fixed layer based feature selection (flutter-mapbox-gl#765)

* fixed feature selection issue for ios * fixed feature selection issue for android
cheers-group · Nov 17, 2021 · b26debb · b26debb
1 parent 035d927
commit b26debb
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Showing 2 changed files with 46 additions and 7 deletions.
diff --git a/android/src/main/java/com/mapbox/mapboxgl/MapboxMapController.java b/android/src/main/java/com/mapbox/mapboxgl/MapboxMapController.java
@@ -71,6 +71,7 @@
 import com.mapbox.mapboxsdk.plugins.annotation.SymbolOptions;
 import com.mapbox.mapboxsdk.plugins.localization.LocalizationPlugin;
 import com.mapbox.mapboxsdk.style.expressions.Expression;
+import com.mapbox.mapboxsdk.style.layers.Layer;
 import com.mapbox.mapboxsdk.style.layers.RasterLayer;
 import com.mapbox.mapboxsdk.style.sources.ImageSource;
 import com.mapbox.mapboxsdk.style.layers.LineLayer;
@@ -523,6 +524,27 @@ private String enableFillManager(@NonNull Style style, @Nullable String belowLay
     return fillManager.getLayerId();
   }
 
+  private Feature firstFeatureOnLayers(RectF in) {
+    if(style != null){
+      final List<Layer> layers = style.getLayers();
+      final List<String> layersInOrder = new ArrayList<String>();
+      for (Layer layer : layers){
+        String id = layer.getId();
+        if(featureLayerIdentifiers.contains(id))
+          layersInOrder.add(id);
+      }
+      Collections.reverse(layersInOrder);
+
+      for(String id: layersInOrder){
+        List<Feature> features = mapboxMap.queryRenderedFeatures(in, id);
+        if(!features.isEmpty()){
+          return features.get(0);
+        }
+      }
+    }
+    return null;
+  } 
+
   @Override
   public void onMethodCall(MethodCall call, MethodChannel.Result result) {
     switch (call.method) {
@@ -1276,10 +1298,10 @@ public boolean onMapClick(@NonNull LatLng point) {
       pointf.x + 10,
       pointf.y + 10
     );
-    List<Feature> featureList = mapboxMap.queryRenderedFeatures(rectF, featureLayerIdentifiers.toArray(new String[0]));
-    if(!featureList.isEmpty()){
+    Feature feature = firstFeatureOnLayers(rectF);
+    if(feature != null){
       final Map<String, Object> arguments = new HashMap<>(1);
-      arguments.put("featureId", featureList.get(0).id());
+      arguments.put("featureId", feature.id());
       methodChannel.invokeMethod("feature#onTap", arguments);
     } else { 
       final Map<String, Object> arguments = new HashMap<>(5);

diff --git a/ios/Classes/MapboxMapController.swift b/ios/Classes/MapboxMapController.swift
@@ -810,6 +810,25 @@ class MapboxMapController: NSObject, FlutterPlatformView, MGLMapViewDelegate, Ma
         return trackCameraPosition ? mapView.camera : nil
 
     }
+    /*
+    *  Scan layers from top to bottom and return the first matching feature
+    */
+    private func firstFeatureOnLayers(at: CGPoint) -> MGLFeature? {
+        guard let style = mapView.style else { return  nil}
+
+        // get layers in order (featureLayerIdentifiers is unordered)
+        let clickableLayers = style.layers.filter{ layer in
+            return featureLayerIdentifiers.contains(layer.identifier)
+        }
+
+        for layer in clickableLayers.reversed() {
+            let features = mapView.visibleFeatures(at: at, styleLayerIdentifiers: [layer.identifier])
+            if let feature = features.first {
+                return feature
+            }
+        }
+        return nil
+    }
 
     /*
     *  UITapGestureRecognizer
@@ -818,15 +837,13 @@ class MapboxMapController: NSObject, FlutterPlatformView, MGLMapViewDelegate, Ma
     @objc @IBAction func handleMapTap(sender: UITapGestureRecognizer) {
         // Get the CGPoint where the user tapped.
         let point = sender.location(in: mapView)
-        let coordinate = mapView.convert(point, toCoordinateFrom: mapView)
 
-        let features = mapView.visibleFeatures(at: point, styleLayerIdentifiers: featureLayerIdentifiers)
-
-        if let feature = features.last, let id = feature.identifier {
+        if let feature = firstFeatureOnLayers(at: point), let id = feature.identifier {
             channel?.invokeMethod("feature#onTap", arguments: [
                         "featureId": id
             ])
         } else {
+            let coordinate = mapView.convert(point, toCoordinateFrom: mapView)
             channel?.invokeMethod("map#onMapClick", arguments: [
                         "x": point.x,
                         "y": point.y,