I have a view (I'll call it parentView) that has about 20-30 subviews. I have added a long press gesture recognizer to the parentView. The gesture recognizer only seems to fire when I press on the parentView, it does not fire when I press and hold on one of the subviews.
I have tried adding the gesture recognizer to self.view and using the gesture location to see if it was within the bounds of the parentView. However the same problem occurs since it does not seem to detect my long press on the subviews.I have also tried running a for loop and adding the gesture recognizer to each individual subview but this also did not work.
This is how I am defining my gesture recognizer if anybody was wondering.
longPress.minimumPressDuration = 1
longPress.addTarget(self, action: #selector(ViewController.handleLongPress)
parentView.addGestureRecognizer(longPress)
How would I get the long press gesture recognizer to detect a long press on the parentView and it's subviews?
Related
I have added a subview to a View Controller's view. This subview is the view of QLPreviewController.
What I am trying to achieve is to recognize swipe gestures on the subview in the parent view, i.e. the View Controller's view. In the end, I want to be able to swipe left /right on the view to load the next document for preview.
I'm aware of hit testing and understand that by just attaching a gesture recognizer to the parent view, those will not be recognized, since the subview will be the "hit-test" view.
Now what is the best (or easiest) way to recognize those gestures?
Note: I didn't manage to attach the gesture recognizers to the subview, this doesn't seem to work.
* UPDATE *
To make this more clear - this is the code from my ViewController. vContent is just a view in my ViewController, where I add the view of the QLPreviewController:
let pvVc = QLPreviewController()
pvVc.dataSource = self
vContent.addSubview(pvVc.view)
I tried adding the swipe recognizers both to the vContent and the pvVc.view. In both cases no event was fired.
let sgrLeft: UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action:Selector("handleSwipe:"))
sgrLeft.direction = UISwipeGestureRecognizerDirection.Left
sgrLeft.delegate = self
On some other view the code works fine.
Any hint is appreciated!
Thx
Eau
Well, the responder chain, the unknown animal … ;-)
You can subclass the superview and override -hitTest:forEvent:.
You rarely need to call this method yourself, but you might override it to hide touch events from subviews.
Gesture Recognizers Get the First Opportunity to Recognize a Touch, so even the subview is hitTest view. the gestureRecognizer attached on superView can recognizer touch event.
I have two UIButtons in a view (one is YES, the other NO). I now want to add a "did not answer", which would be indicated by a downward swipe on the view.
The problem is that the user may swipe down on the view, but in the process hit one of the buttons. When this happens I want to ignore the button press if there was a swipe underway. If it is just a tap on a button, the answer is recorded.
So, if the swipe occurs, I want to call the swipe gesture's action method. If it is determined no swipe occurred but one of the two buttons was touched I want to call their respective action methods. But if a button was touched in the process of a swipe, I want to call only the swipe gesture's action method.
I know there is a way but I'm wondering whether there is an EASY way of doing this. TIA for suggestions.
Since UISwipeGestureRecognizer is a "discrete" gesture, it just triggers a single action when recognized and it won't allow you to detect the end of the gesture.
So to prevent other touches during the gesture, I'd recommend using a UIPanGestureRecognizer instead since it can track your gesture from beginning to end. Then you can try setting your gesture's cancelsTouchesInView property to YES to cancel all other touches in the view that happen while that pan gesture is recognized, ex:
gesture.cancelsTouchesInView = YES;
gesture.delaysTouchesBegan = YES;
Your buttons should be registering touch up in view, so that someone who taps on the button can drag off if they decide not to proceed.
For your other swipe gesture, your buttons will not register a touch up in view during a swipe gesture, even if the swipe passes over the button or ends on it.
Okay, this seems to work. On the gesture recognizer, I used:
UISwipeGestureRecognizer *swipeDown = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(didSwipeDown:)];
swipeDown.direction = UISwipeGestureRecognizerDirectionDown;
swipeDown.delaysTouchesBegan = YES;
swipeDown.delegate = self;
[self addGestureRecognizer:swipeDown];
They delaysTouchesBegan = YES allows it to determine whether the swipe has occurred before passing the touches on to the buttons. So, if you swipe, it calls the swipe GR, and if you touch either button, you get that. Thanks for your answers...
I've a view controller with UISegmentedControl and UITableView as its children. In -viewDidLoad I create a UITapGestureRecognizer and add it to the controller's main view.
When I tap on, for instance, a cell of the table view, the tap gesture recognizer's action is being called and it prevents receiving touches to the table view (that's ok as tapRecognizer.cancelsTouchesInView == YES).
However, the issue is that when I tap on the segmented control, the tap gesture recognizer's action is not being called. Why is it so? How to make the tap gesture recognizer the "top" object which handles touches?
Thanks,
Adam
I add a swipeUp gesture to the whole view.
I add a longPressGestureRecognizer to the whole view, set its minimunPressDuration equals 0.001f so that it can both detect press down action and touches move action, then call the requireGestureToFail function:
UILongPressGestureRecognizer *longPressGestureRecognizer = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPressed:)];
longPressGestureRecognizer.minimumPressDuration = 0.001f;
[longPressGestureRecognizer requireGestureRecognizerToFail:swipeGestureRecognizer];
The problem is:
When user press and hold (don't move) a button, the longPress gesture's state remains UIGestureStatePossible because the swipeUp gesture doesn't fail, So that it won't react to user touch.
If I don't call requireGestureRecognizerToFail all the gesture including swipeUp gesture will be recognised as longPress gesture.
Implmenting shouldRecognizeSimultaneouslyWithGestureRecognizer: is not what I expect.
What I want is when press and hold(don't move) a button, it triggers longPress, then if user swipe up it triggers swipeUp gesture, if user drags but the touch pattern doesn't fit swipeUp it still triggers longPress.
How can I implement this?
I think it would be easier to implement your own UIGestureRecognizer or UIView subclass with multiple gestures. Check this out:
UITapGestureRecognizer - make it work on touch down, not touch up?
https://developer.apple.com/library/ios/documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/GestureRecognizer_basics/GestureRecognizer_basics.html#//apple_ref/doc/uid/TP40009541-CH2-SW2
I have a view controller that consists of three views (self.panedview, self.view, self.sineview) When a swipe up gesture is detected, the highest view (self.panedview) is moved up halfway - revealing two additional views (self.view and self.sineview). self.sineview is a UIView that constantly has an animation running that renders a moving sinewave and takes up half of self.view. I have a swipe down gesture recognizer that works when I swipe down on self.panedview, but doesn't work when I swipe down on self.sineview. If I swipe around self.sineview on self.view it seems to work. When I hide self.sineview and swipe directly down on either self.view or self.paned view, the swipe down works. do you think the animating sine wave gets in the way of the gesture recognition.
UISwipeGestureRecognizer * swipeDownRec = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(handleDownSwipe:)];
[self.panedView addGestureRecognizer:swipeDownRec];
[self.view addGestureRecognizer:swipeDownRec];
[self.sineview addGestureRecognizer:swipeDownRec];
Also I tried varying between these two lines of code but there is no difference:
[self.view insertSubview:self.sineWave belowSubview:self.panedView];
[self.view insertSubview:self.sineWave aboveSubview:self.view];
I also tried adding a separate swipe down gesture recognizer for each view, but it still doesn't work.
The problem was the that the swipe recognizer for self.sinewave couldn't be recognized while the self.sinewave animation was enabled. The solution is simple: add UIViewAnimationOptionAllowUserInteraction as a parameter to the options handler for animateWithDuration:delay:options:animations:completion: