egui-122-slider

This is an example of using checkboxes to change the color of a circle

Source

• src/main.rs
• Project Directory

Screenshots

Description

Sliders, egui::Slider, take two parameters. A mutable variable for the slider value, and a range.

We will create and initialize our color values. They are u8 so we can easily use the values in Color32::from_rgb()

pub struct ExampleApp {
    red: u8,
    green: u8,
    blue: u8,
}

impl Default for ExampleApp {
    fn default() -> Self {
        Self {
            red: 0,
            green: 0,
            blue: 0,
        }
    }
}

We create the sliders like this:

ui.add(egui::Slider::new(&mut self.red, 0..=255).text("Red"));
ui.add(egui::Slider::new(&mut self.green, 0..=255).text("Green"));
ui.add(egui::Slider::new(&mut self.blue, 0..=255).text("Blue"));

We pass it the respective variable and a range. The .text("label") is optional. It will create a label beside the slider.

We can change the values in other ways too. Here we use buttons to set our color values. This change will immedietly be reflected on the slider.

if ui.button("orange").clicked() {
    self.red = 255;
    self.green = 100;
    self.blue = 0;
};

We will put our color variables into a circle.

ui.painter().circle(
    egui::Pos2{x:250.0,y:250.0},
    50.0,
    Color32::from_rgb(self.red, self.green, self.blue),
    Stroke{width: 0.5, color: Color32::from_rgb(255, 255, 255)}
);