Colors

Color Picker for Slint

KitColorPicker · Slint Kit 0.3.0

Color editor with hex text, channel inputs and channel sliders.

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Try the component

Download the complete project, extract it and run cargo run --locked in its folder. Rust 1.92+; Slint Kit 0.3.0 from crates.io. You can also copy the four files below.

Edit a hexadecimal sRGB color or use the picker. Rust validates byte channels, keeps drafts separate and publishes the accepted color.

ui/app.slint

export { KitFormValidation, HtmlInputKind, NumberInputFormat, KitInputConstraints, KitValidationResult, KitValidityState } from "@kit/kit.slint";
import {KitColorPicker,KitThemes,SrgbColorView,ColorChannel,NavigationStep} from "@kit/kit.slint";
export {SrgbColorView,ColorChannel,NavigationStep}
export component App inherits Window {
 title:"color-picker";preferred-width:540px;preferred-height:800px;max-width:100000px;max-height:100000px;background:KitThemes.light.canvas;
 in-out property <string> hex;in property <string> error;in property <string> accepted;in property <SrgbColorView> color-value;in property <color> swatch;
 callback commit(string);callback edit();callback choose(SrgbColorView);callback cancel();in-out property <string> red;in-out property <string> green;in-out property <string> blue;in-out property <string> alpha;
 callback channel(ColorChannel,string);callback position(ColorChannel,float);callback navigate(ColorChannel,NavigationStep);callback begin-gesture(ColorChannel);callback finish(ColorChannel);callback cancel-channel(ColorChannel);
 VerticalLayout{padding:24px;spacing:16px;alignment:start;
 control:=KitColorPicker{label:"Accent color";accepted-color:root.color-value;swatch:root.swatch;color-requested(value)=>{root.choose(value);}hex-text<=>root.hex;red-text<=>root.red;green-text<=>root.green;blue-text<=>root.blue;alpha-text<=>root.alpha;hex-error:root.error;
 hex-edited(value)=>{root.edit();}hex-commit-requested(value)=>{root.commit(value);}
 channel-edited(channel,value)=>{root.edit();}channel-commit-requested(channel,value)=>{root.channel(channel,value);}
 channel-position-requested(channel,position)=>{root.position(channel,position);}channel-navigate(channel,step)=>{root.navigate(channel,step);}
 gesture-started(channel)=>{root.begin-gesture(channel);}committed(channel)=>{root.finish(channel);}cancelled(channel)=>{root.cancel-channel(channel);}}
 Text{text:"Accepted: "+root.accepted;color:KitThemes.light.text-primary;wrap:word-wrap;}
 }
}

src/main.rs

use slint::ComponentHandle;
use slint_kit::{AlphaPolicy, DraftValue, SrgbColor};
use std::{cell::RefCell, rc::Rc};
mod ui {
    slint::include_modules!();
}
fn publish(app: &ui::App, color: SrgbColor, accepted: bool) {
    app.set_hex(color.hex(AlphaPolicy::Opaque).into());
    app.set_color_value(ui::SrgbColorView {
        red: color.red.into(),
        green: color.green.into(),
        blue: color.blue.into(),
        alpha: 255,
    });
    app.set_swatch(slint::Color::from_rgb_u8(
        color.red,
        color.green,
        color.blue,
    ));
    if accepted {
        app.set_accepted(color.hex(AlphaPolicy::Opaque).into());
    }
    app.set_red(color.red.to_string().into());
    app.set_green(color.green.to_string().into());
    app.set_blue(color.blue.to_string().into());
    app.set_alpha("255".into());
}
fn main() -> Result<(), slint::PlatformError> {
    let app = ui::App::new()?;
    slint_kit::init_form_validation!(ui, app);
    let initial = SrgbColor {
        red: 79,
        green: 70,
        blue: 229,
        alpha: 255,
    };
    let state = Rc::new(RefCell::new((initial, initial)));
    publish(&app, initial, true);
    let weak = app.as_weak();
    let shared = state.clone();
    app.on_commit(move |text| {
        if let Some(app) = weak.upgrade() {
            match SrgbColor::parse_hex(&text, AlphaPolicy::Opaque) {
                DraftValue::Parsed(value) => {
                    *shared.borrow_mut() = (value, value);
                    publish(&app, value, true);
                    app.set_error("".into());
                }
                _ => app.set_error("Use #RRGGBB or #RGB hexadecimal".into()),
            }
        }
    });
    let weak = app.as_weak();
    app.on_edit(move || {
        if let Some(app) = weak.upgrade() {
            app.set_error("".into());
        }
    });
    let weak = app.as_weak();
    let shared = state.clone();
    app.on_choose(move |view| {
        if let Some(app) = weak.upgrade() {
            if let (Ok(red), Ok(green), Ok(blue)) = (
                view.red.try_into(),
                view.green.try_into(),
                view.blue.try_into(),
            ) {
                let color = SrgbColor {
                    red,
                    green,
                    blue,
                    alpha: 255,
                };
                *shared.borrow_mut() = (color, color);
                publish(&app, color, true);
                app.set_error("".into());
            }
        }
    });

    fn set(color: &mut SrgbColor, channel: ui::ColorChannel, value: u8) {
        match channel {
            ui::ColorChannel::Red => color.red = value,
            ui::ColorChannel::Green => color.green = value,
            ui::ColorChannel::Blue => color.blue = value,
            ui::ColorChannel::Alpha => {}
        }
    }
    fn get(color: SrgbColor, channel: ui::ColorChannel) -> u8 {
        match channel {
            ui::ColorChannel::Red => color.red,
            ui::ColorChannel::Green => color.green,
            ui::ColorChannel::Blue => color.blue,
            ui::ColorChannel::Alpha => 255,
        }
    }
    let weak = app.as_weak();
    let shared = state.clone();
    app.on_channel(move |_channel, _text| {
        if let Some(app) = weak.upgrade() {
            let channels = app
                .get_red()
                .parse::<u8>()
                .ok()
                .zip(app.get_green().parse::<u8>().ok())
                .zip(app.get_blue().parse::<u8>().ok());
            if let Some(((red, green), blue)) = channels {
                let color = SrgbColor {
                    red,
                    green,
                    blue,
                    alpha: 255,
                };
                *shared.borrow_mut() = (color, color);
                publish(&app, color, true);
                app.set_error("".into());
            } else {
                app.set_error("Use whole sRGB channels from 0 to 255".into());
            }
        }
    });
    let weak = app.as_weak();
    let shared = state.clone();
    app.on_position(move |channel, position| {
        if let Some(app) = weak.upgrade() {
            let mut state = shared.borrow_mut();
            set(
                &mut state.1,
                channel,
                (position.clamp(0.0, 1.0) * 255.0).round() as u8,
            );
            publish(&app, state.1, false);
        }
    });
    let weak = app.as_weak();
    let shared = state.clone();
    app.on_navigate(move |channel, step| {
        if let Some(app) = weak.upgrade() {
            let mut state = shared.borrow_mut();
            let old = get(state.1, channel) as i32;
            let next = match step {
                ui::NavigationStep::First => 0,
                ui::NavigationStep::Last => 255,
                ui::NavigationStep::Next => old + 1,
                ui::NavigationStep::Previous => old - 1,
                ui::NavigationStep::PageNext => old + 16,
                ui::NavigationStep::PagePrevious => old - 16,
            };
            set(&mut state.1, channel, next.clamp(0, 255) as u8);
            state.0 = state.1;
            publish(&app, state.0, true);
        }
    });
    let shared = state.clone();
    app.on_begin_gesture(move |_| {
        let mut state = shared.borrow_mut();
        state.1 = state.0;
    });
    let weak = app.as_weak();
    let shared = state.clone();
    app.on_finish(move |_| {
        if let Some(app) = weak.upgrade() {
            let mut state = shared.borrow_mut();
            state.0 = state.1;
            publish(&app, state.0, true);
        }
    });
    let weak = app.as_weak();
    let shared = state.clone();
    app.on_cancel_channel(move |_| {
        if let Some(app) = weak.upgrade() {
            let mut state = shared.borrow_mut();
            state.1 = state.0;
            publish(&app, state.0, true);
            app.set_error("".into());
        }
    });

    app.run()
}

[package]
name = "slint-kit-color-picker-example"
version = "0.1.0"
edition = "2024"
rust-version = "1.92"
license = "GPL-3.0-or-later"
publish = false

[dependencies]
slint-kit = "=0.3.0"
slint = { version = "=1.18.1", default-features = false, features = ["std", "compat-1-18", "backend-winit", "renderer-skia", "accessibility"] }

[build-dependencies]
slint-kit-build = "=0.3.0"

[workspace]

fn main() {
    slint_kit_build::compile("ui/app.slint").expect("compile component example");
}

Files: Cargo.toml · build.rs · ui/app.slint · src/main.rs

Keep accepted SrgbColor in Rust. Connect channel text commits, position requests and gesture start/commit/cancel callbacks.

The example accepts opaque hex colors and channel values from 0 to 255. Cancel restores the color saved at gesture start.

View source ↗

Choose between built-in options and custom composition

Shared options

• label — built-in property; custom composition example

Visual composition

The file below produces the screenshot. For controller-driven components, it shows the displayed state without supplying the Rust wiring. Create a project.

Show the screenshot source

// SPDX-License-Identifier: GPL-3.0-or-later
import { KitColorPicker, KitTheme, KitThemes } from "@kit/kit.slint";

export component Example inherits Window {
    title: "KitColorPicker example";
    preferred-width: 480px;
    preferred-height: 550px;
    max-width: 100000px;
    max-height: 100000px;
    background: root.theme.canvas;
    in-out property <KitTheme> theme: KitThemes.light;
    in-out property <string> status;
    VerticalLayout {
        padding: 24px; spacing: 16px; alignment: start;
        Text { text: "Color Picker"; color: root.theme.text-primary; font-size: 20px * root.theme.text-scale; font-weight: 600; }
        KitColorPicker { theme: root.theme; label: "Accent color"; swatch: #6366f1; accepted-color: { red: 99, green: 102, blue: 241, alpha: 255 }; hex-text: "#6366F1"; red-text: "99"; green-text: "102"; blue-text: "241"; }
        if root.status != "": Text { text: root.status; color: root.theme.text-secondary; font-size: 12px * root.theme.text-scale; wrap: word-wrap; }
    }
}

Download this example

Public API

Inherits Rectangle.

Properties

Types and variants

Callbacks

• hex-edited(string)
• hex-commit-requested(string)
• color-requested(SrgbColorView)
• channel-edited(ColorChannel,string)
• channel-commit-requested(ColorChannel,string)
• channel-position-requested(ColorChannel,float)
• channel-navigate(ColorChannel,NavigationStep)
• gesture-started(ColorChannel)
• committed(ColorChannel)
• cancelled(ColorChannel)

See also

• Color Field
• Slider