Question

In my code I have an array of objects which are UIImageViews with UIImages in them.

I use a for loop in -(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event to move all objects from the array one by one.

Once they are moved to different positions on the main view I would like to be able to grab any of those objects and move them somewhere else.

I’m not sure how best to do this. Is there a way I can use touchesbegin so that I can drag only the item I clicked on?

Basically, there are five UIImageViews there now and each one has UIImage and I am trying to get to the point where when i click on any of them they are able to move around.

Answer 1

I’ve done something similar with great success using the UIPanGestureRecognizer in my draggable view. To hook it up, it might look something like this:

@implementation DraggableView

-(id)initWithFrame:(CGRect)frame
{
   ...
   ...
   UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)] autorelease];
   [self addGestureRecognizer:panGesture];
   ..
   return self;
}
@end

In your pan: method, you could check the state of the gesture and even capture the gesture’s location and use it to relocate your view. Here’s a rough example of what it might look like:

-(void)pan:(UIPanGestureRecognizer *)gesture
{

   if (gesture.state==UIGestureRecognizerStateChanged)
   {
      //We're moving!
      UIView *aRootView = <perhaps your root view controller's view>;
      CGPoint currentOrigin = [gesture translationInView:aRootView];
      self.frame = CGRectMake(currentOrigin.x,currentOrigin.y,self.frame.size.width,self.frame.size.hight);
      ...
      ...
   }

}

Here is more reading on the UIPanGestureRecognizer.