style.rs

   1use std::{
   2    hash::{Hash, Hasher},
   3    iter, mem,
   4    ops::Range,
   5};
   6
   7use crate::{
   8    AbsoluteLength, App, Background, BackgroundTag, BorderStyle, Bounds, ContentMask, Corners,
   9    CornersRefinement, CursorStyle, DefiniteLength, DevicePixels, Edges, EdgesRefinement, Font,
  10    FontFallbacks, FontFeatures, FontStyle, FontWeight, GridLocation, Hsla, Length, Pixels, Point,
  11    PointRefinement, Rgba, SharedString, Size, SizeRefinement, Styled, TextRun, Window, black, phi,
  12    point, quad, rems, size,
  13};
  14use collections::HashSet;
  15use refineable::Refineable;
  16use schemars::JsonSchema;
  17use serde::{Deserialize, Serialize};
  18
  19/// Use this struct for interfacing with the 'debug_below' styling from your own elements.
  20/// If a parent element has this style set on it, then this struct will be set as a global in
  21/// GPUI.
  22#[cfg(debug_assertions)]
  23pub struct DebugBelow;
  24
  25#[cfg(debug_assertions)]
  26impl crate::Global for DebugBelow {}
  27
  28/// How to fit the image into the bounds of the element.
  29pub enum ObjectFit {
  30    /// The image will be stretched to fill the bounds of the element.
  31    Fill,
  32    /// The image will be scaled to fit within the bounds of the element.
  33    Contain,
  34    /// The image will be scaled to cover the bounds of the element.
  35    Cover,
  36    /// The image will be scaled down to fit within the bounds of the element.
  37    ScaleDown,
  38    /// The image will maintain its original size.
  39    None,
  40}
  41
  42impl ObjectFit {
  43    /// Get the bounds of the image within the given bounds.
  44    pub fn get_bounds(
  45        &self,
  46        bounds: Bounds<Pixels>,
  47        image_size: Size<DevicePixels>,
  48    ) -> Bounds<Pixels> {
  49        let image_size = image_size.map(|dimension| Pixels::from(u32::from(dimension)));
  50        let image_ratio = image_size.width / image_size.height;
  51        let bounds_ratio = bounds.size.width / bounds.size.height;
  52
  53        match self {
  54            ObjectFit::Fill => bounds,
  55            ObjectFit::Contain => {
  56                let new_size = if bounds_ratio > image_ratio {
  57                    size(
  58                        image_size.width * (bounds.size.height / image_size.height),
  59                        bounds.size.height,
  60                    )
  61                } else {
  62                    size(
  63                        bounds.size.width,
  64                        image_size.height * (bounds.size.width / image_size.width),
  65                    )
  66                };
  67
  68                Bounds {
  69                    origin: point(
  70                        bounds.origin.x + (bounds.size.width - new_size.width) / 2.0,
  71                        bounds.origin.y + (bounds.size.height - new_size.height) / 2.0,
  72                    ),
  73                    size: new_size,
  74                }
  75            }
  76            ObjectFit::ScaleDown => {
  77                // Check if the image is larger than the bounds in either dimension.
  78                if image_size.width > bounds.size.width || image_size.height > bounds.size.height {
  79                    // If the image is larger, use the same logic as Contain to scale it down.
  80                    let new_size = if bounds_ratio > image_ratio {
  81                        size(
  82                            image_size.width * (bounds.size.height / image_size.height),
  83                            bounds.size.height,
  84                        )
  85                    } else {
  86                        size(
  87                            bounds.size.width,
  88                            image_size.height * (bounds.size.width / image_size.width),
  89                        )
  90                    };
  91
  92                    Bounds {
  93                        origin: point(
  94                            bounds.origin.x + (bounds.size.width - new_size.width) / 2.0,
  95                            bounds.origin.y + (bounds.size.height - new_size.height) / 2.0,
  96                        ),
  97                        size: new_size,
  98                    }
  99                } else {
 100                    // If the image is smaller than or equal to the container, display it at its original size,
 101                    // centered within the container.
 102                    let original_size = size(image_size.width, image_size.height);
 103                    Bounds {
 104                        origin: point(
 105                            bounds.origin.x + (bounds.size.width - original_size.width) / 2.0,
 106                            bounds.origin.y + (bounds.size.height - original_size.height) / 2.0,
 107                        ),
 108                        size: original_size,
 109                    }
 110                }
 111            }
 112            ObjectFit::Cover => {
 113                let new_size = if bounds_ratio > image_ratio {
 114                    size(
 115                        bounds.size.width,
 116                        image_size.height * (bounds.size.width / image_size.width),
 117                    )
 118                } else {
 119                    size(
 120                        image_size.width * (bounds.size.height / image_size.height),
 121                        bounds.size.height,
 122                    )
 123                };
 124
 125                Bounds {
 126                    origin: point(
 127                        bounds.origin.x + (bounds.size.width - new_size.width) / 2.0,
 128                        bounds.origin.y + (bounds.size.height - new_size.height) / 2.0,
 129                    ),
 130                    size: new_size,
 131                }
 132            }
 133            ObjectFit::None => Bounds {
 134                origin: bounds.origin,
 135                size: image_size,
 136            },
 137        }
 138    }
 139}
 140
 141/// The CSS styling that can be applied to an element via the `Styled` trait
 142#[derive(Clone, Refineable, Debug)]
 143#[refineable(Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
 144pub struct Style {
 145    /// What layout strategy should be used?
 146    pub display: Display,
 147
 148    /// Should the element be painted on screen?
 149    pub visibility: Visibility,
 150
 151    // Overflow properties
 152    /// How children overflowing their container should affect layout
 153    #[refineable]
 154    pub overflow: Point<Overflow>,
 155    /// How much space (in points) should be reserved for the scrollbars of `Overflow::Scroll` and `Overflow::Auto` nodes.
 156    pub scrollbar_width: AbsoluteLength,
 157    /// Whether both x and y axis should be scrollable at the same time.
 158    pub allow_concurrent_scroll: bool,
 159    /// Whether scrolling should be restricted to the axis indicated by the mouse wheel.
 160    ///
 161    /// This means that:
 162    /// - The mouse wheel alone will only ever scroll the Y axis.
 163    /// - Holding `Shift` and using the mouse wheel will scroll the X axis.
 164    ///
 165    /// ## Motivation
 166    ///
 167    /// On the web when scrolling with the mouse wheel, scrolling up and down will always scroll the Y axis, even when
 168    /// the mouse is over a horizontally-scrollable element.
 169    ///
 170    /// The only way to scroll horizontally is to hold down `Shift` while scrolling, which then changes the scroll axis
 171    /// to the X axis.
 172    ///
 173    /// Currently, GPUI operates differently from the web in that it will scroll an element in either the X or Y axis
 174    /// when scrolling with just the mouse wheel. This causes problems when scrolling in a vertical list that contains
 175    /// horizontally-scrollable elements, as when you get to the horizontally-scrollable elements the scroll will be
 176    /// hijacked.
 177    ///
 178    /// Ideally we would match the web's behavior and not have a need for this, but right now we're adding this opt-in
 179    /// style property to limit the potential blast radius.
 180    pub restrict_scroll_to_axis: bool,
 181
 182    // Position properties
 183    /// What should the `position` value of this struct use as a base offset?
 184    pub position: Position,
 185    /// How should the position of this element be tweaked relative to the layout defined?
 186    #[refineable]
 187    pub inset: Edges<Length>,
 188
 189    // Size properties
 190    /// Sets the initial size of the item
 191    #[refineable]
 192    pub size: Size<Length>,
 193    /// Controls the minimum size of the item
 194    #[refineable]
 195    pub min_size: Size<Length>,
 196    /// Controls the maximum size of the item
 197    #[refineable]
 198    pub max_size: Size<Length>,
 199    /// Sets the preferred aspect ratio for the item. The ratio is calculated as width divided by height.
 200    pub aspect_ratio: Option<f32>,
 201
 202    // Spacing Properties
 203    /// How large should the margin be on each side?
 204    #[refineable]
 205    pub margin: Edges<Length>,
 206    /// How large should the padding be on each side?
 207    #[refineable]
 208    pub padding: Edges<DefiniteLength>,
 209    /// How large should the border be on each side?
 210    #[refineable]
 211    pub border_widths: Edges<AbsoluteLength>,
 212
 213    // Alignment properties
 214    /// How this node's children aligned in the cross/block axis?
 215    pub align_items: Option<AlignItems>,
 216    /// How this node should be aligned in the cross/block axis. Falls back to the parents [`AlignItems`] if not set
 217    pub align_self: Option<AlignSelf>,
 218    /// How should content contained within this item be aligned in the cross/block axis
 219    pub align_content: Option<AlignContent>,
 220    /// How should contained within this item be aligned in the main/inline axis
 221    pub justify_content: Option<JustifyContent>,
 222    /// How large should the gaps between items in a flex container be?
 223    #[refineable]
 224    pub gap: Size<DefiniteLength>,
 225
 226    // Flexbox properties
 227    /// Which direction does the main axis flow in?
 228    pub flex_direction: FlexDirection,
 229    /// Should elements wrap, or stay in a single line?
 230    pub flex_wrap: FlexWrap,
 231    /// Sets the initial main axis size of the item
 232    pub flex_basis: Length,
 233    /// 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.
 234    pub flex_grow: f32,
 235    /// 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.
 236    pub flex_shrink: f32,
 237
 238    /// The fill color of this element
 239    pub background: Option<Fill>,
 240
 241    /// The border color of this element
 242    pub border_color: Option<Hsla>,
 243
 244    /// The border style of this element
 245    pub border_style: BorderStyle,
 246
 247    /// The radius of the corners of this element
 248    #[refineable]
 249    pub corner_radii: Corners<AbsoluteLength>,
 250
 251    /// Box shadow of the element
 252    pub box_shadow: Vec<BoxShadow>,
 253
 254    /// The text style of this element
 255    #[refineable]
 256    pub text: TextStyleRefinement,
 257
 258    /// The mouse cursor style shown when the mouse pointer is over an element.
 259    pub mouse_cursor: Option<CursorStyle>,
 260
 261    /// The opacity of this element
 262    pub opacity: Option<f32>,
 263
 264    /// The grid columns of this element
 265    /// Equivalent to the Tailwind `grid-cols-<number>`
 266    pub grid_cols: Option<u16>,
 267
 268    /// The row span of this element
 269    /// Equivalent to the Tailwind `grid-rows-<number>`
 270    pub grid_rows: Option<u16>,
 271
 272    /// The grid location of this element
 273    pub grid_location: Option<GridLocation>,
 274
 275    /// Whether to draw a red debugging outline around this element
 276    #[cfg(debug_assertions)]
 277    pub debug: bool,
 278
 279    /// Whether to draw a red debugging outline around this element and all of its conforming children
 280    #[cfg(debug_assertions)]
 281    pub debug_below: bool,
 282}
 283
 284impl Styled for StyleRefinement {
 285    fn style(&mut self) -> &mut StyleRefinement {
 286        self
 287    }
 288}
 289
 290impl StyleRefinement {
 291    /// The grid location of this element
 292    pub fn grid_location_mut(&mut self) -> &mut GridLocation {
 293        self.grid_location.get_or_insert_default()
 294    }
 295}
 296
 297/// The value of the visibility property, similar to the CSS property `visibility`
 298#[derive(Default, Clone, Copy, Debug, Eq, PartialEq, Serialize, Deserialize, JsonSchema)]
 299pub enum Visibility {
 300    /// The element should be drawn as normal.
 301    #[default]
 302    Visible,
 303    /// The element should not be drawn, but should still take up space in the layout.
 304    Hidden,
 305}
 306
 307/// The possible values of the box-shadow property
 308#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
 309pub struct BoxShadow {
 310    /// What color should the shadow have?
 311    pub color: Hsla,
 312    /// How should it be offset from its element?
 313    pub offset: Point<Pixels>,
 314    /// How much should the shadow be blurred?
 315    pub blur_radius: Pixels,
 316    /// How much should the shadow spread?
 317    pub spread_radius: Pixels,
 318}
 319
 320/// How to handle whitespace in text
 321#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
 322pub enum WhiteSpace {
 323    /// Normal line wrapping when text overflows the width of the element
 324    #[default]
 325    Normal,
 326    /// No line wrapping, text will overflow the width of the element
 327    Nowrap,
 328}
 329
 330/// How to truncate text that overflows the width of the element
 331#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
 332pub enum TextOverflow {
 333    /// Truncate the text when it doesn't fit, and represent this truncation by displaying the
 334    /// provided string.
 335    Truncate(SharedString),
 336}
 337
 338/// How to align text within the element
 339#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, JsonSchema)]
 340pub enum TextAlign {
 341    /// Align the text to the left of the element
 342    #[default]
 343    Left,
 344
 345    /// Center the text within the element
 346    Center,
 347
 348    /// Align the text to the right of the element
 349    Right,
 350}
 351
 352/// The properties that can be used to style text in GPUI
 353#[derive(Refineable, Clone, Debug, PartialEq)]
 354#[refineable(Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
 355pub struct TextStyle {
 356    /// The color of the text
 357    pub color: Hsla,
 358
 359    /// The font family to use
 360    pub font_family: SharedString,
 361
 362    /// The font features to use
 363    pub font_features: FontFeatures,
 364
 365    /// The fallback fonts to use
 366    pub font_fallbacks: Option<FontFallbacks>,
 367
 368    /// The font size to use, in pixels or rems.
 369    pub font_size: AbsoluteLength,
 370
 371    /// The line height to use, in pixels or fractions
 372    pub line_height: DefiniteLength,
 373
 374    /// The font weight, e.g. bold
 375    pub font_weight: FontWeight,
 376
 377    /// The font style, e.g. italic
 378    pub font_style: FontStyle,
 379
 380    /// The background color of the text
 381    pub background_color: Option<Hsla>,
 382
 383    /// The underline style of the text
 384    pub underline: Option<UnderlineStyle>,
 385
 386    /// The strikethrough style of the text
 387    pub strikethrough: Option<StrikethroughStyle>,
 388
 389    /// How to handle whitespace in the text
 390    pub white_space: WhiteSpace,
 391
 392    /// The text should be truncated if it overflows the width of the element
 393    pub text_overflow: Option<TextOverflow>,
 394
 395    /// How the text should be aligned within the element
 396    pub text_align: TextAlign,
 397
 398    /// The number of lines to display before truncating the text
 399    pub line_clamp: Option<usize>,
 400}
 401
 402impl Default for TextStyle {
 403    fn default() -> Self {
 404        TextStyle {
 405            color: black(),
 406            // todo(linux) make this configurable or choose better default
 407            font_family: ".SystemUIFont".into(),
 408            font_features: FontFeatures::default(),
 409            font_fallbacks: None,
 410            font_size: rems(1.).into(),
 411            line_height: phi(),
 412            font_weight: FontWeight::default(),
 413            font_style: FontStyle::default(),
 414            background_color: None,
 415            underline: None,
 416            strikethrough: None,
 417            white_space: WhiteSpace::Normal,
 418            text_overflow: None,
 419            text_align: TextAlign::default(),
 420            line_clamp: None,
 421        }
 422    }
 423}
 424
 425impl TextStyle {
 426    /// Create a new text style with the given highlighting applied.
 427    pub fn highlight(mut self, style: impl Into<HighlightStyle>) -> Self {
 428        let style = style.into();
 429        if let Some(weight) = style.font_weight {
 430            self.font_weight = weight;
 431        }
 432        if let Some(style) = style.font_style {
 433            self.font_style = style;
 434        }
 435
 436        if let Some(color) = style.color {
 437            self.color = self.color.blend(color);
 438        }
 439
 440        if let Some(factor) = style.fade_out {
 441            self.color.fade_out(factor);
 442        }
 443
 444        if let Some(background_color) = style.background_color {
 445            self.background_color = Some(background_color);
 446        }
 447
 448        if let Some(underline) = style.underline {
 449            self.underline = Some(underline);
 450        }
 451
 452        if let Some(strikethrough) = style.strikethrough {
 453            self.strikethrough = Some(strikethrough);
 454        }
 455
 456        self
 457    }
 458
 459    /// Get the font configured for this text style.
 460    pub fn font(&self) -> Font {
 461        Font {
 462            family: self.font_family.clone(),
 463            features: self.font_features.clone(),
 464            fallbacks: self.font_fallbacks.clone(),
 465            weight: self.font_weight,
 466            style: self.font_style,
 467        }
 468    }
 469
 470    /// Returns the rounded line height in pixels.
 471    pub fn line_height_in_pixels(&self, rem_size: Pixels) -> Pixels {
 472        self.line_height.to_pixels(self.font_size, rem_size).round()
 473    }
 474
 475    /// Convert this text style into a [`TextRun`], for the given length of the text.
 476    pub fn to_run(&self, len: usize) -> TextRun {
 477        TextRun {
 478            len,
 479            font: Font {
 480                family: self.font_family.clone(),
 481                features: self.font_features.clone(),
 482                fallbacks: self.font_fallbacks.clone(),
 483                weight: self.font_weight,
 484                style: self.font_style,
 485            },
 486            color: self.color,
 487            background_color: self.background_color,
 488            underline: self.underline,
 489            strikethrough: self.strikethrough,
 490        }
 491    }
 492}
 493
 494/// A highlight style to apply, similar to a `TextStyle` except
 495/// for a single font, uniformly sized and spaced text.
 496#[derive(Copy, Clone, Debug, Default, PartialEq)]
 497pub struct HighlightStyle {
 498    /// The color of the text
 499    pub color: Option<Hsla>,
 500
 501    /// The font weight, e.g. bold
 502    pub font_weight: Option<FontWeight>,
 503
 504    /// The font style, e.g. italic
 505    pub font_style: Option<FontStyle>,
 506
 507    /// The background color of the text
 508    pub background_color: Option<Hsla>,
 509
 510    /// The underline style of the text
 511    pub underline: Option<UnderlineStyle>,
 512
 513    /// The underline style of the text
 514    pub strikethrough: Option<StrikethroughStyle>,
 515
 516    /// Similar to the CSS `opacity` property, this will cause the text to be less vibrant.
 517    pub fade_out: Option<f32>,
 518}
 519
 520impl Eq for HighlightStyle {}
 521
 522impl Hash for HighlightStyle {
 523    fn hash<H: Hasher>(&self, state: &mut H) {
 524        self.color.hash(state);
 525        self.font_weight.hash(state);
 526        self.font_style.hash(state);
 527        self.background_color.hash(state);
 528        self.underline.hash(state);
 529        self.strikethrough.hash(state);
 530        state.write_u32(u32::from_be_bytes(
 531            self.fade_out.map(|f| f.to_be_bytes()).unwrap_or_default(),
 532        ));
 533    }
 534}
 535
 536impl Style {
 537    /// Returns true if the style is visible and the background is opaque.
 538    pub fn has_opaque_background(&self) -> bool {
 539        self.background
 540            .as_ref()
 541            .is_some_and(|fill| fill.color().is_some_and(|color| !color.is_transparent()))
 542    }
 543
 544    /// Get the text style in this element style.
 545    pub fn text_style(&self) -> Option<&TextStyleRefinement> {
 546        if self.text.is_some() {
 547            Some(&self.text)
 548        } else {
 549            None
 550        }
 551    }
 552
 553    /// Get the content mask for this element style, based on the given bounds.
 554    /// If the element does not hide its overflow, this will return `None`.
 555    pub fn overflow_mask(
 556        &self,
 557        bounds: Bounds<Pixels>,
 558        rem_size: Pixels,
 559    ) -> Option<ContentMask<Pixels>> {
 560        match self.overflow {
 561            Point {
 562                x: Overflow::Visible,
 563                y: Overflow::Visible,
 564            } => None,
 565            _ => {
 566                let mut min = bounds.origin;
 567                let mut max = bounds.bottom_right();
 568
 569                if self
 570                    .border_color
 571                    .is_some_and(|color| !color.is_transparent())
 572                {
 573                    min.x += self.border_widths.left.to_pixels(rem_size);
 574                    max.x -= self.border_widths.right.to_pixels(rem_size);
 575                    min.y += self.border_widths.top.to_pixels(rem_size);
 576                    max.y -= self.border_widths.bottom.to_pixels(rem_size);
 577                }
 578
 579                let bounds = match (
 580                    self.overflow.x == Overflow::Visible,
 581                    self.overflow.y == Overflow::Visible,
 582                ) {
 583                    // x and y both visible
 584                    (true, true) => return None,
 585                    // x visible, y hidden
 586                    (true, false) => Bounds::from_corners(
 587                        point(min.x, bounds.origin.y),
 588                        point(max.x, bounds.bottom_right().y),
 589                    ),
 590                    // x hidden, y visible
 591                    (false, true) => Bounds::from_corners(
 592                        point(bounds.origin.x, min.y),
 593                        point(bounds.bottom_right().x, max.y),
 594                    ),
 595                    // both hidden
 596                    (false, false) => Bounds::from_corners(min, max),
 597                };
 598
 599                Some(ContentMask { bounds })
 600            }
 601        }
 602    }
 603
 604    /// Paints the background of an element styled with this style.
 605    pub fn paint(
 606        &self,
 607        bounds: Bounds<Pixels>,
 608        window: &mut Window,
 609        cx: &mut App,
 610        continuation: impl FnOnce(&mut Window, &mut App),
 611    ) {
 612        #[cfg(debug_assertions)]
 613        if self.debug_below {
 614            cx.set_global(DebugBelow)
 615        }
 616
 617        #[cfg(debug_assertions)]
 618        if self.debug || cx.has_global::<DebugBelow>() {
 619            window.paint_quad(crate::outline(bounds, crate::red(), BorderStyle::default()));
 620        }
 621
 622        let rem_size = window.rem_size();
 623        let corner_radii = self
 624            .corner_radii
 625            .to_pixels(rem_size)
 626            .clamp_radii_for_quad_size(bounds.size);
 627
 628        window.paint_shadows(bounds, corner_radii, &self.box_shadow);
 629
 630        let background_color = self.background.as_ref().and_then(Fill::color);
 631        if background_color.is_some_and(|color| !color.is_transparent()) {
 632            let mut border_color = match background_color {
 633                Some(color) => match color.tag {
 634                    BackgroundTag::Solid => color.solid,
 635                    BackgroundTag::LinearGradient => color
 636                        .colors
 637                        .first()
 638                        .map(|stop| stop.color)
 639                        .unwrap_or_default(),
 640                    BackgroundTag::PatternSlash => color.solid,
 641                },
 642                None => Hsla::default(),
 643            };
 644            border_color.a = 0.;
 645            window.paint_quad(quad(
 646                bounds,
 647                corner_radii,
 648                background_color.unwrap_or_default(),
 649                Edges::default(),
 650                border_color,
 651                self.border_style,
 652            ));
 653        }
 654
 655        continuation(window, cx);
 656
 657        if self.is_border_visible() {
 658            let border_widths = self.border_widths.to_pixels(rem_size);
 659            let max_border_width = border_widths.max();
 660            let max_corner_radius = corner_radii.max();
 661
 662            let top_bounds = Bounds::from_corners(
 663                bounds.origin,
 664                bounds.top_right() + point(Pixels::ZERO, max_border_width.max(max_corner_radius)),
 665            );
 666            let bottom_bounds = Bounds::from_corners(
 667                bounds.bottom_left() - point(Pixels::ZERO, max_border_width.max(max_corner_radius)),
 668                bounds.bottom_right(),
 669            );
 670            let left_bounds = Bounds::from_corners(
 671                top_bounds.bottom_left(),
 672                bottom_bounds.origin + point(max_border_width, Pixels::ZERO),
 673            );
 674            let right_bounds = Bounds::from_corners(
 675                top_bounds.bottom_right() - point(max_border_width, Pixels::ZERO),
 676                bottom_bounds.top_right(),
 677            );
 678
 679            let mut background = self.border_color.unwrap_or_default();
 680            background.a = 0.;
 681            let quad = quad(
 682                bounds,
 683                corner_radii,
 684                background,
 685                border_widths,
 686                self.border_color.unwrap_or_default(),
 687                self.border_style,
 688            );
 689
 690            window.with_content_mask(Some(ContentMask { bounds: top_bounds }), |window| {
 691                window.paint_quad(quad.clone());
 692            });
 693            window.with_content_mask(
 694                Some(ContentMask {
 695                    bounds: right_bounds,
 696                }),
 697                |window| {
 698                    window.paint_quad(quad.clone());
 699                },
 700            );
 701            window.with_content_mask(
 702                Some(ContentMask {
 703                    bounds: bottom_bounds,
 704                }),
 705                |window| {
 706                    window.paint_quad(quad.clone());
 707                },
 708            );
 709            window.with_content_mask(
 710                Some(ContentMask {
 711                    bounds: left_bounds,
 712                }),
 713                |window| {
 714                    window.paint_quad(quad);
 715                },
 716            );
 717        }
 718
 719        #[cfg(debug_assertions)]
 720        if self.debug_below {
 721            cx.remove_global::<DebugBelow>();
 722        }
 723    }
 724
 725    fn is_border_visible(&self) -> bool {
 726        self.border_color
 727            .is_some_and(|color| !color.is_transparent())
 728            && self.border_widths.any(|length| !length.is_zero())
 729    }
 730}
 731
 732impl Default for Style {
 733    fn default() -> Self {
 734        Style {
 735            display: Display::Block,
 736            visibility: Visibility::Visible,
 737            overflow: Point {
 738                x: Overflow::Visible,
 739                y: Overflow::Visible,
 740            },
 741            allow_concurrent_scroll: false,
 742            restrict_scroll_to_axis: false,
 743            scrollbar_width: AbsoluteLength::default(),
 744            position: Position::Relative,
 745            inset: Edges::auto(),
 746            margin: Edges::<Length>::zero(),
 747            padding: Edges::<DefiniteLength>::zero(),
 748            border_widths: Edges::<AbsoluteLength>::zero(),
 749            size: Size::auto(),
 750            min_size: Size::auto(),
 751            max_size: Size::auto(),
 752            aspect_ratio: None,
 753            gap: Size::default(),
 754            // Alignment
 755            align_items: None,
 756            align_self: None,
 757            align_content: None,
 758            justify_content: None,
 759            // Flexbox
 760            flex_direction: FlexDirection::Row,
 761            flex_wrap: FlexWrap::NoWrap,
 762            flex_grow: 0.0,
 763            flex_shrink: 1.0,
 764            flex_basis: Length::Auto,
 765            background: None,
 766            border_color: None,
 767            border_style: BorderStyle::default(),
 768            corner_radii: Corners::default(),
 769            box_shadow: Default::default(),
 770            text: TextStyleRefinement::default(),
 771            mouse_cursor: None,
 772            opacity: None,
 773            grid_rows: None,
 774            grid_cols: None,
 775            grid_location: None,
 776
 777            #[cfg(debug_assertions)]
 778            debug: false,
 779            #[cfg(debug_assertions)]
 780            debug_below: false,
 781        }
 782    }
 783}
 784
 785/// The properties that can be applied to an underline.
 786#[derive(
 787    Refineable, Copy, Clone, Default, Debug, PartialEq, Eq, Hash, Serialize, Deserialize, JsonSchema,
 788)]
 789pub struct UnderlineStyle {
 790    /// The thickness of the underline.
 791    pub thickness: Pixels,
 792
 793    /// The color of the underline.
 794    pub color: Option<Hsla>,
 795
 796    /// Whether the underline should be wavy, like in a spell checker.
 797    pub wavy: bool,
 798}
 799
 800/// The properties that can be applied to a strikethrough.
 801#[derive(
 802    Refineable, Copy, Clone, Default, Debug, PartialEq, Eq, Hash, Serialize, Deserialize, JsonSchema,
 803)]
 804pub struct StrikethroughStyle {
 805    /// The thickness of the strikethrough.
 806    pub thickness: Pixels,
 807
 808    /// The color of the strikethrough.
 809    pub color: Option<Hsla>,
 810}
 811
 812/// The kinds of fill that can be applied to a shape.
 813#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, JsonSchema)]
 814pub enum Fill {
 815    /// A solid color fill.
 816    Color(Background),
 817}
 818
 819impl Fill {
 820    /// Unwrap this fill into a solid color, if it is one.
 821    ///
 822    /// If the fill is not a solid color, this method returns `None`.
 823    pub fn color(&self) -> Option<Background> {
 824        match self {
 825            Fill::Color(color) => Some(*color),
 826        }
 827    }
 828}
 829
 830impl Default for Fill {
 831    fn default() -> Self {
 832        Self::Color(Background::default())
 833    }
 834}
 835
 836impl From<Hsla> for Fill {
 837    fn from(color: Hsla) -> Self {
 838        Self::Color(color.into())
 839    }
 840}
 841
 842impl From<Rgba> for Fill {
 843    fn from(color: Rgba) -> Self {
 844        Self::Color(color.into())
 845    }
 846}
 847
 848impl From<Background> for Fill {
 849    fn from(background: Background) -> Self {
 850        Self::Color(background)
 851    }
 852}
 853
 854impl From<TextStyle> for HighlightStyle {
 855    fn from(other: TextStyle) -> Self {
 856        Self::from(&other)
 857    }
 858}
 859
 860impl From<&TextStyle> for HighlightStyle {
 861    fn from(other: &TextStyle) -> Self {
 862        Self {
 863            color: Some(other.color),
 864            font_weight: Some(other.font_weight),
 865            font_style: Some(other.font_style),
 866            background_color: other.background_color,
 867            underline: other.underline,
 868            strikethrough: other.strikethrough,
 869            fade_out: None,
 870        }
 871    }
 872}
 873
 874impl HighlightStyle {
 875    /// Create a highlight style with just a color
 876    pub fn color(color: Hsla) -> Self {
 877        Self {
 878            color: Some(color),
 879            ..Default::default()
 880        }
 881    }
 882    /// Blend this highlight style with another.
 883    /// Non-continuous properties, like font_weight and font_style, are overwritten.
 884    #[must_use]
 885    pub fn highlight(self, other: HighlightStyle) -> Self {
 886        Self {
 887            color: other
 888                .color
 889                .map(|other_color| {
 890                    if let Some(color) = self.color {
 891                        color.blend(other_color)
 892                    } else {
 893                        other_color
 894                    }
 895                })
 896                .or(self.color),
 897            font_weight: other.font_weight.or(self.font_weight),
 898            font_style: other.font_style.or(self.font_style),
 899            background_color: other.background_color.or(self.background_color),
 900            underline: other.underline.or(self.underline),
 901            strikethrough: other.strikethrough.or(self.strikethrough),
 902            fade_out: other
 903                .fade_out
 904                .map(|source_fade| {
 905                    self.fade_out
 906                        .map(|dest_fade| (dest_fade * (1. + source_fade)).clamp(0., 1.))
 907                        .unwrap_or(source_fade)
 908                })
 909                .or(self.fade_out),
 910        }
 911    }
 912}
 913
 914impl From<Hsla> for HighlightStyle {
 915    fn from(color: Hsla) -> Self {
 916        Self {
 917            color: Some(color),
 918            ..Default::default()
 919        }
 920    }
 921}
 922
 923impl From<FontWeight> for HighlightStyle {
 924    fn from(font_weight: FontWeight) -> Self {
 925        Self {
 926            font_weight: Some(font_weight),
 927            ..Default::default()
 928        }
 929    }
 930}
 931
 932impl From<FontStyle> for HighlightStyle {
 933    fn from(font_style: FontStyle) -> Self {
 934        Self {
 935            font_style: Some(font_style),
 936            ..Default::default()
 937        }
 938    }
 939}
 940
 941impl From<Rgba> for HighlightStyle {
 942    fn from(color: Rgba) -> Self {
 943        Self {
 944            color: Some(color.into()),
 945            ..Default::default()
 946        }
 947    }
 948}
 949
 950/// Combine and merge the highlights and ranges in the two iterators.
 951pub fn combine_highlights(
 952    a: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
 953    b: impl IntoIterator<Item = (Range<usize>, HighlightStyle)>,
 954) -> impl Iterator<Item = (Range<usize>, HighlightStyle)> {
 955    let mut endpoints = Vec::new();
 956    let mut highlights = Vec::new();
 957    for (range, highlight) in a.into_iter().chain(b) {
 958        if !range.is_empty() {
 959            let highlight_id = highlights.len();
 960            endpoints.push((range.start, highlight_id, true));
 961            endpoints.push((range.end, highlight_id, false));
 962            highlights.push(highlight);
 963        }
 964    }
 965    endpoints.sort_unstable_by_key(|(position, _, _)| *position);
 966    let mut endpoints = endpoints.into_iter().peekable();
 967
 968    let mut active_styles = HashSet::default();
 969    let mut ix = 0;
 970    iter::from_fn(move || {
 971        while let Some((endpoint_ix, highlight_id, is_start)) = endpoints.peek() {
 972            let prev_index = mem::replace(&mut ix, *endpoint_ix);
 973            if ix > prev_index && !active_styles.is_empty() {
 974                let current_style = active_styles
 975                    .iter()
 976                    .fold(HighlightStyle::default(), |acc, highlight_id| {
 977                        acc.highlight(highlights[*highlight_id])
 978                    });
 979                return Some((prev_index..ix, current_style));
 980            }
 981
 982            if *is_start {
 983                active_styles.insert(*highlight_id);
 984            } else {
 985                active_styles.remove(highlight_id);
 986            }
 987            endpoints.next();
 988        }
 989        None
 990    })
 991}
 992
 993/// Used to control how child nodes are aligned.
 994/// For Flexbox it controls alignment in the cross axis
 995/// For Grid it controls alignment in the block axis
 996///
 997/// [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/align-items)
 998#[derive(Copy, Clone, PartialEq, Eq, Debug, Serialize, Deserialize, JsonSchema)]
 999// Copy of taffy::style type of the same name, to derive JsonSchema.
1000pub enum AlignItems {
1001    /// Items are packed toward the start of the axis
1002    Start,
1003    /// Items are packed toward the end of the axis
1004    End,
1005    /// Items are packed towards the flex-relative start of the axis.
1006    ///
1007    /// For flex containers with flex_direction RowReverse or ColumnReverse this is equivalent
1008    /// to End. In all other cases it is equivalent to Start.
1009    FlexStart,
1010    /// Items are packed towards the flex-relative end of the axis.
1011    ///
1012    /// For flex containers with flex_direction RowReverse or ColumnReverse this is equivalent
1013    /// to Start. In all other cases it is equivalent to End.
1014    FlexEnd,
1015    /// Items are packed along the center of the cross axis
1016    Center,
1017    /// Items are aligned such as their baselines align
1018    Baseline,
1019    /// Stretch to fill the container
1020    Stretch,
1021}
1022/// Used to control how child nodes are aligned.
1023/// Does not apply to Flexbox, and will be ignored if specified on a flex container
1024/// For Grid it controls alignment in the inline axis
1025///
1026/// [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/justify-items)
1027pub type JustifyItems = AlignItems;
1028/// Used to control how the specified nodes is aligned.
1029/// Overrides the parent Node's `AlignItems` property.
1030/// For Flexbox it controls alignment in the cross axis
1031/// For Grid it controls alignment in the block axis
1032///
1033/// [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/align-self)
1034pub type AlignSelf = AlignItems;
1035/// Used to control how the specified nodes is aligned.
1036/// Overrides the parent Node's `JustifyItems` property.
1037/// Does not apply to Flexbox, and will be ignored if specified on a flex child
1038/// For Grid it controls alignment in the inline axis
1039///
1040/// [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/justify-self)
1041pub type JustifySelf = AlignItems;
1042
1043/// Sets the distribution of space between and around content items
1044/// For Flexbox it controls alignment in the cross axis
1045/// For Grid it controls alignment in the block axis
1046///
1047/// [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/align-content)
1048#[derive(Copy, Clone, PartialEq, Eq, Debug, Serialize, Deserialize, JsonSchema)]
1049// Copy of taffy::style type of the same name, to derive JsonSchema.
1050pub enum AlignContent {
1051    /// Items are packed toward the start of the axis
1052    Start,
1053    /// Items are packed toward the end of the axis
1054    End,
1055    /// Items are packed towards the flex-relative start of the axis.
1056    ///
1057    /// For flex containers with flex_direction RowReverse or ColumnReverse this is equivalent
1058    /// to End. In all other cases it is equivalent to Start.
1059    FlexStart,
1060    /// Items are packed towards the flex-relative end of the axis.
1061    ///
1062    /// For flex containers with flex_direction RowReverse or ColumnReverse this is equivalent
1063    /// to Start. In all other cases it is equivalent to End.
1064    FlexEnd,
1065    /// Items are centered around the middle of the axis
1066    Center,
1067    /// Items are stretched to fill the container
1068    Stretch,
1069    /// The first and last items are aligned flush with the edges of the container (no gap)
1070    /// The gap between items is distributed evenly.
1071    SpaceBetween,
1072    /// The gap between the first and last items is exactly THE SAME as the gap between items.
1073    /// The gaps are distributed evenly
1074    SpaceEvenly,
1075    /// The gap between the first and last items is exactly HALF the gap between items.
1076    /// The gaps are distributed evenly in proportion to these ratios.
1077    SpaceAround,
1078}
1079
1080/// Sets the distribution of space between and around content items
1081/// For Flexbox it controls alignment in the main axis
1082/// For Grid it controls alignment in the inline axis
1083///
1084/// [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/justify-content)
1085pub type JustifyContent = AlignContent;
1086
1087/// Sets the layout used for the children of this node
1088///
1089/// The default values depends on on which feature flags are enabled. The order of precedence is: Flex, Grid, Block, None.
1090#[derive(Copy, Clone, PartialEq, Eq, Debug, Default, Serialize, Deserialize, JsonSchema)]
1091// Copy of taffy::style type of the same name, to derive JsonSchema.
1092pub enum Display {
1093    /// The children will follow the block layout algorithm
1094    Block,
1095    /// The children will follow the flexbox layout algorithm
1096    #[default]
1097    Flex,
1098    /// The children will follow the CSS Grid layout algorithm
1099    Grid,
1100    /// The children will not be laid out, and will follow absolute positioning
1101    None,
1102}
1103
1104/// Controls whether flex items are forced onto one line or can wrap onto multiple lines.
1105///
1106/// Defaults to [`FlexWrap::NoWrap`]
1107///
1108/// [Specification](https://www.w3.org/TR/css-flexbox-1/#flex-wrap-property)
1109#[derive(Copy, Clone, PartialEq, Eq, Debug, Default, Serialize, Deserialize, JsonSchema)]
1110// Copy of taffy::style type of the same name, to derive JsonSchema.
1111pub enum FlexWrap {
1112    /// Items will not wrap and stay on a single line
1113    #[default]
1114    NoWrap,
1115    /// Items will wrap according to this item's [`FlexDirection`]
1116    Wrap,
1117    /// Items will wrap in the opposite direction to this item's [`FlexDirection`]
1118    WrapReverse,
1119}
1120
1121/// The direction of the flexbox layout main axis.
1122///
1123/// There are always two perpendicular layout axes: main (or primary) and cross (or secondary).
1124/// Adding items will cause them to be positioned adjacent to each other along the main axis.
1125/// By varying this value throughout your tree, you can create complex axis-aligned layouts.
1126///
1127/// Items are always aligned relative to the cross axis, and justified relative to the main axis.
1128///
1129/// The default behavior is [`FlexDirection::Row`].
1130///
1131/// [Specification](https://www.w3.org/TR/css-flexbox-1/#flex-direction-property)
1132#[derive(Copy, Clone, PartialEq, Eq, Debug, Default, Serialize, Deserialize, JsonSchema)]
1133// Copy of taffy::style type of the same name, to derive JsonSchema.
1134pub enum FlexDirection {
1135    /// Defines +x as the main axis
1136    ///
1137    /// Items will be added from left to right in a row.
1138    #[default]
1139    Row,
1140    /// Defines +y as the main axis
1141    ///
1142    /// Items will be added from top to bottom in a column.
1143    Column,
1144    /// Defines -x as the main axis
1145    ///
1146    /// Items will be added from right to left in a row.
1147    RowReverse,
1148    /// Defines -y as the main axis
1149    ///
1150    /// Items will be added from bottom to top in a column.
1151    ColumnReverse,
1152}
1153
1154/// How children overflowing their container should affect layout
1155///
1156/// In CSS the primary effect of this property is to control whether contents of a parent container that overflow that container should
1157/// be displayed anyway, be clipped, or trigger the container to become a scroll container. However it also has secondary effects on layout,
1158/// the main ones being:
1159///
1160///   - The automatic minimum size Flexbox/CSS Grid items with non-`Visible` overflow is `0` rather than being content based
1161///   - `Overflow::Scroll` nodes have space in the layout reserved for a scrollbar (width controlled by the `scrollbar_width` property)
1162///
1163/// In Taffy, we only implement the layout related secondary effects as we are not concerned with drawing/painting. The amount of space reserved for
1164/// a scrollbar is controlled by the `scrollbar_width` property. If this is `0` then `Scroll` behaves identically to `Hidden`.
1165///
1166/// <https://developer.mozilla.org/en-US/docs/Web/CSS/overflow>
1167#[derive(Copy, Clone, PartialEq, Eq, Debug, Default, Serialize, Deserialize, JsonSchema)]
1168// Copy of taffy::style type of the same name, to derive JsonSchema.
1169pub enum Overflow {
1170    /// The automatic minimum size of this node as a flexbox/grid item should be based on the size of its content.
1171    /// Content that overflows this node *should* contribute to the scroll region of its parent.
1172    #[default]
1173    Visible,
1174    /// The automatic minimum size of this node as a flexbox/grid item should be based on the size of its content.
1175    /// Content that overflows this node should *not* contribute to the scroll region of its parent.
1176    Clip,
1177    /// The automatic minimum size of this node as a flexbox/grid item should be `0`.
1178    /// Content that overflows this node should *not* contribute to the scroll region of its parent.
1179    Hidden,
1180    /// The automatic minimum size of this node as a flexbox/grid item should be `0`. Additionally, space should be reserved
1181    /// for a scrollbar. The amount of space reserved is controlled by the `scrollbar_width` property.
1182    /// Content that overflows this node should *not* contribute to the scroll region of its parent.
1183    Scroll,
1184}
1185
1186/// The positioning strategy for this item.
1187///
1188/// This controls both how the origin is determined for the [`Style::position`] field,
1189/// and whether or not the item will be controlled by flexbox's layout algorithm.
1190///
1191/// WARNING: this enum follows the behavior of [CSS's `position` property](https://developer.mozilla.org/en-US/docs/Web/CSS/position),
1192/// which can be unintuitive.
1193///
1194/// [`Position::Relative`] is the default value, in contrast to the default behavior in CSS.
1195#[derive(Copy, Clone, PartialEq, Eq, Debug, Default, Serialize, Deserialize, JsonSchema)]
1196// Copy of taffy::style type of the same name, to derive JsonSchema.
1197pub enum Position {
1198    /// The offset is computed relative to the final position given by the layout algorithm.
1199    /// Offsets do not affect the position of any other items; they are effectively a correction factor applied at the end.
1200    #[default]
1201    Relative,
1202    /// The offset is computed relative to this item's closest positioned ancestor, if any.
1203    /// Otherwise, it is placed relative to the origin.
1204    /// No space is created for the item in the page layout, and its size will not be altered.
1205    ///
1206    /// WARNING: to opt-out of layouting entirely, you must use [`Display::None`] instead on your [`Style`] object.
1207    Absolute,
1208}
1209
1210impl From<AlignItems> for taffy::style::AlignItems {
1211    fn from(value: AlignItems) -> Self {
1212        match value {
1213            AlignItems::Start => Self::Start,
1214            AlignItems::End => Self::End,
1215            AlignItems::FlexStart => Self::FlexStart,
1216            AlignItems::FlexEnd => Self::FlexEnd,
1217            AlignItems::Center => Self::Center,
1218            AlignItems::Baseline => Self::Baseline,
1219            AlignItems::Stretch => Self::Stretch,
1220        }
1221    }
1222}
1223
1224impl From<AlignContent> for taffy::style::AlignContent {
1225    fn from(value: AlignContent) -> Self {
1226        match value {
1227            AlignContent::Start => Self::Start,
1228            AlignContent::End => Self::End,
1229            AlignContent::FlexStart => Self::FlexStart,
1230            AlignContent::FlexEnd => Self::FlexEnd,
1231            AlignContent::Center => Self::Center,
1232            AlignContent::Stretch => Self::Stretch,
1233            AlignContent::SpaceBetween => Self::SpaceBetween,
1234            AlignContent::SpaceEvenly => Self::SpaceEvenly,
1235            AlignContent::SpaceAround => Self::SpaceAround,
1236        }
1237    }
1238}
1239
1240impl From<Display> for taffy::style::Display {
1241    fn from(value: Display) -> Self {
1242        match value {
1243            Display::Block => Self::Block,
1244            Display::Flex => Self::Flex,
1245            Display::Grid => Self::Grid,
1246            Display::None => Self::None,
1247        }
1248    }
1249}
1250
1251impl From<FlexWrap> for taffy::style::FlexWrap {
1252    fn from(value: FlexWrap) -> Self {
1253        match value {
1254            FlexWrap::NoWrap => Self::NoWrap,
1255            FlexWrap::Wrap => Self::Wrap,
1256            FlexWrap::WrapReverse => Self::WrapReverse,
1257        }
1258    }
1259}
1260
1261impl From<FlexDirection> for taffy::style::FlexDirection {
1262    fn from(value: FlexDirection) -> Self {
1263        match value {
1264            FlexDirection::Row => Self::Row,
1265            FlexDirection::Column => Self::Column,
1266            FlexDirection::RowReverse => Self::RowReverse,
1267            FlexDirection::ColumnReverse => Self::ColumnReverse,
1268        }
1269    }
1270}
1271
1272impl From<Overflow> for taffy::style::Overflow {
1273    fn from(value: Overflow) -> Self {
1274        match value {
1275            Overflow::Visible => Self::Visible,
1276            Overflow::Clip => Self::Clip,
1277            Overflow::Hidden => Self::Hidden,
1278            Overflow::Scroll => Self::Scroll,
1279        }
1280    }
1281}
1282
1283impl From<Position> for taffy::style::Position {
1284    fn from(value: Position) -> Self {
1285        match value {
1286            Position::Relative => Self::Relative,
1287            Position::Absolute => Self::Absolute,
1288        }
1289    }
1290}
1291
1292#[cfg(test)]
1293mod tests {
1294    use crate::{blue, green, px, red, yellow};
1295
1296    use super::*;
1297
1298    use util_macros::perf;
1299
1300    #[perf]
1301    fn test_basic_highlight_style_combination() {
1302        let style_a = HighlightStyle::default();
1303        let style_b = HighlightStyle::default();
1304        let style_a = style_a.highlight(style_b);
1305        assert_eq!(
1306            style_a,
1307            HighlightStyle::default(),
1308            "Combining empty styles should not produce a non-empty style."
1309        );
1310
1311        let mut style_b = HighlightStyle {
1312            color: Some(red()),
1313            strikethrough: Some(StrikethroughStyle {
1314                thickness: px(2.),
1315                color: Some(blue()),
1316            }),
1317            fade_out: Some(0.),
1318            font_style: Some(FontStyle::Italic),
1319            font_weight: Some(FontWeight(300.)),
1320            background_color: Some(yellow()),
1321            underline: Some(UnderlineStyle {
1322                thickness: px(2.),
1323                color: Some(red()),
1324                wavy: true,
1325            }),
1326        };
1327        let expected_style = style_b;
1328
1329        let style_a = style_a.highlight(style_b);
1330        assert_eq!(
1331            style_a, expected_style,
1332            "Blending an empty style with another style should return the other style"
1333        );
1334
1335        let style_b = style_b.highlight(Default::default());
1336        assert_eq!(
1337            style_b, expected_style,
1338            "Blending a style with an empty style should not change the style."
1339        );
1340
1341        let mut style_c = expected_style;
1342
1343        let style_d = HighlightStyle {
1344            color: Some(blue().alpha(0.7)),
1345            strikethrough: Some(StrikethroughStyle {
1346                thickness: px(4.),
1347                color: Some(crate::red()),
1348            }),
1349            fade_out: Some(0.),
1350            font_style: Some(FontStyle::Oblique),
1351            font_weight: Some(FontWeight(800.)),
1352            background_color: Some(green()),
1353            underline: Some(UnderlineStyle {
1354                thickness: px(4.),
1355                color: None,
1356                wavy: false,
1357            }),
1358        };
1359
1360        let expected_style = HighlightStyle {
1361            color: Some(red().blend(blue().alpha(0.7))),
1362            strikethrough: Some(StrikethroughStyle {
1363                thickness: px(4.),
1364                color: Some(red()),
1365            }),
1366            // TODO this does not seem right
1367            fade_out: Some(0.),
1368            font_style: Some(FontStyle::Oblique),
1369            font_weight: Some(FontWeight(800.)),
1370            background_color: Some(green()),
1371            underline: Some(UnderlineStyle {
1372                thickness: px(4.),
1373                color: None,
1374                wavy: false,
1375            }),
1376        };
1377
1378        let style_c = style_c.highlight(style_d);
1379        assert_eq!(
1380            style_c, expected_style,
1381            "Blending styles should blend properties where possible and override all others"
1382        );
1383    }
1384
1385    #[perf]
1386    fn test_combine_highlights() {
1387        assert_eq!(
1388            combine_highlights(
1389                [
1390                    (0..5, green().into()),
1391                    (4..10, FontWeight::BOLD.into()),
1392                    (15..20, yellow().into()),
1393                ],
1394                [
1395                    (2..6, FontStyle::Italic.into()),
1396                    (1..3, blue().into()),
1397                    (21..23, red().into()),
1398                ]
1399            )
1400            .collect::<Vec<_>>(),
1401            [
1402                (
1403                    0..1,
1404                    HighlightStyle {
1405                        color: Some(green()),
1406                        ..Default::default()
1407                    }
1408                ),
1409                (
1410                    1..2,
1411                    HighlightStyle {
1412                        color: Some(blue()),
1413                        ..Default::default()
1414                    }
1415                ),
1416                (
1417                    2..3,
1418                    HighlightStyle {
1419                        color: Some(blue()),
1420                        font_style: Some(FontStyle::Italic),
1421                        ..Default::default()
1422                    }
1423                ),
1424                (
1425                    3..4,
1426                    HighlightStyle {
1427                        color: Some(green()),
1428                        font_style: Some(FontStyle::Italic),
1429                        ..Default::default()
1430                    }
1431                ),
1432                (
1433                    4..5,
1434                    HighlightStyle {
1435                        color: Some(green()),
1436                        font_weight: Some(FontWeight::BOLD),
1437                        font_style: Some(FontStyle::Italic),
1438                        ..Default::default()
1439                    }
1440                ),
1441                (
1442                    5..6,
1443                    HighlightStyle {
1444                        font_weight: Some(FontWeight::BOLD),
1445                        font_style: Some(FontStyle::Italic),
1446                        ..Default::default()
1447                    }
1448                ),
1449                (
1450                    6..10,
1451                    HighlightStyle {
1452                        font_weight: Some(FontWeight::BOLD),
1453                        ..Default::default()
1454                    }
1455                ),
1456                (
1457                    15..20,
1458                    HighlightStyle {
1459                        color: Some(yellow()),
1460                        ..Default::default()
1461                    }
1462                ),
1463                (
1464                    21..23,
1465                    HighlightStyle {
1466                        color: Some(red()),
1467                        ..Default::default()
1468                    }
1469                )
1470            ]
1471        );
1472    }
1473
1474    #[perf]
1475    fn test_text_style_refinement() {
1476        let mut style = Style::default();
1477        style.refine(&StyleRefinement::default().text_size(px(20.0)));
1478        style.refine(&StyleRefinement::default().font_weight(FontWeight::SEMIBOLD));
1479
1480        assert_eq!(
1481            Some(AbsoluteLength::from(px(20.0))),
1482            style.text_style().unwrap().font_size
1483        );
1484
1485        assert_eq!(
1486            Some(FontWeight::SEMIBOLD),
1487            style.text_style().unwrap().font_weight
1488        );
1489    }
1490}