mapcomplete/Logic/Actors/InitialMapPositioning.ts

64 lines
2.2 KiB
TypeScript

import { UIEventSource } from "../UIEventSource"
import LayoutConfig from "../../Models/ThemeConfig/LayoutConfig"
import { LocalStorageSource } from "../Web/LocalStorageSource"
import { QueryParameters } from "../Web/QueryParameters"
/**
* This actor is responsible to set the map location.
* It will attempt to
* - Set the map to the position as passed in by the query parameters (if available)
* - Set the map to the position remembered in LocalStorage (if available)
* - Set the map to the layout default
*
* Additionally, it will save the map location to local storage
*/
export default class InitialMapPositioning {
public zoom: UIEventSource<number>
public location: UIEventSource<{ lon: number; lat: number }>
constructor(layoutToUse: LayoutConfig) {
function localStorageSynced(
key: string,
deflt: number,
docs: string
): UIEventSource<number> {
const localStorage = LocalStorageSource.Get(key)
const previousValue = localStorage.data
const src = UIEventSource.asFloat(
QueryParameters.GetQueryParameter(key, "" + deflt, docs).syncWith(localStorage)
)
if (src.data === deflt) {
const prev = Number(previousValue)
if (!isNaN(prev)) {
src.setData(prev)
}
}
return src
}
// -- Location control initialization
this.zoom = localStorageSynced(
"z",
layoutToUse?.startZoom ?? 1,
"The initial/current zoom level"
)
const lat = localStorageSynced(
"lat",
layoutToUse?.startLat ?? 0,
"The initial/current latitude"
)
const lon = localStorageSynced(
"lon",
layoutToUse?.startLon ?? 0,
"The initial/current longitude of the app"
)
this.location = new UIEventSource({ lon: lon.data, lat: lat.data })
this.location.addCallbackD((loc) => {
lat.setData(loc.lat)
lon.setData(loc.lon)
})
// Note: this syncs only in one direction
}
}