Activating UIImageView with GestureRecognizer in a ScrollView - iphone

Question

I,
I'm currently trying to implement a Gesture recognizer into a ScrollView.
I first created a custom ScrollView in which I integrated ImageView object.
When the user clicks on a ImageView, normally the PanGestureRecognizer activates and the ImageView object follow the move on the screen.
I have read and followed the instructions on Gesture Recognizer and the Raywenderlich blog (which is very well done).
If someone has a clue of what is missing in my code, I would be happy to read it
Thank in advance. Here is my code
#import <Foundation/Foundation.h>
#import "mainInterface03.h"
#import <QuartzCore/QuartzCore.h>
#import "boutonHome.h"
#import "DragGestureRecognizer.h"
#class boutonHome;
#class DragGestureRecognizer;
#interface TapScrollView : UIScrollView {
// id<TapScrollViewDelegate> delegate;
NSMutableArray *classementBoutons;
int n;
int o;
UIView *bouton01;
}
#property (nonatomic, retain) UIView *bouton01;
#property (retain, nonatomic) IBOutletCollection(UIButton) NSMutableSet* buttons;
-(id)init;
-(void)initierScrollView;
-(void) createGestureRecognizers;
-(IBAction)handlePanGesture:(UIPanGestureRecognizer*)sender;
#end
m.file
#import "TapScrollView.h"
#implementation TapScrollView
#synthesize bouton01;
- (id) init
{
if (self = [super init])
{
NSLog(#"Classe TapScrollView initiée");
}
return self;
}
-(void)initierScrollView
{
int i;
for (i=0; i<6; i++) {
UIImage *image = [UIImage imageNamed:#"back.png"];
UIImageView *bouton = [[UIImageView alloc] initWithImage:image];
[bouton setTag:i];
[bouton setFrame:CGRectMake(72*i+20,10,62,55)];
[classementBoutons insertObject:bouton atIndex:i];
[self addSubview:bouton];
}
UIPanGestureRecognizer *recognizer = [[UIPanGestureRecognizer alloc] initWithTarget:bouton01 action:#selector(handlePanGesture:)];
[bouton01 addGestureRecognizer:recognizer];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
[super touchesBegan:touches withEvent:event];
for (o=1; o<6; o++) {
if ([touch view] == [self viewWithTag:o])
{
bouton01 = [self viewWithTag:o];
}
}
return;
}
-(IBAction)handlePanGesture:(UIPanGestureRecognizer*)recognizer
{
NSLog(#"Mouvement ok");
CGPoint translation = [recognizer translationInView:self];
recognizer.view.center = CGPointMake(recognizer.view.center.x + translation.x,
recognizer.view.center.y + translation.y);
[recognizer setTranslation:CGPointMake(0, 0) inView:self];
}
#end

Answer 1

I am not sure if this setup can work. Essentially, you are assigning whatever view has been touched to bouton01, which carries the gesture recognizer. Seems a bit convoluted to me, and also your code is not so efficient.
It seems that when you call [super touchesBegan:touches withEvent:event]; it will pass the touch up the view hierarchy. Only after that do make the assignment to bouton01. So it would seem logical that bouton01 never receives a touch event.
Indeed, it is because of this strange approach of iterating through the views and assigning it the one that has the recognizer that this error arose. I would suggest to assign the same recognizer to all concerned views during setup.