packages/in_app_purchase/in_app_purchase/example/lib/main.dart - mirrors/plugins - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:async';
 import 'dart:io';
 import 'package:flutter/material.dart';
 import 'package:in_app_purchase/in_app_purchase.dart';
 import 'package:in_app_purchase_android/billing_client_wrappers.dart';
 import 'package:in_app_purchase_android/in_app_purchase_android.dart';
 import 'package:in_app_purchase_storekit/in_app_purchase_storekit.dart';
 import 'package:in_app_purchase_storekit/store_kit_wrappers.dart';
 import 'consumable_store.dart';

 void main() {
   WidgetsFlutterBinding.ensureInitialized();

   runApp(_MyApp());
 }

 const bool _kAutoConsume = true;

 const String _kConsumableId = 'consumable';
 const String _kUpgradeId = 'upgrade';
 const String _kSilverSubscriptionId = 'subscription_silver';
 const String _kGoldSubscriptionId = 'subscription_gold';
 const List<String> _kProductIds = <String>[
   _kConsumableId,
   _kUpgradeId,
   _kSilverSubscriptionId,
   _kGoldSubscriptionId,
 ];

 class _MyApp extends StatefulWidget {
   @override
   State<_MyApp> createState() => _MyAppState();
 }

 class _MyAppState extends State<_MyApp> {
   final InAppPurchase _inAppPurchase = InAppPurchase.instance;
   late StreamSubscription<List<PurchaseDetails>> _subscription;
   List<String> _notFoundIds = <String>[];
   List<ProductDetails> _products = <ProductDetails>[];
   List<PurchaseDetails> _purchases = <PurchaseDetails>[];
   List<String> _consumables = <String>[];
   bool _isAvailable = false;
   bool _purchasePending = false;
   bool _loading = true;
   String? _queryProductError;

   @override
   void initState() {
     final Stream<List<PurchaseDetails>> purchaseUpdated =
         _inAppPurchase.purchaseStream;
     _subscription =
         purchaseUpdated.listen((List<PurchaseDetails> purchaseDetailsList) {
       _listenToPurchaseUpdated(purchaseDetailsList);
     }, onDone: () {
       _subscription.cancel();
     }, onError: (Object error) {
       // handle error here.
     });
     initStoreInfo();
     super.initState();
   }

   Future<void> initStoreInfo() async {
     final bool isAvailable = await _inAppPurchase.isAvailable();
     if (!isAvailable) {
       setState(() {
         _isAvailable = isAvailable;
         _products = <ProductDetails>[];
         _purchases = <PurchaseDetails>[];
         _notFoundIds = <String>[];
         _consumables = <String>[];
         _purchasePending = false;
         _loading = false;
       });
       return;
     }

     if (Platform.isIOS) {
       final InAppPurchaseStoreKitPlatformAddition iosPlatformAddition =
           _inAppPurchase
               .getPlatformAddition<InAppPurchaseStoreKitPlatformAddition>();
       await iosPlatformAddition.setDelegate(ExamplePaymentQueueDelegate());
     }

     final ProductDetailsResponse productDetailResponse =
         await _inAppPurchase.queryProductDetails(_kProductIds.toSet());
     if (productDetailResponse.error != null) {
       setState(() {
         _queryProductError = productDetailResponse.error!.message;
         _isAvailable = isAvailable;
         _products = productDetailResponse.productDetails;
         _purchases = <PurchaseDetails>[];
         _notFoundIds = productDetailResponse.notFoundIDs;
         _consumables = <String>[];
         _purchasePending = false;
         _loading = false;
       });
       return;
     }

     if (productDetailResponse.productDetails.isEmpty) {
       setState(() {
         _queryProductError = null;
         _isAvailable = isAvailable;
         _products = productDetailResponse.productDetails;
         _purchases = <PurchaseDetails>[];
         _notFoundIds = productDetailResponse.notFoundIDs;
         _consumables = <String>[];
         _purchasePending = false;
         _loading = false;
       });
       return;
     }

     final List<String> consumables = await ConsumableStore.load();
     setState(() {
       _isAvailable = isAvailable;
       _products = productDetailResponse.productDetails;
       _notFoundIds = productDetailResponse.notFoundIDs;
       _consumables = consumables;
       _purchasePending = false;
       _loading = false;
     });
   }

   @override
   void dispose() {
     if (Platform.isIOS) {
       final InAppPurchaseStoreKitPlatformAddition iosPlatformAddition =
           _inAppPurchase
               .getPlatformAddition<InAppPurchaseStoreKitPlatformAddition>();
       iosPlatformAddition.setDelegate(null);
     }
     _subscription.cancel();
     super.dispose();
   }

   @override
   Widget build(BuildContext context) {
     final List<Widget> stack = <Widget>[];
     if (_queryProductError == null) {
       stack.add(
         ListView(
           children: <Widget>[
             _buildConnectionCheckTile(),
             _buildProductList(),
             _buildConsumableBox(),
             _buildRestoreButton(),
           ],
         ),
       );
     } else {
       stack.add(Center(
         child: Text(_queryProductError!),
       ));
     }
     if (_purchasePending) {
       stack.add(
         Stack(
           children: const <Widget>[
             Opacity(
               opacity: 0.3,
               child: ModalBarrier(dismissible: false, color: Colors.grey),
             ),
             Center(
               child: CircularProgressIndicator(),
             ),
           ],
         ),
       );
     }

     return MaterialApp(
       home: Scaffold(
         appBar: AppBar(
           title: const Text('IAP Example'),
         ),
         body: Stack(
           children: stack,
         ),
       ),
     );
   }

   Card _buildConnectionCheckTile() {
     if (_loading) {
       return const Card(child: ListTile(title: Text('Trying to connect...')));
     }
     final Widget storeHeader = ListTile(
       leading: Icon(_isAvailable ? Icons.check : Icons.block,
           color: _isAvailable ? Colors.green : ThemeData.light().errorColor),
       title:
           Text('The store is ${_isAvailable ? 'available' : 'unavailable'}.'),
     );
     final List<Widget> children = <Widget>[storeHeader];

     if (!_isAvailable) {
       children.addAll(<Widget>[
         const Divider(),
         ListTile(
           title: Text('Not connected',
               style: TextStyle(color: ThemeData.light().errorColor)),
           subtitle: const Text(
               'Unable to connect to the payments processor. Has this app been configured correctly? See the example README for instructions.'),
         ),
       ]);
     }
     return Card(child: Column(children: children));
   }

   Card _buildProductList() {
     if (_loading) {
       return const Card(
           child: ListTile(
               leading: CircularProgressIndicator(),
               title: Text('Fetching products...')));
     }
     if (!_isAvailable) {
       return const Card();
     }
     const ListTile productHeader = ListTile(title: Text('Products for Sale'));
     final List<ListTile> productList = <ListTile>[];
     if (_notFoundIds.isNotEmpty) {
       productList.add(ListTile(
           title: Text('[${_notFoundIds.join(", ")}] not found',
               style: TextStyle(color: ThemeData.light().errorColor)),
           subtitle: const Text(
               'This app needs special configuration to run. Please see example/README.md for instructions.')));
     }

     // This loading previous purchases code is just a demo. Please do not use this as it is.
     // In your app you should always verify the purchase data using the `verificationData` inside the [PurchaseDetails] object before trusting it.
     // We recommend that you use your own server to verify the purchase data.
     final Map<String, PurchaseDetails> purchases =
         Map<String, PurchaseDetails>.fromEntries(
             _purchases.map((PurchaseDetails purchase) {
       if (purchase.pendingCompletePurchase) {
         _inAppPurchase.completePurchase(purchase);
       }
       return MapEntry<String, PurchaseDetails>(purchase.productID, purchase);
     }));
     productList.addAll(_products.map(
       (ProductDetails productDetails) {
         final PurchaseDetails? previousPurchase = purchases[productDetails.id];
         return ListTile(
           title: Text(
             productDetails.title,
           ),
           subtitle: Text(
             productDetails.description,
           ),
           trailing: previousPurchase != null
               ? IconButton(
                   onPressed: () => confirmPriceChange(context),
                   icon: const Icon(Icons.upgrade))
               : TextButton(
                   style: TextButton.styleFrom(
                     backgroundColor: Colors.green[800],
                     primary: Colors.white,
                   ),
                   onPressed: () {
                     late PurchaseParam purchaseParam;

                     if (Platform.isAndroid) {
                       // NOTE: If you are making a subscription purchase/upgrade/downgrade, we recommend you to
                       // verify the latest status of you your subscription by using server side receipt validation
                       // and update the UI accordingly. The subscription purchase status shown
                       // inside the app may not be accurate.
                       final GooglePlayPurchaseDetails? oldSubscription =
                           _getOldSubscription(productDetails, purchases);

                       purchaseParam = GooglePlayPurchaseParam(
                           productDetails: productDetails,
                           applicationUserName: null,
                           changeSubscriptionParam: (oldSubscription != null)
                               ? ChangeSubscriptionParam(
                                   oldPurchaseDetails: oldSubscription,
                                   prorationMode:
                                       ProrationMode.immediateWithTimeProration,
                                 )
                               : null);
                     } else {
                       purchaseParam = PurchaseParam(
                         productDetails: productDetails,
                         applicationUserName: null,
                       );
                     }

                     if (productDetails.id == _kConsumableId) {
                       _inAppPurchase.buyConsumable(
                           purchaseParam: purchaseParam,
                           autoConsume: _kAutoConsume || Platform.isIOS);
                     } else {
                       _inAppPurchase.buyNonConsumable(
                           purchaseParam: purchaseParam);
                     }
                   },
                   child: Text(productDetails.price),
                 ),
         );
       },
     ));

     return Card(
         child: Column(
             children: <Widget>[productHeader, const Divider()] + productList));
   }

   Card _buildConsumableBox() {
     if (_loading) {
       return const Card(
           child: ListTile(
               leading: CircularProgressIndicator(),
               title: Text('Fetching consumables...')));
     }
     if (!_isAvailable || _notFoundIds.contains(_kConsumableId)) {
       return const Card();
     }
     const ListTile consumableHeader =
         ListTile(title: Text('Purchased consumables'));
     final List<Widget> tokens = _consumables.map((String id) {
       return GridTile(
         child: IconButton(
           icon: const Icon(
             Icons.stars,
             size: 42.0,
             color: Colors.orange,
           ),
           splashColor: Colors.yellowAccent,
           onPressed: () => consume(id),
         ),
       );
     }).toList();
     return Card(
         child: Column(children: <Widget>[
       consumableHeader,
       const Divider(),
       GridView.count(
         crossAxisCount: 5,
         shrinkWrap: true,
         padding: const EdgeInsets.all(16.0),
         children: tokens,
       )
     ]));
   }

   Widget _buildRestoreButton() {
     if (_loading) {
       return Container();
     }

     return Padding(
       padding: const EdgeInsets.all(4.0),
       child: Row(
         mainAxisSize: MainAxisSize.max,
         mainAxisAlignment: MainAxisAlignment.end,
         children: <Widget>[
           TextButton(
             style: TextButton.styleFrom(
               backgroundColor: Theme.of(context).primaryColor,
               primary: Colors.white,
             ),
             onPressed: () => _inAppPurchase.restorePurchases(),
             child: const Text('Restore purchases'),
           ),
         ],
       ),
     );
   }

   Future<void> consume(String id) async {
     await ConsumableStore.consume(id);
     final List<String> consumables = await ConsumableStore.load();
     setState(() {
       _consumables = consumables;
     });
   }

   void showPendingUI() {
     setState(() {
       _purchasePending = true;
     });
   }

   Future<void> deliverProduct(PurchaseDetails purchaseDetails) async {
     // IMPORTANT!! Always verify purchase details before delivering the product.
     if (purchaseDetails.productID == _kConsumableId) {
       await ConsumableStore.save(purchaseDetails.purchaseID!);
       final List<String> consumables = await ConsumableStore.load();
       setState(() {
         _purchasePending = false;
         _consumables = consumables;
       });
     } else {
       setState(() {
         _purchases.add(purchaseDetails);
         _purchasePending = false;
       });
     }
   }

   void handleError(IAPError error) {
     setState(() {
       _purchasePending = false;
     });
   }

   Future<bool> _verifyPurchase(PurchaseDetails purchaseDetails) {
     // IMPORTANT!! Always verify a purchase before delivering the product.
     // For the purpose of an example, we directly return true.
     return Future<bool>.value(true);
   }

   void _handleInvalidPurchase(PurchaseDetails purchaseDetails) {
     // handle invalid purchase here if  _verifyPurchase` failed.
   }

   Future<void> _listenToPurchaseUpdated(
       List<PurchaseDetails> purchaseDetailsList) async {
     for (final PurchaseDetails purchaseDetails in purchaseDetailsList) {
       if (purchaseDetails.status == PurchaseStatus.pending) {
         showPendingUI();
       } else {
         if (purchaseDetails.status == PurchaseStatus.error) {
           handleError(purchaseDetails.error!);
         } else if (purchaseDetails.status == PurchaseStatus.purchased ||
             purchaseDetails.status == PurchaseStatus.restored) {
           final bool valid = await _verifyPurchase(purchaseDetails);
           if (valid) {
             deliverProduct(purchaseDetails);
           } else {
             _handleInvalidPurchase(purchaseDetails);
             return;
           }
         }
         if (Platform.isAndroid) {
           if (!_kAutoConsume && purchaseDetails.productID == _kConsumableId) {
             final InAppPurchaseAndroidPlatformAddition androidAddition =
                 _inAppPurchase.getPlatformAddition<
                     InAppPurchaseAndroidPlatformAddition>();
             await androidAddition.consumePurchase(purchaseDetails);
           }
         }
         if (purchaseDetails.pendingCompletePurchase) {
           await _inAppPurchase.completePurchase(purchaseDetails);
         }
       }
     }
   }

   Future<void> confirmPriceChange(BuildContext context) async {
     if (Platform.isAndroid) {
       final InAppPurchaseAndroidPlatformAddition androidAddition =
           _inAppPurchase
               .getPlatformAddition<InAppPurchaseAndroidPlatformAddition>();
       final BillingResultWrapper priceChangeConfirmationResult =
           await androidAddition.launchPriceChangeConfirmationFlow(
         sku: 'purchaseId',
       );
       if (priceChangeConfirmationResult.responseCode == BillingResponse.ok) {
         ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
           content: Text('Price change accepted'),
         ));
       } else {
         ScaffoldMessenger.of(context).showSnackBar(SnackBar(
           content: Text(
             priceChangeConfirmationResult.debugMessage ??
                 'Price change failed with code ${priceChangeConfirmationResult.responseCode}',
           ),
         ));
       }
     }
     if (Platform.isIOS) {
       final InAppPurchaseStoreKitPlatformAddition iapStoreKitPlatformAddition =
           _inAppPurchase
               .getPlatformAddition<InAppPurchaseStoreKitPlatformAddition>();
       await iapStoreKitPlatformAddition.showPriceConsentIfNeeded();
     }
   }

   GooglePlayPurchaseDetails? _getOldSubscription(
       ProductDetails productDetails, Map<String, PurchaseDetails> purchases) {
     // This is just to demonstrate a subscription upgrade or downgrade.
     // This method assumes that you have only 2 subscriptions under a group, 'subscription_silver' & 'subscription_gold'.
     // The 'subscription_silver' subscription can be upgraded to 'subscription_gold' and
     // the 'subscription_gold' subscription can be downgraded to 'subscription_silver'.
     // Please remember to replace the logic of finding the old subscription Id as per your app.
     // The old subscription is only required on Android since Apple handles this internally
     // by using the subscription group feature in iTunesConnect.
     GooglePlayPurchaseDetails? oldSubscription;
     if (productDetails.id == _kSilverSubscriptionId &&
         purchases[_kGoldSubscriptionId] != null) {
       oldSubscription =
           purchases[_kGoldSubscriptionId]! as GooglePlayPurchaseDetails;
     } else if (productDetails.id == _kGoldSubscriptionId &&
         purchases[_kSilverSubscriptionId] != null) {
       oldSubscription =
           purchases[_kSilverSubscriptionId]! as GooglePlayPurchaseDetails;
     }
     return oldSubscription;
   }
 }

 /// Example implementation of the
 /// [`SKPaymentQueueDelegate`](https://developer.apple.com/documentation/storekit/skpaymentqueuedelegate?language=objc).
 ///
 /// The payment queue delegate can be implementated to provide information
 /// needed to complete transactions.
 class ExamplePaymentQueueDelegate implements SKPaymentQueueDelegateWrapper {
   @override
   bool shouldContinueTransaction(
       SKPaymentTransactionWrapper transaction, SKStorefrontWrapper storefront) {
     return true;
   }

   @override
   bool shouldShowPriceConsent() {
     return false;
   }
 }
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:async';
	import 'dart:io';
	import 'package:flutter/material.dart';
	import 'package:in_app_purchase/in_app_purchase.dart';
	import 'package:in_app_purchase_android/billing_client_wrappers.dart';
	import 'package:in_app_purchase_android/in_app_purchase_android.dart';
	import 'package:in_app_purchase_storekit/in_app_purchase_storekit.dart';
	import 'package:in_app_purchase_storekit/store_kit_wrappers.dart';
	import 'consumable_store.dart';

	void main() {
	WidgetsFlutterBinding.ensureInitialized();

	runApp(_MyApp());
	}

	const bool _kAutoConsume = true;

	const String _kConsumableId = 'consumable';
	const String _kUpgradeId = 'upgrade';
	const String _kSilverSubscriptionId = 'subscription_silver';
	const String _kGoldSubscriptionId = 'subscription_gold';
	const List<String> _kProductIds = <String>[
	_kConsumableId,
	_kUpgradeId,
	_kSilverSubscriptionId,
	_kGoldSubscriptionId,
	];

	class _MyApp extends StatefulWidget {
	@override
	State<_MyApp> createState() => _MyAppState();
	}

	class _MyAppState extends State<_MyApp> {
	final InAppPurchase _inAppPurchase = InAppPurchase.instance;
	late StreamSubscription<List<PurchaseDetails>> _subscription;
	List<String> _notFoundIds = <String>[];
	List<ProductDetails> _products = <ProductDetails>[];
	List<PurchaseDetails> _purchases = <PurchaseDetails>[];
	List<String> _consumables = <String>[];
	bool _isAvailable = false;
	bool _purchasePending = false;
	bool _loading = true;
	String? _queryProductError;

	@override
	void initState() {
	final Stream<List<PurchaseDetails>> purchaseUpdated =
	_inAppPurchase.purchaseStream;
	_subscription =
	purchaseUpdated.listen((List<PurchaseDetails> purchaseDetailsList) {
	_listenToPurchaseUpdated(purchaseDetailsList);
	}, onDone: () {
	_subscription.cancel();
	}, onError: (Object error) {
	// handle error here.
	});
	initStoreInfo();
	super.initState();
	}

	Future<void> initStoreInfo() async {
	final bool isAvailable = await _inAppPurchase.isAvailable();
	if (!isAvailable) {
	setState(() {
	_isAvailable = isAvailable;
	_products = <ProductDetails>[];
	_purchases = <PurchaseDetails>[];
	_notFoundIds = <String>[];
	_consumables = <String>[];
	_purchasePending = false;
	_loading = false;
	});
	return;
	}

	if (Platform.isIOS) {
	final InAppPurchaseStoreKitPlatformAddition iosPlatformAddition =
	_inAppPurchase
	.getPlatformAddition<InAppPurchaseStoreKitPlatformAddition>();
	await iosPlatformAddition.setDelegate(ExamplePaymentQueueDelegate());
	}

	final ProductDetailsResponse productDetailResponse =
	await _inAppPurchase.queryProductDetails(_kProductIds.toSet());
	if (productDetailResponse.error != null) {
	setState(() {
	_queryProductError = productDetailResponse.error!.message;
	_isAvailable = isAvailable;
	_products = productDetailResponse.productDetails;
	_purchases = <PurchaseDetails>[];
	_notFoundIds = productDetailResponse.notFoundIDs;
	_consumables = <String>[];
	_purchasePending = false;
	_loading = false;
	});
	return;
	}

	if (productDetailResponse.productDetails.isEmpty) {
	setState(() {
	_queryProductError = null;
	_isAvailable = isAvailable;
	_products = productDetailResponse.productDetails;
	_purchases = <PurchaseDetails>[];
	_notFoundIds = productDetailResponse.notFoundIDs;
	_consumables = <String>[];
	_purchasePending = false;
	_loading = false;
	});
	return;
	}

	final List<String> consumables = await ConsumableStore.load();
	setState(() {
	_isAvailable = isAvailable;
	_products = productDetailResponse.productDetails;
	_notFoundIds = productDetailResponse.notFoundIDs;
	_consumables = consumables;
	_purchasePending = false;
	_loading = false;
	});
	}

	@override
	void dispose() {
	if (Platform.isIOS) {
	final InAppPurchaseStoreKitPlatformAddition iosPlatformAddition =
	_inAppPurchase
	.getPlatformAddition<InAppPurchaseStoreKitPlatformAddition>();
	iosPlatformAddition.setDelegate(null);
	}
	_subscription.cancel();
	super.dispose();
	}

	@override
	Widget build(BuildContext context) {
	final List<Widget> stack = <Widget>[];
	if (_queryProductError == null) {
	stack.add(
	ListView(
	children: <Widget>[
	_buildConnectionCheckTile(),
	_buildProductList(),
	_buildConsumableBox(),
	_buildRestoreButton(),
	],
	),
	);
	} else {
	stack.add(Center(
	child: Text(_queryProductError!),
	));
	}
	if (_purchasePending) {
	stack.add(
	Stack(
	children: const <Widget>[
	Opacity(
	opacity: 0.3,
	child: ModalBarrier(dismissible: false, color: Colors.grey),
	),
	Center(
	child: CircularProgressIndicator(),
	),
	],
	),
	);
	}

	return MaterialApp(
	home: Scaffold(
	appBar: AppBar(
	title: const Text('IAP Example'),
	),
	body: Stack(
	children: stack,
	),
	),
	);
	}

	Card _buildConnectionCheckTile() {
	if (_loading) {
	return const Card(child: ListTile(title: Text('Trying to connect...')));
	}
	final Widget storeHeader = ListTile(
	leading: Icon(_isAvailable ? Icons.check : Icons.block,
	color: _isAvailable ? Colors.green : ThemeData.light().errorColor),
	title:
	Text('The store is ${_isAvailable ? 'available' : 'unavailable'}.'),
	);
	final List<Widget> children = <Widget>[storeHeader];

	if (!_isAvailable) {
	children.addAll(<Widget>[
	const Divider(),
	ListTile(
	title: Text('Not connected',
	style: TextStyle(color: ThemeData.light().errorColor)),
	subtitle: const Text(
	'Unable to connect to the payments processor. Has this app been configured correctly? See the example README for instructions.'),
	),
	]);
	}
	return Card(child: Column(children: children));
	}

	Card _buildProductList() {
	if (_loading) {
	return const Card(
	child: ListTile(
	leading: CircularProgressIndicator(),
	title: Text('Fetching products...')));
	}
	if (!_isAvailable) {
	return const Card();
	}
	const ListTile productHeader = ListTile(title: Text('Products for Sale'));
	final List<ListTile> productList = <ListTile>[];
	if (_notFoundIds.isNotEmpty) {
	productList.add(ListTile(
	title: Text('[${_notFoundIds.join(", ")}] not found',
	style: TextStyle(color: ThemeData.light().errorColor)),
	subtitle: const Text(
	'This app needs special configuration to run. Please see example/README.md for instructions.')));
	}

	// This loading previous purchases code is just a demo. Please do not use this as it is.
	// In your app you should always verify the purchase data using the `verificationData` inside the [PurchaseDetails] object before trusting it.
	// We recommend that you use your own server to verify the purchase data.
	final Map<String, PurchaseDetails> purchases =
	Map<String, PurchaseDetails>.fromEntries(
	_purchases.map((PurchaseDetails purchase) {
	if (purchase.pendingCompletePurchase) {
	_inAppPurchase.completePurchase(purchase);
	}
	return MapEntry<String, PurchaseDetails>(purchase.productID, purchase);
	}));
	productList.addAll(_products.map(
	(ProductDetails productDetails) {
	final PurchaseDetails? previousPurchase = purchases[productDetails.id];
	return ListTile(
	title: Text(
	productDetails.title,
	),
	subtitle: Text(
	productDetails.description,
	),
	trailing: previousPurchase != null
	? IconButton(
	onPressed: () => confirmPriceChange(context),
	icon: const Icon(Icons.upgrade))
	: TextButton(
	style: TextButton.styleFrom(
	backgroundColor: Colors.green[800],
	primary: Colors.white,
	),
	onPressed: () {
	late PurchaseParam purchaseParam;

	if (Platform.isAndroid) {
	// NOTE: If you are making a subscription purchase/upgrade/downgrade, we recommend you to
	// verify the latest status of you your subscription by using server side receipt validation
	// and update the UI accordingly. The subscription purchase status shown
	// inside the app may not be accurate.
	final GooglePlayPurchaseDetails? oldSubscription =
	_getOldSubscription(productDetails, purchases);

	purchaseParam = GooglePlayPurchaseParam(
	productDetails: productDetails,
	applicationUserName: null,
	changeSubscriptionParam: (oldSubscription != null)
	? ChangeSubscriptionParam(
	oldPurchaseDetails: oldSubscription,
	prorationMode:
	ProrationMode.immediateWithTimeProration,
	)
	: null);
	} else {
	purchaseParam = PurchaseParam(
	productDetails: productDetails,
	applicationUserName: null,
	);
	}

	if (productDetails.id == _kConsumableId) {
	_inAppPurchase.buyConsumable(
	purchaseParam: purchaseParam,
	autoConsume: _kAutoConsume \|\| Platform.isIOS);
	} else {
	_inAppPurchase.buyNonConsumable(
	purchaseParam: purchaseParam);
	}
	},
	child: Text(productDetails.price),
	),
	);
	},
	));

	return Card(
	child: Column(
	children: <Widget>[productHeader, const Divider()] + productList));
	}

	Card _buildConsumableBox() {
	if (_loading) {
	return const Card(
	child: ListTile(
	leading: CircularProgressIndicator(),
	title: Text('Fetching consumables...')));
	}
	if (!_isAvailable \|\| _notFoundIds.contains(_kConsumableId)) {
	return const Card();
	}
	const ListTile consumableHeader =
	ListTile(title: Text('Purchased consumables'));
	final List<Widget> tokens = _consumables.map((String id) {
	return GridTile(
	child: IconButton(
	icon: const Icon(
	Icons.stars,
	size: 42.0,
	color: Colors.orange,
	),
	splashColor: Colors.yellowAccent,
	onPressed: () => consume(id),
	),
	);
	}).toList();
	return Card(
	child: Column(children: <Widget>[
	consumableHeader,
	const Divider(),
	GridView.count(
	crossAxisCount: 5,
	shrinkWrap: true,
	padding: const EdgeInsets.all(16.0),
	children: tokens,
	)
	]));
	}

	Widget _buildRestoreButton() {
	if (_loading) {
	return Container();
	}

	return Padding(
	padding: const EdgeInsets.all(4.0),
	child: Row(
	mainAxisSize: MainAxisSize.max,
	mainAxisAlignment: MainAxisAlignment.end,
	children: <Widget>[
	TextButton(
	style: TextButton.styleFrom(
	backgroundColor: Theme.of(context).primaryColor,
	primary: Colors.white,
	),
	onPressed: () => _inAppPurchase.restorePurchases(),
	child: const Text('Restore purchases'),
	),
	],
	),
	);
	}

	Future<void> consume(String id) async {
	await ConsumableStore.consume(id);
	final List<String> consumables = await ConsumableStore.load();
	setState(() {
	_consumables = consumables;
	});
	}

	void showPendingUI() {
	setState(() {
	_purchasePending = true;
	});
	}

	Future<void> deliverProduct(PurchaseDetails purchaseDetails) async {
	// IMPORTANT!! Always verify purchase details before delivering the product.
	if (purchaseDetails.productID == _kConsumableId) {
	await ConsumableStore.save(purchaseDetails.purchaseID!);
	final List<String> consumables = await ConsumableStore.load();
	setState(() {
	_purchasePending = false;
	_consumables = consumables;
	});
	} else {
	setState(() {
	_purchases.add(purchaseDetails);
	_purchasePending = false;
	});
	}
	}

	void handleError(IAPError error) {
	setState(() {
	_purchasePending = false;
	});
	}

	Future<bool> _verifyPurchase(PurchaseDetails purchaseDetails) {
	// IMPORTANT!! Always verify a purchase before delivering the product.
	// For the purpose of an example, we directly return true.
	return Future<bool>.value(true);
	}

	void _handleInvalidPurchase(PurchaseDetails purchaseDetails) {
	// handle invalid purchase here if _verifyPurchase` failed.
	}

	Future<void> _listenToPurchaseUpdated(
	List<PurchaseDetails> purchaseDetailsList) async {
	for (final PurchaseDetails purchaseDetails in purchaseDetailsList) {
	if (purchaseDetails.status == PurchaseStatus.pending) {
	showPendingUI();
	} else {
	if (purchaseDetails.status == PurchaseStatus.error) {
	handleError(purchaseDetails.error!);
	} else if (purchaseDetails.status == PurchaseStatus.purchased \|\|
	purchaseDetails.status == PurchaseStatus.restored) {
	final bool valid = await _verifyPurchase(purchaseDetails);
	if (valid) {
	deliverProduct(purchaseDetails);
	} else {
	_handleInvalidPurchase(purchaseDetails);
	return;
	}
	}
	if (Platform.isAndroid) {
	if (!_kAutoConsume && purchaseDetails.productID == _kConsumableId) {
	final InAppPurchaseAndroidPlatformAddition androidAddition =
	_inAppPurchase.getPlatformAddition<
	InAppPurchaseAndroidPlatformAddition>();
	await androidAddition.consumePurchase(purchaseDetails);
	}
	}
	if (purchaseDetails.pendingCompletePurchase) {
	await _inAppPurchase.completePurchase(purchaseDetails);
	}
	}
	}
	}

	Future<void> confirmPriceChange(BuildContext context) async {
	if (Platform.isAndroid) {
	final InAppPurchaseAndroidPlatformAddition androidAddition =
	_inAppPurchase
	.getPlatformAddition<InAppPurchaseAndroidPlatformAddition>();
	final BillingResultWrapper priceChangeConfirmationResult =
	await androidAddition.launchPriceChangeConfirmationFlow(
	sku: 'purchaseId',
	);
	if (priceChangeConfirmationResult.responseCode == BillingResponse.ok) {
	ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
	content: Text('Price change accepted'),
	));
	} else {
	ScaffoldMessenger.of(context).showSnackBar(SnackBar(
	content: Text(
	priceChangeConfirmationResult.debugMessage ??
	'Price change failed with code ${priceChangeConfirmationResult.responseCode}',
	),
	));
	}
	}
	if (Platform.isIOS) {
	final InAppPurchaseStoreKitPlatformAddition iapStoreKitPlatformAddition =
	_inAppPurchase
	.getPlatformAddition<InAppPurchaseStoreKitPlatformAddition>();
	await iapStoreKitPlatformAddition.showPriceConsentIfNeeded();
	}
	}

	GooglePlayPurchaseDetails? _getOldSubscription(
	ProductDetails productDetails, Map<String, PurchaseDetails> purchases) {
	// This is just to demonstrate a subscription upgrade or downgrade.
	// This method assumes that you have only 2 subscriptions under a group, 'subscription_silver' & 'subscription_gold'.
	// The 'subscription_silver' subscription can be upgraded to 'subscription_gold' and
	// the 'subscription_gold' subscription can be downgraded to 'subscription_silver'.
	// Please remember to replace the logic of finding the old subscription Id as per your app.
	// The old subscription is only required on Android since Apple handles this internally
	// by using the subscription group feature in iTunesConnect.
	GooglePlayPurchaseDetails? oldSubscription;
	if (productDetails.id == _kSilverSubscriptionId &&
	purchases[_kGoldSubscriptionId] != null) {
	oldSubscription =
	purchases[_kGoldSubscriptionId]! as GooglePlayPurchaseDetails;
	} else if (productDetails.id == _kGoldSubscriptionId &&
	purchases[_kSilverSubscriptionId] != null) {
	oldSubscription =
	purchases[_kSilverSubscriptionId]! as GooglePlayPurchaseDetails;
	}
	return oldSubscription;
	}
	}

	/// Example implementation of the
	/// [`SKPaymentQueueDelegate`](https://developer.apple.com/documentation/storekit/skpaymentqueuedelegate?language=objc).
	///
	/// The payment queue delegate can be implementated to provide information
	/// needed to complete transactions.
	class ExamplePaymentQueueDelegate implements SKPaymentQueueDelegateWrapper {
	@override
	bool shouldContinueTransaction(
	SKPaymentTransactionWrapper transaction, SKStorefrontWrapper storefront) {
	return true;
	}

	@override
	bool shouldShowPriceConsent() {
	return false;
	}
	}