touchEvent for subview in UIScrollView - ios

Question

All,
I have an issue and I have looked at all possible answers on StackOverflow (and other internet) but all solutions I try, nothing works....
I have a UIScrollView with a UIImageView as subview to create a board. I can zoom in and out, works fine. Also scrolling works fine!
Now, I want to drag & drop other UIImageViews (tiles) into the ScrollView and also OUT of the ScrollView. But when I drop the UIImageView in the ScrollView, I can not drag/drop the subview.
I have set the setCanCancelContentTouches:NO of the UIScrollView in the viewDidLoad.
I have created a subclass TileImageView and in the init I set the exclusiveTouch to YES.
NB: the boardImage is a 'normal' UIImageView', the tiles are with the subclass!
Addition: when I set the UserInteraction setting of the boardImage to NO, it the ScrollView zooms but touchBegan is not recorded. If I set it to YES, the ScrollView does not zoom, but the touchBegan is recorded..
So I leave it so I can zoom, but the Tiles are not draggable anymore once they are in the ScrollView.
What am I doing wrong? Or what am I missing?
PS: setting the delaysContentTouches property makes scrolling inactive, so that is also not a solution...
Code:
RootViewController_iphone.m
#implementation RootViewController_iphone
#synthesize boardScrollView;
#synthesize dragObject;
#synthesize boardImage;
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
UIImage *image = [UIImage imageNamed:#"greyblue_numbered_15x15_900x900.png"];
self.boardImage = [[UIImageView alloc] initWithImage:image];
self.boardImage.frame = (CGRect){.origin=CGPointMake(0.0f, 0.0f), .size=image.size};
[self.boardScrollView addSubview:self.boardImage];
self.boardImage.userInteractionEnabled = YES;
self.boardScrollView.contentSize = image.size;
self.boardScrollView.userInteractionEnabled = YES;
self.boardScrollView.canCancelContentTouches = NO;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
if ([touches count] == 1) {
// one finger
CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
for (UIImageView *iView in self.view.subviews) {
if ([iView isMemberOfClass:[TileImageView class]]) {
if (touchPoint.x > iView.frame.origin.x &&
touchPoint.x < iView.frame.origin.x + iView.frame.size.width &&
touchPoint.y > iView.frame.origin.y &&
touchPoint.y < iView.frame.origin.y + iView.frame.size.height)
{
self.dragObject = iView;
self.touchOffset = CGPointMake(touchPoint.x - iView.frame.origin.x,
touchPoint.y - iView.frame.origin.y);
self.homePosition = CGPointMake(iView.frame.origin.x,
iView.frame.origin.y);
[self.view bringSubviewToFront:self.dragObject];
}
}
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
CGRect newDragObjectFrame = CGRectMake(touchPoint.x - touchOffset.x,
touchPoint.y - touchOffset.y,
self.dragObject.frame.size.width,
self.dragObject.frame.size.height);
self.dragObject.frame = newDragObjectFrame;
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
NSString *tmp = touch.view.description;
CGPoint touchPointScreen = [[touches anyObject] locationInView:self.view];
CGPoint touchPointImage = [[touches anyObject] locationInView:self.boardImage];
CGPoint touchPointBoard = [[touches anyObject] locationInView:self.boardScrollView];
if (touchPointScreen.x > self.boardScrollView.frame.origin.x &&
touchPointScreen.x < self.boardScrollView.frame.origin.x + self.boardScrollView.frame.size.width &&
touchPointScreen.y > self.boardScrollView.frame.origin.y &&
touchPointScreen.y < self.boardScrollView.frame.origin.y + self.boardScrollView.frame.size.height)
{
self.dragObject.frame = CGRectMake(touchPointImage.x - touchOffset.x,
touchPointImage.y - touchOffset.y,
self.dragObject.frame.size.width,
self.dragObject.frame.size.height);
[self.boardImage addSubview:self.dragObject]; // add to image
}
}
Code:
TileImageView.m
#implementation TileImageView:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
self.exclusiveTouch = YES;
}
return self;
}

Answer 1

You already have subclassed UIImageView, so you can do the following inside your subclass:
1- Override touchsBegan, didEnd, and didMove
2- inside these methods pass them to the superview which is UIScrollView: [self.superview touchsBegan .... ]
3- If your UIImageView not receiving these messages then in init add self.userInteractionEnabled = YES;
Hopefully this going to help you