iOS開發UIResponder之NSUndoManager

1、簡介

　　UIResponder有個屬性：NSUndoManager

@property(nullable, nonatomic,readonly) NSUndoManager *undoManager NS_AVAILABLE_IOS(3_0);

　　NSUndoManager可以叫做撤銷管理器，可以撤銷和重做，類似快捷鍵command+z和command+shift+z；

　　NSUndoManger內部維護兩個棧，undo棧（撤銷）和redo棧（重寫）。

 

2、NSUndoManger的簡單使用

　　2.1、數組的undo和redo

#import "UndoTest.h"

@interface UndoTest()
@end
@implementation UndoTest

- (instancetype)init{
    if (self = [super init]) {
        self.undoManager = [[NSUndoManager alloc] init];
        self.undoArr = [NSMutableArray array];
    }
    return self;
}
- (void)addObjectMethod:(NSString *)anObject{
    [[self.undoManager prepareWithInvocationTarget:self] removeObjectMehtod:anObject];
    [self.undoArr addObject:anObject];
}
- (void)removeObjectMehtod:(NSString *)anObject{
    [[self.undoManager prepareWithInvocationTarget:self] addObjectMethod:anObject];
    if ([self.undoArr containsObject:anObject]) {
        [self.undoArr removeObject:anObject];
    }
}

@end

　　2.2、視圖移動的undo和redo

- (void)viewDidLoad {
    [super viewDidLoad];
    _undoManager = [[NSUndoManager alloc] init];
}
- (void)btnViewAdd{
    [[_undoManager prepareWithInvocationTarget:self] btnViewReduce];
    CGRect rect = self.btnView.frame;
    rect.origin.x +=10;
    self.btnView.frame = rect;
}
- (void)btnViewReduce{
    [[_undoManager prepareWithInvocationTarget:self] btnViewAdd];
    CGRect rect = self.btnView.frame;
    rect.origin.x -=10;
    self.btnView.frame = rect;
}
- (IBAction)addClick:(id)sender {
    [self btnViewAdd];
}
- (IBAction)reduceClick:(id)sender {
    [self btnViewReduce];
}

- (IBAction)undoClick:(UIButton *)sender {
    [_undoManager undo];
}
- (IBAction)redoClick:(UIButton *)sender {
    [_undoManager redo];
}

 

3、NSUndoManger的相關API

NS_CLASS_AVAILABLE(10_0, 3_0)
@interface NSUndoManager : NSObject {
@private
    id             _undoStack;
    id             _redoStack;
    NSArray         *_runLoopModes;
    uint64_t        _NSUndoManagerPrivate1;
    id             _target;
    id            _proxy;
    void        *_NSUndoManagerPrivate2;
    void        *_NSUndoManagerPrivate3;
}

//創建撤銷組
- (void)beginUndoGrouping;  //開始
- (void)endUndoGrouping;    //結束
@property BOOL groupsByEvent; //默認啟用，自動分組，一個RunLoop事件中注冊的所有undomanager為一個頂級組
@property (readonly) NSInteger groupingLevel;//組等級

//啟用和禁用撤消
- (void)disableUndoRegistration;
- (void)enableUndoRegistration;
@property (readonly, getter=isUndoRegistrationEnabled) BOOL undoRegistrationEnabled;

/* Groups By Event */


//限制撤銷堆棧
@property NSUInteger levelsOfUndo;

//在運行循環的周期內處理輸入類型的模式。
@property (copy) NSArray<NSRunLoopMode> *runLoopModes;

//執行撤消和重做
- (void)undo;
- (void)redo;
- (void)undoNestedGroup;

//檢查撤銷能力
@property (readonly) BOOL canUndo;
@property (readonly) BOOL canRedo;

//檢查是否正在執行撤消或重做
@property (readonly, getter=isUndoing) BOOL undoing;
@property (readonly, getter=isRedoing) BOOL redoing;

//移除撤銷操作
- (void)removeAllActions;
- (void)removeAllActionsWithTarget:(id)target;

//注冊撤消操作
- (void)registerUndoWithTarget:(id)target selector:(SEL)selector object:(nullable id)anObject;
- (id)prepareWithInvocationTarget:(id)target;
- (void)registerUndoWithTarget:(id)target handler:(void (^)(id target))undoHandler API_AVAILABLE(macos(10.11), ios(9.0), watchos(2.0), tvos(9.0)) NS_REFINED_FOR_SWIFT;

//如果撤銷組作為一個整體被丟棄，則該密鑰具有對應的true值。
FOUNDATION_EXPORT NSString * const NSUndoManagerGroupIsDiscardableKey API_AVAILABLE(macos(10.7), ios(5.0), watchos(2.0), tvos(9.0));
// used with NSRunLoop's performSelector:target:argument:order:modes:
static const NSUInteger NSUndoCloseGroupingRunLoopOrdering = 350000;

//可撤銷的撤消和重做操作
@property (readonly) BOOL undoActionIsDiscardable API_AVAILABLE(macos(10.7), ios(5.0), watchos(2.0), tvos(9.0));
@property (readonly) BOOL redoActionIsDiscardable API_AVAILABLE(macos(10.7), ios(5.0), watchos(2.0), tvos(9.0));
- (void)setActionIsDiscardable:(BOOL)discardable API_AVAILABLE(macos(10.7), ios(5.0), watchos(2.0), tvos(9.0));

//管理操作名字
@property (readonly, copy) NSString *undoActionName;
@property (readonly, copy) NSString *redoActionName;
- (void)setActionName:(NSString *)actionName;

//獲取和本地化菜單項標題
@property (readonly, copy) NSString *undoMenuItemTitle;
@property (readonly, copy) NSString *redoMenuItemTitle;
- (NSString *)undoMenuTitleForUndoActionName:(NSString *)actionName;
- (NSString *)redoMenuTitleForUndoActionName:(NSString *)actionName;

@end
//通知
//打開或關閉撤銷組
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerCheckpointNotification API_AVAILABLE(macos(10.0), ios(3.0), watchos(2.0), tvos(9.0));
//將要執行一個撤銷操作
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerWillUndoChangeNotification API_AVAILABLE(macos(10.0), ios(3.0), watchos(2.0), tvos(9.0));
//將要執行重做操作
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerWillRedoChangeNotification API_AVAILABLE(macos(10.0), ios(3.0), watchos(2.0), tvos(9.0));
//已經執行一個撤銷操作
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerDidUndoChangeNotification API_AVAILABLE(macos(10.0), ios(3.0), watchos(2.0), tvos(9.0));
//已經執行重做操作
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerDidRedoChangeNotification API_AVAILABLE(macos(10.0), ios(3.0), watchos(2.0), tvos(9.0));

//已經打開一個撤銷組時 beginUndoGrouping
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerDidOpenUndoGroupNotification API_AVAILABLE(macos(10.0), ios(3.0), watchos(2.0), tvos(9.0));
//將要關閉一個撤銷組時 endUndoGrouping
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerWillCloseUndoGroupNotification API_AVAILABLE(macos(10.0), ios(3.0), watchos(2.0), tvos(9.0));
//已經關閉一個撤銷組時 endUndoGrouping
FOUNDATION_EXPORT NSNotificationName const NSUndoManagerDidCloseUndoGroupNotification API_AVAILABLE(macos(10.7), ios(5.0), watchos(2.0), tvos(9.0));

NS_ASSUME_NONNULL_END