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import { useCallback, useEffect, useMemo, useRef, useState } from 'react' |
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import type { DemoStage } from './types' |
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|
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/** |
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* How long each stage holds before the driver advances. Each stage carries one |
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* step of commentary, so it is given long enough to read the callout and take |
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* in what the spotlight is pointing at. The preview step holds longest: there |
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* is code on screen to actually look at. |
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*/ |
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const STAGE_DURATIONS: Partial<Record<DemoStage, number>> = { |
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library: 4800, |
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preview: 5400, |
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download: 4200, |
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synced: 4800 |
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} |
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|
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const DEFAULT_DURATION = 3000 |
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|
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/** Uniform pause between stages when the visitor has asked for reduced motion. */ |
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const REDUCED_MOTION_DURATION = 250 |
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|
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const FOLLOW_UP: Partial<Record<DemoStage, DemoStage>> = { |
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library: 'preview', |
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preview: 'download', |
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download: 'synced', |
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synced: 'finished' |
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} |
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|
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const prefersReducedMotion = (): boolean => |
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window.matchMedia('(prefers-reduced-motion: reduce)').matches |
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|
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export interface CloudLibraryDemoState { |
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stage: DemoStage |
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hasStarted: boolean |
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isFinished: boolean |
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reducedMotion: boolean |
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play: VoidFunction |
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skip: VoidFunction |
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replay: VoidFunction |
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} |
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|
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export const useCloudLibraryDemo = (): CloudLibraryDemoState => { |
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const reducedMotion = useMemo(prefersReducedMotion, []) |
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|
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const [stage, setStage] = useState<DemoStage>('idle') |
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const timers = useRef<number[]>([]) |
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|
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const clearTimers = useCallback(() => { |
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timers.current.forEach(window.clearTimeout) |
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timers.current = [] |
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}, []) |
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|
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useEffect(() => () => { |
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timers.current.forEach(window.clearTimeout) |
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}, []) |
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|
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const advance = useCallback((next: DemoStage) => { |
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setStage(next) |
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|
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const upcoming = FOLLOW_UP[next] |
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|
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if (!upcoming) { |
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return |
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} |
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|
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const delay = reducedMotion |
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? REDUCED_MOTION_DURATION |
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: STAGE_DURATIONS[next] ?? DEFAULT_DURATION |
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|
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timers.current.push(window.setTimeout(() => advance(upcoming), delay)) |
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}, [reducedMotion]) |
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|
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const play = useCallback(() => { |
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clearTimers() |
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advance('library') |
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}, [advance, clearTimers]) |
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|
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const replay = useCallback(() => { |
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clearTimers() |
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setStage('idle') |
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timers.current.push(window.setTimeout(() => advance('library'), REDUCED_MOTION_DURATION)) |
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}, [advance, clearTimers]) |
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|
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const skip = useCallback(() => { |
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clearTimers() |
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setStage('finished') |
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}, [clearTimers]) |
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|
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return { |
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stage, |
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hasStarted: 'idle' !== stage, |
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isFinished: 'finished' === stage, |
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reducedMotion, |
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play, |
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skip, |
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replay |
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} |
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} |
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