More cleanup, first somewhat working version of #171

Logic/FeatureSource/Sources/ChangeGeometryApplicator.ts

@@ -0,0 +1,84 @@
+/**
+ * Applies geometry changes from 'Changes' onto every feature of a featureSource
+ */
+import {Changes} from "../../Osm/Changes";
+import {UIEventSource} from "../../UIEventSource";
+import {FeatureSourceForLayer, IndexedFeatureSource} from "../FeatureSource";
+import FilteredLayer from "../../../Models/FilteredLayer";
+import {ChangeDescription, ChangeDescriptionTools} from "../../Osm/Actions/ChangeDescription";
+
+
+export default class ChangeGeometryApplicator implements FeatureSourceForLayer {
+    public readonly features: UIEventSource<{ feature: any; freshness: Date }[]> = new UIEventSource<{ feature: any; freshness: Date }[]>([]);
+    public readonly name: string;
+    private readonly source: IndexedFeatureSource;
+    private readonly changes: Changes;
+    public readonly layer: FilteredLayer
+
+    constructor(source: (IndexedFeatureSource & FeatureSourceForLayer), changes: Changes) {
+        this.source = source;
+        this.changes = changes;
+        this.layer = source.layer
+
+        this.name = "ChangesApplied(" + source.name + ")"
+        this.features = new UIEventSource<{ feature: any; freshness: Date }[]>(undefined)
+        
+        const self = this;
+        source.features.addCallbackAndRunD(_ => self.update())
+        
+        changes.allChanges.addCallbackAndRunD(_ => self.update())
+
+    }
+
+    private update() {
+        const upstreamFeatures = this.source.features.data
+        const upstreamIds = this.source.containedIds.data
+        const changesToApply = this.changes.allChanges.data
+            ?.filter(ch =>
+                // Does upsteram have this element? If not, we skip
+                upstreamIds.has(ch.type + "/" + ch.id) &&
+                // Are any (geometry) changes defined?
+                ch.changes !== undefined &&
+                // Ignore new elements, they are handled by the NewGeometryFromChangesFeatureSource
+                ch.id > 0)
+
+        if (changesToApply === undefined || changesToApply.length === 0) {
+            // No changes to apply!
+            // Pass the original feature and lets continue our day
+            this.features.setData(upstreamFeatures);
+            return;
+        }
+
+        const changesPerId = new Map<string, ChangeDescription[]>()
+        for (const ch of changesToApply) {
+            const key = ch.type + "/" + ch.id
+            if(changesPerId.has(key)){
+                changesPerId.get(key).push(ch)
+            }else{
+                changesPerId.set(key, [ch])
+            }
+        }
+        const newFeatures: { feature: any, freshness: Date }[] = []
+        for (const feature of upstreamFeatures) {
+            const changesForFeature = changesPerId.get(feature.feature.properties.id)
+            if (changesForFeature === undefined) {
+                // No changes for this element
+                newFeatures.push(feature)
+                continue;
+            }
+            
+            // Allright! We have a feature to rewrite!
+            const copy = {
+                ...feature
+            }
+            // We only apply the last change as that one'll have the latest geometry
+            const change = changesForFeature[changesForFeature.length - 1]
+            copy.feature.geometry = ChangeDescriptionTools.getGeojsonGeometry(change)
+            console.log("Applying a geometry change onto ", feature, change, copy)
+            newFeatures.push(copy)
+        }
+        this.features.setData(newFeatures)
+
+    }
+
+}