egui 0.12.0

Simple, portable immediate mode GUI library for Rust
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191

//! Frame container

use crate::{layers::ShapeIdx, *};
use epaint::*;

/// Color and margin of a rectangular background of a [`Ui`].
#[derive(Clone, Copy, Debug, Default, PartialEq)]
pub struct Frame {
    /// On each side
    pub margin: Vec2,
    pub corner_radius: f32,
    pub shadow: Shadow,
    pub fill: Color32,
    pub stroke: Stroke,
}

impl Frame {
    pub fn none() -> Self {
        Self::default()
    }

    /// For when you want to group a few widgets together within a frame.
    pub fn group(style: &Style) -> Self {
        Self {
            margin: Vec2::new(8.0, 6.0),
            corner_radius: 4.0,
            stroke: style.visuals.window_stroke(),
            ..Default::default()
        }
    }

    pub(crate) fn side_top_panel(style: &Style) -> Self {
        Self {
            margin: Vec2::new(8.0, 2.0),
            corner_radius: 0.0,
            fill: style.visuals.window_fill(),
            stroke: style.visuals.window_stroke(),
            ..Default::default()
        }
    }

    pub(crate) fn central_panel(style: &Style) -> Self {
        Self {
            margin: Vec2::new(8.0, 8.0),
            corner_radius: 0.0,
            fill: style.visuals.window_fill(),
            stroke: Default::default(),
            ..Default::default()
        }
    }

    pub fn window(style: &Style) -> Self {
        Self {
            margin: style.spacing.window_padding,
            corner_radius: style.visuals.window_corner_radius,
            shadow: style.visuals.window_shadow,
            fill: style.visuals.window_fill(),
            stroke: style.visuals.window_stroke(),
        }
    }

    pub fn menu(style: &Style) -> Self {
        Self {
            margin: Vec2::splat(1.0),
            corner_radius: 2.0,
            shadow: Shadow::small(),
            fill: style.visuals.window_fill(),
            stroke: style.visuals.window_stroke(),
        }
    }

    pub fn popup(style: &Style) -> Self {
        Self {
            margin: style.spacing.window_padding,
            corner_radius: 5.0,
            shadow: Shadow::small(),
            fill: style.visuals.window_fill(),
            stroke: style.visuals.window_stroke(),
        }
    }

    /// dark canvas to draw on
    pub fn dark_canvas(style: &Style) -> Self {
        Self {
            margin: Vec2::new(10.0, 10.0),
            corner_radius: 5.0,
            fill: Color32::from_black_alpha(250),
            stroke: style.visuals.window_stroke(),
            ..Default::default()
        }
    }
}

impl Frame {
    pub fn fill(mut self, fill: Color32) -> Self {
        self.fill = fill;
        self
    }

    pub fn stroke(mut self, stroke: Stroke) -> Self {
        self.stroke = stroke;
        self
    }

    pub fn multiply_with_opacity(mut self, opacity: f32) -> Self {
        self.fill = self.fill.linear_multiply(opacity);
        self.stroke.color = self.stroke.color.linear_multiply(opacity);
        self.shadow.color = self.shadow.color.linear_multiply(opacity);
        self
    }
}

pub struct Prepared {
    pub frame: Frame,
    outer_rect_bounds: Rect,
    where_to_put_background: ShapeIdx,
    pub content_ui: Ui,
}

impl Frame {
    pub fn begin(self, ui: &mut Ui) -> Prepared {
        let where_to_put_background = ui.painter().add(Shape::Noop);
        let outer_rect_bounds = ui.available_rect_before_wrap();
        let inner_rect = outer_rect_bounds.shrink2(self.margin);
        let content_ui = ui.child_ui(inner_rect, *ui.layout());

        // content_ui.set_clip_rect(outer_rect_bounds.shrink(self.stroke.width * 0.5)); // Can't do this since we don't know final size yet

        Prepared {
            frame: self,
            outer_rect_bounds,
            where_to_put_background,
            content_ui,
        }
    }

    pub fn show<R>(self, ui: &mut Ui, add_contents: impl FnOnce(&mut Ui) -> R) -> InnerResponse<R> {
        let mut prepared = self.begin(ui);
        let ret = add_contents(&mut prepared.content_ui);
        let response = prepared.end(ui);
        InnerResponse::new(ret, response)
    }

    pub fn paint(&self, outer_rect: Rect) -> Shape {
        let Self {
            margin: _,
            corner_radius,
            shadow,
            fill,
            stroke,
        } = *self;

        let frame_shape = Shape::Rect {
            rect: outer_rect,
            corner_radius,
            fill,
            stroke,
        };

        if shadow == Default::default() {
            frame_shape
        } else {
            let shadow = shadow.tessellate(outer_rect, corner_radius);
            let shadow = Shape::Mesh(shadow);
            Shape::Vec(vec![shadow, frame_shape])
        }
    }
}

impl Prepared {
    pub fn outer_rect(&self) -> Rect {
        Rect::from_min_max(
            self.outer_rect_bounds.min,
            self.content_ui.min_rect().max + self.frame.margin,
        )
    }

    pub fn end(self, ui: &mut Ui) -> Response {
        let outer_rect = self.outer_rect();

        let Prepared {
            frame,
            where_to_put_background,
            ..
        } = self;

        let shape = frame.paint(outer_rect);
        ui.painter().set(where_to_put_background, shape);
        ui.allocate_rect(outer_rect, Sense::hover())
    }
}