Simultaneous gesture recognizers in Iphone SDK

Question

I need to catch two different swipping gestures using UISwipeGestureRecognizer(for example, UISwipeGestureRecognizerDirectionRight and UISwip

Answer 1

The answer: "Um, a quick look at the documentation..." from Phoenix absolutely will not work!

He is setting a mask, then using the same variable to test as if the recognizer cleared it and set a single bit. It stores, as he correctly quoted from the documentation:

The permitted directions of the swipe

sender.direction

will simply return the mask you set initially and in his example, will never resolve to a single direction!

UISwipeGestureRecognizerDirectionRight == 1
UISwipeGestureRecognizerDirectionRight | UISwipeGestureRecognizerDirectionLeft == 3

Additionaly, for most cases you don't need to:

• setup a delegate
• permit simultaneous gesture recognition (unless you want simultaneous swipes; not likely)
• send the recognizer to the selector

The following works for me:

   UISwipeGestureRecognizer* swipe;

   swipe = [[[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeL)] autorelease];
   swipe.direction = UISwipeGestureRecognizerDirectionLeft;
   [view addGestureRecognizer:swipe];

   swipe = [[[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handleSwipeR)] autorelease];
   swipe.direction = UISwipeGestureRecognizerDirectionRight; // default
   [view addGestureRecognizer:swipe];