In-App purchasing demo

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 #include "inappstore.h"
 #include "inapppurchasebackend.h"
 #include "inapptransaction.h"

 #ifdef Q_OS_ANDROID
 #include "../android/androidinapppurchasebackend.h"
 #endif

 #ifdef Q_OS_IOS
 #include "../ios/iosinapppurchasebackend.h"
 #endif

 class IAPRegisterMetaTypes
 {
 public:
     IAPRegisterMetaTypes()
     {
         qRegisterMetaType<InAppProduct::ProductType>("InAppProduct::ProductType");
     }
 } _registerIAPMetaTypes;

 InAppStore::InAppStore(QObject *parent)
     : QObject(parent)
 {
     d = QSharedPointer<InAppStorePrivate>(new InAppStorePrivate);
     setupBackend();
 }

 InAppStore::~InAppStore()
 {
 }

 void InAppStore::setupBackend()
 {
     #ifdef Q_OS_ANDROID
     d->backend = new AndroidInAppPurchaseBackend;
     #endif
     #ifdef Q_OS_IOS
     d->backend = new IosInAppPurchaseBackend;
     #endif
     d->backend->setStore(this);

     connect(d->backend, &InAppPurchaseBackend::ready,
             this, &InAppStore::registerPendingProducts);
     connect(d->backend, &InAppPurchaseBackend::transactionReady,
             this, &InAppStore::transactionReady);
     connect(d->backend, &InAppPurchaseBackend::productQueryFailed,
             this, &InAppStore::productUnknown);
     connect(d->backend, &InAppPurchaseBackend::productQueryDone,
             this, static_cast<void (InAppStore::*)(InAppProduct *)>(&InAppStore::registerProduct));
 }

 void InAppStore::registerProduct(InAppProduct *product)
 {
     d->registeredProducts[product->identifier()] = product;
     emit productRegistered(product);
 }

 void InAppStore::registerPendingProducts()
 {
     QList<InAppPurchaseBackend::Product> products;
     products.reserve(d->pendingProducts.size());

     QHash<QString, InAppProduct::ProductType>::const_iterator it;
     for (it = d->pendingProducts.constBegin(); it != d->pendingProducts.constEnd(); ++it)
         products.append(InAppPurchaseBackend::Product(it.value(), it.key()));
     d->pendingProducts.clear();

     d->backend->queryProducts(products);
     if (d->pendingRestorePurchases)
         restorePurchases();
 }

 void InAppStore::restorePurchases()
 {
     if (d->backend->isReady()) {
         d->pendingRestorePurchases = false;
         d->backend->restorePurchases();
     } else {
         d->pendingRestorePurchases = true;
     }
 }

 void InAppStore::setPlatformProperty(const QString &propertyName, const QString &value)
 {
     d->backend->setPlatformProperty(propertyName, value);
 }

 void InAppStore::registerProduct(InAppProduct::ProductType productType, const QString &identifier)
 {
     if (!d->backend->isReady()) {
         d->pendingProducts[identifier] = productType;
         if (!d->hasCalledInitialize) {
             d->hasCalledInitialize = true;
             d->backend->initialize();
         }
     } else {
         d->backend->queryProduct(productType, identifier);
     }
 }

 InAppProduct *InAppStore::registeredProduct(const QString &identifier) const
 {
     return d->registeredProducts.value(identifier);
 }