style.rs

  1use std::{iter, mem, ops::Range};
  2
  3use crate::{
  4    black, phi, point, rems, AbsoluteLength, BorrowAppContext, BorrowWindow, Bounds, ContentMask,
  5    Corners, CornersRefinement, CursorStyle, DefiniteLength, Edges, EdgesRefinement, Font,
  6    FontFeatures, FontStyle, FontWeight, Hsla, Length, Pixels, Point, PointRefinement, Rgba,
  7    SharedString, Size, SizeRefinement, Styled, TextRun, WindowContext,
  8};
  9use collections::HashSet;
 10use refineable::{Cascade, Refineable};
 11use smallvec::SmallVec;
 12pub use taffy::style::{
 13    AlignContent, AlignItems, AlignSelf, Display, FlexDirection, FlexWrap, JustifyContent,
 14    Overflow, Position,
 15};
 16
 17pub type StyleCascade = Cascade<Style>;
 18
 19#[derive(Clone, Refineable, Debug)]
 20#[refineable(Debug)]
 21pub struct Style {
 22    /// What layout strategy should be used?
 23    pub display: Display,
 24
 25    /// Should the element be painted on screen?
 26    pub visibility: Visibility,
 27
 28    // Overflow properties
 29    /// How children overflowing their container should affect layout
 30    #[refineable]
 31    pub overflow: Point<Overflow>,
 32    /// How much space (in points) should be reserved for the scrollbars of `Overflow::Scroll` and `Overflow::Auto` nodes.
 33    pub scrollbar_width: f32,
 34
 35    // Position properties
 36    /// What should the `position` value of this struct use as a base offset?
 37    pub position: Position,
 38    /// How should the position of this element be tweaked relative to the layout defined?
 39    #[refineable]
 40    pub inset: Edges<Length>,
 41
 42    // Size properies
 43    /// Sets the initial size of the item
 44    #[refineable]
 45    pub size: Size<Length>,
 46    /// Controls the minimum size of the item
 47    #[refineable]
 48    pub min_size: Size<Length>,
 49    /// Controls the maximum size of the item
 50    #[refineable]
 51    pub max_size: Size<Length>,
 52    /// Sets the preferred aspect ratio for the item. The ratio is calculated as width divided by height.
 53    pub aspect_ratio: Option<f32>,
 54
 55    // Spacing Properties
 56    /// How large should the margin be on each side?
 57    #[refineable]
 58    pub margin: Edges<Length>,
 59    /// How large should the padding be on each side?
 60    #[refineable]
 61    pub padding: Edges<DefiniteLength>,
 62    /// How large should the border be on each side?
 63    #[refineable]
 64    pub border_widths: Edges<AbsoluteLength>,
 65
 66    // Alignment properties
 67    /// How this node's children aligned in the cross/block axis?
 68    pub align_items: Option<AlignItems>,
 69    /// How this node should be aligned in the cross/block axis. Falls back to the parents [`AlignItems`] if not set
 70    pub align_self: Option<AlignSelf>,
 71    /// How should content contained within this item be aligned in the cross/block axis
 72    pub align_content: Option<AlignContent>,
 73    /// How should contained within this item be aligned in the main/inline axis
 74    pub justify_content: Option<JustifyContent>,
 75    /// How large should the gaps between items in a flex container be?
 76    #[refineable]
 77    pub gap: Size<DefiniteLength>,
 78
 79    // Flexbox properies
 80    /// Which direction does the main axis flow in?
 81    pub flex_direction: FlexDirection,
 82    /// Should elements wrap, or stay in a single line?
 83    pub flex_wrap: FlexWrap,
 84    /// Sets the initial main axis size of the item
 85    pub flex_basis: Length,
 86    /// The relative rate at which this item grows when it is expanding to fill space, 0.0 is the default value, and this value must be positive.
 87    pub flex_grow: f32,
 88    /// The relative rate at which this item shrinks when it is contracting to fit into space, 1.0 is the default value, and this value must be positive.
 89    pub flex_shrink: f32,
 90
 91    /// The fill color of this element
 92    pub background: Option<Fill>,
 93
 94    /// The border color of this element
 95    pub border_color: Option<Hsla>,
 96
 97    /// The radius of the corners of this element
 98    #[refineable]
 99    pub corner_radii: Corners<AbsoluteLength>,
100
101    /// Box Shadow of the element
102    pub box_shadow: SmallVec<[BoxShadow; 2]>,
103
104    /// TEXT
105    pub text: TextStyleRefinement,
106
107    /// The mouse cursor style shown when the mouse pointer is over an element.
108    pub mouse_cursor: Option<CursorStyle>,
109
110    pub z_index: Option<u32>,
111}
112
113impl Styled for StyleRefinement {
114    fn style(&mut self) -> &mut StyleRefinement {
115        self
116    }
117}
118
119#[derive(Default, Clone, Copy, Debug, Eq, PartialEq)]
120pub enum Visibility {
121    #[default]
122    Visible,
123    Hidden,
124}
125
126#[derive(Clone, Debug)]
127pub struct BoxShadow {
128    pub color: Hsla,
129    pub offset: Point<Pixels>,
130    pub blur_radius: Pixels,
131    pub spread_radius: Pixels,
132}
133
134#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
135pub enum WhiteSpace {
136    #[default]
137    Normal,
138    Nowrap,
139}
140
141#[derive(Refineable, Clone, Debug)]
142#[refineable(Debug)]
143pub struct TextStyle {
144    pub color: Hsla,
145    pub font_family: SharedString,
146    pub font_features: FontFeatures,
147    pub font_size: AbsoluteLength,
148    pub line_height: DefiniteLength,
149    pub font_weight: FontWeight,
150    pub font_style: FontStyle,
151    pub background_color: Option<Hsla>,
152    pub underline: Option<UnderlineStyle>,
153    pub white_space: WhiteSpace,
154}
155
156impl Default for TextStyle {
157    fn default() -> Self {
158        TextStyle {
159            color: black(),
160            font_family: "Helvetica".into(), // todo!("Get a font we know exists on the system")
161            font_features: FontFeatures::default(),
162            font_size: rems(1.).into(),
163            line_height: phi(),
164            font_weight: FontWeight::default(),
165            font_style: FontStyle::default(),
166            background_color: None,
167            underline: None,
168            white_space: WhiteSpace::Normal,
169        }
170    }
171}
172
173impl TextStyle {
174    pub fn highlight(mut self, style: impl Into<HighlightStyle>) -> Self {
175        let style = style.into();
176        if let Some(weight) = style.font_weight {
177            self.font_weight = weight;
178        }
179        if let Some(style) = style.font_style {
180            self.font_style = style;
181        }
182
183        if let Some(color) = style.color {
184            self.color = self.color.blend(color);
185        }
186
187        if let Some(factor) = style.fade_out {
188            self.color.fade_out(factor);
189        }
190
191        if let Some(background_color) = style.background_color {
192            self.background_color = Some(background_color);
193        }
194
195        if let Some(underline) = style.underline {
196            self.underline = Some(underline);
197        }
198
199        self
200    }
201
202    pub fn font(&self) -> Font {
203        Font {
204            family: self.font_family.clone(),
205            features: self.font_features.clone(),
206            weight: self.font_weight,
207            style: self.font_style,
208        }
209    }
210
211    pub fn line_height_in_pixels(&self, rem_size: Pixels) -> Pixels {
212        self.line_height.to_pixels(self.font_size, rem_size)
213    }
214
215    pub fn to_run(&self, len: usize) -> TextRun {
216        TextRun {
217            len,
218            font: Font {
219                family: self.font_family.clone(),
220                features: Default::default(),
221                weight: self.font_weight,
222                style: self.font_style,
223            },
224            color: self.color,
225            background_color: self.background_color,
226            underline: self.underline.clone(),
227        }
228    }
229}
230
231#[derive(Copy, Clone, Debug, Default, PartialEq)]
232pub struct HighlightStyle {
233    pub color: Option<Hsla>,
234    pub font_weight: Option<FontWeight>,
235    pub font_style: Option<FontStyle>,
236    pub background_color: Option<Hsla>,
237    pub underline: Option<UnderlineStyle>,
238    pub fade_out: Option<f32>,
239}
240
241impl Eq for HighlightStyle {}
242
243impl Style {
244    pub fn text_style(&self) -> Option<&TextStyleRefinement> {
245        if self.text.is_some() {
246            Some(&self.text)
247        } else {
248            None
249        }
250    }
251
252    pub fn overflow_mask(&self, bounds: Bounds<Pixels>) -> Option<ContentMask<Pixels>> {
253        match self.overflow {
254            Point {
255                x: Overflow::Visible,
256                y: Overflow::Visible,
257            } => None,
258            _ => {
259                let current_mask = bounds;
260                let min = current_mask.origin;
261                let max = current_mask.lower_right();
262                let bounds = match (
263                    self.overflow.x == Overflow::Visible,
264                    self.overflow.y == Overflow::Visible,
265                ) {
266                    // x and y both visible
267                    (true, true) => return None,
268                    // x visible, y hidden
269                    (true, false) => Bounds::from_corners(
270                        point(min.x, bounds.origin.y),
271                        point(max.x, bounds.lower_right().y),
272                    ),
273                    // x hidden, y visible
274                    (false, true) => Bounds::from_corners(
275                        point(bounds.origin.x, min.y),
276                        point(bounds.lower_right().x, max.y),
277                    ),
278                    // both hidden
279                    (false, false) => bounds,
280                };
281                Some(ContentMask { bounds })
282            }
283        }
284    }
285
286    pub fn apply_text_style<C, F, R>(&self, cx: &mut C, f: F) -> R
287    where
288        C: BorrowAppContext,
289        F: FnOnce(&mut C) -> R,
290    {
291        if self.text.is_some() {
292            cx.with_text_style(Some(self.text.clone()), f)
293        } else {
294            f(cx)
295        }
296    }
297
298    /// Apply overflow to content mask
299    pub fn apply_overflow<C, F, R>(&self, bounds: Bounds<Pixels>, cx: &mut C, f: F) -> R
300    where
301        C: BorrowWindow,
302        F: FnOnce(&mut C) -> R,
303    {
304        let current_mask = cx.content_mask();
305
306        let min = current_mask.bounds.origin;
307        let max = current_mask.bounds.lower_right();
308
309        let mask_bounds = match (
310            self.overflow.x == Overflow::Visible,
311            self.overflow.y == Overflow::Visible,
312        ) {
313            // x and y both visible
314            (true, true) => return f(cx),
315            // x visible, y hidden
316            (true, false) => Bounds::from_corners(
317                point(min.x, bounds.origin.y),
318                point(max.x, bounds.lower_right().y),
319            ),
320            // x hidden, y visible
321            (false, true) => Bounds::from_corners(
322                point(bounds.origin.x, min.y),
323                point(bounds.lower_right().x, max.y),
324            ),
325            // both hidden
326            (false, false) => bounds,
327        };
328        let mask = ContentMask {
329            bounds: mask_bounds,
330        };
331
332        cx.with_content_mask(Some(mask), f)
333    }
334
335    /// Paints the background of an element styled with this style.
336    pub fn paint(&self, bounds: Bounds<Pixels>, cx: &mut WindowContext) {
337        let rem_size = cx.rem_size();
338
339        cx.with_z_index(0, |cx| {
340            cx.paint_shadows(
341                bounds,
342                self.corner_radii.to_pixels(bounds.size, rem_size),
343                &self.box_shadow,
344            );
345        });
346
347        let background_color = self.background.as_ref().and_then(Fill::color);
348        if background_color.is_some() || self.is_border_visible() {
349            cx.with_z_index(1, |cx| {
350                cx.paint_quad(
351                    bounds,
352                    self.corner_radii.to_pixels(bounds.size, rem_size),
353                    background_color.unwrap_or_default(),
354                    self.border_widths.to_pixels(rem_size),
355                    self.border_color.unwrap_or_default(),
356                );
357            });
358        }
359    }
360
361    fn is_border_visible(&self) -> bool {
362        self.border_color
363            .map_or(false, |color| !color.is_transparent())
364            && self.border_widths.any(|length| !length.is_zero())
365    }
366}
367
368impl Default for Style {
369    fn default() -> Self {
370        Style {
371            display: Display::Block,
372            visibility: Visibility::Visible,
373            overflow: Point {
374                x: Overflow::Visible,
375                y: Overflow::Visible,
376            },
377            scrollbar_width: 0.0,
378            position: Position::Relative,
379            inset: Edges::auto(),
380            margin: Edges::<Length>::zero(),
381            padding: Edges::<DefiniteLength>::zero(),
382            border_widths: Edges::<AbsoluteLength>::zero(),
383            size: Size::auto(),
384            min_size: Size::auto(),
385            max_size: Size::auto(),
386            aspect_ratio: None,
387            gap: Size::zero(),
388            // Aligment
389            align_items: None,
390            align_self: None,
391            align_content: None,
392            justify_content: None,
393            // Flexbox
394            flex_direction: FlexDirection::Row,
395            flex_wrap: FlexWrap::NoWrap,
396            flex_grow: 0.0,
397            flex_shrink: 1.0,
398            flex_basis: Length::Auto,
399            background: None,
400            border_color: None,
401            corner_radii: Corners::default(),
402            box_shadow: Default::default(),
403            text: TextStyleRefinement::default(),
404            mouse_cursor: None,
405            z_index: None,
406        }
407    }
408}
409
410#[derive(Refineable, Copy, Clone, Default, Debug, PartialEq, Eq)]
411#[refineable(Debug)]
412pub struct UnderlineStyle {
413    pub thickness: Pixels,
414    pub color: Option<Hsla>,
415    pub wavy: bool,
416}
417
418#[derive(Clone, Debug)]
419pub enum Fill {
420    Color(Hsla),
421}
422
423impl Fill {
424    pub fn color(&self) -> Option<Hsla> {
425        match self {
426            Fill::Color(color) => Some(*color),
427        }
428    }
429}
430
431impl Default for Fill {
432    fn default() -> Self {
433        Self::Color(Hsla::default())
434    }
435}
436
437impl From<Hsla> for Fill {
438    fn from(color: Hsla) -> Self {
439        Self::Color(color)
440    }
441}
442
443impl From<TextStyle> for HighlightStyle {
444    fn from(other: TextStyle) -> Self {
445        Self::from(&other)
446    }
447}
448
449impl From<&TextStyle> for HighlightStyle {
450    fn from(other: &TextStyle) -> Self {
451        Self {
452            color: Some(other.color),
453            font_weight: Some(other.font_weight),
454            font_style: Some(other.font_style),
455            background_color: other.background_color,
456            underline: other.underline.clone(),
457            fade_out: None,
458        }
459    }
460}
461
462impl HighlightStyle {
463    pub fn highlight(&mut self, other: HighlightStyle) {
464        match (self.color, other.color) {
465            (Some(self_color), Some(other_color)) => {
466                self.color = Some(Hsla::blend(other_color, self_color));
467            }
468            (None, Some(other_color)) => {
469                self.color = Some(other_color);
470            }
471            _ => {}
472        }
473
474        if other.font_weight.is_some() {
475            self.font_weight = other.font_weight;
476        }
477
478        if other.font_style.is_some() {
479            self.font_style = other.font_style;
480        }
481
482        if other.background_color.is_some() {
483            self.background_color = other.background_color;
484        }
485
486        if other.underline.is_some() {
487            self.underline = other.underline;
488        }
489
490        match (other.fade_out, self.fade_out) {
491            (Some(source_fade), None) => self.fade_out = Some(source_fade),
492            (Some(source_fade), Some(dest_fade)) => {
493                self.fade_out = Some((dest_fade * (1. + source_fade)).clamp(0., 1.));
494            }
495            _ => {}
496        }
497    }
498}
499
500impl From<Hsla> for HighlightStyle {
501    fn from(color: Hsla) -> Self {
502        Self {
503            color: Some(color),
504            ..Default::default()
505        }
506    }
507}
508
509impl From<FontWeight> for HighlightStyle {
510    fn from(font_weight: FontWeight) -> Self {
511        Self {
512            font_weight: Some(font_weight),
513            ..Default::default()
514        }
515    }
516}
517
518impl From<FontStyle> for HighlightStyle {
519    fn from(font_style: FontStyle) -> Self {
520        Self {
521            font_style: Some(font_style),
522            ..Default::default()
523        }
524    }
525}
526
527impl From<Rgba> for HighlightStyle {
528    fn from(color: Rgba) -> Self {
529        Self {
530            color: Some(color.into()),
531            ..Default::default()
532        }
533    }
534}
535
536pub fn combine_highlights(
537    a: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
538    b: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
539) -> impl Iterator<Item = (Range<usize>, HighlightStyle)> {
540    let mut endpoints = Vec::new();
541    let mut highlights = Vec::new();
542    for (range, highlight) in a.into_iter().chain(b) {
543        if !range.is_empty() {
544            let highlight_id = highlights.len();
545            endpoints.push((range.start, highlight_id, true));
546            endpoints.push((range.end, highlight_id, false));
547            highlights.push(highlight);
548        }
549    }
550    endpoints.sort_unstable_by_key(|(position, _, _)| *position);
551    let mut endpoints = endpoints.into_iter().peekable();
552
553    let mut active_styles = HashSet::default();
554    let mut ix = 0;
555    iter::from_fn(move || {
556        while let Some((endpoint_ix, highlight_id, is_start)) = endpoints.peek() {
557            let prev_index = mem::replace(&mut ix, *endpoint_ix);
558            if ix > prev_index && !active_styles.is_empty() {
559                let mut current_style = HighlightStyle::default();
560                for highlight_id in &active_styles {
561                    current_style.highlight(highlights[*highlight_id]);
562                }
563                return Some((prev_index..ix, current_style));
564            }
565
566            if *is_start {
567                active_styles.insert(*highlight_id);
568            } else {
569                active_styles.remove(highlight_id);
570            }
571            endpoints.next();
572        }
573        None
574    })
575}
576
577#[cfg(test)]
578mod tests {
579    use crate::{blue, green, red, yellow};
580
581    use super::*;
582
583    #[test]
584    fn test_combine_highlights() {
585        assert_eq!(
586            combine_highlights(
587                [
588                    (0..5, green().into()),
589                    (4..10, FontWeight::BOLD.into()),
590                    (15..20, yellow().into()),
591                ],
592                [
593                    (2..6, FontStyle::Italic.into()),
594                    (1..3, blue().into()),
595                    (21..23, red().into()),
596                ]
597            )
598            .collect::<Vec<_>>(),
599            [
600                (
601                    0..1,
602                    HighlightStyle {
603                        color: Some(green()),
604                        ..Default::default()
605                    }
606                ),
607                (
608                    1..2,
609                    HighlightStyle {
610                        color: Some(blue()),
611                        ..Default::default()
612                    }
613                ),
614                (
615                    2..3,
616                    HighlightStyle {
617                        color: Some(blue()),
618                        font_style: Some(FontStyle::Italic),
619                        ..Default::default()
620                    }
621                ),
622                (
623                    3..4,
624                    HighlightStyle {
625                        color: Some(green()),
626                        font_style: Some(FontStyle::Italic),
627                        ..Default::default()
628                    }
629                ),
630                (
631                    4..5,
632                    HighlightStyle {
633                        color: Some(green()),
634                        font_weight: Some(FontWeight::BOLD),
635                        font_style: Some(FontStyle::Italic),
636                        ..Default::default()
637                    }
638                ),
639                (
640                    5..6,
641                    HighlightStyle {
642                        font_weight: Some(FontWeight::BOLD),
643                        font_style: Some(FontStyle::Italic),
644                        ..Default::default()
645                    }
646                ),
647                (
648                    6..10,
649                    HighlightStyle {
650                        font_weight: Some(FontWeight::BOLD),
651                        ..Default::default()
652                    }
653                ),
654                (
655                    15..20,
656                    HighlightStyle {
657                        color: Some(yellow()),
658                        ..Default::default()
659                    }
660                ),
661                (
662                    21..23,
663                    HighlightStyle {
664                        color: Some(red()),
665                        ..Default::default()
666                    }
667                )
668            ]
669        );
670    }
671}