Unable to connect to Google Play billing

Question

I am trying to simple connect to Google play billing & access details such as the title & the pricing but I've been unable to do so.

What I've done so far (step-by-step):

(Added the IAP details on Google play console as well as published the app)

1. Added the Billing permission in the Manifest file -> <uses-permission android:name="com.android.vending.BILLING" />

2. Added the Billing library (v.4.0) -> implementation 'com.android.billingclient:billing:4.0.0'

3. Initialized the BillingClient in MainActivity & on trying to connect to it, I get no response from the onBillingSetupFinished callback method

   private void initializeBillingClient(Context context) {
    billingClient = BillingClient.newBuilder(context)
            .enablePendingPurchases()
            .setListener(this)
            .build();
   
    connectToGooglePlayBilling(context);
   }
   
   
   private void connectToGooglePlayBilling(Context context) {
    billingClient.startConnection(new BillingClientStateListener() {
        @Override
        public void onBillingServiceDisconnected() {
            connectToGooglePlayBilling(context);
        }
   
        @Override
        public void onBillingSetupFinished(@NonNull BillingResult billingResult) {
            Toast.makeText(context, "connected to google play billing", Toast.LENGTH_SHORT).show();
            if (billingResult.getResponseCode() == BillingClient.BillingResponseCode.OK) {
                //I should then fetch & display premium content details
            }
        }
    });
   }
   

Weird enough I noticed that when I enable the Battery Saving Mode (I'm using a Samsung device) the onBillingSetupFinished method gets called as the toast is shown.

What am I doing incorrect & also if anyone can explain why enabling Battery save mode suddenly makes it work?

Answer 1

Make sure that onBillingSetupFinished is called in UI thread.
Try to use runOnUiThread to show the message:

runOnUiThread(() -> 
                Toast.makeText(context, "connected to google play billing", Toast.LENGTH_SHORT).show());