iOS设计模式 - 组合

原理图

Composite.png

说明

将对象组合成树形结构表示"部分-整体"的层次结构, 组合模式使得用户对单个对象和组合对象的使用具有一致性

代码实现

Client

//
//  ViewController.m
//  Composite
//
//  Created by mye on 2019/3/28.
//  Copyright © 2019 mye. All rights reserved.
//

#import "ViewController.h"
#import "File.h"
#import "Directory.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // client
    Directory *root = [[Directory alloc] initWithName:@"root"];
    File *file1 = [[File alloc] initWithName:@"file1"];
    File *file2 = [[File alloc] initWithName:@"file2"];
    File *file3 = [[File alloc] initWithName:@"file3"];
    Directory *subDir1 = [[Directory alloc] initWithName:@"subDir1"];
    [root addFile:file1];
    [root addFile:file2];
    [root addFile:file3];
    [root addFile:subDir1];
    
    File *subFile1 = [[File alloc] initWithName:@"subFile1"];
    File *subFile2 = [[File alloc] initWithName:@"subFile2"];
    File *subFile3 = [[File alloc] initWithName:@"subFile3"];
    [subDir1 addFile:subFile1];
    [subDir1 addFile:subFile2];
    [subDir1 addFile:subFile3];
    
    [root displayAllFile];
}


@end

AbstractFile

//
//  AbstractFile.h
//  Composite
//
//  Created by mye on 2019/3/28.
//  Copyright © 2019 mye. All rights reserved.
//

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface AbstractFile : NSObject

@property (nonatomic, copy) NSString *fileName;

- (instancetype)initWithName:(NSString *)fileName;
- (NSString *)getInfo;

@end

NS_ASSUME_NONNULL_END

//
//  AbstractFile.m
//  Composite
//
//  Created by mye on 2019/3/28.
//  Copyright © 2019 mye. All rights reserved.
//

#import "AbstractFile.h"

@implementation AbstractFile

- (instancetype)initWithName:(NSString *)fileName {
    self = [super init];
    if (self) {
        self.fileName = fileName;
    }
    return self;
}

- (NSString *)getInfo {
    return self.fileName;
}

@end

File

//
//  File.h
//  Composite
//
//  Created by mye on 2019/3/28.
//  Copyright © 2019 mye. All rights reserved.
//

#import "AbstractFile.h"

NS_ASSUME_NONNULL_BEGIN

@interface File : AbstractFile

@end

NS_ASSUME_NONNULL_END

//
//  File.m
//  Composite
//
//  Created by mye on 2019/3/28.
//  Copyright © 2019 mye. All rights reserved.
//

#import "File.h"

@implementation File

@end

Directory

//
//  Directory.h
//  Composite
//
//  Created by mye on 2019/3/28.
//  Copyright © 2019 mye. All rights reserved.
//

#import "AbstractFile.h"

NS_ASSUME_NONNULL_BEGIN

@interface Directory : AbstractFile

@property (nonatomic, strong) NSMutableArray<AbstractFile *> *files;

/**
 添加文件

 @param file 文件
 */
- (void)addFile:(AbstractFile *)file;

/**
 删除文件

 @param file 文件
 */
- (void)removeFile:(AbstractFile *)file;

/**
 显示所有文件
 */
- (void)displayAllFile;

@end

NS_ASSUME_NONNULL_END


//
//  Directory.m
//  Composite
//
//  Created by mye on 2019/3/28.
//  Copyright © 2019 mye. All rights reserved.
//

#import "Directory.h"

@implementation Directory

/**
 添加文件
 
 @param file 文件
 */
- (void)addFile:(AbstractFile *)file {
    [self.files addObject:file];
}

/**
 删除文件
 
 @param file 文件
 */
- (void)removeFile:(AbstractFile *)file {
    [self.files removeObject:file];
}

/**
 显示所有文件
 */
- (void)displayAllFile {
    for (AbstractFile *file in self.files) {
        NSLog(@"%@", [file getInfo]);
        if ([file isKindOfClass:[Directory class]]) {
            Directory *dir = (Directory *)file;
            [dir displayAllFile];
        }
    }
}

- (NSMutableArray<AbstractFile *> *)files {
    if (!_files) {
        _files = [NSMutableArray array];
    }
    return _files;
}

@end