#define ScreenWidth [UIScreen mainScreen].bounds.size.width
#define ScreenHeight [UIScreen mainScreen].bounds.size.height
#import "ViewController.h"

@interface ViewController ()

/**保存图片原来的大小*/
@property (nonatomic, assign) CGRect oldFrame;
/**确定图片放大最大的程度*/
@property (nonatomic, assign) CGRect largeFrame;
/**图片原始属性*/
@property (nonatomic, assign) CGAffineTransform oldTransform;

@property (weak, nonatomic) IBOutlet UIView *RootView;
@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    /// 加载图片
    [_imageView setMultipleTouchEnabled:YES];
    [_imageView setUserInteractionEnabled:YES];
    [_imageView setImage:[UIImage imageNamed:@"1"]];
   
    _oldFrame = self.imageView.frame;
    _oldTransform = self.imageView.transform;
    _largeFrame = CGRectMake(0 - ScreenWidth, 0 - ScreenHeight, 3 * _oldFrame.size.width, 3 * _oldFrame.size.height);
    /// 添加手势
    [self addGestureRecognizerToView:self.imageView];
}

// 添加所有的手势
- (void) addGestureRecognizerToView:(UIView *)view
{
    // 旋转手势
    UIRotationGestureRecognizer *rotationGestureRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotateView:)];
    [view addGestureRecognizer:rotationGestureRecognizer];

    /// 点击手势
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(doubleClick:)];
    [view addGestureRecognizer:tap];
    
    // 缩放手势
    UIPinchGestureRecognizer *pinchGestureRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchView:)];
    [view addGestureRecognizer:pinchGestureRecognizer];
    
    // 移动手势
    UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panView:)];
    [view addGestureRecognizer:panGestureRecognizer];
}

// 处理旋转手势
- (void) rotateView:(UIRotationGestureRecognizer *)rotationGestureRecognizer
{
    UIView *view = rotationGestureRecognizer.view;
    view.transform = CGAffineTransformRotate(view.transform, rotationGestureRecognizer.rotation);
    [rotationGestureRecognizer setRotation:0];
    if (rotationGestureRecognizer.state == UIGestureRecognizerStateBegan || rotationGestureRecognizer.state == UIGestureRecognizerStateChanged) {
    }
}

// 处理缩放手势
- (void) pinchView:(UIPinchGestureRecognizer *)pinchGestureRecognizer
{
    UIView *view = pinchGestureRecognizer.view;
    if (pinchGestureRecognizer.state == UIGestureRecognizerStateBegan || pinchGestureRecognizer.state == UIGestureRecognizerStateChanged) {
        view.transform = CGAffineTransformScale(view.transform, pinchGestureRecognizer.scale, pinchGestureRecognizer.scale);
        /// 控制一下缩放的大小
        if (_imageView.frame.size.width < _oldFrame.size.width) {  
            _imageView.frame = _oldFrame;  
            //让图片无法缩得比原图小  
        }  
        if (_imageView.frame.size.width > 3 * _oldFrame.size.width) {  
            _imageView.frame = _largeFrame;  
        }  
        pinchGestureRecognizer.scale = 1;
    }
}

// 处理拖拉手势
- (void) panView:(UIPanGestureRecognizer *)panGestureRecognizer
{
    UIView *view = panGestureRecognizer.view;
    if (panGestureRecognizer.state == UIGestureRecognizerStateBegan || panGestureRecognizer.state == UIGestureRecognizerStateChanged) {
        CGPoint translation = [panGestureRecognizer translationInView:view.superview];
        [view setCenter:(CGPoint){view.center.x + translation.x, view.center.y + translation.y}];
        [panGestureRecognizer setTranslation:CGPointZero inView:view.superview];
    }
}

/// 点击手势,恢复原始状态
- (void)doubleClick:(UITapGestureRecognizer *)tapGestureRecognizer {
    UIView *view = tapGestureRecognizer.view;
    if (tapGestureRecognizer.state == UIGestureRecognizerStateEnded) {
        view.transform = _oldTransform;
        view.frame = _oldFrame;
    }
}