egui 0.3.0

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

//! Panels are fixed `Ui` regions.
//! Together with `Window` and `Area`:s they are
//! the only places where you can put you widgets.

use crate::*;
use std::sync::Arc;

// ----------------------------------------------------------------------------

/// A panel that covers the entire left side of the screen.
///
/// Panels should be added before adding any `Window`s.
pub struct SidePanel {
    id: Id,
    max_width: f32,
}

impl SidePanel {
    /// The given `max_width` is a soft maximum (as always), and the actual panel may be smaller or larger.
    pub fn left(id: Id, max_width: f32) -> Self {
        Self { id, max_width }
    }
}

impl SidePanel {
    pub fn show<R>(
        self,
        ctx: &Arc<Context>,
        add_contents: impl FnOnce(&mut Ui) -> R,
    ) -> (R, Response) {
        let Self { id, max_width } = self;

        let mut panel_rect = ctx.available_rect();
        panel_rect.max.x = panel_rect.max.x.at_most(panel_rect.min.x + max_width);

        let layer_id = LayerId::background();

        let clip_rect = ctx.input().screen_rect();
        let mut panel_ui = Ui::new(ctx.clone(), layer_id, id, panel_rect, clip_rect);

        let frame = Frame::panel(&ctx.style());
        let r = frame.show(&mut panel_ui, |ui| {
            ui.set_min_height(ui.max_rect_finite().height()); // fill full height
            add_contents(ui)
        });

        let panel_rect = panel_ui.min_rect();
        let response = panel_ui.interact_hover(panel_rect);

        ctx.allocate_left_panel(panel_rect);

        (r, response)
    }
}

// ----------------------------------------------------------------------------

/// A panel that covers the entire top side of the screen.
///
/// Panels should be added before adding any `Window`s.
pub struct TopPanel {
    id: Id,
    max_height: Option<f32>,
}

impl TopPanel {
    /// Default height is that of `interact_size.y` (i.e. a button),
    /// but the panel will expand as needed.
    pub fn top(id: Id) -> Self {
        Self {
            id,
            max_height: None,
        }
    }
}

impl TopPanel {
    pub fn show<R>(
        self,
        ctx: &Arc<Context>,
        add_contents: impl FnOnce(&mut Ui) -> R,
    ) -> (R, Response) {
        let Self { id, max_height } = self;
        let max_height = max_height.unwrap_or_else(|| ctx.style().spacing.interact_size.y);

        let mut panel_rect = ctx.available_rect();
        panel_rect.max.y = panel_rect.max.y.at_most(panel_rect.min.y + max_height);

        let layer_id = LayerId::background();

        let clip_rect = ctx.input().screen_rect();
        let mut panel_ui = Ui::new(ctx.clone(), layer_id, id, panel_rect, clip_rect);

        let frame = Frame::panel(&ctx.style());
        let r = frame.show(&mut panel_ui, |ui| {
            ui.set_min_width(ui.max_rect_finite().width()); // fill full width
            add_contents(ui)
        });

        let panel_rect = panel_ui.min_rect();
        let response = panel_ui.interact_hover(panel_rect);

        ctx.allocate_top_panel(panel_rect);

        (r, response)
    }
}

// ----------------------------------------------------------------------------

/// A panel that covers the remainder of the screen,
/// i.e. whatever area is left after adding other panels.
///
/// `CentralPanel` should be added after all other panels.
/// Any `Window`s and `Area`s will cover the `CentralPanel`.
#[derive(Default)]
pub struct CentralPanel {}

impl CentralPanel {
    pub fn show<R>(
        self,
        ctx: &Arc<Context>,
        add_contents: impl FnOnce(&mut Ui) -> R,
    ) -> (R, Response) {
        let Self {} = self;

        let panel_rect = ctx.available_rect();

        let layer_id = LayerId::background();
        let id = Id::new("central_panel");

        let clip_rect = ctx.input().screen_rect();
        let mut panel_ui = Ui::new(ctx.clone(), layer_id, id, panel_rect, clip_rect);

        let frame = Frame::background(&ctx.style());
        let r = frame.show(&mut panel_ui, |ui| add_contents(ui));

        let panel_rect = panel_ui.min_rect();
        let response = panel_ui.interact_hover(panel_rect);

        ctx.allocate_central_panel(panel_rect);

        (r, response)
    }
}