refactor: simplify CheckoutWidget implementation

Sample/lib/feature/checkout/checkout_screen.dart

@@ -1,17 +1,9 @@
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:flutter/src/painting/text_style.dart' as ts;
 import 'package:logger/logger.dart';
 import 'package:ottu_flutter_checkout/ottu_flutter_checkout.dart';
 import 'package:ottu_flutter_checkout_sample/l10n/app_localizations.dart';
 
-const _defaultCheckoutViewHeight = 200;
-const _methodCheckoutHeight = "METHOD_CHECKOUT_HEIGHT";
-const _methodPaymentSuccessResult = "METHOD_PAYMENT_SUCCESS_RESULT";
-const _methodPaymentErrorResult = "METHOD_PAYMENT_ERROR_RESULT";
-const _methodPaymentCancelResult = "METHOD_PAYMENT_CANCEL_RESULT";
-const _methodChannel = MethodChannel('com.ottu.sample/checkout');
-
 class CheckoutScreen extends StatefulWidget {
   const CheckoutScreen({
     super.key,
@@ -29,7 +21,6 @@ class CheckoutScreen extends StatefulWidget {
 }
 
 class _CheckoutScreenState extends State<CheckoutScreen> {
-  final ValueNotifier<int> _checkoutHeight = ValueNotifier<int>(_defaultCheckoutViewHeight);
   final ValueNotifier<(String, String)> _checkoutMessage = ValueNotifier<(String, String)>((
     "",
     "",
@@ -49,41 +40,6 @@ class _CheckoutScreenState extends State<CheckoutScreen> {
     _checkoutMessage.removeListener(_showMessageDialog);
   }
 
-  @override
-  void didChangeDependencies() {
-    super.didChangeDependencies();
-    _methodChannel.setMethodCallHandler((call) async {
-      switch (call.method) {
-        case _methodCheckoutHeight:
-          {
-            int height = call.arguments as int;
-            logger.d("didChangeDependencies, height: $height");
-            _checkoutHeight.value = height;
-          }
-        case _methodPaymentSuccessResult:
-          {
-            String message = call.arguments as String;
-            logger.d("didChangeDependencies, success: $message");
-            _checkoutMessage.value = ("Success", message);
-          }
-
-        case _methodPaymentCancelResult:
-          {
-            String message = call.arguments as String;
-            logger.d("didChangeDependencies, cancel: $message");
-            _checkoutMessage.value = ("Cancel", message);
-          }
-
-        case _methodPaymentErrorResult:
-          {
-            String message = call.arguments as String;
-            logger.d("didChangeDependencies, error: $message");
-            _checkoutMessage.value = ("Error", message);
-          }
-      }
-    });
-  }
-
   @override
   Widget build(BuildContext context) {
     return Scaffold(
@@ -111,17 +67,12 @@ class _CheckoutScreenState extends State<CheckoutScreen> {
             //End of Merchant content
             Padding(
               padding: const EdgeInsets.all(12.0),
-              child: ValueListenableBuilder<int>(
-                builder: (BuildContext context, int height, Widget? child) {
-                  return SizedBox(
-                    height: height.toDouble(),
-                    child: OttuCheckoutWidget(
-                      arguments: widget.checkoutArguments,
-                      verifyPayment: _verifyPayment,
-                    ),
-                  );
-                },
-                valueListenable: _checkoutHeight,
+              child: OttuCheckoutWidget(
+                arguments: widget.checkoutArguments,
+                verifyPayment: _verifyPayment,
+                successCallback: (message) => _checkoutMessage.value = ("Success", message),
+                cancelCallback: (message) => _checkoutMessage.value = ("Cancel", message),
+                errorCallback: (message) => _checkoutMessage.value = ("Error", message),
               ),
             ),
             const SizedBox(height: 20),

android/src/main/kotlin/com/ottu/flutter/checkout/CheckoutView.kt

@@ -41,9 +41,9 @@ private const val METHOD_CHECKOUT_HEIGHT = "METHOD_CHECKOUT_HEIGHT"
 private const val METHOD_PAYMENT_SUCCESS_RESULT = "METHOD_PAYMENT_SUCCESS_RESULT"
 private const val METHOD_PAYMENT_ERROR_RESULT = "METHOD_PAYMENT_ERROR_RESULT"
 private const val METHOD_PAYMENT_CANCEL_RESULT = "METHOD_PAYMENT_CANCEL_RESULT"
+private const val METHOD_ON_WIDGET_DETACHED = "METHOD_ON_WIDGET_DETACHED"
 private const val METHOD_VERIFY_PAYMENT = "METHOD_VERIFY_PAYMENT"
 private const val CHANNEL = "com.ottu.sample/checkout"
-private const val CHANNEL_PAYMENT_VERIFY = "com.ottu.sample/checkout/payment/verify"
 private const val TAG = "CheckoutView"
 
 private val sessionCoroutineExceptionHandler = CoroutineExceptionHandler { _, t ->
@@ -67,8 +67,6 @@ internal class CheckoutView(
     private val arguments: CheckoutArguments,
 ) : PlatformView {
     private val methodChannel: MethodChannel
-    private val methodChannelVerifyPayment: MethodChannel
-
     private val checkoutView: FrameLayout = LayoutInflater.from(context)
         .inflate(R.layout.fragment_checkout_wrapper_view, null) as FrameLayout
 
@@ -80,7 +78,6 @@ internal class CheckoutView(
         )
         checkoutView.layoutParams = vParams
         methodChannel = MethodChannel(messenger, CHANNEL)
-        methodChannelVerifyPayment = MethodChannel(messenger, CHANNEL_PAYMENT_VERIFY)
     }
 
     override fun getView(): View = checkoutView
@@ -95,6 +92,14 @@ internal class CheckoutView(
     override fun onFlutterViewAttached(flutterView: View) {
         super.onFlutterViewAttached(flutterView)
 
+        methodChannel.setMethodCallHandler { call, _ ->
+            when (call.method) {
+                METHOD_ON_WIDGET_DETACHED -> {
+                    Log.d(TAG, "onFlutterViewAttached, handle onWidgetDetached")
+                }
+            }
+        }
+
         Log.i(TAG, "onFlutterViewAttached, isCheckoutInitializing: ${isCheckoutInitializing.get()}")
         if (isCheckoutInitializing.getAndSet(true).not()) {
             val fa = checkoutView.context as FragmentActivity
@@ -219,7 +224,7 @@ internal class CheckoutView(
 
     private suspend fun verifyPayment(payload: String?): CardVerificationResult<Nothing> {
         val deferredResult = CompletableDeferred<CardVerificationResult<Nothing>>()
-        methodChannelVerifyPayment.invokeMethod(
+        methodChannel.invokeMethod(
             METHOD_VERIFY_PAYMENT,
             payload,
             object : MethodChannel.Result {

ios/ottu_flutter_checkout/Sources/ottu_flutter_checkout/CheckoutPlatformView.swift

@@ -12,8 +12,6 @@ import ottu_checkout_sdk
 //
 
 private let checkoutChannelName = "com.ottu.sample/checkout"
-private let checkoutVerifyPaymentChannelName =
-    "com.ottu.sample/checkout/payment/verify"
 private let methodCheckoutHeight = "METHOD_CHECKOUT_HEIGHT"
 private let _methodPaymentSuccessResult = "METHOD_PAYMENT_SUCCESS_RESULT"
 private let _methodPaymentErrorResult = "METHOD_PAYMENT_ERROR_RESULT"
@@ -24,7 +22,6 @@ private let _methodVerifyPayment = "METHOD_VERIFY_PAYMENT"
 public class CheckoutPlatformView: NSObject, FlutterPlatformView {
     private let viewId: Int64
     private let channel: FlutterMethodChannel
-    private let channelVerifyPayment: FlutterMethodChannel
     private let _view: CheckoutContainerView
     private weak var paymentViewController: UIViewController?
     private var checkout: Checkout?
@@ -58,10 +55,6 @@ public class CheckoutPlatformView: NSObject, FlutterPlatformView {
             name: checkoutChannelName,
             binaryMessenger: messenger
         )
-        self.channelVerifyPayment = FlutterMethodChannel(
-            name: checkoutVerifyPaymentChannelName,
-            binaryMessenger: messenger
-        )
         _view = CheckoutContainerView()
         super.init()
 
@@ -426,7 +419,7 @@ public class CheckoutPlatformView: NSObject, FlutterPlatformView {
         return await withCheckedContinuation { continuation in
             Logger.sdk.info("CheckoutPlatformView.verifyPaymentCallback")
             DispatchQueue.main.async {
-                self.channelVerifyPayment.invokeMethod(
+                self.channel.invokeMethod(
                     _methodVerifyPayment,
                     arguments: payload,
                     result: { [weak self] (result) -> Void in

lib/src/checkout_widget.dart

@@ -6,70 +6,125 @@ import 'package:flutter/services.dart';
 import 'package:ottu_flutter_checkout/ottu_flutter_checkout.dart';
 
 const _checkoutViewType = 'OttuCheckoutWidget';
+const _methodCheckoutHeight = "METHOD_CHECKOUT_HEIGHT";
 const _methodOnWidgetDetached = "METHOD_ON_WIDGET_DETACHED";
 const _methodVerifyPayment = "METHOD_VERIFY_PAYMENT";
+const _methodPaymentSuccessResult = "METHOD_PAYMENT_SUCCESS_RESULT";
+const _methodPaymentErrorResult = "METHOD_PAYMENT_ERROR_RESULT";
+const _methodPaymentCancelResult = "METHOD_PAYMENT_CANCEL_RESULT";
 const _methodChannel = MethodChannel('com.ottu.sample/checkout');
-const _methodChannelPaymentVerify = MethodChannel('com.ottu.sample/checkout/payment/verify');
+
+const _defaultCheckoutViewHeight = 200;
 
 typedef VerifyPaymentDelegate = Future<CardVerificationResult<void, String>> Function(
     String? payload);
 
 class OttuCheckoutWidget extends StatefulWidget {
   final CheckoutArguments arguments;
   final VerifyPaymentDelegate? _verifyPayment;
+  final Function(String message)? _successCallback;
+  final Function(String message)? _cancelCallback;
+  final Function(String message)? _errorCallback;
 
-  const OttuCheckoutWidget(
-      {super.key, required this.arguments, VerifyPaymentDelegate? verifyPayment})
-      : _verifyPayment = verifyPayment;
+  const OttuCheckoutWidget({
+    super.key,
+    required this.arguments,
+    VerifyPaymentDelegate? verifyPayment,
+    Function(String message)? successCallback,
+    Function(String message)? cancelCallback,
+    Function(String message)? errorCallback,
+  })  : _verifyPayment = verifyPayment,
+        _successCallback = successCallback,
+        _cancelCallback = cancelCallback,
+        _errorCallback = errorCallback;
 
   @override
   State<StatefulWidget> createState() => _OttuCheckoutWidgetState();
 }
 
 class _OttuCheckoutWidgetState extends State<OttuCheckoutWidget> {
   static const StandardMessageCodec _decoder = StandardMessageCodec();
+  final ValueNotifier<int> _checkoutHeight = ValueNotifier<int>(_defaultCheckoutViewHeight);
+
+  @override
+  void initState() {
+    super.initState();
+    _methodChannel.setMethodCallHandler(_handleChannelMethod);
+  }
 
   @override
   void dispose() {
-    print("OttuCheckoutWidget.dispose()");
+    if (kDebugMode) {
+      print("OttuCheckoutWidget.dispose()");
+    }
+    _methodChannel.setMethodCallHandler(null);
     _methodChannel.invokeMethod(_methodOnWidgetDetached);
     super.dispose();
   }
 
-  @override
-  void didChangeDependencies() {
-    _methodChannelPaymentVerify.setMethodCallHandler((call) async {
-      print("CheckoutWidget, method call: ${call.method}");
-      switch (call.method) {
-        case _methodVerifyPayment:
-          {
-            final result = await widget._verifyPayment?.call(call.arguments);
+  Future<dynamic> _handleChannelMethod(call) async {
+    switch (call.method) {
+      case _methodCheckoutHeight:
+        {
+          int height = call.arguments as int;
+          _checkoutHeight.value = height;
+        }
+      case _methodPaymentSuccessResult:
+        {
+          String message = call.arguments as String;
+          widget._successCallback?.call(message);
+        }
+
+      case _methodPaymentCancelResult:
+        {
+          String message = call.arguments as String;
+          widget._cancelCallback?.call(message);
+        }
+
+      case _methodPaymentErrorResult:
+        {
+          String message = call.arguments as String;
+          widget._errorCallback?.call(message);
+        }
+      case _methodVerifyPayment:
+        {
+          final result = await widget._verifyPayment?.call(call.arguments);
+          if (kDebugMode) {
             print("CheckoutWidget, verifyPayment, result: ${result.runtimeType}");
-            switch (result) {
-              case Success():
-                return "";
-              case Failure(:final message):
-                throw PlatformException(code: _methodVerifyPayment, message: message);
-              case null:
-                throw PlatformException(code: _methodVerifyPayment, message: "Unknown error");
-            }
           }
-      }
-    });
-    super.didChangeDependencies();
+          switch (result) {
+            case Success():
+              return "";
+            case Failure(:final message):
+              throw PlatformException(code: _methodVerifyPayment, message: message);
+            case null:
+              throw PlatformException(code: _methodVerifyPayment, message: "Unknown error");
+          }
+        }
+    }
   }
 
   @override
   Widget build(BuildContext context) {
     final argsMap = widget.arguments.toJson();
     final jsonArg = json.encode(argsMap);
     final args = {"args": jsonArg};
-    if (defaultTargetPlatform == TargetPlatform.android) {
-      return AndroidView(
-          viewType: _checkoutViewType, creationParams: args, creationParamsCodec: _decoder);
-    } else {
-      return UiKitView(
-          viewType: _checkoutViewType, creationParams: args, creationParamsCodec: _decoder);
-    }
+    return ValueListenableBuilder<int>(
+        valueListenable: _checkoutHeight,
+        builder: (BuildContext context, int height, Widget? child) {
+          return SizedBox(
+              height: height.toDouble(),
+              child: defaultTargetPlatform == TargetPlatform.android
+                  ? AndroidView(
+                      viewType: _checkoutViewType,
+                      creationParams: args,
+                      creationParamsCodec: _decoder)
+                  : defaultTargetPlatform == TargetPlatform.iOS
+                      ? UiKitView(
+                          viewType: _checkoutViewType,
+                          creationParams: args,
+                          creationParamsCodec: _decoder)
+                      : SizedBox.shrink());
+        });
   }
 }