style.rs

  1use std::{iter, mem, ops::Range};
  2
  3use crate::{
  4    black, phi, point, quad, rems, AbsoluteLength, Bounds, ContentMask, Corners, CornersRefinement,
  5    CursorStyle, DefiniteLength, Edges, EdgesRefinement, ElementContext, Font, FontFeatures,
  6    FontStyle, FontWeight, Hsla, Length, Pixels, Point, PointRefinement, Rgba, SharedString, Size,
  7    SizeRefinement, Styled, TextRun,
  8};
  9use collections::HashSet;
 10use refineable::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)]
 18/// Use this struct for interfacing with the 'debug_below' styling from your own elements.
 19/// If a parent element has this style set on it, then this struct will be set as a global in
 20/// GPUI.
 21pub struct DebugBelow;
 22
 23/// The CSS styling that can be applied to an element via the `Styled` trait
 24#[derive(Clone, Refineable, Debug)]
 25#[refineable(Debug)]
 26pub struct Style {
 27    /// What layout strategy should be used?
 28    pub display: Display,
 29
 30    /// Should the element be painted on screen?
 31    pub visibility: Visibility,
 32
 33    // Overflow properties
 34    /// How children overflowing their container should affect layout
 35    #[refineable]
 36    pub overflow: Point<Overflow>,
 37    /// How much space (in points) should be reserved for the scrollbars of `Overflow::Scroll` and `Overflow::Auto` nodes.
 38    pub scrollbar_width: f32,
 39
 40    // Position properties
 41    /// What should the `position` value of this struct use as a base offset?
 42    pub position: Position,
 43    /// How should the position of this element be tweaked relative to the layout defined?
 44    #[refineable]
 45    pub inset: Edges<Length>,
 46
 47    // Size properties
 48    /// Sets the initial size of the item
 49    #[refineable]
 50    pub size: Size<Length>,
 51    /// Controls the minimum size of the item
 52    #[refineable]
 53    pub min_size: Size<Length>,
 54    /// Controls the maximum size of the item
 55    #[refineable]
 56    pub max_size: Size<Length>,
 57    /// Sets the preferred aspect ratio for the item. The ratio is calculated as width divided by height.
 58    pub aspect_ratio: Option<f32>,
 59
 60    // Spacing Properties
 61    /// How large should the margin be on each side?
 62    #[refineable]
 63    pub margin: Edges<Length>,
 64    /// How large should the padding be on each side?
 65    #[refineable]
 66    pub padding: Edges<DefiniteLength>,
 67    /// How large should the border be on each side?
 68    #[refineable]
 69    pub border_widths: Edges<AbsoluteLength>,
 70
 71    // Alignment properties
 72    /// How this node's children aligned in the cross/block axis?
 73    pub align_items: Option<AlignItems>,
 74    /// How this node should be aligned in the cross/block axis. Falls back to the parents [`AlignItems`] if not set
 75    pub align_self: Option<AlignSelf>,
 76    /// How should content contained within this item be aligned in the cross/block axis
 77    pub align_content: Option<AlignContent>,
 78    /// How should contained within this item be aligned in the main/inline axis
 79    pub justify_content: Option<JustifyContent>,
 80    /// How large should the gaps between items in a flex container be?
 81    #[refineable]
 82    pub gap: Size<DefiniteLength>,
 83
 84    // Flexbox properties
 85    /// Which direction does the main axis flow in?
 86    pub flex_direction: FlexDirection,
 87    /// Should elements wrap, or stay in a single line?
 88    pub flex_wrap: FlexWrap,
 89    /// Sets the initial main axis size of the item
 90    pub flex_basis: Length,
 91    /// 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.
 92    pub flex_grow: f32,
 93    /// 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.
 94    pub flex_shrink: f32,
 95
 96    /// The fill color of this element
 97    pub background: Option<Fill>,
 98
 99    /// The border color of this element
100    pub border_color: Option<Hsla>,
101
102    /// The radius of the corners of this element
103    #[refineable]
104    pub corner_radii: Corners<AbsoluteLength>,
105
106    /// Box Shadow of the element
107    pub box_shadow: SmallVec<[BoxShadow; 2]>,
108
109    /// The text style of this element
110    pub text: TextStyleRefinement,
111
112    /// The mouse cursor style shown when the mouse pointer is over an element.
113    pub mouse_cursor: Option<CursorStyle>,
114
115    /// The z-index to set for this element
116    pub z_index: Option<u16>,
117
118    /// Whether to draw a red debugging outline around this element
119    #[cfg(debug_assertions)]
120    pub debug: bool,
121
122    /// Whether to draw a red debugging outline around this element and all of it's conforming children
123    #[cfg(debug_assertions)]
124    pub debug_below: bool,
125}
126
127impl Styled for StyleRefinement {
128    fn style(&mut self) -> &mut StyleRefinement {
129        self
130    }
131}
132
133/// The value of the visibility property, similar to the CSS property `visibility`
134#[derive(Default, Clone, Copy, Debug, Eq, PartialEq)]
135pub enum Visibility {
136    /// The element should be drawn as normal.
137    #[default]
138    Visible,
139    /// The element should not be drawn, but should still take up space in the layout.
140    Hidden,
141}
142
143/// The possible values of the box-shadow property
144#[derive(Clone, Debug)]
145pub struct BoxShadow {
146    /// What color should the shadow have?
147    pub color: Hsla,
148    /// How should it be offset from it's element?
149    pub offset: Point<Pixels>,
150    /// How much should the shadow be blurred?
151    pub blur_radius: Pixels,
152    /// How much should the shadow spread?
153    pub spread_radius: Pixels,
154}
155
156/// How to handle whitespace in text
157#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
158pub enum WhiteSpace {
159    /// Normal line wrapping when text overflows the width of the element
160    #[default]
161    Normal,
162    /// No line wrapping, text will overflow the width of the element
163    Nowrap,
164}
165
166/// The properties that can be used to style text in GPUI
167#[derive(Refineable, Clone, Debug, PartialEq)]
168#[refineable(Debug)]
169pub struct TextStyle {
170    /// The color of the text
171    pub color: Hsla,
172
173    /// The font family to use
174    pub font_family: SharedString,
175
176    /// The font features to use
177    pub font_features: FontFeatures,
178
179    /// The font size to use, in pixels or rems.
180    pub font_size: AbsoluteLength,
181
182    /// The line height to use, in pixels or fractions
183    pub line_height: DefiniteLength,
184
185    /// The font weight, e.g. bold
186    pub font_weight: FontWeight,
187
188    /// The font style, e.g. italic
189    pub font_style: FontStyle,
190
191    /// The background color of the text
192    pub background_color: Option<Hsla>,
193
194    /// The underline style of the text
195    pub underline: Option<UnderlineStyle>,
196
197    /// How to handle whitespace in the text
198    pub white_space: WhiteSpace,
199}
200
201impl Default for TextStyle {
202    fn default() -> Self {
203        TextStyle {
204            color: black(),
205            // Helvetica is a web safe font, so it should be available
206            font_family: "Helvetica".into(),
207            font_features: FontFeatures::default(),
208            font_size: rems(1.).into(),
209            line_height: phi(),
210            font_weight: FontWeight::default(),
211            font_style: FontStyle::default(),
212            background_color: None,
213            underline: None,
214            white_space: WhiteSpace::Normal,
215        }
216    }
217}
218
219impl TextStyle {
220    /// Create a new text style with the given highlighting applied.
221    pub fn highlight(mut self, style: impl Into<HighlightStyle>) -> Self {
222        let style = style.into();
223        if let Some(weight) = style.font_weight {
224            self.font_weight = weight;
225        }
226        if let Some(style) = style.font_style {
227            self.font_style = style;
228        }
229
230        if let Some(color) = style.color {
231            self.color = self.color.blend(color);
232        }
233
234        if let Some(factor) = style.fade_out {
235            self.color.fade_out(factor);
236        }
237
238        if let Some(background_color) = style.background_color {
239            self.background_color = Some(background_color);
240        }
241
242        if let Some(underline) = style.underline {
243            self.underline = Some(underline);
244        }
245
246        self
247    }
248
249    /// Get the font configured for this text style.
250    pub fn font(&self) -> Font {
251        Font {
252            family: self.font_family.clone(),
253            features: self.font_features,
254            weight: self.font_weight,
255            style: self.font_style,
256        }
257    }
258
259    /// Returns the rounded line height in pixels.
260    pub fn line_height_in_pixels(&self, rem_size: Pixels) -> Pixels {
261        self.line_height.to_pixels(self.font_size, rem_size).round()
262    }
263
264    /// Convert this text style into a [`TextRun`], for the given length of the text.
265    pub fn to_run(&self, len: usize) -> TextRun {
266        TextRun {
267            len,
268            font: Font {
269                family: self.font_family.clone(),
270                features: Default::default(),
271                weight: self.font_weight,
272                style: self.font_style,
273            },
274            color: self.color,
275            background_color: self.background_color,
276            underline: self.underline,
277        }
278    }
279}
280
281/// A highlight style to apply, similar to a `TextStyle` except
282/// for a single font, uniformly sized and spaced text.
283#[derive(Copy, Clone, Debug, Default, PartialEq)]
284pub struct HighlightStyle {
285    /// The color of the text
286    pub color: Option<Hsla>,
287
288    /// The font weight, e.g. bold
289    pub font_weight: Option<FontWeight>,
290
291    /// The font style, e.g. italic
292    pub font_style: Option<FontStyle>,
293
294    /// The background color of the text
295    pub background_color: Option<Hsla>,
296
297    /// The underline style of the text
298    pub underline: Option<UnderlineStyle>,
299
300    /// Similar to the CSS `opacity` property, this will cause the text to be less vibrant.
301    pub fade_out: Option<f32>,
302}
303
304impl Eq for HighlightStyle {}
305
306impl Style {
307    /// Get the text style in this element style.
308    pub fn text_style(&self) -> Option<&TextStyleRefinement> {
309        if self.text.is_some() {
310            Some(&self.text)
311        } else {
312            None
313        }
314    }
315
316    /// Get the content mask for this element style, based on the given bounds.
317    /// If the element does not hide it's overflow, this will return `None`.
318    pub fn overflow_mask(
319        &self,
320        bounds: Bounds<Pixels>,
321        rem_size: Pixels,
322    ) -> Option<ContentMask<Pixels>> {
323        match self.overflow {
324            Point {
325                x: Overflow::Visible,
326                y: Overflow::Visible,
327            } => None,
328            _ => {
329                let mut min = bounds.origin;
330                let mut max = bounds.lower_right();
331
332                if self
333                    .border_color
334                    .map_or(false, |color| !color.is_transparent())
335                {
336                    min.x += self.border_widths.left.to_pixels(rem_size);
337                    max.x -= self.border_widths.right.to_pixels(rem_size);
338                    min.y += self.border_widths.top.to_pixels(rem_size);
339                    max.y -= self.border_widths.bottom.to_pixels(rem_size);
340                }
341
342                let bounds = match (
343                    self.overflow.x == Overflow::Visible,
344                    self.overflow.y == Overflow::Visible,
345                ) {
346                    // x and y both visible
347                    (true, true) => return None,
348                    // x visible, y hidden
349                    (true, false) => Bounds::from_corners(
350                        point(min.x, bounds.origin.y),
351                        point(max.x, bounds.lower_right().y),
352                    ),
353                    // x hidden, y visible
354                    (false, true) => Bounds::from_corners(
355                        point(bounds.origin.x, min.y),
356                        point(bounds.lower_right().x, max.y),
357                    ),
358                    // both hidden
359                    (false, false) => Bounds::from_corners(min, max),
360                };
361
362                Some(ContentMask { bounds })
363            }
364        }
365    }
366
367    /// Paints the background of an element styled with this style.
368    pub fn paint(
369        &self,
370        bounds: Bounds<Pixels>,
371        cx: &mut ElementContext,
372        continuation: impl FnOnce(&mut ElementContext),
373    ) {
374        #[cfg(debug_assertions)]
375        if self.debug_below {
376            cx.set_global(DebugBelow)
377        }
378
379        #[cfg(debug_assertions)]
380        if self.debug || cx.has_global::<DebugBelow>() {
381            cx.paint_quad(crate::outline(bounds, crate::red()));
382        }
383
384        let rem_size = cx.rem_size();
385
386        cx.with_z_index(0, |cx| {
387            cx.paint_shadows(
388                bounds,
389                self.corner_radii.to_pixels(bounds.size, rem_size),
390                &self.box_shadow,
391            );
392        });
393
394        let background_color = self.background.as_ref().and_then(Fill::color);
395        if background_color.map_or(false, |color| !color.is_transparent()) {
396            cx.with_z_index(1, |cx| {
397                let mut border_color = background_color.unwrap_or_default();
398                border_color.a = 0.;
399                cx.paint_quad(quad(
400                    bounds,
401                    self.corner_radii.to_pixels(bounds.size, rem_size),
402                    background_color.unwrap_or_default(),
403                    Edges::default(),
404                    border_color,
405                ));
406            });
407        }
408
409        cx.with_z_index(2, |cx| {
410            continuation(cx);
411        });
412
413        if self.is_border_visible() {
414            cx.with_z_index(3, |cx| {
415                let corner_radii = self.corner_radii.to_pixels(bounds.size, rem_size);
416                let border_widths = self.border_widths.to_pixels(rem_size);
417                let max_border_width = border_widths.max();
418                let max_corner_radius = corner_radii.max();
419
420                let top_bounds = Bounds::from_corners(
421                    bounds.origin,
422                    bounds.upper_right()
423                        + point(Pixels::ZERO, max_border_width.max(max_corner_radius)),
424                );
425                let bottom_bounds = Bounds::from_corners(
426                    bounds.lower_left()
427                        - point(Pixels::ZERO, max_border_width.max(max_corner_radius)),
428                    bounds.lower_right(),
429                );
430                let left_bounds = Bounds::from_corners(
431                    top_bounds.lower_left(),
432                    bottom_bounds.origin + point(max_border_width, Pixels::ZERO),
433                );
434                let right_bounds = Bounds::from_corners(
435                    top_bounds.lower_right() - point(max_border_width, Pixels::ZERO),
436                    bottom_bounds.upper_right(),
437                );
438
439                let mut background = self.border_color.unwrap_or_default();
440                background.a = 0.;
441                let quad = quad(
442                    bounds,
443                    corner_radii,
444                    background,
445                    border_widths,
446                    self.border_color.unwrap_or_default(),
447                );
448
449                cx.with_content_mask(Some(ContentMask { bounds: top_bounds }), |cx| {
450                    cx.paint_quad(quad.clone());
451                });
452                cx.with_content_mask(
453                    Some(ContentMask {
454                        bounds: right_bounds,
455                    }),
456                    |cx| {
457                        cx.paint_quad(quad.clone());
458                    },
459                );
460                cx.with_content_mask(
461                    Some(ContentMask {
462                        bounds: bottom_bounds,
463                    }),
464                    |cx| {
465                        cx.paint_quad(quad.clone());
466                    },
467                );
468                cx.with_content_mask(
469                    Some(ContentMask {
470                        bounds: left_bounds,
471                    }),
472                    |cx| {
473                        cx.paint_quad(quad);
474                    },
475                );
476            });
477        }
478
479        #[cfg(debug_assertions)]
480        if self.debug_below {
481            cx.remove_global::<DebugBelow>();
482        }
483    }
484
485    fn is_border_visible(&self) -> bool {
486        self.border_color
487            .map_or(false, |color| !color.is_transparent())
488            && self.border_widths.any(|length| !length.is_zero())
489    }
490}
491
492impl Default for Style {
493    fn default() -> Self {
494        Style {
495            display: Display::Block,
496            visibility: Visibility::Visible,
497            overflow: Point {
498                x: Overflow::Visible,
499                y: Overflow::Visible,
500            },
501            scrollbar_width: 0.0,
502            position: Position::Relative,
503            inset: Edges::auto(),
504            margin: Edges::<Length>::zero(),
505            padding: Edges::<DefiniteLength>::zero(),
506            border_widths: Edges::<AbsoluteLength>::zero(),
507            size: Size::auto(),
508            min_size: Size::auto(),
509            max_size: Size::auto(),
510            aspect_ratio: None,
511            gap: Size::default(),
512            // Alignment
513            align_items: None,
514            align_self: None,
515            align_content: None,
516            justify_content: None,
517            // Flexbox
518            flex_direction: FlexDirection::Row,
519            flex_wrap: FlexWrap::NoWrap,
520            flex_grow: 0.0,
521            flex_shrink: 1.0,
522            flex_basis: Length::Auto,
523            background: None,
524            border_color: None,
525            corner_radii: Corners::default(),
526            box_shadow: Default::default(),
527            text: TextStyleRefinement::default(),
528            mouse_cursor: None,
529            z_index: None,
530
531            #[cfg(debug_assertions)]
532            debug: false,
533            #[cfg(debug_assertions)]
534            debug_below: false,
535        }
536    }
537}
538
539/// The properties that can be applied to an underline.
540#[derive(Refineable, Copy, Clone, Default, Debug, PartialEq, Eq)]
541#[refineable(Debug)]
542pub struct UnderlineStyle {
543    /// The thickness of the underline.
544    pub thickness: Pixels,
545
546    /// The color of the underline.
547    pub color: Option<Hsla>,
548
549    /// Whether the underline should be wavy, like in a spell checker.
550    pub wavy: bool,
551}
552
553/// The kinds of fill that can be applied to a shape.
554#[derive(Clone, Debug)]
555pub enum Fill {
556    /// A solid color fill.
557    Color(Hsla),
558}
559
560impl Fill {
561    /// Unwrap this fill into a solid color, if it is one.
562    pub fn color(&self) -> Option<Hsla> {
563        match self {
564            Fill::Color(color) => Some(*color),
565        }
566    }
567}
568
569impl Default for Fill {
570    fn default() -> Self {
571        Self::Color(Hsla::default())
572    }
573}
574
575impl From<Hsla> for Fill {
576    fn from(color: Hsla) -> Self {
577        Self::Color(color)
578    }
579}
580
581impl From<Rgba> for Fill {
582    fn from(color: Rgba) -> Self {
583        Self::Color(color.into())
584    }
585}
586
587impl From<TextStyle> for HighlightStyle {
588    fn from(other: TextStyle) -> Self {
589        Self::from(&other)
590    }
591}
592
593impl From<&TextStyle> for HighlightStyle {
594    fn from(other: &TextStyle) -> Self {
595        Self {
596            color: Some(other.color),
597            font_weight: Some(other.font_weight),
598            font_style: Some(other.font_style),
599            background_color: other.background_color,
600            underline: other.underline,
601            fade_out: None,
602        }
603    }
604}
605
606impl HighlightStyle {
607    /// Blend this highlight style with another.
608    /// Non-continuous properties, like font_weight and font_style, are overwritten.
609    pub fn highlight(&mut self, other: HighlightStyle) {
610        match (self.color, other.color) {
611            (Some(self_color), Some(other_color)) => {
612                self.color = Some(Hsla::blend(other_color, self_color));
613            }
614            (None, Some(other_color)) => {
615                self.color = Some(other_color);
616            }
617            _ => {}
618        }
619
620        if other.font_weight.is_some() {
621            self.font_weight = other.font_weight;
622        }
623
624        if other.font_style.is_some() {
625            self.font_style = other.font_style;
626        }
627
628        if other.background_color.is_some() {
629            self.background_color = other.background_color;
630        }
631
632        if other.underline.is_some() {
633            self.underline = other.underline;
634        }
635
636        match (other.fade_out, self.fade_out) {
637            (Some(source_fade), None) => self.fade_out = Some(source_fade),
638            (Some(source_fade), Some(dest_fade)) => {
639                self.fade_out = Some((dest_fade * (1. + source_fade)).clamp(0., 1.));
640            }
641            _ => {}
642        }
643    }
644}
645
646impl From<Hsla> for HighlightStyle {
647    fn from(color: Hsla) -> Self {
648        Self {
649            color: Some(color),
650            ..Default::default()
651        }
652    }
653}
654
655impl From<FontWeight> for HighlightStyle {
656    fn from(font_weight: FontWeight) -> Self {
657        Self {
658            font_weight: Some(font_weight),
659            ..Default::default()
660        }
661    }
662}
663
664impl From<FontStyle> for HighlightStyle {
665    fn from(font_style: FontStyle) -> Self {
666        Self {
667            font_style: Some(font_style),
668            ..Default::default()
669        }
670    }
671}
672
673impl From<Rgba> for HighlightStyle {
674    fn from(color: Rgba) -> Self {
675        Self {
676            color: Some(color.into()),
677            ..Default::default()
678        }
679    }
680}
681
682/// Combine and merge the highlights and ranges in the two iterators.
683pub fn combine_highlights(
684    a: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
685    b: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
686) -> impl Iterator<Item = (Range<usize>, HighlightStyle)> {
687    let mut endpoints = Vec::new();
688    let mut highlights = Vec::new();
689    for (range, highlight) in a.into_iter().chain(b) {
690        if !range.is_empty() {
691            let highlight_id = highlights.len();
692            endpoints.push((range.start, highlight_id, true));
693            endpoints.push((range.end, highlight_id, false));
694            highlights.push(highlight);
695        }
696    }
697    endpoints.sort_unstable_by_key(|(position, _, _)| *position);
698    let mut endpoints = endpoints.into_iter().peekable();
699
700    let mut active_styles = HashSet::default();
701    let mut ix = 0;
702    iter::from_fn(move || {
703        while let Some((endpoint_ix, highlight_id, is_start)) = endpoints.peek() {
704            let prev_index = mem::replace(&mut ix, *endpoint_ix);
705            if ix > prev_index && !active_styles.is_empty() {
706                let mut current_style = HighlightStyle::default();
707                for highlight_id in &active_styles {
708                    current_style.highlight(highlights[*highlight_id]);
709                }
710                return Some((prev_index..ix, current_style));
711            }
712
713            if *is_start {
714                active_styles.insert(*highlight_id);
715            } else {
716                active_styles.remove(highlight_id);
717            }
718            endpoints.next();
719        }
720        None
721    })
722}
723
724#[cfg(test)]
725mod tests {
726    use crate::{blue, green, red, yellow};
727
728    use super::*;
729
730    #[test]
731    fn test_combine_highlights() {
732        assert_eq!(
733            combine_highlights(
734                [
735                    (0..5, green().into()),
736                    (4..10, FontWeight::BOLD.into()),
737                    (15..20, yellow().into()),
738                ],
739                [
740                    (2..6, FontStyle::Italic.into()),
741                    (1..3, blue().into()),
742                    (21..23, red().into()),
743                ]
744            )
745            .collect::<Vec<_>>(),
746            [
747                (
748                    0..1,
749                    HighlightStyle {
750                        color: Some(green()),
751                        ..Default::default()
752                    }
753                ),
754                (
755                    1..2,
756                    HighlightStyle {
757                        color: Some(green()),
758                        ..Default::default()
759                    }
760                ),
761                (
762                    2..3,
763                    HighlightStyle {
764                        color: Some(green()),
765                        font_style: Some(FontStyle::Italic),
766                        ..Default::default()
767                    }
768                ),
769                (
770                    3..4,
771                    HighlightStyle {
772                        color: Some(green()),
773                        font_style: Some(FontStyle::Italic),
774                        ..Default::default()
775                    }
776                ),
777                (
778                    4..5,
779                    HighlightStyle {
780                        color: Some(green()),
781                        font_weight: Some(FontWeight::BOLD),
782                        font_style: Some(FontStyle::Italic),
783                        ..Default::default()
784                    }
785                ),
786                (
787                    5..6,
788                    HighlightStyle {
789                        font_weight: Some(FontWeight::BOLD),
790                        font_style: Some(FontStyle::Italic),
791                        ..Default::default()
792                    }
793                ),
794                (
795                    6..10,
796                    HighlightStyle {
797                        font_weight: Some(FontWeight::BOLD),
798                        ..Default::default()
799                    }
800                ),
801                (
802                    15..20,
803                    HighlightStyle {
804                        color: Some(yellow()),
805                        ..Default::default()
806                    }
807                ),
808                (
809                    21..23,
810                    HighlightStyle {
811                        color: Some(red()),
812                        ..Default::default()
813                    }
814                )
815            ]
816        );
817    }
818}