| 1 | interface StyleTarget { |
| 2 | style: { |
| 3 | setProperty(name: string, value: string): void; |
| 4 | }; |
| 5 | } |
| 6 | |
| 7 | interface AriaTarget { |
| 8 | setAttribute(name: string, value: string): void; |
| 9 | } |
| 10 | |
| 11 | interface RafResizeUpdaterOptions { |
| 12 | target: StyleTarget; |
| 13 | separator?: AriaTarget | null; |
| 14 | cssVar: string; |
| 15 | onApply?: (value: number) => void; |
| 16 | } |
| 17 | |
| 18 | export interface RafResizeUpdater { |
| 19 | schedule(value: number): void; |
| 20 | flush(): void; |
| 21 | cancel(): void; |
| 22 | } |
| 23 | |
| 24 | function roundedPixel(value: number): number { |
| 25 | return Math.round(value); |
| 26 | } |
| 27 | |
| 28 | export function createRafResizeUpdater({ target, separator, cssVar, onApply }: RafResizeUpdaterOptions): RafResizeUpdater { |
| 29 | let frame: number | null = null; |
| 30 | let latest: number | null = null; |
| 31 | |
| 32 | const apply = () => { |
| 33 | frame = null; |
| 34 | if (latest === null) return; |
| 35 | const rounded = roundedPixel(latest); |
| 36 | target.style.setProperty(cssVar, `${rounded}px`); |
| 37 | separator?.setAttribute("aria-valuenow", String(rounded)); |
| 38 | onApply?.(rounded); |
| 39 | }; |
| 40 | |
| 41 | return { |
| 42 | schedule(value: number) { |
| 43 | latest = value; |
| 44 | if (frame !== null) return; |
| 45 | frame = requestAnimationFrame(apply); |
| 46 | }, |
| 47 | flush() { |
| 48 | if (frame !== null) { |
| 49 | cancelAnimationFrame(frame); |
| 50 | frame = null; |
| 51 | } |
| 52 | apply(); |
| 53 | }, |
| 54 | cancel() { |
| 55 | if (frame === null) return; |
| 56 | cancelAnimationFrame(frame); |
| 57 | frame = null; |
| 58 | }, |
| 59 | }; |
| 60 | } |
| 61 |