egui_knob 0.3.11

A simple knob widget for egui
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

use eframe::egui;
use egui_knob::{Knob, KnobStyle, LabelPosition};

fn main() -> eframe::Result<()> {
    let options = eframe::NativeOptions {
        viewport: egui::ViewportBuilder::default()
            .with_inner_size([600.0, 350.0])
            .with_title("Knob demo"),
        ..Default::default()
    };

    eframe::run_native(
        "Knob demo",
        options,
        Box::new(|_cc| Ok(Box::new(KnobDemo::default()))),
    )
}

struct KnobDemo {
    values: [f32; 6],
    show_bg_arc: bool,
    show_filled: bool,
    use_step: bool,
    logarithmic_scaling: bool,
    knob_color: egui::Color32,
    line_color: egui::Color32,
    text_color: egui::Color32,
}

impl Default for KnobDemo {
    fn default() -> Self {
        Self {
            values: [f32::NAN; 6],
            show_bg_arc: true,
            show_filled: true,
            use_step: false,
            logarithmic_scaling: false,
            knob_color: egui::Color32::DARK_GRAY,
            line_color: egui::Color32::LIGHT_BLUE,
            text_color: egui::Color32::WHITE,
        }
    }
}

impl eframe::App for KnobDemo {
    fn ui(&mut self, ui: &mut egui::Ui, _frame: &mut eframe::Frame) {
        ui.heading("Knob demo");
        ui.separator();

        ui.horizontal(|ui| {
            ui.label("Global Settings:");
            ui.checkbox(&mut self.show_bg_arc, "Background arc");
            ui.checkbox(&mut self.show_filled, "Filled segment");
            ui.checkbox(&mut self.use_step, "Step (0.02)");
            ui.checkbox(&mut self.logarithmic_scaling, "Logarithmic");
        });

        ui.horizontal(|ui| {
            ui.label("Color Theme:");
            ui.color_edit_button_srgba(&mut self.knob_color);
            ui.label("Knob");
            ui.color_edit_button_srgba(&mut self.line_color);
            ui.label("Indicator");
            ui.color_edit_button_srgba(&mut self.text_color);
            ui.label("Text");
        });

        ui.separator();

        ui.add_space(10.0);
        egui::Grid::new("knob_grid")
            .num_columns(3)
            .spacing([30.0, 20.0])
            .show(ui, |ui| {
                for (i, (label, config)) in [
                    ("Basic Dot", KnobStyle::Dot),
                    ("Wiper, Sweep", KnobStyle::Wiper),
                    ("Thick Stroke", KnobStyle::Wiper),
                    ("360° Sweep", KnobStyle::Wiper),
                    ("Multi-Turn", KnobStyle::Dot),
                    ("Large Font", KnobStyle::Wiper),
                ]
                .iter()
                .enumerate()
                {
                    ui.vertical(|ui| {
                        let mut knob = Knob::new(&mut self.values[i], 0., 1., *config)
                            .with_label(*label, LabelPosition::Bottom)
                            .with_background_arc(self.show_bg_arc)
                            .with_show_filled_segments(self.show_filled)
                            .with_colors(self.knob_color, self.line_color, self.text_color)
                            .with_step(self.use_step.then_some(0.02))
                            .with_double_click_reset(0.5)
                            .with_middle_scroll();

                        if self.logarithmic_scaling {
                            knob = knob.with_logarithmic_scaling();
                        }

                        if *label == "Wiper, Sweep" {
                            knob = knob.with_sweep_range(0.25, 0.75).with_size(50.0);
                        }
                        if *label == "Thick Stroke" {
                            knob = knob.with_stroke_width(4.0).with_size(60.0);
                        }
                        if *label == "360° Sweep" {
                            knob = knob.with_sweep_range(0.5, 1.0);
                        }
                        if *label == "Multi-Turn" {
                            knob = knob.with_sweep_range(0.0, 2.5);
                        }
                        if *label == "Large Font" {
                            knob = knob.with_size(70.0).with_font_size(18.0);
                        }

                        ui.add(knob);
                    });

                    if (i + 1) % 3 == 0 {
                        ui.end_row();
                    }
                }
            });

        ui.add_space(10.0);
        ui.separator();
    }
}