Android Add Map Marker Error: java.lang.IllegalStateException: Not on the main thread

Question

I'm subscribing to a data stream that gets pushed coordinates, I want to place a marker on the map every time the listener gets a new point. What do I need to do to put the drawMarker code on the correct thread or in the correct scope?

@Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        enableMyLocation();
        subscribe();
    }

    public void drawLatestPoint(LatLng p) {
        System.out.println(p);
        mMap.addMarker(new MarkerOptions().position(p).title("Marker in Sydney"));
    }

    private void subscribe(){
        pubNub.subscribe()
                .channels(Arrays.asList("my_channel")) // subscribe to channel groups
                .execute();

        pubNub.addListener(new SubscribeCallback() {

            @Override
            public void message(PubNub pubnub, PNMessageResult message) {
                if (message.getMessage().get("lat") != null && message.getMessage().get("lng") != null) {
                    double lat = message.getMessage().get("lat").doubleValue();
                    double lng = message.getMessage().get("lng").doubleValue();
                    LatLng point = new LatLng(lat,lng);
                    drawLatestPoint(point);
                }
            }
        });
    }

score 2 · Accepted Answer · answered Sep 02 '16 at 23:20

2

You can use runOnUiThread to run the code in the GUI thread:

runOnUiThread(new Runnable() {
    @Override
    public void run() {
       // Your code to run in GUI thread here
    }
});

answered Sep 02 '16 at 23:20

fernandospr

2,976
2
22
43

Thanks, I didn't realize you could simply invoke other threads. – Strelok Sep 02 '16 at 23:51

score 0 · Answer 2 · edited May 23 '17 at 12:09

0

Make sure that your pubsub has access to a Context object (can be the Application context or the Service context). Then put the required code inside the run method :

// Get a handler that can be used to post to the main thread
Handler mainHandler = new Handler(context.getMainLooper());

Runnable myRunnable = new Runnable() {
    @Override 
    public void run() {....} // This is your code
};
mainHandler.post(myRunnable);

Reference

edited May 23 '17 at 12:09

Community

1
1

answered Sep 02 '16 at 23:17

Passer by

562
9
14

Where is Handler coming from? AS tells me it doesn't exist. – Strelok Sep 02 '16 at 23:52
[android.os.Handler](https://developer.android.com/reference/android/os/Handler.html) is a class in the Android framework. – Passer by Sep 03 '16 at 00:18

Android Add Map Marker Error: java.lang.IllegalStateException: Not on the main thread

2 Answers2

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