Merge pull request 'Feature/slider' (#47) from feature/slider into main
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Reviewed-on: #47
This commit was merged in pull request #47.
This commit is contained in:
2026-06-02 12:10:42 +00:00
6 changed files with 436 additions and 63 deletions
+1 -3
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@@ -10,7 +10,7 @@ const { Story } = defineMeta({
docs: { docs: {
description: { description: {
component: component:
'Styled bits-ui slider component with red accent (#ff3b30). Thumb is a 45° rotated square with hover/active scale animations.', 'Single-value slider (native, no bits-ui) with brand accent. Diamond thumb (45° rotated square) with hover/active scale. Supports pointer drag, click-to-seek, touch, and keyboard (arrows, Home/End, PageUp/Down).',
}, },
story: { inline: false }, // Render stories in iframe for state isolation story: { inline: false }, // Render stories in iframe for state isolation
}, },
@@ -39,8 +39,6 @@ const { Story } = defineMeta({
<script lang="ts"> <script lang="ts">
import type { ComponentProps } from 'svelte'; import type { ComponentProps } from 'svelte';
let value = $state(50); let value = $state(50);
let valueLow = $state(25);
let valueHigh = $state(75);
</script> </script>
<Story <Story
+197 -60
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@@ -1,13 +1,16 @@
<!-- <!--
Component: Slider Component: Slider
Single-value slider using bits-ui Slider primitive. Single-value slider built on a native role="slider" element (no bits-ui).
Supports pointer drag, click-to-seek, touch, and full keyboard nav.
Swiss design: 1px track, diamond thumb (rotate-45), brand accent. Swiss design: 1px track, diamond thumb (rotate-45), brand accent.
--> -->
<script lang="ts"> <script lang="ts">
import { import {
type Orientation, pointerToValue,
Slider, snapToStep,
} from 'bits-ui'; } from './slider-math';
type Orientation = 'horizontal' | 'vertical';
interface Props { interface Props {
/** /**
@@ -67,8 +70,122 @@ let {
class: className, class: className,
}: Props = $props(); }: Props = $props();
/**
* PageUp/PageDown move by this multiple of `step`.
*/
const LARGE_STEP_MULTIPLIER = 10;
const isVertical = $derived(orientation === 'vertical'); const isVertical = $derived(orientation === 'vertical');
/**
* Thumb/range offset as a clamped percentage of the track.
*/
const percent = $derived.by(() => {
if (max <= min) {
return 0;
}
return Math.min(Math.max(((value - min) / (max - min)) * 100, 0), 100);
});
let trackEl: HTMLElement | undefined = $state();
let thumbEl: HTMLElement | undefined = $state();
let dragging = $state(false);
/**
* Apply a candidate value: snap, clamp, store, and notify only on change.
*/
function commit(raw: number): void {
const next = snapToStep(raw, { min, max, step });
if (next !== value) {
value = next;
onValueChange?.(next);
}
}
/**
* Keep an externally-supplied value normalized to the step grid and range.
* Mirrors the bits-ui primitive's behavior so out-of-range or off-grid
* props don't desync the thumb position from aria-valuenow / the label.
* Converges in one pass: once snapped, the value equals its own snap.
*/
$effect(() => {
const normalized = snapToStep(value, { min, max, step });
if (normalized !== value) {
value = normalized;
onValueChange?.(normalized);
}
});
/**
* Resolve a pointer event to a value using the live track rect.
*/
function seek(event: PointerEvent): void {
if (!trackEl) {
return;
}
const rect = trackEl.getBoundingClientRect();
commit(pointerToValue(event, rect, { min, max, step, orientation }));
}
function handlePointerDown(event: PointerEvent): void {
if (disabled) {
return;
}
dragging = true;
thumbEl?.focus();
(event.currentTarget as HTMLElement).setPointerCapture?.(event.pointerId);
seek(event);
}
function handlePointerMove(event: PointerEvent): void {
if (!dragging || disabled) {
return;
}
seek(event);
}
function handlePointerUp(event: PointerEvent): void {
if (!dragging) {
return;
}
dragging = false;
(event.currentTarget as HTMLElement).releasePointerCapture?.(event.pointerId);
}
function handleKeyDown(event: KeyboardEvent): void {
if (disabled) {
return;
}
const large = step * LARGE_STEP_MULTIPLIER;
let next: number | undefined;
switch (event.key) {
case 'ArrowRight':
case 'ArrowUp':
next = value + step;
break;
case 'ArrowLeft':
case 'ArrowDown':
next = value - step;
break;
case 'PageUp':
next = value + large;
break;
case 'PageDown':
next = value - large;
break;
case 'Home':
next = min;
break;
case 'End':
next = max;
break;
default:
return;
}
event.preventDefault();
commit(next);
}
const labelClasses = `font-mono text-2xs tabular-nums shrink-0 const labelClasses = `font-mono text-2xs tabular-nums shrink-0
text-subtle text-subtle
group-hover:text-neutral-700 dark:group-hover:text-neutral-300 group-hover:text-neutral-700 dark:group-hover:text-neutral-300
@@ -91,81 +208,101 @@ const thumbClasses = `block w-2.5 h-2.5 bg-brand
{format(value)} {format(value)}
</span> </span>
<Slider.Root <div
type="single" bind:this={trackEl}
orientation="vertical" role="presentation"
bind:value onpointerdown={handlePointerDown}
{min} onpointermove={handlePointerMove}
{max} onpointerup={handlePointerUp}
{step} onpointercancel={handlePointerUp}
{disabled}
onValueChange={(v => onValueChange?.(v))}
class=" class="
relative flex flex-col items-center select-none touch-none relative flex flex-col items-center select-none touch-none
w-5 h-full grow cursor-row-resize w-5 h-full grow cursor-row-resize
disabled:opacity-50 disabled:cursor-not-allowed disabled:opacity-50 disabled:cursor-not-allowed
" "
class:opacity-50={disabled}
class:cursor-not-allowed={disabled}
> >
{#snippet children({ thumbItems })} <span
class="
bg-neutral-200 dark:bg-neutral-800
relative grow w-px overflow-visible
group-hover:bg-neutral-300 dark:group-hover:bg-neutral-700
transition-colors
"
>
<span <span
class=" class="absolute bottom-0 left-0 bg-brand w-full"
bg-neutral-200 dark:bg-neutral-800 style="height: {percent}%"
relative grow w-px overflow-visible ></span>
group-hover:bg-neutral-300 dark:group-hover:bg-neutral-700 </span>
transition-colors
"
>
<Slider.Range class="absolute bg-brand w-full" />
</span>
{#each thumbItems as thumb (thumb)} <span
<Slider.Thumb role="slider"
index={thumb.index} bind:this={thumbEl}
class={thumbClasses} tabindex={disabled ? -1 : 0}
aria-label="Value" aria-label="Value"
/> aria-orientation="vertical"
{/each} aria-valuemin={min}
{/snippet} aria-valuemax={max}
</Slider.Root> aria-valuenow={value}
aria-valuetext={String(format(value))}
aria-disabled={disabled ? 'true' : undefined}
data-active={dragging ? '' : undefined}
onkeydown={handleKeyDown}
class="{thumbClasses} absolute left-1/2 -translate-x-1/2 translate-y-1/2"
style="bottom: {percent}%"
></span>
</div>
</div> </div>
{:else} {:else}
<div class="flex items-center gap-4 group w-full {className ?? ''}"> <div class="flex items-center gap-4 group w-full {className ?? ''}">
<Slider.Root <div
type="single" bind:this={trackEl}
orientation="horizontal" role="presentation"
bind:value onpointerdown={handlePointerDown}
{min} onpointermove={handlePointerMove}
{max} onpointerup={handlePointerUp}
{step} onpointercancel={handlePointerUp}
{disabled}
onValueChange={(v => onValueChange?.(v))}
class=" class="
relative flex items-center select-none touch-none relative flex items-center select-none touch-none
w-full h-5 cursor-col-resize w-full h-5 cursor-col-resize
disabled:opacity-50 disabled:cursor-not-allowed disabled:opacity-50 disabled:cursor-not-allowed
" "
class:opacity-50={disabled}
class:cursor-not-allowed={disabled}
> >
{#snippet children({ thumbItems })} <span
class="
bg-neutral-200 dark:bg-neutral-800
relative grow h-px overflow-visible
group-hover:bg-neutral-300 dark:group-hover:bg-neutral-700
transition-colors
"
>
<span <span
class=" class="absolute top-0 left-0 bg-brand h-full"
bg-neutral-200 dark:bg-neutral-800 style="width: {percent}%"
relative grow h-px overflow-visible ></span>
group-hover:bg-neutral-300 dark:group-hover:bg-neutral-700 </span>
transition-colors
"
>
<Slider.Range class="absolute bg-brand h-full" />
</span>
{#each thumbItems as thumb (thumb)} <span
<Slider.Thumb role="slider"
index={thumb.index} bind:this={thumbEl}
class={thumbClasses} tabindex={disabled ? -1 : 0}
aria-label="Value" aria-label="Value"
/> aria-orientation="horizontal"
{/each} aria-valuemin={min}
{/snippet} aria-valuemax={max}
</Slider.Root> aria-valuenow={value}
aria-valuetext={String(format(value))}
aria-disabled={disabled ? 'true' : undefined}
data-active={dragging ? '' : undefined}
onkeydown={handleKeyDown}
class="{thumbClasses} absolute top-1/2 -translate-y-1/2 -translate-x-1/2"
style="left: {percent}%"
></span>
</div>
<!-- Label: right of slider --> <!-- Label: right of slider -->
<span class="{labelClasses} w-12 text-right"> <span class="{labelClasses} w-12 text-right">
+107
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@@ -1,4 +1,5 @@
import { import {
fireEvent,
render, render,
screen, screen,
} from '@testing-library/svelte'; } from '@testing-library/svelte';
@@ -60,3 +61,109 @@ describe('Slider', () => {
}); });
}); });
}); });
describe('Keyboard', () => {
it('increments by step on ArrowRight / ArrowUp', async () => {
const onValueChange = vi.fn();
render(Slider, { value: 50, step: 5, onValueChange });
const thumb = screen.getByRole('slider');
await fireEvent.keyDown(thumb, { key: 'ArrowRight' });
expect(thumb).toHaveAttribute('aria-valuenow', '55');
expect(onValueChange).toHaveBeenCalledWith(55);
});
it('decrements by step on ArrowLeft / ArrowDown', async () => {
render(Slider, { value: 50, step: 5 });
const thumb = screen.getByRole('slider');
await fireEvent.keyDown(thumb, { key: 'ArrowDown' });
expect(thumb).toHaveAttribute('aria-valuenow', '45');
});
it('jumps to min on Home and max on End', async () => {
render(Slider, { value: 50, min: 10, max: 90 });
const thumb = screen.getByRole('slider');
await fireEvent.keyDown(thumb, { key: 'Home' });
expect(thumb).toHaveAttribute('aria-valuenow', '10');
await fireEvent.keyDown(thumb, { key: 'End' });
expect(thumb).toHaveAttribute('aria-valuenow', '90');
});
it('moves by step*10 on PageUp / PageDown', async () => {
render(Slider, { value: 50, step: 2 });
const thumb = screen.getByRole('slider');
await fireEvent.keyDown(thumb, { key: 'PageUp' });
expect(thumb).toHaveAttribute('aria-valuenow', '70');
await fireEvent.keyDown(thumb, { key: 'PageDown' });
expect(thumb).toHaveAttribute('aria-valuenow', '50');
});
it('clamps at the bounds', async () => {
render(Slider, { value: 98, max: 100, step: 5 });
const thumb = screen.getByRole('slider');
await fireEvent.keyDown(thumb, { key: 'End' });
expect(thumb).toHaveAttribute('aria-valuenow', '100');
});
it('does nothing when disabled', async () => {
const onValueChange = vi.fn();
render(Slider, { value: 50, disabled: true, onValueChange });
const thumb = screen.getByRole('slider');
await fireEvent.keyDown(thumb, { key: 'ArrowRight' });
expect(thumb).toHaveAttribute('aria-valuenow', '50');
expect(onValueChange).not.toHaveBeenCalled();
});
});
describe('Pointer', () => {
/**
* Force a deterministic track rect since jsdom has no layout.
*/
function mockTrackRect(container: HTMLElement) {
const track = container.querySelector('[role="presentation"]') as HTMLElement;
track.getBoundingClientRect = () =>
({ left: 0, right: 200, top: 0, bottom: 20, width: 200, height: 20 }) as DOMRect;
return track;
}
it('seeks to the clicked position (click-to-seek)', async () => {
const onValueChange = vi.fn();
const { container } = render(Slider, { value: 0, min: 0, max: 100, onValueChange });
const track = mockTrackRect(container);
await fireEvent.pointerDown(track, { clientX: 100, clientY: 10, pointerId: 1 });
expect(screen.getByRole('slider')).toHaveAttribute('aria-valuenow', '50');
expect(onValueChange).toHaveBeenCalledWith(50);
});
it('updates while dragging after pointerdown', async () => {
const { container } = render(Slider, { value: 0, min: 0, max: 100 });
const track = mockTrackRect(container);
await fireEvent.pointerDown(track, { clientX: 50, clientY: 10, pointerId: 1 });
await fireEvent.pointerMove(track, { clientX: 150, clientY: 10, pointerId: 1 });
expect(screen.getByRole('slider')).toHaveAttribute('aria-valuenow', '75');
});
it('ignores pointer when disabled', async () => {
const { container } = render(Slider, { value: 0, disabled: true });
const track = mockTrackRect(container);
await fireEvent.pointerDown(track, { clientX: 100, clientY: 10, pointerId: 1 });
expect(screen.getByRole('slider')).toHaveAttribute('aria-valuenow', '0');
});
it('focuses the thumb on pointerdown so arrow keys work immediately', async () => {
const { container } = render(Slider, { value: 0, min: 0, max: 100 });
const track = container.querySelector('[role="presentation"]') as HTMLElement;
track.getBoundingClientRect = () =>
({ left: 0, right: 200, top: 0, bottom: 20, width: 200, height: 20 }) as DOMRect;
await fireEvent.pointerDown(track, { clientX: 100, clientY: 10, pointerId: 1 });
expect(screen.getByRole('slider')).toBe(document.activeElement);
});
it('maps a vertical drag with the inverted axis (bottom→min, top→max)', async () => {
const { container } = render(Slider, { value: 0, min: 0, max: 100, orientation: 'vertical' });
const track = container.querySelector('[role="presentation"]') as HTMLElement;
track.getBoundingClientRect = () =>
({ left: 0, right: 20, top: 0, bottom: 200, width: 20, height: 200 }) as DOMRect;
await fireEvent.pointerDown(track, { clientX: 10, clientY: 50, pointerId: 1 });
expect(screen.getByRole('slider')).toHaveAttribute('aria-valuenow', '75');
});
});
+55
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@@ -0,0 +1,55 @@
import {
pointerToValue,
snapToStep,
} from './slider-math';
describe('snapToStep', () => {
it('snaps a raw value to the nearest step on the grid', () => {
expect(snapToStep(53, { min: 0, max: 100, step: 10 })).toBe(50);
expect(snapToStep(56, { min: 0, max: 100, step: 10 })).toBe(60);
});
it('clamps below min and above max', () => {
expect(snapToStep(-20, { min: 0, max: 100, step: 1 })).toBe(0);
expect(snapToStep(200, { min: 0, max: 100, step: 1 })).toBe(100);
});
it('respects a non-zero min when snapping', () => {
expect(snapToStep(13, { min: 10, max: 90, step: 5 })).toBe(15);
});
it('preserves fractional step precision', () => {
expect(snapToStep(1.34, { min: 0, max: 2, step: 0.05 })).toBe(1.35);
expect(snapToStep(0.31, { min: 0, max: 1, step: 0.1 })).toBe(0.3);
});
});
describe('pointerToValue', () => {
const rect = { left: 100, right: 300, top: 50, bottom: 250, width: 200, height: 200 } as DOMRect;
it('maps horizontal pointer position left→min, right→max', () => {
const opts = { min: 0, max: 100, step: 1, orientation: 'horizontal' as const };
expect(pointerToValue({ clientX: 100, clientY: 0 }, rect, opts)).toBe(0);
expect(pointerToValue({ clientX: 200, clientY: 0 }, rect, opts)).toBe(50);
expect(pointerToValue({ clientX: 300, clientY: 0 }, rect, opts)).toBe(100);
});
it('inverts vertical: bottom→min, top→max', () => {
const opts = { min: 0, max: 100, step: 1, orientation: 'vertical' as const };
expect(pointerToValue({ clientX: 0, clientY: 250 }, rect, opts)).toBe(0);
expect(pointerToValue({ clientX: 0, clientY: 150 }, rect, opts)).toBe(50);
expect(pointerToValue({ clientX: 0, clientY: 50 }, rect, opts)).toBe(100);
});
it('clamps when pointer is outside the track', () => {
const opts = { min: 0, max: 100, step: 1, orientation: 'horizontal' as const };
expect(pointerToValue({ clientX: 0, clientY: 0 }, rect, opts)).toBe(0);
expect(pointerToValue({ clientX: 9999, clientY: 0 }, rect, opts)).toBe(100);
});
it('returns min for a zero-size track without NaN', () => {
const zero = { left: 0, right: 0, top: 0, bottom: 0, width: 0, height: 0 } as DOMRect;
const opts = { min: 5, max: 95, step: 1, orientation: 'horizontal' as const };
expect(pointerToValue({ clientX: 0, clientY: 0 }, zero, opts)).toBe(5);
});
});
+59
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@@ -0,0 +1,59 @@
import {
clampNumber,
roundToStepPrecision,
} from '$shared/lib/utils';
/**
* Geometry/range options shared by the math helpers.
*/
type SliderMathOpts = {
/**
* Minimum value (inclusive)
*/
min: number;
/**
* Maximum value (inclusive)
*/
max: number;
/**
* Step increment
*/
step: number;
};
/**
* Snap a raw value onto the step grid, then clamp to [min, max].
*
* Snapping is anchored to `min` so non-zero ranges land on valid stops.
* `roundToStepPrecision` removes IEEE-754 drift from fractional steps.
*/
export function snapToStep(raw: number, { min, max, step }: SliderMathOpts): number {
if (step <= 0) {
return clampNumber(raw, min, max);
}
const snapped = min + Math.round((raw - min) / step) * step;
return clampNumber(roundToStepPrecision(snapped, step), min, max);
}
/**
* Convert a pointer coordinate into a slider value.
*
* Horizontal maps leftmin, rightmax. Vertical is inverted so that
* upmax, matching natural slider expectations. The DOMRect is passed in
* to keep this pure and unit-testable without layout.
*/
export function pointerToValue(
point: { clientX: number; clientY: number },
rect: DOMRect,
opts: SliderMathOpts & { orientation: 'horizontal' | 'vertical' },
): number {
const { min, max, orientation } = opts;
const size = orientation === 'vertical' ? rect.height : rect.width;
if (size <= 0) {
return snapToStep(min, opts);
}
const ratio = orientation === 'vertical'
? (rect.bottom - point.clientY) / size
: (point.clientX - rect.left) / size;
return snapToStep(min + clampNumber(ratio, 0, 1) * (max - min), opts);
}
+17
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@@ -44,3 +44,20 @@ Object.defineProperty(window, 'localStorage', {
value: localStorageMock, value: localStorageMock,
writable: true, writable: true,
}); });
// jsdom lacks PointerEvent; back it with MouseEvent so clientX/clientY survive.
if (typeof PointerEvent === 'undefined') {
class PointerEventPolyfill extends MouseEvent {
pointerId: number;
constructor(type: string, params: PointerEventInit = {}) {
super(type, params);
this.pointerId = params.pointerId ?? 1;
}
}
// @ts-expect-error assigning polyfill to the global scope
global.PointerEvent = PointerEventPolyfill;
}
// jsdom lacks pointer capture
HTMLElement.prototype.setPointerCapture = vi.fn();
HTMLElement.prototype.releasePointerCapture = vi.fn();