Refactor and migrate FlutterUndoManagerPlugin to ARC

Author: jmagman

shell/platform/darwin/ios/BUILD.gn

@@ -84,6 +84,9 @@ source_set("flutter_framework_source_arc") {
     "framework/Source/FlutterTextureRegistryRelay.mm",
     "framework/Source/FlutterUIPressProxy.h",
     "framework/Source/FlutterUIPressProxy.mm",
+    "framework/Source/FlutterUndoManagerDelegate.h",
+    "framework/Source/FlutterUndoManagerPlugin.h",
+    "framework/Source/FlutterUndoManagerPlugin.mm",
     "framework/Source/KeyCodeMap.g.mm",
     "framework/Source/KeyCodeMap_Internal.h",
     "framework/Source/UIViewController+FlutterScreenAndSceneIfLoaded.h",
@@ -157,9 +160,6 @@ source_set("flutter_framework_source") {
     "framework/Source/FlutterPluginAppLifeCycleDelegate.mm",
     "framework/Source/FlutterSemanticsScrollView.h",
     "framework/Source/FlutterSemanticsScrollView.mm",
-    "framework/Source/FlutterUndoManagerDelegate.h",
-    "framework/Source/FlutterUndoManagerPlugin.h",
-    "framework/Source/FlutterUndoManagerPlugin.mm",
     "framework/Source/FlutterView.h",
     "framework/Source/FlutterView.mm",
     "framework/Source/FlutterViewController.mm",

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

@@ -430,7 +430,6 @@ - (void)setViewController:(FlutterViewController*)viewController {
   [self maybeSetupPlatformViewChannels];
   [self updateDisplays];
   _textInputPlugin.get().viewController = viewController;
-  _undoManagerPlugin.get().viewController = viewController;
 
   if (viewController) {
     __block FlutterEngine* blockSelf = self;
@@ -465,7 +464,6 @@ - (void)setFlutterViewControllerWillDeallocObserver:(id<NSObject>)observer {
 - (void)notifyViewControllerDeallocated {
   [[self lifecycleChannel] sendMessage:@"AppLifecycleState.detached"];
   _textInputPlugin.get().viewController = nil;
-  _undoManagerPlugin.get().viewController = nil;
   if (!_allowHeadlessExecution) {
     [self destroyContext];
   } else if (_shell) {

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

@@ -7,6 +7,8 @@
 
 #import <Foundation/Foundation.h>
 
+#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.h"
+
 NS_ASSUME_NONNULL_BEGIN
 
 typedef NS_ENUM(NSInteger, FlutterUndoRedoDirection) {
@@ -19,8 +21,14 @@ typedef NS_ENUM(NSInteger, FlutterUndoRedoDirection) {
 @class FlutterUndoManagerPlugin;
 
 @protocol FlutterUndoManagerDelegate <NSObject>
+
+@property(nonatomic, weak) UIResponder* viewController;
+
+- (FlutterTextInputPlugin*)textInputPlugin;
+
 - (void)flutterUndoManagerPlugin:(FlutterUndoManagerPlugin*)undoManagerPlugin
          handleUndoWithDirection:(FlutterUndoRedoDirection)direction;
+
 @end
 NS_ASSUME_NONNULL_END
 

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

@@ -7,15 +7,11 @@
 
 #import <UIKit/UIKit.h>
 
-#import "flutter/fml/memory/weak_ptr.h"
 #import "flutter/shell/platform/darwin/common/framework/Headers/FlutterChannels.h"
-#import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterUndoManagerDelegate.h"
 
 @interface FlutterUndoManagerPlugin : NSObject
 
-@property(nonatomic, assign) FlutterViewController* viewController;
-
 - (instancetype)init NS_UNAVAILABLE;
 + (instancetype)new NS_UNAVAILABLE;
 

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

@@ -3,12 +3,8 @@
 // found in the LICENSE file.
 
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterUndoManagerPlugin.h"
-#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterEngine_Internal.h"
 
-#import <Foundation/Foundation.h>
-#import <UIKit/UIKit.h>
-
-#include "flutter/fml/logging.h"
+#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.h"
 
 #pragma mark - UndoManager channel method names.
 static NSString* const kSetUndoStateMethod = @"UndoManager.setUndoState";
@@ -17,15 +13,16 @@
 static NSString* const kCanUndo = @"canUndo";
 static NSString* const kCanRedo = @"canRedo";
 
-@implementation FlutterUndoManagerPlugin {
-  id<FlutterUndoManagerDelegate> _undoManagerDelegate;
-}
+@interface FlutterUndoManagerPlugin ()
+@property(nonatomic, weak, readonly) id<FlutterUndoManagerDelegate> undoManagerDelegate;
+@end
+
+@implementation FlutterUndoManagerPlugin
 
 - (instancetype)initWithDelegate:(id<FlutterUndoManagerDelegate>)undoManagerDelegate {
   self = [super init];
 
   if (self) {
-    // `_undoManagerDelegate` is a weak reference because it should retain FlutterUndoManagerPlugin.
     _undoManagerDelegate = undoManagerDelegate;
   }
 
@@ -34,7 +31,6 @@ - (instancetype)initWithDelegate:(id<FlutterUndoManagerDelegate>)undoManagerDele
 
 - (void)dealloc {
   [self resetUndoManager];
-  [super dealloc];
 }
 
 - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
@@ -49,45 +45,47 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
 }
 
 - (NSUndoManager*)undoManager {
-  return _viewController.undoManager;
+  return self.undoManagerDelegate.viewController.undoManager;
 }
 
 - (void)resetUndoManager API_AVAILABLE(ios(9.0)) {
   [[self undoManager] removeAllActionsWithTarget:self];
 }
 
 - (void)registerUndoWithDirection:(FlutterUndoRedoDirection)direction API_AVAILABLE(ios(9.0)) {
-  [[self undoManager] beginUndoGrouping];
-  [[self undoManager] registerUndoWithTarget:self
-                                     handler:^(id target) {
-                                       // Register undo with opposite direction.
-                                       FlutterUndoRedoDirection newDirection =
-                                           (direction == FlutterUndoRedoDirectionRedo)
-                                               ? FlutterUndoRedoDirectionUndo
-                                               : FlutterUndoRedoDirectionRedo;
-                                       [target registerUndoWithDirection:newDirection];
-                                       // Invoke method on delegate.
-                                       [_undoManagerDelegate flutterUndoManagerPlugin:self
-                                                              handleUndoWithDirection:direction];
-                                     }];
-  [[self undoManager] endUndoGrouping];
+  NSUndoManager* undoManager = [self undoManager];
+  [undoManager beginUndoGrouping];
+  [undoManager registerUndoWithTarget:self
+                              handler:^(FlutterUndoManagerPlugin* target) {
+                                // Register undo with opposite direction.
+                                FlutterUndoRedoDirection newDirection =
+                                    (direction == FlutterUndoRedoDirectionRedo)
+                                        ? FlutterUndoRedoDirectionUndo
+                                        : FlutterUndoRedoDirectionRedo;
+                                [target registerUndoWithDirection:newDirection];
+                                // Invoke method on delegate.
+                                [target.undoManagerDelegate flutterUndoManagerPlugin:target
+                                                             handleUndoWithDirection:direction];
+                              }];
+  [undoManager endUndoGrouping];
 }
 
 - (void)registerRedo API_AVAILABLE(ios(9.0)) {
-  [[self undoManager] beginUndoGrouping];
-  [[self undoManager]
-      registerUndoWithTarget:self
-                     handler:^(id target) {
-                       // Register undo with opposite direction.
-                       [target registerUndoWithDirection:FlutterUndoRedoDirectionRedo];
-                     }];
-  [[self undoManager] endUndoGrouping];
-  [[self undoManager] undo];
+  NSUndoManager* undoManager = [self undoManager];
+  [undoManager beginUndoGrouping];
+  [undoManager registerUndoWithTarget:self
+                              handler:^(id target) {
+                                // Register undo with opposite direction.
+                                [target registerUndoWithDirection:FlutterUndoRedoDirectionRedo];
+                              }];
+  [undoManager endUndoGrouping];
+  [undoManager undo];
 }
 
 - (void)setUndoState:(NSDictionary*)dictionary API_AVAILABLE(ios(9.0)) {
-  BOOL groupsByEvent = [self undoManager].groupsByEvent;
-  [self undoManager].groupsByEvent = NO;
+  NSUndoManager* undoManager = [self undoManager];
+  BOOL groupsByEvent = undoManager.groupsByEvent;
+  undoManager.groupsByEvent = NO;
   BOOL canUndo = [dictionary[kCanUndo] boolValue];
   BOOL canRedo = [dictionary[kCanRedo] boolValue];
 
@@ -99,16 +97,15 @@ - (void)setUndoState:(NSDictionary*)dictionary API_AVAILABLE(ios(9.0)) {
   if (canRedo) {
     [self registerRedo];
   }
-
-  if (_viewController.engine.textInputPlugin.textInputView != nil) {
+  UIView<UITextInput>* textInputView = [self.undoManagerDelegate.textInputPlugin textInputView];
+  if (textInputView != nil) {
     // This is needed to notify the iPadOS keyboard that it needs to update the
     // state of the UIBarButtons. Otherwise, the state changes to NSUndoManager
     // will not show up until the next keystroke (or other trigger).
-    UITextInputAssistantItem* assistantItem =
-        _viewController.engine.textInputPlugin.textInputView.inputAssistantItem;
+    UITextInputAssistantItem* assistantItem = textInputView.inputAssistantItem;
     assistantItem.leadingBarButtonGroups = assistantItem.leadingBarButtonGroups;
   }
-  [self undoManager].groupsByEvent = groupsByEvent;
+  undoManager.groupsByEvent = groupsByEvent;
 }
 
 @end

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

@@ -8,51 +8,48 @@
 #import <XCTest/XCTest.h>
 
 #import "flutter/shell/platform/darwin/common/framework/Headers/FlutterMacros.h"
-#import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterEngine.h"
-#import "flutter/shell/platform/darwin/ios/framework/Headers/FlutterViewController.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterTextInputPlugin.h"
 
 FLUTTER_ASSERT_ARC
 
-@interface FlutterEngine ()
-- (nonnull FlutterUndoManagerPlugin*)undoManagerPlugin;
-- (nonnull FlutterTextInputPlugin*)textInputPlugin;
+@interface FlutterUndoManagerDelegateForTest : NSObject <FlutterUndoManagerDelegate>
+@property(nonatomic, weak) UIResponder* viewController;
+@property(nonatomic) FlutterTextInputPlugin* textInputPlugin;
 @end
 
-@interface FlutterUndoManagerPluginForTest : FlutterUndoManagerPlugin
-@property(nonatomic, assign) NSUndoManager* undoManager;
-@end
+@implementation FlutterUndoManagerDelegateForTest
 
-@implementation FlutterUndoManagerPluginForTest {
+- (void)flutterUndoManagerPlugin:(FlutterUndoManagerPlugin*)undoManagerPlugin
+         handleUndoWithDirection:(FlutterUndoRedoDirection)direction {
 }
 @end
 
 @interface FlutterUndoManagerPluginTest : XCTestCase
-@property(nonatomic, strong) id engine;
-@property(nonatomic, strong) FlutterUndoManagerPluginForTest* undoManagerPlugin;
-@property(nonatomic, strong) FlutterViewController* viewController;
-@property(nonatomic, strong) NSUndoManager* undoManager;
+@property(nonatomic) id undoManagerDelegate;
+@property(nonatomic) FlutterUndoManagerPlugin* undoManagerPlugin;
+@property(nonatomic) UIResponder* viewController;
+@property(nonatomic) NSUndoManager* undoManager;
 @end
 
-@implementation FlutterUndoManagerPluginTest {
-}
+@implementation FlutterUndoManagerPluginTest
 
 - (void)setUp {
   [super setUp];
-  self.engine = OCMClassMock([FlutterEngine class]);
-
-  self.undoManagerPlugin = [[FlutterUndoManagerPluginForTest alloc] initWithDelegate:self.engine];
+  self.undoManagerDelegate = OCMClassMock([FlutterUndoManagerDelegateForTest class]);
 
-  self.viewController = [[FlutterViewController alloc] init];
-  self.undoManagerPlugin.viewController = self.viewController;
+  self.undoManagerPlugin =
+      [[FlutterUndoManagerPlugin alloc] initWithDelegate:self.undoManagerDelegate];
 
   self.undoManager = OCMClassMock([NSUndoManager class]);
-  self.undoManagerPlugin.undoManager = self.undoManager;
+
+  self.viewController = OCMClassMock([UIResponder class]);
+  OCMStub([self.viewController undoManager]).andReturn(self.undoManager);
+  OCMStub([self.undoManagerDelegate viewController]).andReturn(self.viewController);
 }
 
 - (void)tearDown {
   [self.undoManager removeAllActionsWithTarget:self.undoManagerPlugin];
-  self.engine = nil;
+  self.undoManagerDelegate = nil;
   self.viewController = nil;
   self.undoManager = nil;
   [super tearDown];
@@ -75,14 +72,14 @@ - (void)testSetUndoState {
         removeAllActionsCount++;
       });
   __block int delegateUndoCount = 0;
-  OCMStub([self.engine flutterUndoManagerPlugin:[OCMArg any]
-                        handleUndoWithDirection:FlutterUndoRedoDirectionUndo])
+  OCMStub([self.undoManagerDelegate flutterUndoManagerPlugin:[OCMArg any]
+                                     handleUndoWithDirection:FlutterUndoRedoDirectionUndo])
       .andDo(^(NSInvocation* invocation) {
         delegateUndoCount++;
       });
   __block int delegateRedoCount = 0;
-  OCMStub([self.engine flutterUndoManagerPlugin:[OCMArg any]
-                        handleUndoWithDirection:FlutterUndoRedoDirectionRedo])
+  OCMStub([self.undoManagerDelegate flutterUndoManagerPlugin:[OCMArg any]
+                                     handleUndoWithDirection:FlutterUndoRedoDirectionRedo])
       .andDo(^(NSInvocation* invocation) {
         delegateRedoCount++;
       });
@@ -143,14 +140,10 @@ - (void)testSetUndoState {
 
 - (void)testSetUndoStateDoesInteractWithInputDelegate {
   // Regression test for https://github.com/flutter/flutter/issues/133424
-  FlutterViewController* viewController = OCMPartialMock(self.viewController);
-  self.undoManagerPlugin.viewController = self.viewController;
-
   FlutterTextInputPlugin* textInputPlugin = OCMClassMock([FlutterTextInputPlugin class]);
   FlutterTextInputView* textInputView = OCMClassMock([FlutterTextInputView class]);
 
-  OCMStub([viewController engine]).andReturn(self.engine);
-  OCMStub([self.engine textInputPlugin]).andReturn(textInputPlugin);
+  OCMStub([self.undoManagerDelegate textInputPlugin]).andReturn(textInputPlugin);
   OCMStub([textInputPlugin textInputView]).andReturn(textInputView);
 
   FlutterMethodCall* setUndoStateCall =