Obj-C 实现设计模式 -- Duck

自这一篇开始，准备用Obj-C 实现下HF设计模式里面的例子，权当对设计模式的学习。

鉴于OC中协议与Java接口的概念相似这一特性，先遵循针对接口编程的原则，设计两个协议类。

@protocol QuackBehaviorProtocol <NSObject>
@required
- (void) quack;
@end

@protocol FlyBehaviorProtocol <NSObject>
@required
- (void) fly;
@end

准备三个类遵守一下协议并予以实现。

@interface FlyBehavior : NSObject <FlyBehaviorProtocol>{
    
}
- (void) fly;
@end

@interface FlyWithWings : NSObject <FlyBehaviorProtocol> {

}
- (void)fly;
@end

@interface FlyNoWay : NSObject <FlyBehaviorProtocol> {

}
- (void)fly;
@end

@implementation FlyBehavior
- (void) fly{
    NSLog(@"Fly Behavior running.");
}
@end

@implementation FlyNoWay
- (void) fly{
    NSLog(@"FlyNoWay running");
}
@end

@implementation FlyWithWings
- (void) fly{
    NSLog(@"FlyWithWings running");
}
@end

@interface QuackBehavior : NSObject <QuackBehaviorProtocol>{
    
}
- (void) quack;
@end

@interface MuteQuack : NSObject <QuackBehaviorProtocol>{

}
- (void) quack;
@end

@interface SqueakQuack : NSObject <QuackBehaviorProtocol> {

}
- (void)quack;
@end

@implementation QuackBehavior

- (void) quack{
    NSLog(@"QuackBehavior running");
}
@end

@implementation MuteQuack

- (void) quack{
    NSLog(@"MuteQuack running");
}
@end

@implementation SqueakQuack
- (void) quack{
    NSLog(@"SqueakQuack running");
}
@end

Ok.有了上面的协议和对协议的实现，下面实现下Duck类，这个作为所有DuckModel的父类进行实现，明确好对应的接口和接口的set方法。

#import "QuackBehaviorProtocol.h"
#import "FlyBehaviorProtocol.h"

@interface Duck : NSObject {
    id<QuackBehaviorProtocol> _quackDelegate;
    id<FlyBehaviorProtocol> _flyDelegate;
}
@property (nonatomic, assign) id<QuackBehaviorProtocol> quackDelegate;
@property (nonatomic, assign) id<FlyBehaviorProtocol> flyDelegate;

- (id) initDuckWithQuackDelegate:(id)quackDelegate withFlyDelegate:(id)flyDelegate;
- (void) swim;
- (void) display;
@end

@implementation Duck
@synthesize flyDelegate = _flyDelegate;
@synthesize quackDelegate = _quackDelegate;

- (id) initDuckWithQuackDelegate:(id)quackDelegate withFlyDelegate:(id)flyDelegate{
    self = [super init];
    if (self) {
        
    }
    return self;
}

- (void) swim{
    NSLog(@"Duck Swimming");
}

- (void) display{
    NSLog(@"Duck Display");
}

- (void)dealloc{
    [_flyDelegate release];
    [_quackDelegate release];
    [super dealloc];
}
@end

最后，尽情的对Duck进行各种各样的实例化吧。

- (void)viewDidLoad
{
    [super viewDidLoad];
    ModelDuck * duck = [[ModelDuck alloc] init];
    FlyWithWings * fly = [[FlyWithWings alloc] init];
    SqueakQuack * quack = [[SqueakQuack alloc] init];
    [duck setFlyDelegate:fly];
    [duck setQuackDelegate:quack];
    
    [duck.quackDelegate quack];
    [duck.flyDelegate fly];
    [duck swim];    
}