// // KBBackspaceUndoManager.h // CustomKeyboard // #import NS_ASSUME_NONNULL_BEGIN extern NSNotificationName const KBBackspaceUndoStateDidChangeNotification; @interface KBBackspaceUndoManager : NSObject @property (nonatomic, readonly) BOOL hasUndo; + (instancetype)shared; /// 记录一次“立刻清空”删除的内容(基于 documentContextBeforeInput) - (void)recordClearWithContext:(NSString *)context; /// 在指定 responder 处执行撤销(向光标处插回删除的内容) - (void)performUndoFromResponder:(UIResponder *)responder; /// 非清空行为触发时,清理撤销状态 - (void)registerNonClearAction; @end NS_ASSUME_NONNULL_END