I have problem with tap gesture. My case is:
- A view with UITapGestureRecognizer to dismiss keyboard
- A label on view, which has 2 gesture. One UITapGestureRecognizer to open popup, and UITapGestureRecognizer (number of touches is 2) to quickly confirm popup.
But when I tap on label, the UITapGestureRecognizer on view always receive the action. How can I forward action to UILabel.
Thanks
To get taps on label, you need to enable user interaction for that label
To receive 2 taps you need to do following
In short [tap requireGestureRecognizerToFail:dTap]; will do trick for you making single tap to wait for a while to check if double tap is to happen
UITapGestureRecognizer *dTap = [[UITapGestureRecognizer alloc]
initWithTarget:self
action:#selector(doubleTapped:)];
dTap.delegate = self;
dTap.numberOfTapsRequired = 2;
dTap.numberOfTouchesRequired = 1;
[label addGestureRecognizer:dTap];
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]
initWithTarget:self
action:#selector(tapped:)];
tap.delegate = self;
tap.numberOfTapsRequired = 1;
tap.numberOfTouchesRequired = 1;
[label addGestureRecognizer:tap];
[tap requireGestureRecognizerToFail:dTap];
// it Enables user interaction on you Lable, by default its NO, so you have to do it.
[lbl setUserInteractionEnabled:YES];
Related
Actually i want to implement swipe left and right in UIScrollview. i have scrollview with content size (768,1500). i have tried this but problem is that sometimes its not detecting swipe and perform scrolling there. so now i want to disable scrolling on 2 finger touch.
swipeGesture = [[[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(nextswipedScreen:)] autorelease];
swipeGesture.numberOfTouchesRequired=2;
swipeGesture.direction = UISwipeGestureRecognizerDirectionLeft;
[self addGestureRecognizer:swipeGesture];
swipeGesture = [[[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(previousswipedScreen:)] autorelease];
swipeGesture.numberOfTouchesRequired=2;
swipeGesture.direction = UISwipeGestureRecognizerDirectionRight;
[self addGestureRecognizer:swipeGesture];
i have tried custom scrollview for that but i have problem with touchesBegan method. its not calling every time. even i tried this but not able to stop two finger scroll in UIScrollview.
for (UIGestureRecognizer *mgestureRecognizer in _scrollView.gestureRecognizers) {
if ([mgestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]])
{
UIPanGestureRecognizer *mpanGR = (UIPanGestureRecognizer *) mgestureRecognizer;
mpanGR.minimumNumberOfTouches = 1;
mpanGR.maximumNumberOfTouches = 1;
}
}
Let me know if you have any solution or alternative for that.
I had the same problem; I needed to disable two-finger scrolling so that I could detect a two-finger swipe to the left or right. Here's what I did to set up my scroll view:
- (void) setUpGestureHandlersOnScrollView:(UIScrollView *)scrollView {
// set up a two-finger pan recognizer as a dummy to steal two-finger scrolls from the scroll view
// we initialize without a target or action because we don't want the two-finger pan to be handled
UIPanGestureRecognizer *twoFingerPan = [[UIPanGestureRecognizer alloc] init];
twoFingerPan.minimumNumberOfTouches = 2;
twoFingerPan.maximumNumberOfTouches = 2;
[scrollView addGestureRecognizer:twoFingerPan];
// set up the two-finger left and right swipe recognizers
UISwipeGestureRecognizer *twoFingerSwipeLeft = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleGestureFrom:)];
twoFingerSwipeLeft.direction = UISwipeGestureRecognizerDirectionLeft;
twoFingerSwipeLeft.numberOfTouchesRequired = 2;
[scrollView addGestureRecognizer:twoFingerSwipeLeft];
UISwipeGestureRecognizer *twoFingerSwipeRight = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleGestureFrom:)];
twoFingerSwipeRight.direction = UISwipeGestureRecognizerDirectionRight;
twoFingerSwipeRight.numberOfTouchesRequired = 2;
[scrollView addGestureRecognizer:twoFingerSwipeRight];
// prevent the two-finger pan recognizer from stealing the two-finger swipe gestures
// this is essential for the swipe recognizers to work
[twoFingerPan requireGestureRecognizerToFail:twoFingerSwipeLeft];
[twoFingerPan requireGestureRecognizerToFail:twoFingerSwipeRight];
}
The handler method should look something like this:
- (void)handleGestureFrom:(UISwipeGestureRecognizer *)recognizer {
if ([recognizer numberOfTouches] == 2) {
// do whatever you need to do
}
}
You can create two gesture recognizers, one for single tap and one for double tap:
UITapGestureRecognizer *singleTapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTouchesOne:)];
singleTapGesture.cancelsTouchesInView = NO;
singleTapGesture.delaysTouchesEnded = NO;
singleTapGesture.numberOfTouchesRequired = 1; // One finger single tap
singleTapGesture.numberOfTapsRequired = 1;
[Scroll_view addGestureRecognizer:singleTapGesture];
[singleTapGesture release];
UITapGestureRecognizer *doubleTapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTouchesTwo:)];
doubleTapGesture.cancelsTouchesInView = NO;
doubleTapGesture.delaysTouchesEnded = NO;
doubleTapGesture.numberOfTouchesRequired = 1; // One finger double tap
doubleTapGesture.numberOfTapsRequired = 2;
[Scroll_view addGestureRecognizer:doubleTapGesture];
[doubleTapGesture release];
And then, here comes the punch:
[singleTapGesture requireGestureRecognizerToFail : doubleTapGesture];
requireGestureRecognizerToFail Reference
The last line, makes your single tap handler work only if the double tap fails. So, you get both single tap and double tap in your application.
And So you can do like, in "doubleTapGesture" method you just specified the scrollview with content size (0,0), In "singleTapGesture" method you specified the scrollview with content size (768,1500).
Source knowledge
In the UIView, there is several sub views of UIImageView objects.
Since I need to detect the touch events from the UIImageView and from the remaining area of the UIView.
Can I implement touch events in UIView and UIImagView simultaneously ?
Thanks.
Based on your comment, I think you should consider gesture recognizers. Use the UITapGestureRecognizer to identify and respond to taps on a view.
UITapGestureRecognizer *tapGesture;
tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTapOnView:)];
tapGesture.numberOfTapsRequired = 1;
tapGesture.numberOfTouchesRequired = 1;
[view addGesture:tapGesture];
[tapGesture release];
...
tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTapOnImage:)];
tapGesture.numberOfTapsRequired = 1;
tapGesture.numberOfTouchesRequired = 1;
[imageView addGesture:tapGesture];
[tapGesture release];
...
define -(void)handleTapOnView:(UITapGestureRecognizer*)gesture and -(void)handleTapOnImage:(UITapGestureRecognizer*)gestureand handle the touches there.
There are other kinds of gestures too. You can read more about them here.
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;
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
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.