In-App purchasing demo

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 #include <QtCore/qcoreevent.h>

 #include "inappproductqmltype.h"
 #include "inappstoreqmltype.h"
 #include "../inapp/inapptransaction.h"
 #include "../inapp/inappstore.h"

 InAppProductQmlType::InAppProductQmlType(QObject *parent)
     : QObject(parent)
     , m_status(Uninitialized)
     , m_type(InAppProductQmlType::ProductType(-1))
     , m_componentComplete(false)
     , m_store(0)
     , m_product(0)
 {
 }

 void InAppProductQmlType::setStore(InAppStoreQmlType *store)
 {
     if (m_store == store)
         return;

     if (m_store != 0)
         m_store->store()->disconnect(this);

     m_store = store;
     connect(m_store->store(), &InAppStore::productRegistered,
             this, &InAppProductQmlType::handleProductRegistered);
     connect(m_store->store(), &InAppStore::productUnknown,
             this, &InAppProductQmlType::handleProductUnknown);
     connect(m_store->store(), &InAppStore::transactionReady,
                      this, &InAppProductQmlType::handleTransaction);

     updateProduct();

     emit storeChanged();
 }

 InAppStoreQmlType *InAppProductQmlType::store() const
 {
     return m_store;
 }

 void InAppProductQmlType::componentComplete()
 {
     if (!m_componentComplete) {
         m_componentComplete = true;
         updateProduct();
     }
 }

 void InAppProductQmlType::setIdentifier(const QString &identifier)
 {
     if (m_identifier == identifier)
         return;

     if (m_status != Uninitialized) {
         qWarning("A product's identifier cannot be changed once the product has been initialized.");
         return;
     }

     m_identifier = identifier;
     if (m_componentComplete)
         updateProduct();
     emit identifierChanged();
 }

 void InAppProductQmlType::updateProduct()
 {
     if (m_store == 0)
         return;

     Status oldStatus = m_status;
     InAppProduct *product = 0;
     if (m_identifier.isEmpty() || m_type == InAppProductQmlType::ProductType(-1)) {
         m_status = Uninitialized;
     } else {
         product = m_store->store()->registeredProduct(m_identifier);
         if (product != 0 && product == m_product)
             return;

         if (product == 0) {
             m_status = PendingRegistration;
             m_store->store()->registerProduct(InAppProduct::ProductType(m_type), m_identifier);
         } else if (product->productType() != InAppProduct::ProductType(m_type)) {
             qWarning("Product registered multiple times with different product types.");
             product = 0;
             m_status = Uninitialized;
         } else {
             m_status = Registered;
         }
     }

     setProduct(product);
     if (oldStatus != m_status)
         emit statusChanged();
 }

 void InAppProductQmlType::resetStatus()
 {
     updateProduct();
 }

 QString InAppProductQmlType::identifier() const
 {
     return m_identifier;
 }

 void InAppProductQmlType::setType(InAppProductQmlType::ProductType type)
 {
     if (m_type == type)
         return;

     if (m_status != Uninitialized) {
         qWarning("A product's type cannot be changed once the product has been initialized.");
         return;
     }

     m_type = type;
     if (m_componentComplete)
         updateProduct();

     emit typeChanged();
 }

 InAppProductQmlType::ProductType InAppProductQmlType::type() const
 {
     return m_type;
 }

 InAppProductQmlType::Status InAppProductQmlType::status() const
 {
     return m_status;
 }

 QString InAppProductQmlType::price() const
 {
     return m_product != 0 ? m_product->price() : QString();
 }

 QString InAppProductQmlType::title() const
 {
     return m_product != 0 ? m_product->title() : QString();
 }

 QString InAppProductQmlType::description() const
 {
     return m_product != 0 ? m_product->description() : QString();
 }

 void InAppProductQmlType::setProduct(InAppProduct *product)
 {
     if (m_product == product)
         return;

     QString oldPrice = price();
     QString oldTitle = title();
     QString oldDescription = description();
     m_product = product;
     if (price() != oldPrice)
         emit priceChanged();
     if (title() != oldTitle)
         emit titleChanged();
     if (description() != oldDescription)
         emit descriptionChanged();
 }

 void InAppProductQmlType::handleProductRegistered(InAppProduct *product)
 {
     if (product->identifier() == m_identifier) {
         Q_ASSERT(product->productType() == InAppProduct::ProductType(m_type));
         setProduct(product);
         if (m_status != Registered) {
             m_status = Registered;
             emit statusChanged();
         }
     }
 }

 void InAppProductQmlType::handleProductUnknown(InAppProduct::ProductType, const QString &identifier)
 {
     if (identifier == m_identifier) {
         setProduct(0);
         if (m_status != Unknown) {
             m_status = Unknown;
             emit statusChanged();
         }
     }
 }

 void InAppProductQmlType::handleTransaction(InAppTransaction *transaction)
 {
     if (transaction->product()->identifier() != m_identifier)
         return;

     if (transaction->status() == InAppTransaction::PurchaseApproved)
         emit purchaseSucceeded(transaction);
     else if (transaction->status() == InAppTransaction::PurchaseRestored)
         emit purchaseRestored(transaction);
     else{
         emit purchaseFailed(transaction);}
 }

 void InAppProductQmlType::purchase()
 {
     if (m_product != 0 && m_status == Registered)
         m_product->purchase();
     else
         qWarning("Attempted to purchase unregistered product");
 }