almost compiles

Author: goderbauer

shell/platform/darwin/ios/framework/Headers/FlutterEngine.h

@@ -135,7 +135,30 @@ FLUTTER_EXPORT
  */
 - (instancetype)initWithName:(NSString*)labelPrefix
                      project:(nullable FlutterDartProject*)project
-      allowHeadlessExecution:(BOOL)allowHeadlessExecution NS_DESIGNATED_INITIALIZER;
+      allowHeadlessExecution:(BOOL)allowHeadlessExecution;
+
+/**
+ * Initialize this FlutterEngine with a `FlutterDartProject`.
+ *
+ * If the FlutterDartProject is not specified, the FlutterEngine will attempt to locate
+ * the project in a default location (the flutter_assets folder in the iOS application
+ * bundle).
+ *
+ * A newly initialized engine will not run the `FlutterDartProject` until either
+ * `-runWithEntrypoint:` or `-runWithEntrypoint:libraryURI:` is called.
+ *
+ * @param labelPrefix The label prefix used to identify threads for this instance. Should
+ *   be unique across FlutterEngine instances, and is used in instrumentation to label
+ *   the threads used by this FlutterEngine.
+ * @param project The `FlutterDartProject` to run.
+ * @param allowHeadlessExecution Whether or not to allow this instance to continue
+ *   running after passing a nil `FlutterViewController` to `-setViewController:`.
+ * @param waitForRestorationData TODO
+ */
+- (instancetype)initWithName:(NSString*)labelPrefix
+                     project:(nullable FlutterDartProject*)project
+      allowHeadlessExecution:(BOOL)allowHeadlessExecution
+          restorationEnabled:(BOOL)restorationEnabled NS_DESIGNATED_INITIALIZER;
 
 + (instancetype)new NS_UNAVAILABLE;
 
@@ -273,6 +296,16 @@ FLUTTER_EXPORT
  */
 @property(nonatomic, readonly) FlutterMethodChannel* navigationChannel;
 
+/**
+ * The `FlutterMethodChannel` used for restoration related platform messages.
+ *
+ * Can be nil after `destroyContext` is called.
+ *
+ * @see [Navigation
+ * Channel](https://docs.flutter.io/flutter/services/SystemChannels/restoration-constant.html)
+ */
+@property(nonatomic, readonly) FlutterMethodChannel* restorationChannel;
+
 /**
  * The `FlutterMethodChannel` used for core platform messages, such as
  * information about the screen orientation.

shell/platform/darwin/ios/framework/Headers/FlutterHeadlessDartRunner.h

@@ -64,7 +64,27 @@ FLUTTER_DEPRECATED("FlutterEngine should be used rather than FlutterHeadlessDart
  */
 - (instancetype)initWithName:(NSString*)labelPrefix
                      project:(FlutterDartProject*)projectOrNil
-      allowHeadlessExecution:(BOOL)allowHeadlessExecution NS_DESIGNATED_INITIALIZER;
+      allowHeadlessExecution:(BOOL)allowHeadlessExecution;
+
+/**
+ * Iniitalize this FlutterHeadlessDartRunner with a `FlutterDartProject`.
+ *
+ * If the FlutterDartProject is not specified, the FlutterHeadlessDartRunner will attempt to locate
+ * the project in a default location.
+ *
+ * A newly initialized engine will not run the `FlutterDartProject` until either
+ * `-runWithEntrypoint:` or `-runWithEntrypoint:libraryURI` is called.
+ *
+ * @param labelPrefix The label prefix used to identify threads for this instance. Should
+ * be unique across FlutterEngine instances
+ * @param projectOrNil The `FlutterDartProject` to run.
+ * @param allowHeadlessExecution Must be set to `YES`.
+ * @param restorationEnabled TODO
+ */
+- (instancetype)initWithName:(NSString*)labelPrefix
+                     project:(FlutterDartProject*)projectOrNil
+      allowHeadlessExecution:(BOOL)allowHeadlessExecution
+          restorationEnabled:(BOOL)restorationEnabled NS_DESIGNATED_INITIALIZER;
 
 /**
  * Not recommended for use - will initialize with a default label ("io.flutter.headless")

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

@@ -4,6 +4,8 @@
 
 #import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterAppDelegate.h"
 
+#include <iostream>
+
 #import "flutter/fml/logging.h"
 #import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterPluginAppLifeCycleDelegate.h"
 #import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h"
@@ -24,6 +26,7 @@ @implementation FlutterAppDelegate {
 }
 
 - (instancetype)init {
+  NSLog(@"MIKE: HELLOO");
   if (self = [super init]) {
     _lifeCycleDelegate = [[FlutterPluginAppLifeCycleDelegate alloc] init];
   }
@@ -307,5 +310,33 @@ - (void)logCapabilityConfigurationWarningIfNeeded:(SEL)selector {
     }
   }
 }
+  
+#pragma mark - State Restoration
 
+- (BOOL)application:(UIApplication *)application shouldSaveApplicationState:(NSCoder *)coder {
+  [coder encodeInt64: self.lastAppModificationTime forKey:@"mod-date"];
+  return YES;
+}
+  
+- (BOOL)application:(UIApplication *)application shouldRestoreApplicationState:(NSCoder *)coder {
+  int64_t stateDate = [coder decodeInt64ForKey:@"mod-date"];
+  return self.lastAppModificationTime == stateDate;
+}
+  
+- (BOOL)application:(UIApplication *)application shouldSaveSecureApplicationState:(NSCoder *)coder {
+  [coder encodeInt64: self.lastAppModificationTime forKey:@"mod-date"];
+  return YES;
+}
+
+- (BOOL)application:(UIApplication *)application shouldRestoreSecureApplicationState:(NSCoder *)coder {
+  int64_t stateDate = [coder decodeInt64ForKey:@"mod-date"];
+  return self.lastAppModificationTime == stateDate;
+}
+  
+- (int64_t)lastAppModificationTime {
+  NSDate *fileDate;
+  [[[NSBundle mainBundle] executableURL] getResourceValue:&fileDate forKey:NSURLContentModificationDateKey error:nil];
+  return [fileDate timeIntervalSince1970];
+}
+  
 @end

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

@@ -71,8 +71,10 @@ @implementation FlutterEngine {
   // Channels
   fml::scoped_nsobject<FlutterPlatformPlugin> _platformPlugin;
   fml::scoped_nsobject<FlutterTextInputPlugin> _textInputPlugin;
+  fml::scoped_nsobject<FlutterRestorationPlugin> _restorationPlugin;
   fml::scoped_nsobject<FlutterMethodChannel> _localizationChannel;
   fml::scoped_nsobject<FlutterMethodChannel> _navigationChannel;
+  fml::scoped_nsobject<FlutterMethodChannel> _restorationChannel;
   fml::scoped_nsobject<FlutterMethodChannel> _platformChannel;
   fml::scoped_nsobject<FlutterMethodChannel> _platformViewsChannel;
   fml::scoped_nsobject<FlutterMethodChannel> _textInputChannel;
@@ -84,6 +86,7 @@ @implementation FlutterEngine {
   int64_t _nextTextureId;
 
   BOOL _allowHeadlessExecution;
+  BOOL _restorationEnabled;
   FlutterBinaryMessengerRelay* _binaryMessenger;
   std::unique_ptr<flutter::ConnectionCollection> _connections;
 }
@@ -103,10 +106,18 @@ - (instancetype)initWithName:(NSString*)labelPrefix project:(FlutterDartProject*
 - (instancetype)initWithName:(NSString*)labelPrefix
                      project:(FlutterDartProject*)project
       allowHeadlessExecution:(BOOL)allowHeadlessExecution {
+  return [self initWithName:labelPrefix project:project allowHeadlessExecution:allowHeadlessExecution restorationEnabled:NO];
+}
+
+- (instancetype)initWithName:(NSString*)labelPrefix
+                     project:(FlutterDartProject*)project
+      allowHeadlessExecution:(BOOL)allowHeadlessExecution
+          restorationEnabled:(BOOL)restorationEnabled {
   self = [super init];
   NSAssert(self, @"Super init cannot be nil");
   NSAssert(labelPrefix, @"labelPrefix is required");
 
+  _restorationEnabled = restorationEnabled;
   _allowHeadlessExecution = allowHeadlessExecution;
   _labelPrefix = [labelPrefix copy];
 
@@ -331,12 +342,18 @@ - (FlutterPlatformPlugin*)platformPlugin {
 - (FlutterTextInputPlugin*)textInputPlugin {
   return _textInputPlugin.get();
 }
+- (FlutterRestorationPlugin*)restorationPlugin {
+  return _restorationPlugin.get();
+}
 - (FlutterMethodChannel*)localizationChannel {
   return _localizationChannel.get();
 }
 - (FlutterMethodChannel*)navigationChannel {
   return _navigationChannel.get();
 }
+- (FlutterMethodChannel*)restorationChannel {
+  return _restorationChannel.get();
+}
 - (FlutterMethodChannel*)platformChannel {
   return _platformChannel.get();
 }
@@ -363,6 +380,7 @@ - (NSURL*)observatoryUrl {
 - (void)resetChannels {
   _localizationChannel.reset();
   _navigationChannel.reset();
+  _restorationChannel.reset();
   _platformChannel.reset();
   _platformViewsChannel.reset();
   _textInputChannel.reset();
@@ -413,6 +431,11 @@ - (void)setupChannels {
     _initialRoute = nil;
   }
 
+  _restorationChannel.reset([[FlutterMethodChannel alloc]
+         initWithName:@"flutter/restoration"
+      binaryMessenger:self.binaryMessenger
+                codec:[FlutterStandardMethodCodec sharedInstance]]);
+  
   _platformChannel.reset([[FlutterMethodChannel alloc]
          initWithName:@"flutter/platform"
       binaryMessenger:self.binaryMessenger
@@ -452,6 +475,8 @@ - (void)setupChannels {
   _textInputPlugin.get().textInputDelegate = self;
 
   _platformPlugin.reset([[FlutterPlatformPlugin alloc] initWithEngine:[self getWeakPtr]]);
+  
+  _restorationPlugin.reset([[FlutterRestorationPlugin alloc] initWithChannel:_restorationChannel.get() restorationEnabled:_restorationEnabled]);
 }
 
 - (void)maybeSetupPlatformViewChannels {

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

@@ -18,6 +18,7 @@
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterDartProject_Internal.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformPlugin.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h"
+#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterRestorationPlugin.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputDelegate.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.h"
 #import "flutter/shell/platform/darwin/ios/platform_view_ios.h"
@@ -42,6 +43,7 @@ extern NSString* const FlutterEngineWillDealloc;
 - (FlutterPlatformPlugin*)platformPlugin;
 - (std::shared_ptr<flutter::FlutterPlatformViewsController>&)platformViewsController;
 - (FlutterTextInputPlugin*)textInputPlugin;
+- (FlutterRestorationPlugin*)restorationPlugin;
 - (void)launchEngine:(NSString*)entrypoint libraryURI:(NSString*)libraryOrNil;
 - (BOOL)createShell:(NSString*)entrypoint
          libraryURI:(NSString*)libraryOrNil

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

@@ -35,10 +35,24 @@ - (instancetype)initWithName:(NSString*)labelPrefix
       allowHeadlessExecution:(BOOL)allowHeadlessExecution {
   NSAssert(allowHeadlessExecution == YES,
            @"Cannot initialize a FlutterHeadlessDartRunner without headless execution.");
+  return [self initWithName:labelPrefix
+                     project:projectOrNil
+      allowHeadlessExecution:allowHeadlessExecution
+          restorationEnabled:NO];
+}
+
+- (instancetype)initWithName:(NSString*)labelPrefix
+                     project:(FlutterDartProject*)projectOrNil
+      allowHeadlessExecution:(BOOL)allowHeadlessExecution
+          restorationEnabled:(BOOL)restorationEnabled{
+  NSAssert(allowHeadlessExecution == YES,
+           @"Cannot initialize a FlutterHeadlessDartRunner without headless execution.");
   return [super initWithName:labelPrefix
                      project:projectOrNil
-      allowHeadlessExecution:allowHeadlessExecution];
+      allowHeadlessExecution:allowHeadlessExecution
+          restorationEnabled:restorationEnabled];
 }
+
 - (instancetype)init {
   return [self initWithName:@"io.flutter.headless" project:nil];
 }

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

@@ -0,0 +1,23 @@
+// 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.
+
+#ifndef SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERRESTORATIONPLUGIN_H_
+#define SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERRESTORATIONPLUGIN_H_
+
+#import <UIKit/UIKit.h>
+
+#include "flutter/fml/memory/weak_ptr.h"
+#import "flutter/shell/platform/darwin/common/framework/Headers/FlutterChannels.h"
+
+@interface FlutterRestorationPlugin : NSObject
+
+- (instancetype)init NS_UNAVAILABLE;
++ (instancetype)new NS_UNAVAILABLE;
+- (instancetype)initWithChannel:(fml::WeakPtr<FlutterMethodChannel>)channel restorationEnabled:(BOOL)waitForData  NS_DESIGNATED_INITIALIZER;
+
+- (NSData*)restorationData;
+- (void)restorationData:(NSData *)data;
+- (void)restorationComplete;
+@end
+#endif  // SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTERRESTORATIONPLUGIN_H_

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

@@ -0,0 +1,98 @@
+// 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 "flutter/shell/platform/darwin/ios/framework/Source/FlutterRestorationPlugin.h"
+
+#import <Foundation/Foundation.h>
+#import <UIKit/UIKit.h>
+
+#include "flutter/fml/logging.h"
+
+
+@implementation FlutterRestorationPlugin {
+  BOOL _waitForData;
+  BOOL _restorationEnabled;
+  FlutterResult _pendingRequest;
+  NSData* _restorationData;
+}
+
+- (instancetype)init {
+  @throw([NSException exceptionWithName:@"FlutterRestorationPlugin must initWithEngine"
+                                 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 {
+  FML_DCHECK(channel) << "channel must be set";
+  self = [super init];
+  if (self) {
+    [channel.get() setMethodCallHandler:^(FlutterMethodCall* call, FlutterResult result) {
+      [self handleMethodCall:call result:result];
+    }];
+    _restorationEnabled = restorationEnabled;
+    _waitForData = restorationEnabled;
+  }
+  return self;
+}
+
+- (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
+  if ([[call method] isEqualToString:@"put"]) {
+    FlutterStandardTypedData* data = [call arguments];
+    NSData* newData = [[data data] retain];
+    if (_restorationData != nil) {
+      [_restorationData release];
+    }
+    _restorationData = newData;
+    result(nil);
+  } else if ([[call method] isEqualToString:@"get"]) {
+    if (!_restorationEnabled || !_waitForData) {
+      result( [self dataForFramework] );
+      return;
+    }
+    _pendingRequest = [result retain];
+  } else {
+    result(FlutterMethodNotImplemented);
+  }
+}
+
+_ (NSData*)restorationData {
+  return _restorationData;
+}
+
+- (void)restorationData:(NSData*)data {
+  NSData* newData = [data retain];
+  if (_restorationData != nil) {
+    [_restorationData release];
+  }
+  _restorationData = newData;
+  if (_pendingRequest != nil) {
+    _pendingRequest( [self dataForFramework] );
+    [_pendingRequest release];
+    _pendingRequest = nil;
+    _waitForData = NO;
+  }
+}
+
+- (void)restorationComplete {
+  _waitForData = NO;
+  if (_pendingRequest != nil) {
+    NSAssert(_restorationEnabled, @"No request can be pending when restoration is disabled.");
+    _pendingRequest( [self dataForFramework] );
+    [_pendingRequest release];
+    _pendingRequest = nil;
+  }
+}
+
+- (NSDictionary*)dataForFramework {
+  if (!_restorationEnabled) {
+    return @{ @"enabled": @NO };
+  }
+  if (_restorationData == nil) {
+    return @{ @"enabled": @YES };
+  }
+  return @{@"enabled": @YES, @"data": [FlutterStandardTypedData typedDataWithBytes:_restorationData]};
+}
+
+@end