mapcomplete/Logic/FeatureSource/Sources/NewGeometryFromChangesFeatureSource.ts
2022-06-13 01:35:50 +02:00

131 lines
No EOL
5.4 KiB
TypeScript

import {Changes} from "../../Osm/Changes";
import {OsmNode, OsmObject, OsmRelation, OsmWay} from "../../Osm/OsmObject";
import FeatureSource from "../FeatureSource";
import {UIEventSource} from "../../UIEventSource";
import {ChangeDescription} from "../../Osm/Actions/ChangeDescription";
import {ElementStorage} from "../../ElementStorage";
export class NewGeometryFromChangesFeatureSource implements FeatureSource {
// This class name truly puts the 'Java' into 'Javascript'
/**
* A feature source containing exclusively new elements.
*
* These elements are probably created by the 'SimpleAddUi' which generates a new point, but the import functionality might create a line or polygon too.
* Other sources of new points are e.g. imports from nodes
*/
public readonly features: UIEventSource<{ feature: any; freshness: Date }[]> = new UIEventSource<{ feature: any; freshness: Date }[]>([]);
public readonly name: string = "newFeatures";
constructor(changes: Changes, allElementStorage: ElementStorage, backendUrl: string) {
const seenChanges = new Set<ChangeDescription>();
const features = this.features.data;
const self = this;
changes.pendingChanges.stabilized(100).addCallbackAndRunD(changes => {
if (changes.length === 0) {
return;
}
const now = new Date();
let somethingChanged = false;
function add(feature) {
feature.id = feature.properties.id
features.push({
feature: feature,
freshness: now
})
somethingChanged = true;
}
for (const change of changes) {
if (seenChanges.has(change)) {
// Already handled
continue;
}
seenChanges.add(change)
if (change.tags === undefined) {
// If tags is undefined, this is probably a new point that is part of a split road
continue
}
if (change.id > 0) {
// This is an already existing object
// In _most_ of the cases, this means that this _isn't_ a new object
// However, when a point is snapped to an already existing point, we have to create a representation for this point!
// For this, we introspect the change
if (allElementStorage.has(change.type + "/" + change.id)) {
// The current point already exists, we don't have to do anything here
continue;
}
console.debug("Detected a reused point")
// The 'allElementsStore' does _not_ have this point yet, so we have to create it
OsmObject.DownloadObjectAsync(change.type + "/" + change.id).then(feat => {
console.log("Got the reused point:", feat)
for (const kv of change.tags) {
feat.tags[kv.k] = kv.v
}
const geojson = feat.asGeoJson();
allElementStorage.addOrGetElement(geojson)
self.features.data.push({feature: geojson, freshness: new Date()})
self.features.ping()
})
continue
} else if (change.id < 0 && change.changes === undefined) {
// The geometry is not described - not a new point
if (change.id < 0) {
console.error("WARNING: got a new point without geometry!")
}
continue;
}
try {
const tags = {}
for (const kv of change.tags) {
tags[kv.k] = kv.v
}
tags["id"] = change.type + "/" + change.id
tags["_backend"] = backendUrl
switch (change.type) {
case "node":
const n = new OsmNode(change.id)
n.tags = tags
n.lat = change.changes["lat"]
n.lon = change.changes["lon"]
const geojson = n.asGeoJson()
add(geojson)
break;
case "way":
const w = new OsmWay(change.id)
w.tags = tags
w.nodes = change.changes["nodes"]
w.coordinates = change.changes["coordinates"].map(([lon, lat]) => [lat, lon])
add(w.asGeoJson())
break;
case "relation":
const r = new OsmRelation(change.id)
r.tags = tags
r.members = change.changes["members"]
add(r.asGeoJson())
break;
}
} catch (e) {
console.error("Could not generate a new geometry to render on screen for:", e)
}
}
if (somethingChanged) {
self.features.ping()
}
})
}
}