MapComplete/src/Logic/State/GeoLocationState.ts

253 lines
9.9 KiB
TypeScript

import { Store, UIEventSource } from "../UIEventSource"
import { LocalStorageSource } from "../Web/LocalStorageSource"
import { QueryParameters } from "../Web/QueryParameters"
import { Translation } from "../../UI/i18n/Translation"
import Translations from "../../UI/i18n/Translations"
import { AndroidPolyfill } from "../Web/AndroidPolyfill"
export type GeolocationPermissionState = "prompt" | "requested" | "granted" | "denied"
export interface GeoLocationPointProperties extends GeolocationCoordinates {
id: "gps"
"user:location": "yes"
date: string
}
/**
* An abstract representation of the current state of the geolocation, keeping track of permissions and if a location is known.
*/
export class GeoLocationState {
/**
* What do we know about the current state of having access to the GPS?
* If 'prompt', then we just started and didn't request access yet
* 'requested' means the user tapped the 'locate me' button at least once
* 'granted' means that it is granted
* 'denied' means that we don't have access
*/
public readonly permission: UIEventSource<GeolocationPermissionState> = new UIEventSource(
"prompt",
)
/**
* If an error occurs with a code indicating "gps unavailable", this will be set to "false".
* This is about the physical availability of the GPS-signal; this might e.g. become false if the user is in a tunnel
*/
private readonly _gpsAvailable: UIEventSource<boolean> = new UIEventSource<boolean>(true)
public readonly gpsAvailable: Store<boolean> = this._gpsAvailable
/**
* Important to determine e.g. if we move automatically on fix or not
*/
public readonly requestMoment: UIEventSource<Date | undefined> = new UIEventSource(undefined)
/**
* If true: the map will center (and re-center) to the current GPS-location
*/
public readonly allowMoving: UIEventSource<boolean> = new UIEventSource<boolean>(true)
/**
* The latest GeoLocationCoordinates, as given by the WebAPI
*/
public readonly currentGPSLocation: UIEventSource<GeolocationCoordinates | undefined> =
new UIEventSource<GeolocationCoordinates | undefined>(undefined)
/**
* A small flag on localstorage. If the user previously granted the geolocation, it will be set.
* On firefox, the permissions api is broken (probably fingerprint resistiance) and "granted + don't ask again" doesn't stick between sessions.
*
* Instead, we set this flag. If this flag is set upon loading the page, we start geolocating immediately.
* If the user denies the geolocation this time, we unset this flag
* @private
*/
private readonly _previousLocationGrant: UIEventSource<boolean> =
LocalStorageSource.getParsed<boolean>("geolocation-permissions", false)
/**
* Used to detect a permission retraction
*/
private readonly _grantedThisSession: UIEventSource<boolean> = new UIEventSource<boolean>(false)
/**
* A human explanation of the current gps state, to be shown on the home screen or as tooltip
*/
public readonly gpsStateExplanation: Store<Translation>
constructor() {
const self = this
this.permission.addCallbackAndRunD(async (state) => {
if (state === "granted") {
self._previousLocationGrant.setData(true)
self._grantedThisSession.setData(true)
}
if (state === "prompt" && self._grantedThisSession.data) {
// This is _really_ weird: we had a grant earlier, but it's 'prompt' now?
// This means that the rights have been revoked again!
self._previousLocationGrant.setData(false)
self.permission.setData("denied")
self.currentGPSLocation.setData(undefined)
console.warn("Detected a downgrade in permissions!")
}
if (state === "denied") {
self._previousLocationGrant.setData(false)
}
})
console.log("Previous location grant:", this._previousLocationGrant.data)
if (this._previousLocationGrant.data) {
// A previous visit successfully granted permission. Chance is high that we are allowed to use it again!
// We set the flag to false again. If the user only wanted to share their location once, we are not gonna keep bothering them
this._previousLocationGrant.setData(false)
console.log("Requesting access to GPS as this was previously granted")
const latLonGivenViaUrl =
QueryParameters.wasInitialized("lat") || QueryParameters.wasInitialized("lon")
if (!latLonGivenViaUrl) {
this.requestMoment.setData(new Date())
}
this.requestPermission()
}
this.gpsStateExplanation = this.gpsAvailable.map(
(available) => {
if (this.currentGPSLocation.data !== undefined) {
if (!this.allowMoving.data) {
return Translations.t.general.visualFeedback.islocked
}
return Translations.t.general.labels.jumpToLocation
}
if (!available) {
return Translations.t.general.labels.locationNotAvailable
}
if (this.permission.data === "denied") {
return Translations.t.general.geopermissionDenied
}
if (this.permission.data === "prompt") {
return Translations.t.general.labels.jumpToLocation
}
if (this.permission.data === "requested") {
return Translations.t.general.waitingForGeopermission
}
return Translations.t.general.waitingForLocation
},
[this.allowMoving, this.permission, this.currentGPSLocation],
)
}
/**
* Requests the user to allow access to their position.
* When granted, will be written to the 'geolocationState'.
* This class will start watching
*/
public requestPermission() {
this.requestPermissionAsync()
}
public static isSafari(): boolean {
return navigator.permissions === undefined && navigator.geolocation !== undefined
}
/**
* Requests the user to allow access to their position.
* When granted, will be written to the 'geolocationState'.
* This class will start watching
*/
public async requestPermissionAsync() {
if (typeof navigator === "undefined") {
// Not compatible with this browser
this.permission.setData("denied")
return
}
if (this.permission.data !== "prompt" && this.permission.data !== "requested") {
// If the user denies the first prompt, revokes the deny and then tries again, we have to run the flow as well
// Hence that we continue the flow if it is "requested"
return
}
if(AndroidPolyfill.inAndroid.data){
this.permission.setData("requested")
this.permission.addCallbackAndRunD(p => {
if(p === "granted"){
this.startWatching()
return true
}
})
AndroidPolyfill.requestGeoPermission().then(state => {
const granted = state.value === "true"
this.permission.set(granted ? "granted" : "denied")
})
return
}
if (GeoLocationState.isSafari()) {
/*
This is probably safari
Safari does not support the 'permissions'-API for geolocation,
so we just start watching right away
*/
this.permission.setData("requested")
this.startWatching()
return
}
this.permission.setData("requested")
try {
const status = await navigator?.permissions?.query({ name: "geolocation" })
console.log("Got geolocation state", status.state)
if (status.state === "granted" || status.state === "denied") {
this.permission.setData(status.state)
this.startWatching()
return
}
status.addEventListener("change", () => {
this.permission.setData(status.state)
})
// The code above might have reset it to 'prompt', but we _did_ request permission!
this.permission.setData("requested")
// We _must_ call 'startWatching', as that is the actual trigger for the popup...
this.startWatching()
} catch (e) {
console.error("Could not get permission:", e)
}
}
/**
* Installs the listener for updates
* @private
*/
private async startWatching() {
if(AndroidPolyfill.inAndroid.data){
AndroidPolyfill.watchLocation( this.currentGPSLocation, location => {
console.log(JSON.stringify(location))
})
}
navigator.geolocation.watchPosition(
(position: GeolocationPosition) => {
this._gpsAvailable.set(true)
this.currentGPSLocation.setData(position.coords)
this._previousLocationGrant.setData(true)
},
(e: GeolocationPositionError) => {
if (e.code === 2 || e.code === 3) {
this._gpsAvailable.set(false)
return
}
this._gpsAvailable.set(true) // We go back to the default assumption that the location is physically available
if (e.code === 1) {
this.permission.set("denied")
this._grantedThisSession.setData(false)
return
}
console.warn("Could not get location with navigator.geolocation due to", e)
},
{
enableHighAccuracy: true,
}
)
}
}