GestureRecognizerで移動、拡大・縮小、回転

GestureView.h

#import <UIKit/UIKit.h>

@interface GestureView : UIView <UIGestureRecognizerDelegate>

@end

GestureView.m

#import "GestureView.h"

@interface GestureView ()
@property (nonatomic, strong) UIImageView *imageView;
@end

@implementation GestureView

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self initializeView];
    }
    return self;
}

- (void)initializeView
{
    self.imageView = [[UIImageView alloc] initWithFrame:self.frame];
    self.imageView.image = [UIImage imageNamed:@"image"];
    self.imageView.contentMode = UIViewContentModeScaleAspectFill;
    [self addSubview:self.imageView];

    self.userInteractionEnabled = YES;

    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGesture:)];
    pan.delegate = self;
    [self addGestureRecognizer:pan];

    UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotationGesture:)];
    rotation.delegate = self;
    [self addGestureRecognizer:rotation];

    UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinchGesture:)];
    pinch.delegate = self;
    [self addGestureRecognizer:pinch];

}

// 複数のジェスチャを認識させるために必要
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}

// 移動
- (void)panGesture:(UIPanGestureRecognizer *)gesture
{
    CGPoint translation = [gesture translationInView:self];
    self.imageView.center = CGPointMake(self.imageView.center.x + translation.x, self.imageView.center.y + translation.y);
    [gesture setTranslation:CGPointZero inView:self];
}

// 回転
- (void)rotationGesture:(UIRotationGestureRecognizer *)gesture
{
    [self.imageView setTransform:CGAffineTransformRotate(self.imageView.transform, gesture.rotation)];
    gesture.rotation = 0;
}

// 拡大・縮小
- (void)pinchGesture: (UIPinchGestureRecognizer *)gesture
{
    [self.imageView setTransform:CGAffineTransformScale(self.imageView.transform, gesture.scale, gesture.scale)];
    gesture.scale = 1;
}