71 lines
1.8 KiB
TypeScript
Executable file
71 lines
1.8 KiB
TypeScript
Executable file
import { Subscribable } from './subscribable'
|
|
import { isServer } from './utils'
|
|
|
|
type Listener = (online: boolean) => void
|
|
type SetupFn = (setOnline: Listener) => (() => void) | undefined
|
|
|
|
export class OnlineManager extends Subscribable<Listener> {
|
|
#online = true
|
|
#cleanup?: () => void
|
|
|
|
#setup: SetupFn
|
|
|
|
constructor() {
|
|
super()
|
|
this.#setup = (onOnline) => {
|
|
// addEventListener does not exist in React Native, but window does
|
|
// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
|
|
if (!isServer && window.addEventListener) {
|
|
const onlineListener = () => onOnline(true)
|
|
const offlineListener = () => onOnline(false)
|
|
// Listen to online
|
|
window.addEventListener('online', onlineListener, false)
|
|
window.addEventListener('offline', offlineListener, false)
|
|
|
|
return () => {
|
|
// Be sure to unsubscribe if a new handler is set
|
|
window.removeEventListener('online', onlineListener)
|
|
window.removeEventListener('offline', offlineListener)
|
|
}
|
|
}
|
|
|
|
return
|
|
}
|
|
}
|
|
|
|
protected onSubscribe(): void {
|
|
if (!this.#cleanup) {
|
|
this.setEventListener(this.#setup)
|
|
}
|
|
}
|
|
|
|
protected onUnsubscribe() {
|
|
if (!this.hasListeners()) {
|
|
this.#cleanup?.()
|
|
this.#cleanup = undefined
|
|
}
|
|
}
|
|
|
|
setEventListener(setup: SetupFn): void {
|
|
this.#setup = setup
|
|
this.#cleanup?.()
|
|
this.#cleanup = setup(this.setOnline.bind(this))
|
|
}
|
|
|
|
setOnline(online: boolean): void {
|
|
const changed = this.#online !== online
|
|
|
|
if (changed) {
|
|
this.#online = online
|
|
this.listeners.forEach((listener) => {
|
|
listener(online)
|
|
})
|
|
}
|
|
}
|
|
|
|
isOnline(): boolean {
|
|
return this.#online
|
|
}
|
|
}
|
|
|
|
export const onlineManager = new OnlineManager()
|