Usertests: add 'centermessage' again which indicates if data is loading or is present, see #1457

Logic/Actors/NoElementsInViewDetector.ts

@@ -0,0 +1,90 @@
+import { BBox } from "../BBox"
+import { Store } from "../UIEventSource"
+import ThemeViewState from "../../Models/ThemeViewState"
+import Constants from "../../Models/Constants"
+
+export type FeatureViewState =
+    | "no-data"
+    | "zoom-to-low"
+    | "has-visible-feature"
+    | "all-filtered-away"
+export default class NoElementsInViewDetector {
+    public readonly hasFeatureInView: Store<FeatureViewState>
+
+    constructor(themeViewState: ThemeViewState) {
+        const state = themeViewState
+        const minZoom = Math.min(
+            ...themeViewState.layout.layers
+                .filter((l) => Constants.priviliged_layers.indexOf(<any>l.id) < 0)
+                .map((l) => l.minzoom)
+        )
+        const mapProperties = themeViewState.mapProperties
+
+        const priviliged: Set<string> = new Set(Constants.priviliged_layers)
+
+        this.hasFeatureInView = state.mapProperties.bounds.stabilized(100).map(
+            (bbox) => {
+                if (mapProperties.zoom.data < minZoom) {
+                    // Not a single layer will display anything as the zoom is to low
+                    return "zoom-to-low"
+                }
+
+                for (const [layerName, source] of themeViewState.perLayerFiltered) {
+                    if (priviliged.has(layerName)) {
+                        continue
+                    }
+                    if (
+                        mapProperties.zoom.data < themeViewState.layout.getLayer(layerName).minzoom
+                    ) {
+                        continue
+                    }
+                    if (!state.layerState.filteredLayers.get(layerName).isDisplayed.data) {
+                        continue
+                    }
+                    const feats = source.features.data
+                    if (!(feats?.length > 0)) {
+                        // Nope, no data loaded
+                        continue
+                    }
+
+                    for (const feat of feats) {
+                        if (BBox.get(feat).overlapsWith(bbox)) {
+                            // We found at least one item which has visible data
+                            return "has-visible-feature"
+                        }
+                    }
+                }
+
+                // If we arrive here, data might have been filtered away
+                for (const [layerName, source] of themeViewState.perLayer) {
+                    if (priviliged.has(layerName)) {
+                        continue
+                    }
+                    if (
+                        mapProperties.zoom.data < themeViewState.layout.getLayer(layerName).minzoom
+                    ) {
+                        continue
+                    }
+                    const feats = source.features.data
+                    if (!(feats?.length > 0)) {
+                        // Nope, no data loaded
+                        continue
+                    }
+
+                    for (const feat of feats) {
+                        if (BBox.get(feat).overlapsWith(bbox)) {
+                            // We found at least one item, but as we didn't find it before, it is filtered away
+                            return "all-filtered-away"
+                        }
+                    }
+                }
+                return "no-data"
+            },
+            [
+                ...Array.from(themeViewState.perLayerFiltered.values()).map((f) => f.features),
+                mapProperties.zoom,
+                ...Array.from(state.layerState.filteredLayers.values()).map((fl) => fl.isDisplayed),
+            ]
+        )
+    }
+}

Logic/FeatureSource/Sources/LayoutSource.ts

@@ -69,7 +69,7 @@ export default class LayoutSource extends FeatureSourceMerger {
 
         const self = this
         function setIsLoading() {
-            const loading = overpassSource?.runningQuery?.data && osmApiSource?.isRunning?.data
+            const loading = overpassSource?.runningQuery?.data || osmApiSource?.isRunning?.data
             self._isLoading.setData(loading)
         }
 

Logic/UIEventSource.ts

@@ -384,7 +384,6 @@ class ListenerTracker<T> {
 
 /**
  * The mapped store is a helper type which does the mapping of a function.
- * It'll fuse
  */
 class MappedStore<TIn, T> extends Store<T> {
     private readonly _upstream: Store<TIn>