iOS development touch events and gestures

/**
  * Called when the finger starts to touch the view
  *
  * @param touches <#touches description#>
  * @param event <#event description#>
  */
- (void)touchesBegan:(NSSet&lt;UITouch *&gt; *)touches withEvent:(UIEvent *)event {
   
  NSLog(@"%s",__func__);
}
 
/**
  * Called when the finger moves on the view
  *
  * @param touches <#touches description#>
  * @param event <#event description#>
  */
- (void)touchesMoved:(NSSet&lt;UITouch *&gt; *)touches withEvent:(UIEvent *)event {
  NSLog(@"%s",__func__);
}
 
/**
  * Called when the finger leaves the view
  *
  * @param touches <#touches description#>
  * @param event <#event description#>
  */
- (void)touchesEnded:(NSSet&lt;UITouch *&gt; *)touches withEvent:(UIEvent *)event {
   
  NSLog(@"%s",__func__);
}
 
/**
  * Called when the touch event is interrupted by the system event
  *
  * @param touches <#touches description#>
  * @param event <#event description#>
  */
- (void)touchesCancelled:(NSSet&lt;UITouch *&gt; *)touches withEvent:(UIEvent *)event {
   
  NSLog(@"%s",__func__);
}

@interface UITouch : NSObject
 
@property(nonatomic,readonly) NSTimeInterval   timestamp;
@property(nonatomic,readonly) UITouchPhase    phase;
@property(nonatomic,readonly) NSUInteger     tapCount;  // touch down within a certain point within a certain amount of time
 
// majorRadius and majorRadiusTolerance are in points
// The majorRadius will be accurate +/- the majorRadiusTolerance
@property(nonatomic,readonly) CGFloat majorRadius NS_AVAILABLE_IOS(8_0);
@property(nonatomic,readonly) CGFloat majorRadiusTolerance NS_AVAILABLE_IOS(8_0);
 
@property(nullable,nonatomic,readonly,strong) UIWindow            *window;
@property(nullable,nonatomic,readonly,strong) UIView             *view;
@property(nullable,nonatomic,readonly,copy)  NSArray <UIGestureRecognizer *> *gestureRecognizers NS_AVAILABLE_IOS(3_2);
 
//Get the current location- (CGPoint)locationInView:(nullable UIView *)view;
//Get the location of the previous touch point- (CGPoint)previousLocationInView:(nullable UIView *)view;
 
// Force of the touch, where 1.0 represents the force of an average touch
@property(nonatomic,readonly) CGFloat force NS_AVAILABLE_IOS(9_0);
// Maximum possible force with this input mechanism
@property(nonatomic,readonly) CGFloat maximumPossibleForce NS_AVAILABLE_IOS(9_0);
 
@end

/**
  * Called when the finger moves on the view
  *
  * @param touches <#touches description#>
  * @param event <#event description#>
  */
- (void)touchesMoved:(NSSet&lt;UITouch *&gt; *)touches withEvent:(UIEvent *)event {
  NSLog(@"%s",__func__);
   
  //Get UITouch object  UITouch *touch = [touches anyObject];
   
  //Get the current point's location  CGPoint curP = [touch locationInView:self];
   
  //Get the position of the previous point  CGPoint preP = [touch previousLocationInView:self];
   
  // Calculate the offset of x  CGFloat offsetX =  - ;
   
  // Calculate the offset of y  CGFloat offsetY =  = ;
   
  //Modify the location of the view   = CGAffineTransformTranslate(, offsetX, offsetY);
}

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
   
  //Judge whether the current control can receive touch events  if ( == NO ||  == YES ||  <= 0.01) {
    return nil;
  }
   
  //Judge whether the touch point is on the current control  if ([self pointInside:point withEvent:event] == NO) {
    return nil;
  }
   
  //Transfer your own child control from behind to front  NSInteger count = ;
  for (NSInteger i = count - 1; i >= 0; i--) {
    UIView *childView = [i];
     
    //Convert the coordinate system on the current control to the coordinate system on the subcontrol    CGPoint childPoint = [self convertPoint:point toView:childView];
     
    //Recursively call the hitTest method to find the most suitable view    UIView *fitView = [childView hitTest:childPoint withEvent:event];
     
    if (fitView) {
      return fitView;
    }
  }
   
  //The loop ends, there is no more suitable view than yourself, return to yourself  return self;
   
}

//Tap gesture//  UITapGestureRecognizer *tap = [UITapGestureRecognizer alloc]initWithTarget:<#(nullable id)#> action:<#(nullable SEL)#>
   
  //Long press gesture is triggered twice by default//  UILongPressGestureRecognizer *longP = [UILongPressGestureRecognizer alloc]initWithTarget:<#(nullable id)#> action:<#(nullable SEL)#>
   
  //Swipe gesture The default direction is to go to the right//  UISwipeGestureRecognizer *swipe = [UISwipeGestureRecognizer alloc]initWithTarget:<#(nullable id)#> action:<#(nullable SEL)#>
   
  //Swivel gesture//  UIRotationGestureRecognizer *rotation = [UIRotationGestureRecognizer alloc]initWithTarget:<#(nullable id)#> action:<#(nullable SEL)#>
 
  //Pinch gesture//  UIPinchGestureRecognizer *pinch = [UIPinchGestureRecognizer alloc]initWithTarget:<#(nullable id)#> action:<#(nullable SEL)#>
   
  //Drag gesture//  UIPanGestureRecognizer *pan = [UIPanGestureRecognizer alloc]initWithTarget:<#(nullable id)#> action:<#(nullable SEL)#>

@interface ViewController ()<UIGestureRecognizerDelegate>
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
 
@end
 
@implementation ViewController
 
- (void)viewDidLoad {
  [super viewDidLoad];
 
  [self setUpPinch];
   
  [self setUpRotation];
 
  [self setUpPan];
   
}
#pragma mark - Gesture Proxy Method// Whether to enable triggering gestures//- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
//{
//  return NO;
//}
 
// Whether to support multiple gestures at the same time, the default is that multiple gestures are not supported// Return to yes to support multiple gestures- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
  return YES;
}
 
// Whether to accept finger touch points//- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
// // Get the current touch point//  CGPoint curP = [touch locationInView:];
//  
//  if ( <  * 0.5) {
//    return NO;
//  }else{
//    return YES;
//  }
//}
 
 
#pragma mark - Tap gesture 
- (void)setUpTap
{
  // Create a tap gesture  UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tap:)];
   
   = self;
   
  [_imageView addGestureRecognizer:tap];
}
 
- (void)tap:(UITapGestureRecognizer *)tap
{
  NSLog(@"%s",__func__);
}
 
#pragma mark - long press gesture// It will be triggered twice by default- (void)setUpLongPress
{
  UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPress:)];
   
  [ addGestureRecognizer:longPress];
}
 
 
- (void)longPress:(UILongPressGestureRecognizer *)longPress
{
   
  if ( == UIGestureRecognizerStateBegan) {
     
    NSLog(@"%s",__func__);
  }
}
 
#pragma mark - swipe- (void)setUpSwipe
{
  // The default swipe direction is to the right  UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe)];
   
   = UISwipeGestureRecognizerDirectionUp;
   
  [ addGestureRecognizer:swipe];
   
  // If you want a control to support swipes in multiple directions in the future, you must create multiple swipes, and a swipe gesture only supports one direction.  // The default swipe direction is to the right  UISwipeGestureRecognizer *swipeDown = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(swipe)];
   
   = UISwipeGestureRecognizerDirectionDown;
   
  [ addGestureRecognizer:swipeDown];
 
   
}
 
- (void)swipe
{
  NSLog(@"%s",__func__);
}
 
#pragma mark - Rotate gesture- (void)setUpRotation
{
  UIRotationGestureRecognizer *rotation = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:@selector(rotation:)];
   = self;
  [ addGestureRecognizer:rotation];
}
 
// The angle of rotation passed by default is relative to the initial position- (void)rotation:(UIRotationGestureRecognizer *)rotation
{
   
   = CGAffineTransformRotate(, );
   
  // Reset   = 0;
   
  // Get the angle of the gesture rotation  NSLog(@"%f",);
}
 
#pragma mark - pinch- (void)setUpPinch
{
  UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@selector(pinch:)];
   = self;
  [ addGestureRecognizer:pinch];
}
 
- (void)pinch:(UIPinchGestureRecognizer *)pinch
{
   = CGAffineTransformScale(, , );
   
  // Reset   
   = 1;
}
 
#pragma mark - drag and drop- (void)setUpPan
{
  UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];
   
   
  [ addGestureRecognizer:pan];
}
 
- (void)pan:(UIPanGestureRecognizer *)pan
{
  // Get the touch point of gesture  // CGPoint curP = [pan locationInView:];
   
  // Mobile view  // Get the movement of the gesture, which is also relative to the initial position  CGPoint transP = [pan translationInView:];
   
   = CGAffineTransformTranslate(, , );
   
  // Reset  [pan setTranslation:CGPointZero inView:];
   
 // NSLog(@"%@",NSStringFromCGPoint(curP));
}
 
@end