it works

Author: goderbauer

shell/platform/darwin/ios/BUILD.gn

@@ -66,6 +66,8 @@ source_set("flutter_framework_source") {
     "framework/Source/FlutterPlatformViews_Internal.h",
     "framework/Source/FlutterPlatformViews_Internal.mm",
     "framework/Source/FlutterPluginAppLifeCycleDelegate.mm",
+    "framework/Source/FlutterRestorationPlugin.h",
+    "framework/Source/FlutterRestorationPlugin.mm",
     "framework/Source/FlutterTextInputDelegate.h",
     "framework/Source/FlutterTextInputPlugin.h",
     "framework/Source/FlutterTextInputPlugin.mm",

shell/platform/darwin/ios/framework/Source/FlutterRestorationPlugin.h

@@ -14,7 +14,7 @@
 
 - (instancetype)init NS_UNAVAILABLE;
 + (instancetype)new NS_UNAVAILABLE;
-- (instancetype)initWithChannel:(fml::WeakPtr<FlutterMethodChannel>)channel restorationEnabled:(BOOL)waitForData  NS_DESIGNATED_INITIALIZER;
+- (instancetype)initWithChannel:(FlutterMethodChannel*)channel restorationEnabled:(BOOL)waitForData  NS_DESIGNATED_INITIALIZER;
 
 - (NSData*)restorationData;
 - (void)restorationData:(NSData *)data;

shell/platform/darwin/ios/framework/Source/FlutterRestorationPlugin.mm

@@ -18,17 +18,16 @@ @implementation FlutterRestorationPlugin {
 }
 
 - (instancetype)init {
-  @throw([NSException exceptionWithName:@"FlutterRestorationPlugin must initWithEngine"
+  @throw([NSException exceptionWithName:@"FlutterRestorationPlugin must initWithChannel:restorationEnabled:"
                                  reason:nil
                                userInfo:nil]);
-  /Users/goderbauer/dev/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterRestorationPlugin.h
 }
 
-- (instancetype)initWithChannel:(fml::WeakPtr<FlutterMethodChannel>)channel restorationEnabled:(BOOL)restorationEnabled {
+- (instancetype)initWithChannel:(FlutterMethodChannel*)channel restorationEnabled:(BOOL)restorationEnabled {
   FML_DCHECK(channel) << "channel must be set";
   self = [super init];
   if (self) {
-    [channel.get() setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
+    [channel setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
       [self handleMethodCall:call result:result];
     }];
     _restorationEnabled = restorationEnabled;
@@ -57,7 +56,7 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
   }
 }
 
-_ (NSData*)restorationData {
+- (NSData*)restorationData {
   return _restorationData;
 }
 

shell/platform/darwin/ios/framework/Source/FlutterViewController.mm

@@ -1438,14 +1438,14 @@ - (BOOL)isPresentingViewController {
 #pragma mark - State Restoration
 
 - (void)encodeRestorableStateWithCoder:(NSCoder *)coder {
-  NSLog(@"FlutterViewController: encodeRestorableStateWithCoder");
   NSData* restorationData = [[_engine.get() restorationPlugin] restorationData];
+  NSLog(@"FlutterViewController: encodeRestorableStateWithCoder %@", restorationData);
   [coder encodeDataObject:restorationData];
 }
 
 - (void)decodeRestorableStateWithCoder:(NSCoder *)coder {
-  NSLog(@"FlutterViewController: decodeRestorableStateWithCoder");
   NSData* restorationData = [coder decodeDataObject];
+  NSLog(@"FlutterViewController: decodeRestorableStateWithCoder %@", restorationData);
   [[_engine.get() restorationPlugin] restorationData:restorationData];
 }