Checkpoint

crates/gpui2/src/style.rs

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+use crate::{
+    black, phi, point, rems, AbsoluteLength, BorrowAppContext, BorrowWindow, Bounds, ContentMask,
+    Corners, CornersRefinement, DefiniteLength, Edges, EdgesRefinement, Font, FontFeatures,
+    FontStyle, FontWeight, Hsla, Length, Pixels, Point, PointRefinement, Rems, Result,
+    SharedString, Size, SizeRefinement, Styled, TextRun, ViewContext, WindowContext,
+};
+use refineable::{Cascade, Refineable};
+use smallvec::SmallVec;
+pub use taffy::style::{
+    AlignContent, AlignItems, AlignSelf, Display, FlexDirection, FlexWrap, JustifyContent,
+    Overflow, Position,
+};
+
+pub type StyleCascade = Cascade<Style>;
+
+#[derive(Clone, Refineable, Debug)]
+#[refineable(debug)]
+pub struct Style {
+    /// What layout strategy should be used?
+    pub display: Display,
+
+    // Overflow properties
+    /// How children overflowing their container should affect layout
+    #[refineable]
+    pub overflow: Point<Overflow>,
+    /// How much space (in points) should be reserved for the scrollbars of `Overflow::Scroll` and `Overflow::Auto` nodes.
+    pub scrollbar_width: f32,
+
+    // Position properties
+    /// What should the `position` value of this struct use as a base offset?
+    pub position: Position,
+    /// How should the position of this element be tweaked relative to the layout defined?
+    #[refineable]
+    pub inset: Edges<Length>,
+
+    // Size properies
+    /// Sets the initial size of the item
+    #[refineable]
+    pub size: Size<Length>,
+    /// Controls the minimum size of the item
+    #[refineable]
+    pub min_size: Size<Length>,
+    /// Controls the maximum size of the item
+    #[refineable]
+    pub max_size: Size<Length>,
+    /// Sets the preferred aspect ratio for the item. The ratio is calculated as width divided by height.
+    pub aspect_ratio: Option<f32>,
+
+    // Spacing Properties
+    /// How large should the margin be on each side?
+    #[refineable]
+    pub margin: Edges<Length>,
+    /// How large should the padding be on each side?
+    #[refineable]
+    pub padding: Edges<DefiniteLength>,
+    /// How large should the border be on each side?
+    #[refineable]
+    pub border_widths: Edges<AbsoluteLength>,
+
+    // Alignment properties
+    /// How this node's children aligned in the cross/block axis?
+    pub align_items: Option<AlignItems>,
+    /// How this node should be aligned in the cross/block axis. Falls back to the parents [`AlignItems`] if not set
+    pub align_self: Option<AlignSelf>,
+    /// How should content contained within this item be aligned in the cross/block axis
+    pub align_content: Option<AlignContent>,
+    /// How should contained within this item be aligned in the main/inline axis
+    pub justify_content: Option<JustifyContent>,
+    /// How large should the gaps between items in a flex container be?
+    #[refineable]
+    pub gap: Size<DefiniteLength>,
+
+    // Flexbox properies
+    /// Which direction does the main axis flow in?
+    pub flex_direction: FlexDirection,
+    /// Should elements wrap, or stay in a single line?
+    pub flex_wrap: FlexWrap,
+    /// Sets the initial main axis size of the item
+    pub flex_basis: Length,
+    /// 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.
+    pub flex_grow: f32,
+    /// 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.
+    pub flex_shrink: f32,
+
+    /// The fill color of this element
+    pub background: Option<Fill>,
+
+    /// The border color of this element
+    pub border_color: Option<Hsla>,
+
+    /// The radius of the corners of this element
+    #[refineable]
+    pub corner_radii: Corners<AbsoluteLength>,
+
+    /// Box Shadow of the element
+    pub box_shadow: SmallVec<[BoxShadow; 2]>,
+
+    /// TEXT
+    pub text: TextStyleRefinement,
+
+    pub z_index: Option<u32>,
+}
+
+impl Styled for StyleRefinement {
+    fn style(&mut self) -> &mut StyleRefinement {
+        self
+    }
+}
+
+#[derive(Clone, Debug)]
+pub struct BoxShadow {
+    pub color: Hsla,
+    pub offset: Point<Pixels>,
+    pub blur_radius: Pixels,
+    pub spread_radius: Pixels,
+}
+
+#[derive(Refineable, Clone, Debug)]
+#[refineable(debug)]
+pub struct TextStyle {
+    pub color: Hsla,
+    pub font_family: SharedString,
+    pub font_features: FontFeatures,
+    pub font_size: Rems,
+    pub line_height: DefiniteLength,
+    pub font_weight: FontWeight,
+    pub font_style: FontStyle,
+    pub underline: Option<UnderlineStyle>,
+}
+
+impl Default for TextStyle {
+    fn default() -> Self {
+        TextStyle {
+            color: black(),
+            font_family: "Helvetica".into(), // todo!("Get a font we know exists on the system")
+            font_features: FontFeatures::default(),
+            font_size: rems(1.),
+            line_height: phi(),
+            font_weight: FontWeight::default(),
+            font_style: FontStyle::default(),
+            underline: None,
+        }
+    }
+}
+
+impl TextStyle {
+    pub fn highlight(mut self, style: HighlightStyle) -> Result<Self> {
+        if let Some(weight) = style.font_weight {
+            self.font_weight = weight;
+        }
+        if let Some(style) = style.font_style {
+            self.font_style = style;
+        }
+
+        if let Some(color) = style.color {
+            self.color = self.color.blend(color);
+        }
+
+        if let Some(factor) = style.fade_out {
+            self.color.fade_out(factor);
+        }
+
+        if let Some(underline) = style.underline {
+            self.underline = Some(underline);
+        }
+
+        Ok(self)
+    }
+
+    pub fn to_run(&self, len: usize) -> TextRun {
+        TextRun {
+            len,
+            font: Font {
+                family: self.font_family.clone(),
+                features: Default::default(),
+                weight: self.font_weight,
+                style: self.font_style,
+            },
+            color: self.color,
+            underline: self.underline.clone(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq)]
+pub struct HighlightStyle {
+    pub color: Option<Hsla>,
+    pub font_weight: Option<FontWeight>,
+    pub font_style: Option<FontStyle>,
+    pub underline: Option<UnderlineStyle>,
+    pub fade_out: Option<f32>,
+}
+
+impl Eq for HighlightStyle {}
+
+impl Style {
+    pub fn text_style(&self, _cx: &WindowContext) -> Option<&TextStyleRefinement> {
+        if self.text.is_some() {
+            Some(&self.text)
+        } else {
+            None
+        }
+    }
+
+    pub fn apply_text_style<C, F, R>(&self, cx: &mut C, f: F) -> R
+    where
+        C: BorrowAppContext,
+        F: FnOnce(&mut C) -> R,
+    {
+        if self.text.is_some() {
+            cx.with_text_style(self.text.clone(), f)
+        } else {
+            f(cx)
+        }
+    }
+
+    /// Apply overflow to content mask
+    pub fn apply_overflow<C, F, R>(&self, bounds: Bounds<Pixels>, cx: &mut C, f: F) -> R
+    where
+        C: BorrowWindow,
+        F: FnOnce(&mut C) -> R,
+    {
+        let current_mask = cx.content_mask();
+
+        let min = current_mask.bounds.origin;
+        let max = current_mask.bounds.lower_right();
+
+        let mask_bounds = match (
+            self.overflow.x == Overflow::Visible,
+            self.overflow.y == Overflow::Visible,
+        ) {
+            // x and y both visible
+            (true, true) => return f(cx),
+            // x visible, y hidden
+            (true, false) => Bounds::from_corners(
+                point(min.x, bounds.origin.y),
+                point(max.x, bounds.lower_right().y),
+            ),
+            // x hidden, y visible
+            (false, true) => Bounds::from_corners(
+                point(bounds.origin.x, min.y),
+                point(bounds.lower_right().x, max.y),
+            ),
+            // both hidden
+            (false, false) => bounds,
+        };
+        let mask = ContentMask {
+            bounds: mask_bounds,
+        };
+
+        cx.with_content_mask(mask, f)
+    }
+
+    /// Paints the background of an element styled with this style.
+    pub fn paint<V: 'static>(&self, bounds: Bounds<Pixels>, cx: &mut ViewContext<V>) {
+        let rem_size = cx.rem_size();
+
+        cx.stack(0, |cx| {
+            cx.paint_shadows(
+                bounds,
+                self.corner_radii.to_pixels(bounds.size, rem_size),
+                &self.box_shadow,
+            );
+        });
+
+        let background_color = self.background.as_ref().and_then(Fill::color);
+        if background_color.is_some() || self.is_border_visible() {
+            cx.stack(1, |cx| {
+                cx.paint_quad(
+                    bounds,
+                    self.corner_radii.to_pixels(bounds.size, rem_size),
+                    background_color.unwrap_or_default(),
+                    self.border_widths.to_pixels(rem_size),
+                    self.border_color.unwrap_or_default(),
+                );
+            });
+        }
+    }
+
+    fn is_border_visible(&self) -> bool {
+        self.border_color
+            .map_or(false, |color| !color.is_transparent())
+            && self.border_widths.any(|length| !length.is_zero())
+    }
+}
+
+impl Default for Style {
+    fn default() -> Self {
+        Style {
+            display: Display::Block,
+            overflow: Point {
+                x: Overflow::Visible,
+                y: Overflow::Visible,
+            },
+            scrollbar_width: 0.0,
+            position: Position::Relative,
+            inset: Edges::auto(),
+            margin: Edges::<Length>::zero(),
+            padding: Edges::<DefiniteLength>::zero(),
+            border_widths: Edges::<AbsoluteLength>::zero(),
+            size: Size::auto(),
+            min_size: Size::auto(),
+            max_size: Size::auto(),
+            aspect_ratio: None,
+            gap: Size::zero(),
+            // Aligment
+            align_items: None,
+            align_self: None,
+            align_content: None,
+            justify_content: None,
+            // Flexbox
+            flex_direction: FlexDirection::Row,
+            flex_wrap: FlexWrap::NoWrap,
+            flex_grow: 0.0,
+            flex_shrink: 1.0,
+            flex_basis: Length::Auto,
+            background: None,
+            border_color: None,
+            corner_radii: Corners::default(),
+            box_shadow: Default::default(),
+            text: TextStyleRefinement::default(),
+            z_index: None,
+        }
+    }
+}
+
+#[derive(Refineable, Clone, Default, Debug, PartialEq, Eq)]
+#[refineable(debug)]
+pub struct UnderlineStyle {
+    pub thickness: Pixels,
+    pub color: Option<Hsla>,
+    pub wavy: bool,
+}
+
+#[derive(Clone, Debug)]
+pub enum Fill {
+    Color(Hsla),
+}
+
+impl Fill {
+    pub fn color(&self) -> Option<Hsla> {
+        match self {
+            Fill::Color(color) => Some(*color),
+        }
+    }
+}
+
+impl Default for Fill {
+    fn default() -> Self {
+        Self::Color(Hsla::default())
+    }
+}
+
+impl From<Hsla> for Fill {
+    fn from(color: Hsla) -> Self {
+        Self::Color(color)
+    }
+}
+
+impl From<TextStyle> for HighlightStyle {
+    fn from(other: TextStyle) -> Self {
+        Self::from(&other)
+    }
+}
+
+impl From<&TextStyle> for HighlightStyle {
+    fn from(other: &TextStyle) -> Self {
+        Self {
+            color: Some(other.color),
+            font_weight: Some(other.font_weight),
+            font_style: Some(other.font_style),
+            underline: other.underline.clone(),
+            fade_out: None,
+        }
+    }
+}
+
+impl HighlightStyle {
+    pub fn highlight(&mut self, other: HighlightStyle) {
+        match (self.color, other.color) {
+            (Some(self_color), Some(other_color)) => {
+                self.color = Some(Hsla::blend(other_color, self_color));
+            }
+            (None, Some(other_color)) => {
+                self.color = Some(other_color);
+            }
+            _ => {}
+        }
+
+        if other.font_weight.is_some() {
+            self.font_weight = other.font_weight;
+        }
+
+        if other.font_style.is_some() {
+            self.font_style = other.font_style;
+        }
+
+        if other.underline.is_some() {
+            self.underline = other.underline;
+        }
+
+        match (other.fade_out, self.fade_out) {
+            (Some(source_fade), None) => self.fade_out = Some(source_fade),
+            (Some(source_fade), Some(dest_fade)) => {
+                self.fade_out = Some((dest_fade * (1. + source_fade)).clamp(0., 1.));
+            }
+            _ => {}
+        }
+    }
+}
+
+impl From<Hsla> for HighlightStyle {
+    fn from(color: Hsla) -> Self {
+        Self {
+            color: Some(color),
+            ..Default::default()
+        }
+    }
+}