Forms

Number Input

Edit a bounded number with typing, step controls or the mouse wheel.

Blinc 0.6.0stable API

Number Input interaction recorded with the Blinc headless renderer

Hybrid · dark · native recording · 2×

Dark

Theme

Disabled

Recorded Number Input preview while the live runtime loads

custom.css

Enable JavaScript to use the live preview.

Rust · component usage

use blinc_cn as cn;
use blinc_core::reactive::{Signal, computed};
use blinc_layout::{binding::IntoReactive, prelude::*};

pub fn number_input_demo(number: Signal<f64>, disabled: Signal<bool>) -> Div {
    div()
        .class("demo-stack")
        .child(cn::label("Quantity"))
        .child(cn::number_input(number).min(0.0).max(99.0).step(1.0).disabled(disabled))
        .child(
            bound_text(computed(move |g| {
                format!("{} items", g.get(number).unwrap_or(0.0) as u32)
            }))
            .class("demo-caption"),
        )
}

fn bound_text(value: impl IntoReactive<String>) -> Text {
    Text::bound(value.into_reactive())
}

Default component CSS

@layer components {
  .cn-number-input-group {
    box-shadow: var(--shadow-sm);
    background: var(--input-bg);
    border-color: var(--border);
  }

  .cn-number-input-group:disabled {
    background: var(--input-bg-disabled);
    box-shadow: none;
  }

  .cn-number-input-step {
    background: transparent;
    color: var(--text-secondary);
    transition:
      background-color var(--duration-fast) var(--ease-state),
      color var(--duration-fast) var(--ease-state);
  }

  .cn-number-input-step--dec {
    border-right: 1px solid var(--border);
  }

  .cn-number-input-step--inc {
    border-left: 1px solid var(--border);
  }

  .cn-number-input-step:hover:not(:disabled) {
    background: color-mix(in srgb, var(--text-primary) 6%, transparent);
    color: var(--text-primary);
  }

  .cn-number-input-step:active:not(:disabled) {
    background: color-mix(in srgb, var(--text-primary) 10%, transparent);
  }

  .cn-number-input-step:disabled {
    color: var(--text-tertiary);
  }
}

JavaScript is needed for Live and tab controls. Read the Rust source or read the default component CSS.

Usage and properties

Edit a bounded number with typing, step controls or the mouse wheel. Apply CSS after the component layer to restyle the documented parts.

Use the installation guide to add blinc_cn and its component stylesheet. Create the fixture bindings once, and return the demo from your UI builder. Values marked Bound accept Signal/Computed sources where the API supports them; structural options configure the component at construction.

Property	Type	Update model	This example
`value`	`Signal<f64>`	Bound	42
`min / max / step`	`f64`	Construction	0 / 99 / 1
`disabled`	`bool or IntoReactive<bool>`	Bound	values.disabled

Keyboard and interaction

Tab focuses the field. Typing, the up and down arrows, the stepper buttons and the mouse wheel all clamp to the minimum and maximum. :focus-visible marks keyboard focus.

Customizing it

Add application CSS after the default component layer. These selectors are the restyling surface for this component:

.cn-number-input-group
.cn-number-input-field
.cn-number-input-step

Theme and component variables: --primary, --text-primary, --text-secondary, --surface, --border, --radius-default, --duration-fast, --ease-state.

Built-in themes

The Live theme control installs Blinc's own theme bundles, including their colours, focus rings, corner shapes and motion tokens.

pub fn theme_bundle_for(name: &str) -> blinc_theme::ThemeBundle {
    match name {
        "restrained" => blinc_theme::RestrainedTheme::bundle(),
        "expressive" => blinc_theme::ExpressiveTheme::bundle(),
        _ => blinc_theme::HybridTheme::bundle(),
    }
    .with_css(blinc_cn::cn_styles::CN_STYLES)
}

Download the default widget and component stylesheets. Sample assets and licenses are available in the asset guide.

Documentation

From the canonical component guide.

A number between a − and a +, bound to a Signal<f64>:

let qty = ctx.use_signal(1.0);

cn::number_input(qty)
    .min(0.0)
    .max(99.0)
    .step(1.0)
    .precision(0)
    .size(InputSize::Medium)
    .on_change(|value| println!("qty: {value}"))

.size(..) picks a scale of its own, a step smaller than a text input's, so the control sits in a row beside others. The group carries the size as data-size for rules to key on:

Size	`data-size`	Row	Steps	Field (at least)	Text
`InputSize::Small`	`sm`	24px	24px	40px	12px
`InputSize::Medium` (default)	`md`	32px	32px	48px	13px
`InputSize::Large`	`lg`	40px	36px	52px	14px

Typing, the arrow keys, the buttons and the mouse wheel all clamp to min and max. One wheel line is one step and wheel up increases the value; trackpad movement accumulates into steps, and a disabled input ignores the wheel. The width follows the bounds, not the value, so typing never resizes it.

The group is one bordered element (.cn-number-input-group) with a borderless field and two steps (.cn-number-input-step--dec and --inc). A step tints on :hover and :active, and is disabled, so dimmed and inert, where a step would change nothing. These are rules with a transition; restyle them with rules of your own.

Platforms and version

The component API is available in Blinc 0.6.0. The Live example runs in a dedicated worker and requires a compatible GPU surface. Preview and Code remain available when Live cannot start. The canvas has a descriptive label; a full screen-reader DOM mirror is not provided. The gallery integration is based on revision e2e55c24e078.

Recordings and live demos use the default Hybrid theme with bundled Noto Sans. The recording uses a 560 × 320 logical viewport at twice that resolution. Live follows its container and actual display density. Source base revision · Exact build source · Artifact versions and checksums · Font license.