style.rs

  1use std::{iter, mem, ops::Range};
  2
  3use crate::{
  4    black, phi, point, quad, rems, AbsoluteLength, BorrowAppContext, BorrowWindow, Bounds,
  5    ContentMask, Corners, CornersRefinement, CursorStyle, DefiniteLength, Edges, EdgesRefinement,
  6    Font, 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
 17#[cfg(debug_assertions)]
 18pub struct DebugBelow;
 19
 20pub type StyleCascade = Cascade<Style>;
 21
 22#[derive(Clone, Refineable, Debug)]
 23#[refineable(Debug)]
 24pub struct Style {
 25    /// What layout strategy should be used?
 26    pub display: Display,
 27
 28    /// Should the element be painted on screen?
 29    pub visibility: Visibility,
 30
 31    // Overflow properties
 32    /// How children overflowing their container should affect layout
 33    #[refineable]
 34    pub overflow: Point<Overflow>,
 35    /// How much space (in points) should be reserved for the scrollbars of `Overflow::Scroll` and `Overflow::Auto` nodes.
 36    pub scrollbar_width: f32,
 37
 38    // Position properties
 39    /// What should the `position` value of this struct use as a base offset?
 40    pub position: Position,
 41    /// How should the position of this element be tweaked relative to the layout defined?
 42    #[refineable]
 43    pub inset: Edges<Length>,
 44
 45    // Size properies
 46    /// Sets the initial size of the item
 47    #[refineable]
 48    pub size: Size<Length>,
 49    /// Controls the minimum size of the item
 50    #[refineable]
 51    pub min_size: Size<Length>,
 52    /// Controls the maximum size of the item
 53    #[refineable]
 54    pub max_size: Size<Length>,
 55    /// Sets the preferred aspect ratio for the item. The ratio is calculated as width divided by height.
 56    pub aspect_ratio: Option<f32>,
 57
 58    // Spacing Properties
 59    /// How large should the margin be on each side?
 60    #[refineable]
 61    pub margin: Edges<Length>,
 62    /// How large should the padding be on each side?
 63    #[refineable]
 64    pub padding: Edges<DefiniteLength>,
 65    /// How large should the border be on each side?
 66    #[refineable]
 67    pub border_widths: Edges<AbsoluteLength>,
 68
 69    // Alignment properties
 70    /// How this node's children aligned in the cross/block axis?
 71    pub align_items: Option<AlignItems>,
 72    /// How this node should be aligned in the cross/block axis. Falls back to the parents [`AlignItems`] if not set
 73    pub align_self: Option<AlignSelf>,
 74    /// How should content contained within this item be aligned in the cross/block axis
 75    pub align_content: Option<AlignContent>,
 76    /// How should contained within this item be aligned in the main/inline axis
 77    pub justify_content: Option<JustifyContent>,
 78    /// How large should the gaps between items in a flex container be?
 79    #[refineable]
 80    pub gap: Size<DefiniteLength>,
 81
 82    // Flexbox properies
 83    /// Which direction does the main axis flow in?
 84    pub flex_direction: FlexDirection,
 85    /// Should elements wrap, or stay in a single line?
 86    pub flex_wrap: FlexWrap,
 87    /// Sets the initial main axis size of the item
 88    pub flex_basis: Length,
 89    /// 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.
 90    pub flex_grow: f32,
 91    /// 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.
 92    pub flex_shrink: f32,
 93
 94    /// The fill color of this element
 95    pub background: Option<Fill>,
 96
 97    /// The border color of this element
 98    pub border_color: Option<Hsla>,
 99
100    /// The radius of the corners of this element
101    #[refineable]
102    pub corner_radii: Corners<AbsoluteLength>,
103
104    /// Box Shadow of the element
105    pub box_shadow: SmallVec<[BoxShadow; 2]>,
106
107    /// TEXT
108    pub text: TextStyleRefinement,
109
110    /// The mouse cursor style shown when the mouse pointer is over an element.
111    pub mouse_cursor: Option<CursorStyle>,
112
113    pub z_index: Option<u8>,
114
115    #[cfg(debug_assertions)]
116    pub debug: bool,
117    #[cfg(debug_assertions)]
118    pub debug_below: bool,
119}
120
121impl Styled for StyleRefinement {
122    fn style(&mut self) -> &mut StyleRefinement {
123        self
124    }
125}
126
127#[derive(Default, Clone, Copy, Debug, Eq, PartialEq)]
128pub enum Visibility {
129    #[default]
130    Visible,
131    Hidden,
132}
133
134#[derive(Clone, Debug)]
135pub struct BoxShadow {
136    pub color: Hsla,
137    pub offset: Point<Pixels>,
138    pub blur_radius: Pixels,
139    pub spread_radius: Pixels,
140}
141
142#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
143pub enum WhiteSpace {
144    #[default]
145    Normal,
146    Nowrap,
147}
148
149#[derive(Refineable, Clone, Debug)]
150#[refineable(Debug)]
151pub struct TextStyle {
152    pub color: Hsla,
153    pub font_family: SharedString,
154    pub font_features: FontFeatures,
155    pub font_size: AbsoluteLength,
156    pub line_height: DefiniteLength,
157    pub font_weight: FontWeight,
158    pub font_style: FontStyle,
159    pub background_color: Option<Hsla>,
160    pub underline: Option<UnderlineStyle>,
161    pub white_space: WhiteSpace,
162}
163
164impl Default for TextStyle {
165    fn default() -> Self {
166        TextStyle {
167            color: black(),
168            font_family: "Helvetica".into(), // todo!("Get a font we know exists on the system")
169            font_features: FontFeatures::default(),
170            font_size: rems(1.).into(),
171            line_height: phi(),
172            font_weight: FontWeight::default(),
173            font_style: FontStyle::default(),
174            background_color: None,
175            underline: None,
176            white_space: WhiteSpace::Normal,
177        }
178    }
179}
180
181impl TextStyle {
182    pub fn highlight(mut self, style: impl Into<HighlightStyle>) -> Self {
183        let style = style.into();
184        if let Some(weight) = style.font_weight {
185            self.font_weight = weight;
186        }
187        if let Some(style) = style.font_style {
188            self.font_style = style;
189        }
190
191        if let Some(color) = style.color {
192            self.color = self.color.blend(color);
193        }
194
195        if let Some(factor) = style.fade_out {
196            self.color.fade_out(factor);
197        }
198
199        if let Some(background_color) = style.background_color {
200            self.background_color = Some(background_color);
201        }
202
203        if let Some(underline) = style.underline {
204            self.underline = Some(underline);
205        }
206
207        self
208    }
209
210    pub fn font(&self) -> Font {
211        Font {
212            family: self.font_family.clone(),
213            features: self.font_features.clone(),
214            weight: self.font_weight,
215            style: self.font_style,
216        }
217    }
218
219    /// Returns the rounded line height in pixels.
220    pub fn line_height_in_pixels(&self, rem_size: Pixels) -> Pixels {
221        self.line_height.to_pixels(self.font_size, rem_size).round()
222    }
223
224    pub fn to_run(&self, len: usize) -> TextRun {
225        TextRun {
226            len,
227            font: Font {
228                family: self.font_family.clone(),
229                features: Default::default(),
230                weight: self.font_weight,
231                style: self.font_style,
232            },
233            color: self.color,
234            background_color: self.background_color,
235            underline: self.underline.clone(),
236        }
237    }
238}
239
240#[derive(Copy, Clone, Debug, Default, PartialEq)]
241pub struct HighlightStyle {
242    pub color: Option<Hsla>,
243    pub font_weight: Option<FontWeight>,
244    pub font_style: Option<FontStyle>,
245    pub background_color: Option<Hsla>,
246    pub underline: Option<UnderlineStyle>,
247    pub fade_out: Option<f32>,
248}
249
250impl Eq for HighlightStyle {}
251
252impl Style {
253    pub fn text_style(&self) -> Option<&TextStyleRefinement> {
254        if self.text.is_some() {
255            Some(&self.text)
256        } else {
257            None
258        }
259    }
260
261    pub fn overflow_mask(
262        &self,
263        bounds: Bounds<Pixels>,
264        rem_size: Pixels,
265    ) -> Option<ContentMask<Pixels>> {
266        match self.overflow {
267            Point {
268                x: Overflow::Visible,
269                y: Overflow::Visible,
270            } => None,
271            _ => {
272                let mut min = bounds.origin;
273                let mut max = bounds.lower_right();
274
275                if self
276                    .border_color
277                    .map_or(false, |color| !color.is_transparent())
278                {
279                    min.x += self.border_widths.left.to_pixels(rem_size);
280                    max.x -= self.border_widths.right.to_pixels(rem_size);
281                    min.y += self.border_widths.top.to_pixels(rem_size);
282                    max.y -= self.border_widths.bottom.to_pixels(rem_size);
283                }
284
285                let bounds = match (
286                    self.overflow.x == Overflow::Visible,
287                    self.overflow.y == Overflow::Visible,
288                ) {
289                    // x and y both visible
290                    (true, true) => return None,
291                    // x visible, y hidden
292                    (true, false) => Bounds::from_corners(
293                        point(min.x, bounds.origin.y),
294                        point(max.x, bounds.lower_right().y),
295                    ),
296                    // x hidden, y visible
297                    (false, true) => Bounds::from_corners(
298                        point(bounds.origin.x, min.y),
299                        point(bounds.lower_right().x, max.y),
300                    ),
301                    // both hidden
302                    (false, false) => Bounds::from_corners(min, max),
303                };
304
305                Some(ContentMask { bounds })
306            }
307        }
308    }
309
310    // pub fn apply_text_style<C, F, R>(&self, cx: &mut C, f: F) -> R
311    // where
312    //     C: BorrowAppContext,
313    //     F: FnOnce(&mut C) -> R,
314    // {
315    //     if self.text.is_some() {
316    //         cx.with_text_style(Some(self.text.clone()), f)
317    //     } else {
318    //         f(cx)
319    //     }
320    // }
321
322    // /// Apply overflow to content mask
323    // pub fn apply_overflow<C, F, R>(&self, bounds: Bounds<Pixels>, cx: &mut C, f: F) -> R
324    // where
325    //     C: BorrowWindow,
326    //     F: FnOnce(&mut C) -> R,
327    // {
328    //     let current_mask = cx.content_mask();
329
330    //     let min = current_mask.bounds.origin;
331    //     let max = current_mask.bounds.lower_right();
332
333    //     let mask_bounds = match (
334    //         self.overflow.x == Overflow::Visible,
335    //         self.overflow.y == Overflow::Visible,
336    //     ) {
337    //         // x and y both visible
338    //         (true, true) => return f(cx),
339    //         // x visible, y hidden
340    //         (true, false) => Bounds::from_corners(
341    //             point(min.x, bounds.origin.y),
342    //             point(max.x, bounds.lower_right().y),
343    //         ),
344    //         // x hidden, y visible
345    //         (false, true) => Bounds::from_corners(
346    //             point(bounds.origin.x, min.y),
347    //             point(bounds.lower_right().x, max.y),
348    //         ),
349    //         // both hidden
350    //         (false, false) => bounds,
351    //     };
352    //     let mask = ContentMask {
353    //         bounds: mask_bounds,
354    //     };
355
356    //     cx.with_content_mask(Some(mask), f)
357    // }
358
359    /// Paints the background of an element styled with this style.
360    pub fn paint(
361        &self,
362        bounds: Bounds<Pixels>,
363        cx: &mut WindowContext,
364        continuation: impl FnOnce(&mut WindowContext),
365    ) {
366        #[cfg(debug_assertions)]
367        if self.debug_below {
368            cx.set_global(DebugBelow)
369        }
370
371        #[cfg(debug_assertions)]
372        if self.debug || cx.has_global::<DebugBelow>() {
373            cx.paint_quad(crate::outline(bounds, crate::red()));
374        }
375
376        let rem_size = cx.rem_size();
377
378        cx.with_z_index(0, |cx| {
379            cx.paint_shadows(
380                bounds,
381                self.corner_radii.to_pixels(bounds.size, rem_size),
382                &self.box_shadow,
383            );
384        });
385
386        let background_color = self.background.as_ref().and_then(Fill::color);
387        if background_color.is_some() {
388            cx.with_z_index(1, |cx| {
389                cx.paint_quad(quad(
390                    bounds,
391                    self.corner_radii.to_pixels(bounds.size, rem_size),
392                    background_color.unwrap_or_default(),
393                    Edges::default(),
394                    Hsla::transparent_black(),
395                ));
396            });
397        }
398
399        cx.with_z_index(2, |cx| {
400            continuation(cx);
401        });
402
403        if self.is_border_visible() {
404            cx.with_z_index(3, |cx| {
405                cx.paint_quad(quad(
406                    bounds,
407                    self.corner_radii.to_pixels(bounds.size, rem_size),
408                    Hsla::transparent_black(),
409                    self.border_widths.to_pixels(rem_size),
410                    self.border_color.unwrap_or_default(),
411                ));
412            });
413        }
414
415        #[cfg(debug_assertions)]
416        if self.debug_below {
417            cx.remove_global::<DebugBelow>();
418        }
419    }
420
421    fn is_border_visible(&self) -> bool {
422        self.border_color
423            .map_or(false, |color| !color.is_transparent())
424            && self.border_widths.any(|length| !length.is_zero())
425    }
426}
427
428impl Default for Style {
429    fn default() -> Self {
430        Style {
431            display: Display::Block,
432            visibility: Visibility::Visible,
433            overflow: Point {
434                x: Overflow::Visible,
435                y: Overflow::Visible,
436            },
437            scrollbar_width: 0.0,
438            position: Position::Relative,
439            inset: Edges::auto(),
440            margin: Edges::<Length>::zero(),
441            padding: Edges::<DefiniteLength>::zero(),
442            border_widths: Edges::<AbsoluteLength>::zero(),
443            size: Size::auto(),
444            min_size: Size::auto(),
445            max_size: Size::auto(),
446            aspect_ratio: None,
447            gap: Size::default(),
448            // Aligment
449            align_items: None,
450            align_self: None,
451            align_content: None,
452            justify_content: None,
453            // Flexbox
454            flex_direction: FlexDirection::Row,
455            flex_wrap: FlexWrap::NoWrap,
456            flex_grow: 0.0,
457            flex_shrink: 1.0,
458            flex_basis: Length::Auto,
459            background: None,
460            border_color: None,
461            corner_radii: Corners::default(),
462            box_shadow: Default::default(),
463            text: TextStyleRefinement::default(),
464            mouse_cursor: None,
465            z_index: None,
466
467            #[cfg(debug_assertions)]
468            debug: false,
469            #[cfg(debug_assertions)]
470            debug_below: false,
471        }
472    }
473}
474
475#[derive(Refineable, Copy, Clone, Default, Debug, PartialEq, Eq)]
476#[refineable(Debug)]
477pub struct UnderlineStyle {
478    pub thickness: Pixels,
479    pub color: Option<Hsla>,
480    pub wavy: bool,
481}
482
483#[derive(Clone, Debug)]
484pub enum Fill {
485    Color(Hsla),
486}
487
488impl Fill {
489    pub fn color(&self) -> Option<Hsla> {
490        match self {
491            Fill::Color(color) => Some(*color),
492        }
493    }
494}
495
496impl Default for Fill {
497    fn default() -> Self {
498        Self::Color(Hsla::default())
499    }
500}
501
502impl From<Hsla> for Fill {
503    fn from(color: Hsla) -> Self {
504        Self::Color(color)
505    }
506}
507
508impl From<TextStyle> for HighlightStyle {
509    fn from(other: TextStyle) -> Self {
510        Self::from(&other)
511    }
512}
513
514impl From<&TextStyle> for HighlightStyle {
515    fn from(other: &TextStyle) -> Self {
516        Self {
517            color: Some(other.color),
518            font_weight: Some(other.font_weight),
519            font_style: Some(other.font_style),
520            background_color: other.background_color,
521            underline: other.underline.clone(),
522            fade_out: None,
523        }
524    }
525}
526
527impl HighlightStyle {
528    pub fn highlight(&mut self, other: HighlightStyle) {
529        match (self.color, other.color) {
530            (Some(self_color), Some(other_color)) => {
531                self.color = Some(Hsla::blend(other_color, self_color));
532            }
533            (None, Some(other_color)) => {
534                self.color = Some(other_color);
535            }
536            _ => {}
537        }
538
539        if other.font_weight.is_some() {
540            self.font_weight = other.font_weight;
541        }
542
543        if other.font_style.is_some() {
544            self.font_style = other.font_style;
545        }
546
547        if other.background_color.is_some() {
548            self.background_color = other.background_color;
549        }
550
551        if other.underline.is_some() {
552            self.underline = other.underline;
553        }
554
555        match (other.fade_out, self.fade_out) {
556            (Some(source_fade), None) => self.fade_out = Some(source_fade),
557            (Some(source_fade), Some(dest_fade)) => {
558                self.fade_out = Some((dest_fade * (1. + source_fade)).clamp(0., 1.));
559            }
560            _ => {}
561        }
562    }
563}
564
565impl From<Hsla> for HighlightStyle {
566    fn from(color: Hsla) -> Self {
567        Self {
568            color: Some(color),
569            ..Default::default()
570        }
571    }
572}
573
574impl From<FontWeight> for HighlightStyle {
575    fn from(font_weight: FontWeight) -> Self {
576        Self {
577            font_weight: Some(font_weight),
578            ..Default::default()
579        }
580    }
581}
582
583impl From<FontStyle> for HighlightStyle {
584    fn from(font_style: FontStyle) -> Self {
585        Self {
586            font_style: Some(font_style),
587            ..Default::default()
588        }
589    }
590}
591
592impl From<Rgba> for HighlightStyle {
593    fn from(color: Rgba) -> Self {
594        Self {
595            color: Some(color.into()),
596            ..Default::default()
597        }
598    }
599}
600
601pub fn combine_highlights(
602    a: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
603    b: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
604) -> impl Iterator<Item = (Range<usize>, HighlightStyle)> {
605    let mut endpoints = Vec::new();
606    let mut highlights = Vec::new();
607    for (range, highlight) in a.into_iter().chain(b) {
608        if !range.is_empty() {
609            let highlight_id = highlights.len();
610            endpoints.push((range.start, highlight_id, true));
611            endpoints.push((range.end, highlight_id, false));
612            highlights.push(highlight);
613        }
614    }
615    endpoints.sort_unstable_by_key(|(position, _, _)| *position);
616    let mut endpoints = endpoints.into_iter().peekable();
617
618    let mut active_styles = HashSet::default();
619    let mut ix = 0;
620    iter::from_fn(move || {
621        while let Some((endpoint_ix, highlight_id, is_start)) = endpoints.peek() {
622            let prev_index = mem::replace(&mut ix, *endpoint_ix);
623            if ix > prev_index && !active_styles.is_empty() {
624                let mut current_style = HighlightStyle::default();
625                for highlight_id in &active_styles {
626                    current_style.highlight(highlights[*highlight_id]);
627                }
628                return Some((prev_index..ix, current_style));
629            }
630
631            if *is_start {
632                active_styles.insert(*highlight_id);
633            } else {
634                active_styles.remove(highlight_id);
635            }
636            endpoints.next();
637        }
638        None
639    })
640}
641
642#[cfg(test)]
643mod tests {
644    use crate::{blue, green, red, yellow};
645
646    use super::*;
647
648    #[test]
649    fn test_combine_highlights() {
650        assert_eq!(
651            combine_highlights(
652                [
653                    (0..5, green().into()),
654                    (4..10, FontWeight::BOLD.into()),
655                    (15..20, yellow().into()),
656                ],
657                [
658                    (2..6, FontStyle::Italic.into()),
659                    (1..3, blue().into()),
660                    (21..23, red().into()),
661                ]
662            )
663            .collect::<Vec<_>>(),
664            [
665                (
666                    0..1,
667                    HighlightStyle {
668                        color: Some(green()),
669                        ..Default::default()
670                    }
671                ),
672                (
673                    1..2,
674                    HighlightStyle {
675                        color: Some(green()),
676                        ..Default::default()
677                    }
678                ),
679                (
680                    2..3,
681                    HighlightStyle {
682                        color: Some(green()),
683                        font_style: Some(FontStyle::Italic),
684                        ..Default::default()
685                    }
686                ),
687                (
688                    3..4,
689                    HighlightStyle {
690                        color: Some(green()),
691                        font_style: Some(FontStyle::Italic),
692                        ..Default::default()
693                    }
694                ),
695                (
696                    4..5,
697                    HighlightStyle {
698                        color: Some(green()),
699                        font_weight: Some(FontWeight::BOLD),
700                        font_style: Some(FontStyle::Italic),
701                        ..Default::default()
702                    }
703                ),
704                (
705                    5..6,
706                    HighlightStyle {
707                        font_weight: Some(FontWeight::BOLD),
708                        font_style: Some(FontStyle::Italic),
709                        ..Default::default()
710                    }
711                ),
712                (
713                    6..10,
714                    HighlightStyle {
715                        font_weight: Some(FontWeight::BOLD),
716                        ..Default::default()
717                    }
718                ),
719                (
720                    15..20,
721                    HighlightStyle {
722                        color: Some(yellow()),
723                        ..Default::default()
724                    }
725                ),
726                (
727                    21..23,
728                    HighlightStyle {
729                        color: Some(red()),
730                        ..Default::default()
731                    }
732                )
733            ]
734        );
735    }
736}