PurchaseHelper.java

public class PurchaseHelper{

    // Billing response codes
    public static final int BILLING_RESPONSE_USER_CLOSED_PURCHASE_WINDOW = -1;
    public static final int BILLING_RESPONSE_RESULT_OK = 0;
    public static final int BILLING_RESPONSE_RESULT_USER_CANCELED = 1;
    public static final int BILLING_RESPONSE_RESULT_BILLING_UNAVAILABLE = 3;
    public static final int BILLING_RESPONSE_RESULT_ITEM_UNAVAILABLE = 4;
    public static final int BILLING_RESPONSE_RESULT_DEVELOPER_ERROR = 5;
    public static final int BILLING_RESPONSE_RESULT_ERROR = 6;
    public static final int BILLING_RESPONSE_RESULT_ITEM_ALREADY_OWNED = 7;
    public static final int BILLING_RESPONSE_RESULT_ITEM_NOT_OWNED = 8;

    
    public static String PREMIUM_SKU; // BE SURE TO SET THIS!

    static{
        if(BuildConfig.DEBUG){
            //Debug build detected. Overriding premium SKU with test purchase
            PREMIUM_SKU = "android.test.purchased";
        }
    }

    public interface QueryIsFreeResultCallback{
        void onQueryResult(boolean result);
    }

    public interface GetSkuDetailsCallback{
        void onSkuDetailsResult(List<SkuDetails> result);
    }

    public interface PurchasePremiumVersionFlowResultCallback {
        void onPurchaseFlowStartResult(int resultCode);
    }

    public interface PurchasePremiumVersionResultCallback{
        void onPurchaseResult(int resultCode);
    }

    public interface GooglePlayServicesSupportedCallback{
        void isPlaySupported(boolean result);
    }

    private static Subscription purchaseFlowSubscription;

    public static void queryIsFree(Context context, QueryIsFreeResultCallback callback) {
        ReactiveBilling.getInstance(context)
        .getPurchases(PurchaseType.PRODUCT, null)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(
            (response) ->{
                boolean isFree = false;
                if(response.isSuccess()){
                    List<GetPurchasesResponse.PurchaseResponse> purchases = response.getList();
                    for (GetPurchasesResponse.PurchaseResponse p : purchases) {
                        if(p.getProductId().equals(PREMIUM_SKU)){
                            isFree = false;
                            break;
                        }
                    }
                }
                callback.onQueryResult(isFree);
            },
            (throwable) ->{
                callback.onQueryResult(false);
            }
        );
    }

    public static void getSkuDetails(Context context, GetSkuDetailsCallback callback){
        ReactiveBilling.getInstance(context)
        .getSkuDetails(PurchaseType.PRODUCT, PREMIUM_SKU)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(
            (response) -> {
                DebugLog.d("Sku response code: " + response.getResponseCode());
                if(response.isSuccess()){
                    callback.onSkuDetailsResult(response.getList());
                }
            },
            (throwable) -> {
                callback.onSkuDetailsResult(new ArrayList<>());
            });
    }

    /**
     * Starts the purchase flow for premium version of the app. Result
     * is whether or not purchase flow STARTED, NOT succeeded.
     */
    public static void startPremiumVersionPurchaseFlow(Context context, PurchasePremiumVersionFlowResultCallback callback) {
        ReactiveBilling.getInstance(context)
           .startPurchase(PREMIUM_SKU, PurchaseType.PRODUCT, null, null)
           .subscribeOn(Schedulers.io())
           .observeOn(AndroidSchedulers.mainThread())
           .subscribe(
               (response) -> {
                   callback.onPurchaseFlowStartResult(response.getResponseCode());
               },
               (throwable) -> {
                   callback.onPurchaseFlowStartResult(BILLING_RESPONSE_RESULT_ERROR);
               }
           );
    }

    public static Subscription getPurchaseResults(Context context, PurchasePremiumVersionResultCallback callback){
        //Purchase window will fail to show if a subscription to the observable already exists, so ensure it's cleaned up
        if(purchaseFlowSubscription != null){
            try {
                purchaseFlowSubscription.unsubscribe();
            }
            catch(Exception e){}
        }
        purchaseFlowSubscription = ReactiveBilling.getInstance(context)
        .purchaseFlow()
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(
            (response) -> {
                callback.onPurchaseResult(response.getResponseCode());
            },
            (throwable -> {
                callback.onPurchaseResult(BILLING_RESPONSE_RESULT_DEVELOPER_ERROR);
            })
        );
        return purchaseFlowSubscription;
    }

    public static void isGooglePlayServicesSupported(Context context, GooglePlayServicesSupportedCallback callback) {
        ReactiveBilling.getInstance(context)
        .isBillingSupported(PurchaseType.PRODUCT)
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(
            (response) -> {
                callback.isPlaySupported(response.isSuccess());
            },
            (throwable) -> {
                callback.isPlaySupported(false);
            }
        );
    }
}