IOS第15天(3,事件处理，手势处理）

7> 手势识别
    使用UIImageView原因：之前既能看见图片，又能监听点击的只有UIButton,学了手势，我们的UIImageView也可以。
    * tap(代理：左边不能点，右边能点)
    * longPress(allowableMovement:触发之前，最大的移动范围)
        > 默认调用两次，开始一次，结束一次。
    * swipe:(一个手势只能识别一个方向)
    * 旋转：
      基于上一次旋转
    * 复位：(手势的取值都是相对最原始的位置，我们应该是需要相对上一次，因此每次调用，就复位一下，每次都是从零开始旋转角度)
      缩放：复位
    * 如何同时支持旋转和缩放？默认不支持多个手指，
      Simultaneously：同时
      当使用一个手势的时候会调用代理的Simultaneously方法，询问是否支持多个手势
    * pan
      获取平移的位置：translationInView
      复位：setTranslation:inView: 需要传一个view，因为点的位置跟坐标系有关系，看他是基于哪个坐标系被清空的。

#import "HMViewController.h"

@interface HMViewController ()<UIGestureRecognizerDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *imagView;

@end

@implementation HMViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    // pan
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
  
    
    [_imagView addGestureRecognizer:pan];
}

- (void)pan:(UIPanGestureRecognizer *)pan
{
    // 获取手指移动的位置
    CGPoint trans = [pan translationInView:_imagView];
    
    _imagView.transform = CGAffineTransformTranslate(_imagView.transform, trans.x, trans.y);
    
    // 复位
    [pan setTranslation:CGPointZero inView:_imagView];
    NSLog(@"%@",NSStringFromCGPoint(trans));
    
}

#warning pinch
- (void)addPinch
{
    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)];
    // 设置代理的原因：想要同时支持多个手势
    pinch.delegate = self;
    [_imagView addGestureRecognizer:pinch];
    
}

- (void)pinch:(UIPinchGestureRecognizer *)pinch
{
    _imagView.transform = CGAffineTransformScale(_imagView.transform, pinch.scale, pinch.scale);
    
    // 复位
    pinch.scale = 1;
}

// Simultaneous:同时
// 默认是不支持多个手势
// 当你使用一个手势的时候就会调用
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}



#warning rotation
- (void)addRotation
{
    // rotation
    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)];
    rotation.delegate = self;
    [_imagView addGestureRecognizer:rotation];
}



- (void)rotation:(UIRotationGestureRecognizer *)rotation
{
    NSLog(@"%f",rotation.rotation);
//    _imagView.transform = CGAffineTransformMakeRotation(rotation.rotation);
    _imagView.transform = CGAffineTransformRotate(_imagView.transform, rotation.rotation);
    
    // 复位
    rotation.rotation = 0;
}

#warning Swipe
- (void)addSwipe
{
    // Swipe
    // 一个手势只能识别一个方向
    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe:)];
    swipe.direction = UISwipeGestureRecognizerDirectionRight;
    [_imagView addGestureRecognizer:swipe];
}

- (void)swipe:(UISwipeGestureRecognizer *)swipe
{
    NSLog(@"swipe");
}

#warning longPress
- (void)addLongPress
{
    // longPress
    UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
    
    [_imagView addGestureRecognizer:longPress];
}


- (void)longPress:(UILongPressGestureRecognizer *)longPress
{
    // 根据状态执行事件
    if (longPress.state == UIGestureRecognizerStateBegan) {
        
        NSLog(@"longPress");
    }
}


#warning tap
- (void)addTap
{
    // tap
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)];
    // 点按多少次才能触发手势
    //    tap.numberOfTapsRequired = 2;
    //
    //    // 必须多少个手指触摸才能触发手势
    //    tap.numberOfTouchesRequired = 2;
    
    tap.delegate = self;
    
    [_imagView addGestureRecognizer:tap];
}

// 这个触摸点能否触发手势
//- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
//{
//    CGPoint currentPoint = [touch locationInView:_imagView];
//    
//    if (currentPoint.x < _imagView.bounds.size.width * 0.5) {
//        return NO;
//    }else{
//        
//        return YES;
//    }
//}

- (void)tap:(UITapGestureRecognizer *)tap
{
    NSLog(@"tap");
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end