CODEWITHSUNDEEP
iphoneobjective-cuigesturerecognizer
Centurion
Centurion

Reputation: 14304

How to attach one UIPanGestureRecognizer object for several views?

Is it possible to alloc only one UIPanGestureRecognizer and attach to multiple views? I have multiple on-screen UIImageView objects that user can move (pan). If I'm making alloc and attaching the same UIPanGestureRecognizer object to all views then the pan gesture works only on the last attached view. I did a workaround by making multiple alloc/init of UIPanGestureRecognizer, I mean one different UIPanGestureRecognizer object for each view. Here's the code:

- (void)viewDidLoad
{
  [super viewDidLoad];

  UIPanGestureRecognizer * pgr = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(updateImagePosition:)];
  [self.panningBtn1 addGestureRecognizer:pgr];
  [pgr release];

  pgr = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(updateImagePosition:)];
  [self.panningBtn2 addGestureRecognizer:pgr];
  [pgr release];

  ...

PS. I also have enabled MultipleTouchEnabled & UserInteractionEnabled. Are there any more elegant solutions?

Upvotes: 2

Views: 1846

Answers (1)

Benjie
Benjie

Reputation: 7946

No - each UIGestureRecognizer can only belong to one view. Just create multiple with the same properties and assign them to the different views.

I suggest creating the gesture recognizer in a method:

-(UIGestureRecognizer *)myGRMethod {
  UIPanGestureRecognizer *pgr = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(updateImagePosition:)];
  return [pgr autorelease];
}

and then just doing 

for (UIView *view in views) {
    [view addGestureRecognizer:[self myGRMethod]];
}

Upvotes: 4

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