Transmission and response of events and use cases

Where response chains are used in a project

1. stay scrollView Add slider

// -  Scheme 1 
-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event{

    if (CGRectContainsPoint(self.subView.frame, point)) {
        self.scrollEnabled = NO;
        return YES;
    }
    self.scrollEnabled = YES;
    return YES;
}

// -  Option two 
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
    if (CGRectContainsPoint(self.subView.frame, point)) {
        self.scrollEnabled = NO;
        return [super hitTest:point withEvent:event];
    }
    self.scrollEnabled = YES;
    return [super hitTest:point withEvent:event];
}

// -  Option three 
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
   UIView *view = [super hitTest:point withEvent:event];
   if([view isKindOfClass:[UISlider class]]) {
       self.scrollEnabled = NO;
   } else {
      self.scrollEnabled = YES;
   }
   return view;
}

2. Set up scrollview Do the tab view On the first option, you can slide back to the left

// -  Set up  scrollview  Do the tab  view  On the first option, you can slide back to the left 

-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{

    if ([[super hitTest:point withEvent:event] isKindOfClass:[UIControl class]]) {
        return [super hitTest:point withEvent:event];
    }else{
        if ((self.contentOffset.x == 0) && (point.x < 30)) {
            return nil;
        }
         return [super hitTest:point withEvent:event];
    }

}

3. Let events penetrate view

// -  Set events to penetrate  view
@implementation DYContainerBgView
/**  Through events  */
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
    if ([super hitTest:point withEvent:event] == self) return nil;
    return [super hitTest:point withEvent:event];
}

@end

4. Resolution of event transmission

1. A term is used to explain
   1. events : The order from top to bottom （UIApplication–>UIWindow–> Recursively find the most suitable View）, That is, the search process from parent control to child control ( The most important thing in event transmission is to find the right View To receive events , Find from parent view to child view , Same parent view , Add to parent view from behind To First add to view The order of traversal );
   2. Event response : The order from bottom to top （ Realization View Of touchesBegan Method , If it's time to View Unable to handle event , Is passed up to its parent control ）, Pass from child control to parent control ( Find the right View This... Will then be called View Of touches Method to handle specific events , If the current view Do not respond to touch Method , Just find the last responder (superviwe, perhaps view The controller ) To respond to events );

// -  Sample code  : 
- (void)viewDidLoad {
    [super viewDidLoad];
    
    QGView *v1 = [[QGView alloc]initWithFrame:CGRectMake(90, 90, 200, 200)];
    v1.backgroundColor = [UIColor redColor];
    v1.testStr = @"v1";
    [self.view addSubview:v1];
    
    QGView *v2 = [[QGView alloc]initWithFrame:CGRectMake(90, 90, 180, 180)];
    v2.backgroundColor = [UIColor greenColor];
    v2.testStr = @"v2";
    [self.view addSubview:v2];
    
    QGView *v3 = [[QGView alloc]initWithFrame:CGRectMake(90, 90, 160, 160)];
    v3.testStr = @"v3";
    v3.backgroundColor = [UIColor redColor];
    [self.view addSubview:v3];
    
    QGView *v31 = [[QGView alloc]initWithFrame:CGRectMake(0, 0, 120, 120)];
    v31.backgroundColor = [UIColor greenColor];
    v31.testStr = @"v31";
    [v3 addSubview:v31];
    
    QGView *v32 = [[QGView alloc]initWithFrame:CGRectMake(0, 0, 100, 100)];
    v32.testStr = @"v32";
    v32.backgroundColor = [UIColor redColor];
    [v3 addSubview:v32];
    
    QGView *v33 = [[QGView alloc]initWithFrame:CGRectMake(0, 0, 80, 80)];
    v33.backgroundColor = [UIColor greenColor];
    v33.testStr = @"v33";
    [v3 addSubview:v33];
}

stay self.view.subView Array , Added after view, The more the element next to the array , stay view The higher the level in , The closer to the user

// -  test  : 
1.  Click on v3
2020-05-11 11:12:54.027766+0800 Demo_001[2008:56637] pointInside v3, ruturn : 1
2020-05-11 11:12:54.027995+0800 Demo_001[2008:56637] pointInside v33, ruturn : 0
2020-05-11 11:12:54.028168+0800 Demo_001[2008:56637] hitTest v33, ruturn : (null)
2020-05-11 11:12:54.028309+0800 Demo_001[2008:56637] pointInside v32, ruturn : 0
2020-05-11 11:12:54.028438+0800 Demo_001[2008:56637] hitTest v32, ruturn : (null)
2020-05-11 11:12:54.028569+0800 Demo_001[2008:56637] pointInside v31, ruturn : 0
2020-05-11 11:12:54.028674+0800 Demo_001[2008:56637] hitTest v31, ruturn : (null)
2020-05-11 11:12:54.029436+0800 Demo_001[2008:56637] hitTest v3, ruturn : <QGView: 0x7f9bede05ad0; frame = (90 90; 160 160); layer = <CALayer: 0x600003ec0780>>

2.  Click on v33
2020-05-11 11:13:54.777979+0800 Demo_001[2008:56637] pointInside v3, ruturn : 1
2020-05-11 11:13:54.778181+0800 Demo_001[2008:56637] pointInside v33, ruturn : 1
2020-05-11 11:13:54.778399+0800 Demo_001[2008:56637] hitTest v33, ruturn : <QGView: 0x7f9bede0ca40; frame = (0 0; 80 80); layer = <CALayer: 0x600003ec0aa0>>
2020-05-11 11:13:54.778587+0800 Demo_001[2008:56637] hitTest v3, ruturn : <QGView: 0x7f9bede0ca40; frame = (0 0; 80 80); layer = <CALayer: 0x600003ec0aa0>>

3.  Click on v31
2020-05-11 11:15:13.166848+0800 Demo_001[2008:56637] pointInside v3, ruturn : 1
2020-05-11 11:15:13.167039+0800 Demo_001[2008:56637] pointInside v33, ruturn : 0
2020-05-11 11:15:13.167145+0800 Demo_001[2008:56637] hitTest v33, ruturn : (null)
2020-05-11 11:15:13.167275+0800 Demo_001[2008:56637] pointInside v32, ruturn : 0
2020-05-11 11:15:13.167396+0800 Demo_001[2008:56637] hitTest v32, ruturn : (null)
2020-05-11 11:15:13.167503+0800 Demo_001[2008:56637] pointInside v31, ruturn : 1
2020-05-11 11:15:13.167669+0800 Demo_001[2008:56637] hitTest v31, ruturn : <QGView: 0x7f9bede08420; frame = (0 0; 120 120); layer = <CALayer: 0x600003ec0a40>>
2020-05-11 11:15:13.167813+0800 Demo_001[2008:56637] hitTest v3, ruturn : <QGView: 0x7f9bede08420; frame = (0 0; 120 120); layer = <CALayer: 0x600003ec0a40>>

4.  Click on v1
2020-05-11 11:16:01.172527+0800 Demo_001[2008:56637] pointInside v3, ruturn : 0
2020-05-11 11:16:01.172711+0800 Demo_001[2008:56637] hitTest v3, ruturn : (null)
2020-05-11 11:16:01.172835+0800 Demo_001[2008:56637] pointInside v2, ruturn : 0
2020-05-11 11:16:01.172931+0800 Demo_001[2008:56637] hitTest v2, ruturn : (null)
2020-05-11 11:16:01.173068+0800 Demo_001[2008:56637] pointInside v1, ruturn : 1
2020-05-11 11:16:01.173249+0800 Demo_001[2008:56637] hitTest v1, ruturn : <QGView: 0x7f9bede06520; frame = (90 90; 200 200); layer = <CALayer: 0x600003ec01e0>>

Conclusion : Current vc All of the subView, Call from outside to inside ; Find it from view Of subView in , Call from outside to inside