How can an UIImageView can be touched while it is animating to alpha 0?

Question

Somebody help!

Here is what I want to implement :

• While an UIImageView is becoming alpha 0 (hidden)
• it can be touched
• so that its alpha becomes one (unhidden).

But UIImageView is not touched while it is animating (=becoming alpha 0).

I tried hundred skills at stackoverflow, but didn't work.

They are.......

1. UIViewAnimationOptionAllowUserInteraction
2. setUserInteractionEnabled:YES;
3. touchesBegan
4. GestureRecognizer options
5. etc..

Only function 'hitTest' worked but not during animation.

Please reply . Thank you. Below is my codes.

#import "ViewController.h"
#define AD @"text.png"
#import <QuartzCore/QuartzCore.h>

@interface ViewController ()

@end

@implementation ViewController


@synthesize scrollData=_scrollData;
@synthesize adImage=_adImage;



   - (void)viewDidLoad
    {
        //_adImage is UIImageView
        _adImage=[[adImage alloc] initWithImage:[UIImage imageNamed:AD]];
_scrollData.scrollView.delegate = self;

    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTapGestureCaptured:)];

        [_adImage addGestureRecognizer:singleTap];
        [_adImage setMultipleTouchEnabled:YES];
        [_adImage setUserInteractionEnabled:YES];

        [self.view addSubview:_adImage];
        _adImage.alpha=0;
        [_adImage setUp_pt:CGPointMake(160,250)];
        _adImage.center=_adImage.up_pt;

        [super viewDidLoad];
        [self hideImage:_adImage delay:0];
        [self becomeFirstResponder];
    }


    - (void)hideImageComplete:(UIView*)v
    {
        [self hideImage:v delay:0];
    }

    - (void)hideImage:(UIImageView*)v delay:(int)nDelay
    {
        [_adImage becomeFirstResponder];

        [UIView animateWithDuration:1
                              delay:nDelay
                            options:
         (UIViewAnimationOptionCurveEaseIn | UIViewAnimationOptionAllowUserInteraction)
                         animations: ^
         {
                 _adImage.alpha=0.0f;
         }
                         completion:^(BOOL completed){
                             [self hideImageComplete:v];
                         }];
    }

- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
    NSLog(@"Gesture event on view");
    _adImage.alpha=1;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    return YES;
}

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
    return YES;
}




- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
    NSLog(@"hit!!");
    [super touchesBegan:touches withEvent:event];
    UITouch *touch = [touches anyObject];
    CGPoint touchPoint = [touch locationInView:self.view];
    CGPoint touchLocation = [touch locationInView:self.view];
    _adImage.alpha=1;

}


@end



@implementation adImage
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint touchPoint = [touch locationInView:self];
    if ([[[self layer] presentationLayer] hitTest:touchPoint]) {
        [self.layer removeAllAnimations];
    }
}
-(UIView*)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
    if ([[self.layer presentationLayer] hitTest:point]) {
        NSLog(@"hit!!");
        self.alpha=1;
        return self;
    }
    return [super hitTest:point withEvent:event];
}

@synthesize up_pt;


@end

Here is my ViewController.h codes.

#import <UIKit/UIKit.h>


@interface adImage : UIImageView {
}


//@property (strong, nonatomic) UIImageView *imageView;

@property (assign)CGPoint up_pt;


@end



@interface ViewController : UIViewController <UIScrollViewDelegate>{
}

- (void)hideImageComplete:(UIView*)v;
- (void)hideImage:(UIView*)v delay:(int)nDelay;

@property (strong, nonatomic) adImage *adImage;
@property(nonatomic, strong) IBOutlet UIWebView *scrollData;


@end

Answer 1

I have the answer for you, but first:

• always name a class with a starting capital letter, ie AdImageView (its an image view not a pure view subclass too)

• I took your code but commented out all your touch methods, which you may or may not need

• the root issue here is that a UIGestureRecognizer won't work if alpha is 0, so you will see the animation to alpha=0 is broken into two pieces, almost to 0, then to 0. If the user taps to cancel, then the final completion block returns the view to 0

Code:

- (void)hideImage:(UIImageView*)v delay:(int)nDelay
{
    //[_adImage becomeFirstResponder];

    [UIView animateWithDuration:(3.0f - 0.1f)
                          delay:nDelay
                        options: (UIViewAnimationOptionCurveEaseIn | 
                                  UIViewAnimationOptionAllowUserInteraction)
                     animations: ^
     {
             _adImage.alpha=0.1f;
     }
                     completion:^(BOOL completed)
                     {
                        NSLog(@"completed=%d", completed);
                        if(completed) {
                            [UIView animateWithDuration:0.1f animations:^{
                                _adImage.alpha=0.0f;
                            }];
                        } else {
                            _adImage.alpha=1;
                        }
                     }];
}

- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
    NSLog(@"Gesture event on view");
    [_adImage.layer removeAllAnimations];
}