_CONTENT: Point<T> = Point { x: T::MIN_CONTENT, y: T::MIN_CONTENT };
232}
233impl<T: TaffyMinContent> Point<T> {
234    /// Returns a Point where both the x and y values are the min_content value of the contained type
235    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
236    pub const fn min_content() -> Self {
237        min_content::<Self>()
238    }
239}
240impl<T: TaffyMinContent> TaffyMinContent for Line<T> {
241    const MIN_CONTENT: Line<T> = Line { start: T::MIN_CONTENT, end: T::MIN_CONTENT };
242}
243impl<T: TaffyMinContent> Line<T> {
244    /// Returns a Line where both the start and end values are the min_content value of the contained type
245    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
246    pub const fn min_content() -> Self {
247        min_content::<Self>()
248    }
249}
250impl<T: TaffyMinContent> TaffyMinContent for Size<T> {
251    const MIN_CONTENT: Size<T> = Size { width: T::MIN_CONTENT, height: T::MIN_CONTENT };
252}
253impl<T: TaffyMinContent> Size<T> {
254    /// Returns a Size where both the width and height values are the min_content value of the contained type
255    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
256    pub const fn min_content() -> Self {
257        min_content::<Self>()
258    }
259}
260impl<T: TaffyMinContent> TaffyMinContent for Rect<T> {
261    const MIN_CONTENT: Rect<T> =
262        Rect { left: T::MIN_CONTENT, right: T::MIN_CONTENT, top: T::MIN_CONTENT, bottom: T::MIN_CONTENT };
263}
264impl<T: TaffyMinContent> Rect<T> {
265    /// Returns a Rect where the left, right, top, and bottom values are all the min_content value of the contained type
266    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
267    pub const fn min_content() -> Self {
268        min_content::<Self>()
269    }
270}
271
272/// Returns the auto value for that type
273pub const fn max_content<T: TaffyMaxContent>() -> T {
274    T::MAX_CONTENT
275}
276
277/// Trait to abstract over max_content values
278pub trait TaffyMaxContent {
279    /// The max_content value for type implementing TaffyZero
280    const MAX_CONTENT: Self;
281}
282impl<T: TaffyMaxContent> TaffyMaxContent for Option<T> {
283    const MAX_CONTENT: Option<T> = Some(T::MAX_CONTENT);
284}
285impl<T: TaffyMaxContent> TaffyMaxContent for Point<T> {
286    const MAX_CONTENT: Point<T> = Point { x: T::MAX_CONTENT, y: T::MAX_CONTENT };
287}
288impl<T: TaffyMaxContent> Point<T> {
289    /// Returns a Point where both the x and y values are the max_content value of the contained type
290    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
291    pub const fn max_content() -> Self {
292        max_content::<Self>()
293    }
294}
295impl<T: TaffyMaxContent> TaffyMaxContent for Line<T> {
296    const MAX_CONTENT: Line<T> = Line { start: T::MAX_CONTENT, end: T::MAX_CONTENT };
297}
298impl<T: TaffyMaxContent> Line<T> {
299    /// Returns a Line where both the start and end values are the max_content value of the contained type
300    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
301    pub const fn max_content() -> Self {
302        max_content::<Self>()
303    }
304}
305impl<T: TaffyMaxContent> TaffyMaxContent for Size<T> {
306    const MAX_CONTENT: Size<T> = Size { width: T::MAX_CONTENT, height: T::MAX_CONTENT };
307}
308impl<T: TaffyMaxContent> Size<T> {
309    /// Returns a Size where both the width and height values are the max_content value of the contained type
310    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
311    pub const fn max_content() -> Self {
312        max_content::<Self>()
313    }
314}
315impl<T: TaffyMaxContent> TaffyMaxContent for Rect<T> {
316    const MAX_CONTENT: Rect<T> =
317        Rect { left: T::MAX_CONTENT, right: T::MAX_CONTENT, top: T::MAX_CONTENT, bottom: T::MAX_CONTENT };
318}
319impl<T: TaffyMaxContent> Rect<T> {
320    /// Returns a Rect where the left, right, top, and bottom values are all the max_content value of the contained type
321    /// (e.g. Dimension::Auto or LengthPercentageAuto::Auto)
322    pub const fn max_content() -> Self {
323        max_content::<Self>()
324    }
325}
326
327/// Returns a value of the inferred type which represent a `fit-content(…)` value
328/// with the given argument.
329pub fn fit_content<T: TaffyFitContent>(argument: LengthPercentage) -> T {
330    T::fit_content(argument)
331}
332
333/// Trait to create `fit-content(…)` values from plain numbers
334pub trait TaffyFitContent {
335    /// Converts a LengthPercentage into Self
336    fn fit_content(argument: LengthPercentage) -> Self;
337}
338impl<T: TaffyFitContent> TaffyFitContent for Point<T> {
339    fn fit_content(argument: LengthPercentage) -> Self {
340        Point { x: T::fit_content(argument), y: T::fit_content(argument) }
341    }
342}
343impl<T: TaffyFitContent> Point<T> {
344    /// Returns a Point with x and y set to the same `fit-content(…)` value
345    /// with the given argument.
346    pub fn fit_content(argument: LengthPercentage) -> Self {
347        fit_content(argument)
348    }
349}
350impl<T: TaffyFitContent> TaffyFitContent for Line<T> {
351    fn fit_content(argument: LengthPercentage) -> Self {
352        Line { start: T::fit_content(argument), end: T::fit_content(argument) }
353    }
354}
355impl<T: TaffyFitContent> Line<T> {
356    /// Returns a Line with start and end set to the same `fit-content(…)` value
357    /// with the given argument.
358    pub fn fit_content(argument: LengthPercentage) -> Self {
359        fit_content(argument)
360    }
361}
362impl<T: TaffyFitContent> TaffyFitContent for Size<T> {
363    fn fit_content(argument: LengthPercentage) -> Self {
364        Size { width: T::fit_content(argument), height: T::fit_content(argument) }
365    }
366}
367impl<T: TaffyFitContent> Size<T> {
368    /// Returns a Size where with width and height set to the same `fit-content(…)` value
369    /// with the given argument.
370    pub fn fit_content(argument: LengthPercentage) -> Self {
371        fit_content(argument)
372    }
373}
374impl<T: TaffyFitContent> TaffyFitContent for Rect<T> {
375    fn fit_content(argument: LengthPercentage) -> Self {
376        Rect {
377            left: T::fit_content(argument),
378            right: T::fit_content(argument),
379            top: T::fit_content(argument),
380            bottom: T::fit_content(argument),
381        }
382    }
383}
384impl<T: TaffyFitContent> Rect<T> {
385    /// Returns a Rect where the left, right, top and bottom values are all constant fit_content value of the contained type
386    /// (e.g. 2.1, Some(2.1), or Dimension::Length(2.1))
387    pub fn fit_content(argument: LengthPercentage) -> Self {
388        fit_content(argument)
389    }
390}
391
392/// Returns a value of the inferred type which represent an absolute length
393pub fn length<Input: Into<f32> + Copy, T: FromLength>(value: Input) -> T {
394    T::from_length(value)
395}
396
397/// Trait to create absolute length values from plain numbers
398pub trait FromLength {
399    /// Converts into an `Into<f32>` into Self
400    fn from_length<Input: Into<f32> + Copy>(value: Input) -> Self;
401}
402impl FromLength for f32 {
403    fn from_length<Input: Into<f32> + Copy>(value: Input) -> Self {
404        value.into()
405    }
406}
407impl FromLength for Option<f32> {
408    fn from_length<Input: Into<f32> + Copy>(value: Input) -> Self {
409        Some(value.into())
410    }
411}
412impl<T: FromLength> FromLength for Point<T> {
413    fn from_length<Input: Into<f32> + Copy>(value: Input) -> Self {
414        Point { x: T::from_length(value.into()), y: T::from_length(value.into()) }
415    }
416}
417impl<T: FromLength> Point<T> {
418    /// Returns a Point where x and y values are the same given absolute length
419    pub fn length<Input: Into<f32> + Copy>(value: Input) -> Self {
420        length::<Input, Self>(value)
421    }
422}
423impl<T: FromLength> FromLength for Line<T> {
424    fn from_length<Input: Into<f32> + Copy>(value: Input) -> Self {
425        Line { start: T::from_length(value.into()), end: T::from_length(value.into()) }
426    }
427}
428impl<T: FromLength> Line<T> {
429    /// Returns a Line where both the start and end values are the same given absolute length
430    pub fn length<Input: Into<f32> + Copy>(value: Input) -> Self {
431        length::<Input, Self>(value)
432    }
433}
434impl<T: FromLength> FromLength for Size<T> {
435    fn from_length<Input: Into<f32> + Copy>(value: Input) -> Self {
436        Size { width: T::from_length(value.into()), height: T::from_length(value.into()) }
437    }
438}
439impl<T: FromLength> Size<T> {
440    /// Returns a Size where both the width and height values the same given absolute length
441    pub fn length<Input: Into<f32> + Copy>(value: Input) -> Self {
442        length::<Input, Self>(value)
443    }
444}
445impl<T: FromLength> FromLength for Rect<T> {
446    fn from_length<Input: Into<f32> + Copy>(value: Input) -> Self {
447        Rect {
448            left: T::from_length(value.into()),
449            right: T::from_length(value.into()),
450            top: T::from_length(value.into()),
451            bottom: T::from_length(value.into()),
452        }
453    }
454}
455impl<T: FromLength> Rect<T> {
456    /// Returns a Rect where the left, right, top and bottom values are all the same given absolute length
457    pub fn length<Input: Into<f32> + Copy>(value: Input) -> Self {
458        length::<Input, Self>(value)
459    }
460}
461
462/// Returns a value of the inferred type which represent a percentage
463pub fn percent<Input: Into<f32> + Copy, T: FromPercent>(percent: Input) -> T {
464    T::from_percent(percent)
465}
466
467/// Trait to create constant percent values from plain numbers
468pub trait FromPercent {
469    /// Converts into an `Into<f32>` into Self
470    fn from_percent<Input: Into<f32> + Copy>(percent: Input) -> Self;
471}
472impl FromPercent for f32 {
473    fn from_percent<Input: Into<f32> + Copy>(percent: Input) -> Self {
474        percent.into()
475    }
476}
477impl FromPercent for Option<f32> {
478    fn from_percent<Input: Into<f32> + Copy>(percent: Input) -> Self {
479        Some(percent.into())
480    }
481}
482impl<T: FromPercent> FromPercent for Point<T> {
483    fn from_percent<Input: Into<f32> + Copy>(percent: Input) -> Self {
484        Point { x: T::from_percent(percent.into()), y: T::from_percent(percent.into()) }
485    }
486}
487impl<T: FromPercent> Point<T> {
488    /// Returns a Point where both the x and y values are the constant percent value of the contained type
489    /// (e.g. 2.1, Some(2.1), or Dimension::Length(2.1))
490    pub fn percent<Input: Into<f32> + Copy>(percent_value: Input) -> Self {
491        percent::<Input, Self>(percent_value)
492    }
493}
494impl<T: FromPercent> FromPercent for Line<T> {
495    fn from_percent<Input: Into<f32> + Copy>(percent: Input) -> Self {
496        Line { start: T::from_percent(percent.into()), end: T::from_percent(percent.into()) }
497    }
498}
499impl<T: FromPercent> Line<T> {
500    /// Returns a Line where both the start and end values are the constant percent value of the contained type
501    /// (e.g. 2.1, Some(2.1), or Dimension::Length(2.1))
502    pub fn percent<Input: Into<f32> + Copy>(percent_value: Input) -> Self {
503        percent::<Input, Self>(percent_value)
504    }
505}
506impl<T: FromPercent> FromPercent for Size<T> {
507    fn from_percent<Input: Into<f32> + Copy>(percent: Input) -> Self {
508        Size { width: T::from_percent(percent.into()), height: T::from_percent(percent.into()) }
509    }
510}
511impl<T: FromPercent> Size<T> {
512    /// Returns a Size where both the width and height values are the constant percent value of the contained type
513    /// (e.g. 2.1, Some(2.1), or Dimension::Length(2.1))
514    pub fn percent<Input: Into<f32> + Copy>(percent_value: Input) -> Self {
515        percent::<Input, Self>(percent_value)
516    }
517}
518impl<T: FromPercent> FromPercent for Rect<T> {
519    fn from_percent<Input: Into<f32> + Copy>(percent: Input) -> Self {
520        Rect {
521            left: T::from_percent(percent.into()),
522            right: T::from_percent(percent.into()),
523            top: T::from_percent(percent.into()),
524            bottom: T::from_percent(percent.into()),
525        }
526    }
527}
528impl<T: FromPercent> Rect<T> {
529    /// Returns a Rect where the left, right, top and bottom values are all constant percent value of the contained type
530    /// (e.g. 2.1, Some(2.1), or Dimension::Length(2.1))
531    pub fn percent<Input: Into<f32> + Copy>(percent_value: Input) -> Self {
532        percent::<Input, Self>(percent_value)
533    }
534}
535
536/// Create a `Fraction` track sizing function (`fr` in CSS)
537#[cfg(feature = "grid")]
538pub fn fr<Input: Into<f32> + Copy, T: FromFlex>(flex: Input) -> T {
539    T::from_flex(flex)
540}
541
542/// Trait to create constant percent values from plain numbers
543pub trait FromFlex {
544    /// Converts into an `Into<f32>` into Self
545    fn from_flex<Input: Into<f32> + Copy>(flex: Input) -> Self;
546}
taffy/style_helpers.rs

taffy/
style_helpers.rs
