`<channel-slider>`

A <color-slider> for a specific channel, intended for color picking.

Usage

This is a higher level component than <color-slider> for the cases where you want to control a single channel of a color space. It offers many conveniences for these cases:

It takes care of applying the right min, max, and step values to the slider
It automatically generates the start and end colors
It can provide an editable tooltip as a tooltip that both shows and edits the current value
Already includes a suitable label

Static

Basic example:

<channel-slider space="oklch" channel="h"></channel-slider>

The alpha channel is also supported:

<channel-slider space="oklch" channel="alpha"></channel-slider>

In most cases you’d also want to set a color to set the other channels and the initial value:

<channel-slider space="oklch" channel="h" color="oklch(80% 20% 130)"></channel-slider>

This will automatically use the whole reference range of that component in the specified color space, and use the current value of the component as the starting value (unless value is also specified).

The color does not actually need to be in the same color space, it will be converted if needed:

<channel-slider space="oklch" channel="h" color="deeppink"></channel-slider>

Colors and color spaces not supported by the browser also work:

<channel-slider space="okhsl" channel="h" color="color(--okhsl 180 100% 50%)"></channel-slider>

If you don’t want to show the whole range you can also specify min and max attributes.

<channel-slider space="oklch" channel="l" color="red" min=".3" max=".95"></channel-slider>

Dynamic

You can listen to the colorchange event and grab the color property to get the current color value. Here we are using a <color-swatch> to not just display the CSS code but also the actual color:

<channel-slider space="oklch" channel="h" color="oklch(50% 50% 180)"
				oncolorchange="this.nextElementSibling.textContent = this.color"></channel-slider>
<color-swatch></color-swatch>

All attributes are reactive:

<label>
	Space:
	<select id="space_select" size="3">
		<option>oklch</option>
		<option>oklab</option>
		<option>okhsl</option>
		<option>lab</option>
		<option>lch</option>
		<option>hsl</option>
		<option>srgb</option>
	</select>
</label>
<label>
	Channel:
	<select id="channel_select" size=3>
		<option>l</option>
		<option>c</option>
		<option>h</option>
		<option>alpha</option>
	</select>
</label>

<channel-slider id="dynamic_slider" space="oklch" channel="h" color="oklch(50% 50% 180)"
				oncolorchange="this.nextElementSibling.textContent = this.color"></channel-slider>
<color-swatch></color-swatch>
<script>
	function fromSlider () {
		space_select.value = dynamic_slider.space.id;
		channel_select.innerHTML = [...Object.keys(dynamic_slider.space.coords).map(c => `<option>${c}</option>`), "<option>alpha</option>"].join('\n');
		channel_select.value = dynamic_slider.channel || channel_select.options[0].value;
	}

	function fromSelects () {
		dynamic_slider.space = space_select.value;
		dynamic_slider.channel = channel_select.value || channel_select.options[0].value;
	}

	space_select.oninput = channel_select.oninput = fromSelects;

	customElements.whenDefined("channel-slider").then(fromSlider);
	dynamic_slider.addEventListener("propchange", fromSlider);
</script>

Reference

Slots

Name	Description
(default)	The channel slider’s label.

Attributes & Properties

Attribute	Property	Property type	Default value	Description
`space`	`space`	`ColorSpace` \| `string`	`oklch`	The color space to use for interpolation.
`channel`	`channel`	`string`	`h`	The component to use for the gradient.
`min`	`min`	`number`	`this.refRange[0]`	The minimum value for the slider.
`max`	`max`	`number`	`this.refRange[1]`	The maximum value for the slider.
`step`	`step`	`number`	Computed automatically based on `this.min` and `this.max`.	The granularity that the slider’s current value must adhere to.
`value`	`value`	`number`	`(this.min + this.max) / 2`	The current value of the slider.
`color`	`color`	`Color` \| `string`	`oklch(50% 50% 180)`	The current color value.

Getters

These properties are read-only.

Property	Type	Description
`minColor`	`Color`	The color corresponding to the minimum value of the slider.
`maxColor`	`Color`	The color corresponding to the maximum value of the slider.
`stops`	`Array<Color>`	The array of the slider color stops used for rendering. Unsupported color spaces or angular channels (hues) will have more color stops, while other channels may have as little as two: `minColor` and `maxColor`.
`progress`	`number`	The slider value converted to a 0-1 number with `0` corresponding to the min of the range and `1` to the max.
`channelName`	`string`	The name of the channel (e.g. `Hue` or `Alpha`).

Events

Name	Description
`input`	Fired when the color changes due to user action.
`change`	Fired when the color changes due to user action.
`valuechange`	Fired when the value changes for any reason, and once during initialization.
`colorchange`	Fired when the color changes for any reason, and once during initialization.

Parts

Name	Description
`color_slider`	The internal `<color-slider>` element.
`slider`	The `slider` part of the internal `<color-slider>` element.
`label`	The internal `<label>` element used as a wrapper around the default slot and the slider.

Installation

To install all color elements, check out the instructions on the homepage. The rest of this section is about using only <channel-slider>.

The quick and dirty way is straight from the CDN (kindly provided by Netlify):

<script src="https://elements.colorjs.io/src/channel-slider/channel-slider.js" type="module"></script>

or in JS:

import "https://elements.colorjs.io/src/channel-slider/channel-slider.js";

If you are using npm to manage your dependencies, you can import it via:

import "color-elements/channel-slider";

or:

import { ChannelSlider } from "color-elements";