[refactor] better names for widget style members

egui/src/containers/frame.rs

@@ -18,7 +18,7 @@ impl Frame {
             margin: style.window_padding,
             corner_radius: style.window.corner_radius,
             fill: Some(style.background_fill),
-            outline: style.interact.inactive.rect_outline, // because we can resize windows
+            outline: style.interact.inactive.bg_outline, // because we can resize windows
         }
     }
 

egui/src/containers/scroll_area.rs

@@ -237,8 +237,8 @@ impl Prepared {
             }
 
             let style = ui.style();
-            let handle_fill = style.interact(&response).fill;
+            let handle_fill = style.interact(&response).main_fill;
-            let handle_outline = style.interact(&response).rect_outline;
+            let handle_outline = style.interact(&response).bg_outline;
 
             ui.painter().add(paint::PaintCmd::Rect {
                 rect: outer_scroll_rect,

egui/src/containers/window.rs

@@ -567,7 +567,7 @@ fn paint_frame_interaction(
         path,
         closed: false,
         fill: None,
-        outline: style.rect_outline,
+        outline: style.bg_outline,
     });
 }
 
@@ -671,7 +671,7 @@ impl TitleBar {
             let y = content_rect.top() + ui.style().item_spacing.y * 0.5;
             ui.painter().line_segment(
                 [pos2(left, y), pos2(right, y)],
-                ui.style().interact.inactive.rect_outline.unwrap(),
+                ui.style().interact.inactive.bg_outline.unwrap(),
             );
         }
 

egui/src/menu.rs

@@ -63,11 +63,11 @@ pub fn bar<R>(ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> (R, Rect)
             let mut style = ui.style().clone();
             style.button_padding = vec2(2.0, 0.0);
             // style.interact.active.bg_fill = None;
-            style.interact.active.rect_outline = None;
+            style.interact.active.bg_outline = None;
             // style.interact.hovered.bg_fill = None;
-            style.interact.hovered.rect_outline = None;
+            style.interact.hovered.bg_outline = None;
             style.interact.inactive.bg_fill = None;
-            style.interact.inactive.rect_outline = None;
+            style.interact.inactive.bg_outline = None;
             ui.set_style(style);
 
             // Take full width and fixed height:
@@ -108,7 +108,7 @@ fn menu_impl<'c>(
     let mut button = Button::new(title);
 
     if bar_state.open_menu == Some(menu_id) {
-        button = button.fill(Some(ui.style().interact.active.fill));
+        button = button.fill(Some(ui.style().interact.active.main_fill));
     }
 
     let button_response = ui.add(button);
@@ -129,11 +129,11 @@ fn menu_impl<'c>(
                     let mut style = ui.style().clone();
                     style.button_padding = vec2(2.0, 0.0);
                     // style.interact.active.bg_fill = None;
-                    style.interact.active.rect_outline = None;
+                    style.interact.active.bg_outline = None;
                     // style.interact.hovered.bg_fill = None;
-                    style.interact.hovered.rect_outline = None;
+                    style.interact.hovered.bg_outline = None;
                     style.interact.inactive.bg_fill = None;
-                    style.interact.inactive.rect_outline = None;
+                    style.interact.inactive.bg_outline = None;
                     ui.set_style(style);
                     ui.set_layout(Layout::justified(Direction::Vertical));
                     add_contents(ui)

egui/src/paint/color.rs

@@ -7,7 +7,7 @@ pub struct Srgba {
     pub r: u8,
     pub g: u8,
     pub b: u8,
-    /// Linear space (not subject to sRGBA gamma conversion)
+    /// Alpha is in linear space (not subject to sRGBA gamma conversion)
     pub a: u8,
 }
 /// 0-1 linear space `RGBA` color with premultiplied alpha.
@@ -110,7 +110,42 @@ impl Srgba {
     }
 }
 
+// ----------------------------------------------------------------------------
+
+pub const TRANSPARENT: Srgba = srgba(0, 0, 0, 0);
+pub const BLACK: Srgba = srgba(0, 0, 0, 255);
+pub const LIGHT_GRAY: Srgba = srgba(220, 220, 220, 255);
+pub const GRAY: Srgba = srgba(160, 160, 160, 255);
+pub const WHITE: Srgba = srgba(255, 255, 255, 255);
+pub const RED: Srgba = srgba(255, 0, 0, 255);
+pub const GREEN: Srgba = srgba(0, 255, 0, 255);
+pub const BLUE: Srgba = srgba(0, 0, 255, 255);
+pub const YELLOW: Srgba = srgba(255, 255, 0, 255);
+pub const LIGHT_BLUE: Srgba = srgba(140, 160, 255, 255);
+
+// ----------------------------------------------------------------------------
+
 impl Rgba {
+    pub const TRANSPARENT: Rgba = Rgba::new(0.0, 0.0, 0.0, 0.0);
+    pub const BLACK: Rgba = Rgba::new(0.0, 0.0, 0.0, 1.0);
+    pub const WHITE: Rgba = Rgba::new(1.0, 1.0, 1.0, 1.0);
+    pub const RED: Rgba = Rgba::new(1.0, 0.0, 0.0, 1.0);
+    pub const GREEN: Rgba = Rgba::new(0.0, 1.0, 0.0, 1.0);
+    pub const BLUE: Rgba = Rgba::new(0.0, 0.0, 1.0, 1.0);
+
+    pub const fn new(r: f32, g: f32, b: f32, a: f32) -> Self {
+        Self { r, g, b, a }
+    }
+
+    pub const fn gray(l: f32) -> Self {
+        Self {
+            r: l,
+            g: l,
+            b: l,
+            a: 1.0,
+        }
+    }
+
     pub fn luminance_alpha(l: f32, a: f32) -> Self {
         debug_assert!(0.0 <= l && l <= 1.0);
         debug_assert!(0.0 <= a && a <= 1.0);
@@ -122,13 +157,14 @@ impl Rgba {
         }
     }
 
-    pub fn white_alpha(l: f32) -> Self {
+    /// Transparent white
-        debug_assert!(0.0 <= l && l <= 1.0);
+    pub fn white_alpha(a: f32) -> Self {
+        debug_assert!(0.0 <= a && a <= 1.0);
         Self {
-            r: l,
+            r: a,
-            g: l,
+            g: a,
-            b: l,
+            b: a,
-            a: l,
+            a,
         }
     }
 
@@ -143,13 +179,38 @@ impl Rgba {
     }
 }
 
-pub const TRANSPARENT: Srgba = srgba(0, 0, 0, 0);
+impl std::ops::Add for Rgba {
-pub const BLACK: Srgba = srgba(0, 0, 0, 255);
+    type Output = Rgba;
-pub const LIGHT_GRAY: Srgba = srgba(220, 220, 220, 255);
+    fn add(self, rhs: Rgba) -> Rgba {
-pub const GRAY: Srgba = srgba(160, 160, 160, 255);
+        Rgba {
-pub const WHITE: Srgba = srgba(255, 255, 255, 255);
+            r: self.r + rhs.r,
-pub const RED: Srgba = srgba(255, 0, 0, 255);
+            g: self.g + rhs.g,
-pub const GREEN: Srgba = srgba(0, 255, 0, 255);
+            b: self.b + rhs.b,
-pub const BLUE: Srgba = srgba(0, 0, 255, 255);
+            a: self.a + rhs.a,
-pub const YELLOW: Srgba = srgba(255, 255, 0, 255);
+        }
-pub const LIGHT_BLUE: Srgba = srgba(140, 160, 255, 255);
+    }
+}
+
+impl std::ops::Mul<f32> for Rgba {
+    type Output = Rgba;
+    fn mul(self, factor: f32) -> Rgba {
+        Rgba {
+            r: self.r * factor,
+            g: self.g * factor,
+            b: self.b * factor,
+            a: self.a * factor,
+        }
+    }
+}
+
+impl std::ops::Mul<Rgba> for f32 {
+    type Output = Rgba;
+    fn mul(self, rgba: Rgba) -> Rgba {
+        Rgba {
+            r: self * rgba.r,
+            g: self * rgba.g,
+            b: self * rgba.b,
+            a: self * rgba.a,
+        }
+    }
+}

egui/src/style.rs

@@ -117,35 +117,35 @@ impl Default for Interact {
         Self {
             active: WidgetStyle {
                 bg_fill: Some(Srgba::black_alpha(128)),
-                fill: srgba(120, 120, 200, 255),
+                bg_outline: Some(LineStyle::new(2.0, WHITE)),
+                corner_radius: 0.0,
+                main_fill: srgba(120, 120, 200, 255),
                 stroke_color: WHITE,
                 stroke_width: 2.0,
-                rect_outline: Some(LineStyle::new(2.0, WHITE)),
-                corner_radius: 0.0,
             },
             hovered: WidgetStyle {
                 bg_fill: None,
-                fill: srgba(100, 100, 150, 255),
+                bg_outline: Some(LineStyle::new(1.0, WHITE)),
+                corner_radius: 2.0,
+                main_fill: srgba(100, 100, 150, 255),
                 stroke_color: Srgba::gray(240),
                 stroke_width: 1.5,
-                rect_outline: Some(LineStyle::new(1.0, WHITE)),
-                corner_radius: 2.0,
             },
             inactive: WidgetStyle {
                 bg_fill: None,
-                fill: srgba(60, 60, 80, 255),
+                bg_outline: Some(LineStyle::new(1.0, Srgba::gray(128))),
+                corner_radius: 4.0,
+                main_fill: srgba(60, 60, 80, 255),
                 stroke_color: Srgba::gray(200), // Mustn't look grayed out!
                 stroke_width: 1.0,
-                rect_outline: Some(LineStyle::new(1.0, Srgba::gray(128))),
-                corner_radius: 4.0,
             },
             disabled: WidgetStyle {
                 bg_fill: None,
-                fill: srgba(50, 50, 50, 255),
+                bg_outline: Some(LineStyle::new(0.5, Srgba::gray(128))),
+                corner_radius: 4.0,
+                main_fill: srgba(50, 50, 50, 255),
                 stroke_color: Srgba::gray(128), // Should look grayed out
                 stroke_width: 0.5,
-                rect_outline: Some(LineStyle::new(0.5, Srgba::gray(128))),
-                corner_radius: 4.0,
             },
         }
     }
@@ -171,22 +171,28 @@ pub struct WidgetStyle {
     /// Background color of widget
     pub bg_fill: Option<Srgba>,
 
+    /// For surrounding rectangle of things that need it,
+    /// like buttons, the box of the checkbox, etc.
+    pub bg_outline: Option<LineStyle>,
+
+    /// Button frames etc
+    pub corner_radius: f32,
+
     /// Fill color of the interactive part of a component (slider grab, checkbox, ...)
     /// When you need a fill.
-    pub fill: Srgba,
+    pub main_fill: Srgba,
 
     /// Stroke and text color of the interactive part of a component (button, slider grab, checkbox, ...)
     pub stroke_color: Srgba,
 
     /// For lines etc
     pub stroke_width: f32,
+}
 
-    /// For surrounding rectangle of things that need it,
+impl WidgetStyle {
-    /// like buttons, the box of the checkbox, etc.
+    pub fn line_style(&self) -> LineStyle {
-    pub rect_outline: Option<LineStyle>,
+        LineStyle::new(self.stroke_width, self.stroke_color)
-
+    }
-    /// Button frames etc
-    pub corner_radius: f32,
 }
 
 #[derive(Clone, Copy, Debug)]

egui/src/widgets.rs

@@ -292,7 +292,7 @@ impl Widget for Button {
             rect: response.rect,
             corner_radius: ui.style().interact(&response).corner_radius,
             fill: bg_fill,
-            outline: ui.style().interact(&response).rect_outline,
+            outline: ui.style().interact(&response).bg_outline,
         });
         let stroke_color = ui.style().interact(&response).stroke_color;
         let text_color = text_color.unwrap_or(stroke_color);
@@ -356,7 +356,7 @@ impl<'a> Widget for Checkbox<'a> {
             rect: big_icon_rect,
             corner_radius: ui.style().interact(&response).corner_radius,
             fill: ui.style().interact(&response).bg_fill,
-            outline: ui.style().interact(&response).rect_outline,
+            outline: ui.style().interact(&response).bg_outline,
         });
 
         let stroke_color = ui.style().interact(&response).stroke_color;
@@ -437,7 +437,7 @@ impl Widget for RadioButton {
             center: big_icon_rect.center(),
             radius: big_icon_rect.width() / 2.0,
             fill: bg_fill,
-            outline: ui.style().interact(&response).rect_outline, // TODO
+            outline: ui.style().interact(&response).bg_outline,
         });
 
         if checked {

egui/src/widgets/slider.rs

@@ -171,7 +171,7 @@ impl<'a> Slider<'a> {
             ui.painter().add(PaintCmd::Circle {
                 center: pos2(marker_center_x, rail_rect.center().y),
                 radius: handle_radius(rect),
-                fill: Some(ui.style().interact(response).fill),
+                fill: Some(ui.style().interact(response).main_fill),
                 outline: Some(LineStyle::new(
                     ui.style().interact(response).stroke_width,
                     ui.style().interact(response).stroke_color,

egui/src/widgets/text_edit.rs

@@ -184,7 +184,7 @@ impl<'t> Widget for TextEdit<'t> {
                 rect: bg_rect,
                 corner_radius: ui.style().interact(&response).corner_radius,
                 fill: Some(ui.style().dark_bg_color),
-                outline: ui.style().interact(&response).rect_outline,
+                outline: ui.style().interact(&response).bg_outline,
             });
         }