Source added by Style.addSource is destroyed after the MapView is destroyed

[grab-liyanjin]

MapLibre Android Version

Newest master, last commit 691384b

Android SDK Version

Android 14

Device

Google Pixel 5

What happened?

App crash

Steps to reproduce

Add button in SimpleMapActivity in the demo app and add a click listener like this

           button.setOnClickListener {
            val sourceID = "geoJsonSource1"
            val layerID = "symbolLayer"
            val source1 = GeoJsonSource(sourceID)
            val layer = SymbolLayer(layerID, sourceID)
            val style: Style = mapLibreMap.style!!
            style.addSource(source1)
            style.addLayer(layer)
//            style.removeSource(source1.id)
//            val source2 = style.getSource(sourceID) // these two lines are for grab crash issue
            mapView.onDestroy()
            Log.d("SimpleMapActivity", "source id :${source1?.id} ")
        }

Renderer

OpenGL (choose this if you are unsure)

Relevant log output

2025-03-03 18:19:36.081 12537-12537 AndroidRuntime          org.maplibre.android.testapp         E  FATAL EXCEPTION: main
                                                                                                    Process: org.maplibre.android.testapp, PID: 12537
                                                                                                    java.lang.IllegalStateException: invalid native peer
                                                                                                    	at org.maplibre.android.style.sources.Source.nativeGetId(Native Method)
                                                                                                    	at org.maplibre.android.style.sources.Source.getId(Source.java:56)
                                                                                                    	at org.maplibre.android.testapp.activity.maplayout.SimpleMapActivity.onCreate$lambda$1(SimpleMapActivity.kt:63)
                                                                                                    	at org.maplibre.android.testapp.activity.maplayout.SimpleMapActivity.$r8$lambda$fHdMdfqknUyYDBH_FgnttCUew88(Unknown Source:0)
                                                                                                    	at org.maplibre.android.testapp.activity.maplayout.SimpleMapActivity$$ExternalSyntheticLambda2.onClick(D8$$SyntheticClass:0)
                                                                                                    	at android.view.View.performClick(View.java:7659)
                                                                                                    	at android.view.View.performClickInternal(View.java:7636)
                                                                                                    	at android.view.View.-$$Nest$mperformClickInternal(Unknown Source:0)
                                                                                                    	at android.view.View$PerformClick.run(View.java:30156)
                                                                                                    	at android.os.Handler.handleCallback(Handler.java:958)
                                                                                                    	at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                                                    	at android.os.Looper.loopOnce(Looper.java:205)
                                                                                                    	at android.os.Looper.loop(Looper.java:294)
                                                                                                    	at android.app.ActivityThread.main(ActivityThread.java:8177)
                                                                                                    	at java.lang.reflect.Method.invoke(Native Method)
                                                                                                    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:552)
                                                                                                    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971)

Additional context

our app is using an old mapbox-based map, one difference I found is:
In old Mapbox, Android Style.clear is like this, need to call nativeMap.removeSource explicitly

void clear() {
  for (BitmapImageConversionTask task : tasks) {
    if (task == null) {
      continue;
    }
    if (!task.isCancelled()) {
      task.cancel(true);
    }
  }
  tasks.clear();

  fullyLoaded = false;
  clearLayers();
  // clearSources must be called after clearLayers
  clearSources();
  clearImages();
}

void clearSources() {
  for (Source source : sources.values()) {
    if (source != null) {
      source.setDetached();
      nativeMap.removeSource(source);
    }
  }
  sources.clear();
}

But in the newest master MapLibre, the Style.clear() just clear the java source peer, but how could its C++ peer be destroyed.. I checked the cpp part, didn't find any clue

void clear() {
  fullyLoaded = false;
  for (Layer layer : layers.values()) {
    if (layer != null) {
      layer.setDetached();
    }
  }

  for (Source source : sources.values()) {
    if (source != null) {
      source.setDetached();
    }
  }

  for (Map.Entry<String, Bitmap> bitmapEntry : images.entrySet()) {
    nativeMap.removeImage(bitmapEntry.getKey());
    bitmapEntry.getValue().recycle();
  }

  sources.clear();
  layers.clear();
  images.clear();
}

[louwers]

Confirmed.

[louwers]

This is by design, after the source is added to a map instance it is owned by that map instance. So when the map instance is gone so is the source. For this reason you need to create a new source before adding it to a map.

Is this a problem?

[grab-liyanjin]

@louwers Understood, I think your point makes sense. Could you please help me understand how MapLibre implements this mechanism that the source can be destroyed automatically when the MapView is destroyed. Thanks