Detecting taps in uiimageview inside uiscrollview - iphone

I have a UIScrollView with multiple UIImageViews in it created like this.
frame = [[UIImageView alloc] initWithImage:bg];
frame.frame = CGRectMake(FRAME_SEPARATOR + numPage*1024 + numColumn*(FRAME_SEPARATOR+230), 10 +numRow*(FRAME_SEPARATOR+145), 230, 145);
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
[frame addGestureRecognizer:tap];
[tap release];
[scroll addSubView:frame];
The problem is that imageTapped is not being called when tapping over an image.
If I add the gesture recognizer to the scrollview like this:
UITapGestureRecognizer *tap =
[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
[scroll addGestureRecognizer:tap];
[tap release];
imageTapped is called.
How can I detect the taps over the UIImageViews?
Thanks

Make sure userInteractionEnabled is set to YES on the UIImageView:
frame.userInteractionEnabled = YES;
I'd also recommend using a different name for the UIImageView variable (eg. imageView instead of frame). Otherwise, you can easily confuse it with the view's frame property.

Related

Gesture recognizer does not recognise a view which is created over an UIImageView

I have an UIImageview with tap gesture on it, such that any tap over it creates a rectangular view with white background. Which I can move any where over imageview. Like this I can create infinite views over that imageview.
Now my problem is that I want to add double tap gestures to newly created views but when I click on any of those views then a new view is created over that view.
But what I want is that if I tap on a view then no new view must be created over that view.
Currently gestureRecognizer recognises UIImageView even if I have created a new view over UIImageView.
ImageView,
UIImageView *imageView = [[UIImageView alloc]init];
UITapGestureRecognizer * tapRecognizer = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(createNewView)];
[tapRecognizer setNumberOfTapsRequired:1]; // allow to create new view
UITapGestureRecognizer * tapRecognizerToFail = [[UITapGestureRecognizer alloc]init];
[tapRecognizer setNumberOfTapsRequired:2]; // to disallow more than 1 tap.
[tapRecognizer requireGestureRecognizerToFail:tapRecognizerToFail];
[imageView setGestureRecognizers:[NSArray arrayWithObjects:tapRecognizer,tapRecognizerToFail,nil]];
// New View Creation over ImageView
-(void)createNewView
{
UIView * view = [[UIView alloc]init];
UITapGestureRecognizer * tapRecognizer = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(newViewAction)];
[tapRecognizer setNumberOfTapsRequired:2];
[view addGestureRecognizer:tapRecognizer];
[imageView addSubview:view];
}
// Double tap action over newly created view
-(void)newViewAction
{
// goes here
}
You can use requireGestureRecognizerToFail: to declare a dependency between your two recognizers.
[secondaryGesture requireGestureRecognizerToFail:primaryGesture];

UIImageView zoom, tap, gestures don't work

I am using Apple code for just zoom the UIImageView on taps and gestures. But its not work ?
Please see this Apple's link apple code for image zooming by taps and gestures
-(void)veiwDidLoad
{
[super viewDidLoad];// Edited my self
imageView.userInteractionEnabled = YES; // Edited my self
//All code below same.... like Apple's code
// set the tag for the image view
[imageView setTag:ZOOM_VIEW_TAG];
// add gesture recognizers to the image view
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleSingleTap:)];
UITapGestureRecognizer *doubleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleDoubleTap:)];
UITapGestureRecognizer *twoFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTwoFingerTap:)];
[doubleTap setNumberOfTapsRequired:2];
[twoFingerTap setNumberOfTouchesRequired:2];
[imageView addGestureRecognizer:singleTap];
[imageView addGestureRecognizer:doubleTap];
[imageView addGestureRecognizer:twoFingerTap];
[singleTap release];
[doubleTap release];
[twoFingerTap release];
// calculate minimum scale to perfectly fit image width, and begin at that scale
float minimumScale = [imageScrollView frame].size.width / [imageView frame].size.width;
[imageScrollView setMinimumZoomScale:minimumScale];
[imageScrollView setZoomScale:minimumScale];
}
Make sure that you set your imageView to be userInteractionEnabled = YES; .. its assign to NO by default.
change the function name from
-(void) veiwDidLoad
to
-(void) viewDidLoad
I has a problem like that as well, does that fix it?

How to control the recognition of UIPanGestureRecognizer?

For UITapGestureRecognizer, you can set number of taps required to control the recognition of the UITapGestureRecognizer. If you set numberOfTapsRequired to 2 and user taps only once, then the UITapGestureRecognizer won't be triggered.
My question is How about for UIPanGestureRecognizer? How to control its recognition?
I have a view. Once I set a UIPanGestureRecognizer to it, any dragging will trigger the action. But what I want is only the dragging in X-axis. And for non-X-axis dragging, all touch events should be sent to other views underneath.
How can I do it?
THanks
Set its delegate and implement
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer;
Then use
- (CGPoint)velocityInView:(UIView *)view;
on the gesture recogniser to calculate whether the gesture recognizer should handle it or not.
Check How to stop UIPanGestureRecognizer when object moved to certain frame. It may help you.
UIView *holderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, image.size.width, image.size.height)];
UIImageView *imageview = [[UIImageView alloc] initWithFrame:[holderView frame]];
[imageview setImage:image];
[holderView addSubview:imageview];
UIPinchGestureRecognizer *pinchRecognizer = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(scale:)];
[pinchRecognizer setDelegate:self];
[holderView addGestureRecognizer:pinchRecognizer];
UIRotationGestureRecognizer *rotationRecognizer = [[UIRotationGestureRecognizer alloc] initWithTarget:self action:#selector(rotate:)];
[rotationRecognizer setDelegate:self];
[holderView addGestureRecognizer:rotationRecognizer];
UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(move:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[holderView addGestureRecognizer:panRecognizer];
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapped:)];
[tapRecognizer setNumberOfTapsRequired:1];
[tapRecognizer setDelegate:self];
[holderView addGestureRecognizer:tapRecognizer];
[self.view addSubview:holderView];
Raees
Assume that your gestureRecognizer triggers the action _panRecogPanned below. You can see how the center of a subview ( the view that carries the gesture recognizer itself) moves following the transition. To disable panning on y axis, you simply set the center as the calculated new center, whereas the translation.y is omitted.
To move other subviews on the y axis, get their frame, update their origin.x property and reset the frame, they should follow your finger only on the y axis.
- (IBAction)_panRecogPanned:(id)sender{
CGPoint translation = [_panRecog translationInView:_statementFilterView];
//This subview only moves horizontally
_panRecog.view.center = CGPointMake(translation.x + _panRecog.view.center.x, _panRecog.view.center.y);
//This subview only moves vertically
CGRect newFrame = anotherSubview.frame;
newFrame.origin.y = anotherSubview.frame.origin.y + translation.y;
anotherSubview.frame = newFrame;
[_panRecog setTranslation:CGPointMake(0, 0) inView:self.view];
}

UITapGestureRecognizer action not triggered

I have an UIImageView inside a subclass of UITableViewCell in which I wired up with UITapGestureRecognizer. However, when I press on the image the action is not triggered. What's being triggered is the didSelectRowAtIndexPath.. why is this?
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTapGesture:)];
tapGesture.numberOfTapsRequired = 1;
tapGesture.numberOfTouchesRequired = 1;
[imageView addGestureRecognizer:tapGesture]; [tapGesture release];
Also one minor question is that I have a UITextView in the cell, however when I click on the text it did not trigger the didSelectRowAtIndexPath, why is this and how do I change it?
UIImageView has userInteractionEnabled set to NO by default. Try setting it to YES
imageView.userInteractionEnabled = YES;
For your other question, try setting the editable property to NO for the UITextView.
textView.editable = NO;

UILongPressGestureRecognizer of Superview gets called instead of Subview

i got a strange problem. I got a Superview with customcontrols as subviews.
Their are GestureRecognizer both in superview and subviews.
If i tap a subview its GestureRecognizer gets called and on tap on the superview its tap gets called.
but on long press in the subview SOMETIMES the GestureRecognizer of the superview gets called. I add the GestureRecognizers in the same functions but there is a different attitude.
Superview
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapPiece:)];
tapGesture.numberOfTapsRequired = 1;
//contenView is the area where my controls can be
[self.contentView addGestureRecognizer:tapGesture];
[tapGesture release];
UILongPressGestureRecognizer *longTapGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longTapPiece:)];
tapGesture.numberOfTapsRequired = 1;
[self.contentView addGestureRecognizer:longTapGesture];
[longTapGesture release];
Subviews
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(selectPiece:)];
tapGesture.numberOfTapsRequired = 1;
[self addGestureRecognizer:tapGesture];
UILongPressGestureRecognizer *longPressGesture = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPiece:)];
longPressGesture.numberOfTapsRequired = 1;
[self addGestureRecognizer:longPressGesture];
Can anyone tell me why the longtap doen't response to my subview and how to fix it.
THANK YOU
got a solution but this is not what i wanted i set the duration of the control lower than the one of the superview [longPressGesture setMinimumPressDuration:0.4]; But the gestureRecognizer should be independend