UX: when clicking on the map, all (way) features within 20px are inspected and the closest one is inspected. Fixes #2261

src/Models/MapProperties.ts

@@ -1,6 +1,7 @@
 import { Store, UIEventSource } from "../Logic/UIEventSource"
 import { BBox } from "../Logic/BBox"
 import { RasterLayerPolygon } from "./RasterLayers"
+import { Feature } from "geojson"
 
 export interface KeyNavigationEvent {
     date: Date
@@ -19,7 +20,10 @@ export interface MapProperties {
     readonly allowRotating: UIEventSource<true | boolean>
     readonly rotation: UIEventSource<number>
     readonly pitch: UIEventSource<number>
-    readonly lastClickLocation: Store<{ lon: number; lat: number }>
+    readonly lastClickLocation: Store<{ lon: number; lat: number ; /**
+         * The nearest feature from a MapComplete layer
+         */
+        nearestFeature?: Feature}>
     readonly allowZooming: UIEventSource<true | boolean>
     readonly useTerrain: Store<boolean>
     readonly showScale: UIEventSource<boolean>

src/Models/ThemeViewState.ts

@@ -178,7 +178,7 @@ export default class ThemeViewState implements SpecialVisualizationState {
         this.map = new UIEventSource<MlMap>(undefined)
         const geolocationState = new GeoLocationState()
         const initial = new InitialMapPositioning(layout, geolocationState)
-        this.mapProperties = new MapLibreAdaptor(this.map, initial)
+        this.mapProperties = new MapLibreAdaptor(this.map, initial, {correctClick: 20})
 
         this.featureSwitchIsTesting = this.featureSwitches.featureSwitchIsTesting
         this.featureSwitchUserbadge = this.featureSwitches.featureSwitchEnableLogin
@@ -554,6 +554,16 @@ export default class ThemeViewState implements SpecialVisualizationState {
         })
     }
 
+    private setSelectedElement(feature: Feature){
+        const current = this.selectedElement.data
+        if(current?.properties?.id !== undefined && current.properties.id === feature.properties.id  ){
+            console.log("Not setting selected, same id", current, feature)
+            return // already set
+        }
+        // this.selectedElement.setData(undefined)
+        this.selectedElement.setData(feature)
+    }
+
     /**
      * Selects the feature that is 'i' closest to the map center
      */
@@ -570,13 +580,11 @@ export default class ThemeViewState implements SpecialVisualizationState {
                 if (!toSelect) {
                     return
                 }
-                this.selectedElement.setData(undefined)
+                this.setSelectedElement(toSelect)
-                this.selectedElement.setData(toSelect)
             })
             return
         }
-        this.selectedElement.setData(undefined)
+        this.setSelectedElement(toSelect)
-        this.selectedElement.setData(toSelect)
     }
 
     private initHotkeys() {
@@ -992,6 +1000,15 @@ export default class ThemeViewState implements SpecialVisualizationState {
             this.userRelatedState.recentlyVisitedSearch.add(r)
         })
 
+        this.mapProperties.lastClickLocation.addCallbackD(lastClick => {
+            if(lastClick.mode !== "left" || !lastClick.nearestFeature){
+                return
+            }
+            const f = lastClick.nearestFeature
+            this.setSelectedElement(f)
+
+        })
+
         this.userRelatedState.showScale.addCallbackAndRun((showScale) => {
             this.mapProperties.showScale.set(showScale)
         })

src/UI/Map/MapLibreAdaptor.ts

@@ -1,10 +1,5 @@
 import { ImmutableStore, Store, UIEventSource } from "../../Logic/UIEventSource"
-import maplibregl, {
+import maplibregl, { Map as MLMap, Map as MlMap, ScaleControl, SourceSpecification } from "maplibre-gl"
-    Map as MLMap,
-    Map as MlMap,
-    ScaleControl,
-    SourceSpecification,
-} from "maplibre-gl"
 import { RasterLayerPolygon } from "../../Models/RasterLayers"
 import { Utils } from "../../Utils"
 import { BBox } from "../../Logic/BBox"
@@ -16,6 +11,8 @@ import * as htmltoimage from "html-to-image"
 import RasterLayerHandler from "./RasterLayerHandler"
 import Constants from "../../Models/Constants"
 import { Protocol } from "pmtiles"
+import { GeoOperations } from "../../Logic/GeoOperations"
+import { Feature, LineString } from "geojson"
 
 /**
  * The 'MapLibreAdaptor' bridges 'MapLibre' with the various properties of the `MapProperties`
@@ -46,7 +43,10 @@ export class MapLibreAdaptor implements MapProperties, ExportableMap {
     readonly allowRotating: UIEventSource<true | boolean | undefined>
     readonly allowZooming: UIEventSource<true | boolean | undefined>
     readonly lastClickLocation: Store<
-        undefined | { lon: number; lat: number; mode: "left" | "right" | "middle" }
+        undefined | { lon: number; lat: number; mode: "left" | "right" | "middle" , /**
+         * The nearest feature from a MapComplete layer
+         */
+        nearestFeature?: Feature }
     >
     readonly minzoom: UIEventSource<number>
     readonly maxzoom: UIEventSource<number>
@@ -64,7 +64,9 @@ export class MapLibreAdaptor implements MapProperties, ExportableMap {
 
     private readonly _maplibreMap: Store<MLMap>
 
-    constructor(maplibreMap: Store<MLMap>, state?: Partial<MapProperties>) {
+    constructor(maplibreMap: Store<MLMap>, state?: Partial<MapProperties>, options?:{
+        correctClick?: number
+    }) {
         if (!MapLibreAdaptor.pmtilesInited) {
             maplibregl.addProtocol("pmtiles", new Protocol().tile)
             MapLibreAdaptor.pmtilesInited = true
@@ -104,7 +106,8 @@ export class MapLibreAdaptor implements MapProperties, ExportableMap {
         const lastClickLocation = new UIEventSource<{
             lat: number
             lon: number
-            mode: "left" | "right" | "middle"
+            mode: "left" | "right" | "middle",
+            nearestFeature?: Feature
         }>(undefined)
         this.lastClickLocation = lastClickLocation
         const self = this
@@ -122,8 +125,40 @@ export class MapLibreAdaptor implements MapProperties, ExportableMap {
             const lat = e.lngLat.lat
             const mouseEvent: MouseEvent = e.originalEvent
             mode = mode ?? clickmodes[mouseEvent.button]
+            let nearestFeature: Feature = undefined
+            if(options?.correctClick && maplibreMap.data){
+                const map = maplibreMap.data
+                const point = e.point
+                const buffer = options?.correctClick
+                const features = map.queryRenderedFeatures([
+                    [point.x - buffer, point.y - buffer],
+                    [point.x + buffer, point.y + buffer]
+                ]).filter(f => f.source.startsWith("mapcomplete_"))
+                if(features.length === 1){
+                    nearestFeature = features[0]
+                }else{
+                    let nearestD: number = undefined
+                    for (const feature of features) {
+                        let d: number // in meter
+                        if(feature.geometry.type === "LineString"){
+                            const way = <Feature<LineString>> feature
+                            const lngLat:[number,number] = [e.lngLat.lng, e.lngLat.lat]
+                            const p = GeoOperations.nearestPoint(way, lngLat)
+                            console.log(">>>",p, way, lngLat)
+                            if(!p){
+                                continue
+                            }
+                            d = p.properties.dist * 1000
+                            if(nearestFeature === undefined || d < nearestD){
+                                nearestFeature = way
+                                nearestD = d
+                            }
+                        }
+                    }
+                }
+            }
+            lastClickLocation.setData({ lon, lat, mode, nearestFeature })
 
-            lastClickLocation.setData({ lon, lat, mode })
         }
 
         maplibreMap.addCallbackAndRunD((map) => {

src/UI/Map/ShowDataLayer.ts

@@ -568,7 +568,6 @@ export default class ShowDataLayer {
             return
         }
         const bbox = BBox.bboxAroundAll(features.map(BBox.get))
-        console.debug("Zooming to features", bbox.asGeoJson())
         window.requestAnimationFrame(() => {
             map.resize()
             map.fitBounds(bbox.toLngLat(), {

src/UI/ThemeViewGUI.svelte

@@ -54,7 +54,6 @@
 
   let theme = state.theme
   let maplibremap: UIEventSource<MlMap> = state.map
-  let state_selectedElement = state.selectedElement
   let selectedElement: UIEventSource<Feature> = new UIEventSource<Feature>(undefined)
   let compass = Orientation.singleton.alpha
   let compassLoaded = Orientation.singleton.gotMeasurement
@@ -99,7 +98,7 @@
 
   state.mapProperties.installCustomKeyboardHandler(viewport)
 
-  let selectedLayer: Store<LayerConfig> = state.selectedElement.mapD((element) => {
+  let selectedLayer: Store<LayerConfig> = selectedElement.mapD((element) => {
     if (element.properties.id.startsWith("current_view")) {
       return currentViewLayer
     }
@@ -458,7 +457,7 @@
       }}
     >
       <div slot="close-button" />
-      <SelectedElementPanel {state} selected={$state_selectedElement} />
+      <SelectedElementPanel {state} selected={$selectedElement} />
     </Drawer>
   {/if}
 
@@ -472,7 +471,7 @@
         }}
       >
         <span slot="close-button" />
-        <SelectedElementPanel absolute={false} {state} selected={$state_selectedElement} />
+        <SelectedElementPanel absolute={false} {state} selected={$selectedElement} />
       </FloatOver>
     {:else}
       <FloatOver
@@ -483,7 +482,7 @@
         <SelectedElementView
           {state}
           layer={$selectedLayer}
-          selectedElement={$state_selectedElement}
+          selectedElement={$selectedElement}
         />
       </FloatOver>
     {/if}