I have a UIViewController that has UIPageViewController's view added to it. That UIPageViewController has a page with a subview that has a UITableView added as a subview. I am using iOS 6 and the method didSelectRowAtIndexPath is not being called when I click on the cell. There is a weird "bug" though... If I turn the page halfway and then come back to the page I was on (without completing the page turn), I'm then able to select the cell. I assume this has something to do with gesture recognizers, but I can't figure it out. I tried removing the gesture recognizers from the instantiation of the UIPageViewController, but was unable to get that to work.
I remove the tap gesture recognizers from the UIPageViewController like so, but still the buggy behavior exists...
for (UIGestureRecognizer *recognizer in pageViewController.gestureRecognizers) {
if ([recognizer isKindOfClass:[UITapGestureRecognizer class]]) {
recognizer.enabled = NO;
}
}
Any suggestions?
Subclass UIView with UITableView. let say myUIView.
Implement the UITableView delegates in myUIView.
Add myUIView as a subview of UIPageControl.
UITableView delegates in myUIView will trigger.
It turned out to be something very simple. On my UIViewController I had the autoresizingMask set to FlexibleHeight. Changing it to None for some reason fixed my problem.
// self.contentView.autoresizingMask = UIViewAutoresizingFlexibleHeight;
// Changed to :
self.contentView.autoresizingMask = UIViewAutoresizingNone;
If anyone can shed some light onto the reasons why this is the case, I'd appreciate it.
Related
I have added a UILongPressGestureRecognizer to my UICollectionView that is within a subclass of UIScrollView. (The UIScrollView is paged so there are 3 horizontally stacked UIViewControllers).
My code to add the UILongPressGestureRecognizer:
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(handleLongPress:)];
longPress.delegate = self;
longPress.minimumPressDuration = 0.5;
longPress.delaysTouchesBegan = YES;
[self.collectionView addGestureRecognizer:longPress];
And an NSLog in my handleLongPress: method. Currently I hold down on a UICollectionViewCell, it highlights, but the long press is not activated. I believe my UIScrollView subclass is consuming the long press and not passing along to the UICollectionView. When I lift my finger, the didSelectItemAtIndexPath: method is called.
In my UIScrollView subclass, the only customization I have is the following:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRequireFailureOfGestureRecognizer:(nonnull UIGestureRecognizer *)otherGestureRecognizer {
// This line enables the swipe to delete in the Messaging VC.
return ([otherGestureRecognizer.view.superview isKindOfClass:[UITableView class]]);
}
This was done to enable cell swiping in my UITableView, which is one of the pages of my UIScrollView. The swiping works no problem, and I have tried a number of similar checks for UICollectionView and UICollectionViewCell here but have not gotten the long press to register yet. Any advice appreciated.
Edit: I have added the long press on another UICollectionView and it is functional, but the cell never shows highlighted/selected status. I guess that is a clue as to why I can't get this long press gesture to fire.
My issue was that I was adding the gesture recognizer in the -init method. That did not work. Simply moving the code to -viewDidLoad fixed the problem.
I try to insert UISlider to UITableViewCell, but swipe gesture doesn't work correctly. For sliding needed hold and move the thumb, but i want to get swipe gesture without holding. I think tableview's own gestures not allow do this, but i don't know how to disable it.
Use - gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:
to set the property to YES. Then you can add a check in a function to decide which gesture to act on.
I've encountered the same problem recently. It happens for me in static cell of UITableViewController, it's instantiated from storyboard. I have found an ugly workaround, but will be happy to see a better solution for this.
So i've disabled all gesture recognisers of self.view and self.view.superview of UITableViewController:
- (void)disableGestureRecognisersInView:(UIView*)view {
for ( UIView *subview in view.subviews ) {
for ( UIGestureRecognizer *rec in subview.gestureRecognizers ) {
rec.enabled = NO;
}
}
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
[self disableGestureRecognisersInView:self.view];
[self disableGestureRecognisersInView:self.view.superview];
}
And now UISlider works normally, didn't noticed any other problems because of this workaround too. But i still don't like it.
I have a custom UICollectionViewCell that has a few custom UIView objects residing inside them. Each of these UIViews has a UIButton which responds to Touch Down and Touch Up Inside linked by IBActions. Basically, I want these buttons to shrink down when pressed down and spring back to their original size when let go. I can easily accomplish this with the controls and the press down and press up works. However, the problem I am facing happens when scrolling is introduced into the mix. The UICollectionView these cells are apart of is a scrolling one. If I happen to touch a button as I start my scroll, the Touch Down event is triggered as well as the scrolling event of the UICollectionView. If I recall correctly, this was never the case pre-iOS7. When a scrolling event was started, the UIButton event wasnt fired off, I think it had to do with the delaysContentTouches. This looks to be broken or changed now. It actually still works decently on iPhone, just not on iPad. If I scroll my view on iPad, with my touch starting inside the embedded UIButton, the button will shrink and the buttons action will be fired off.
So to restate the issue as plainly as I can: Is there anyway to ignore touches on embedded UIButtons when scrolling is occurring? Touches work fine when there is no scrolling triggered, I just dont want the events to fire off if the user is indeed scrolling. Is there any workaround?
If you need any more specific details, I would be happy to help you understand.
you need to subclass scrollView (collectionView or tableView) and override
- (BOOL)touchesShouldCancelInContentView:(UIView *)view {
if ([view isKindOfClass:UIButton.class]) {
return YES;
}
return [super touchesShouldCancelInContentView:view];
}
swift
override func touchesShouldCancelInContentView(view: UIView) -> Bool {
if view is UIButton {
return true
}
return super.touchesShouldCancelInContentView(view)
}
thats it now you can scroll over button and not lose button tap event.
In a UICollectionView of mine, buttons inside of UICollectionViewCells registered TouchUpInside-taps even though the UICollectionView was still decelerating, which sounds like a similar problem to what you're having. I created a UIButton subclass that overrides beginTrackingWithTouch:withEvent and will return NO in case the UIScrollView it's contained in is decelerating or dragging.
- (BOOL)beginTrackingWithTouch:(UITouch *)touch withEvent:(UIEvent *)event
{
UIView *superView = self;
while((superView = [superView superview])) {
if ([superView isKindOfClass:UIScrollView.class]) {
UIScrollView *scrollView = (UIScrollView *)superView;
if (scrollView.isDecelerating || scrollView.isDragging) {
return NO;
}
}
}
return [super beginTrackingWithTouch:touch withEvent:event];
}
The easiest thing to try that comes to mind is to check if the UIScrollView (your UICollectionView) is scrolling or dragging when the button action is triggered.
if(! self.collectionView.dragging && ! self.collectionView.decelerating)
{
// do action because we are not moving
}
Have you tried that?
Pressing the button quickly and not holding for a short time, will not highlight the button.
Different from a UIButton on a common UIView.
Like the head photo in official Twitter client got same issue.
Instagram client seems solved this, all buttons works fine.
Find same question here:
Why doesn't UIButton showsTouchWhenHighlighted work when the button is on a UITableViewCell?
But I still don't know how to fix it.
Well... a UITableView is a subclass of UIScrollView and the UIScrollView class is known to eat touches for it's own purpose.
When it realizes the touch was not meant for it, it passes it to it's immediate subview.
This feature is the delaysContentTouches property (which by default is YES).
Which is why, the UIButton shows it's highlighted state only after a extended touch because the touch event was with the UITableView for a short while until it determined whether the touch was meant for scrolling or swiping the cell and on realizing the touch was for neither, it immediately passes the touch event to the subView directly below it.
In case of a quick-tap, the button's highlighted state is bypassed due to this delay and the target selector method is called directly.
To show the highlighted state of the button in a UITableView (just as it would on a UIView) do:
For iOS7+:
In -viewDidLoad or anywhere appropriate do:
[yourTableViewObject setDelaysContentTouches:NO];
Also... The cell.subviews has a class UITableViewCellScrollView which apparently is another scrollView and we need to disable the delaysContentTouches property of this class as well.
So... in the -cellForRowAtIndexPath: method (just before return cell;) do:
NSArray *test = cell.subviews;
for (UIView *currentView in cell.subviews) {
if ([NSStringFromClass([currentView class]) isEqualToString:#"UITableViewCellScrollView"]) {
UIScrollView *svTemp = (UIScrollView *) currentView;
[svTemp setDelaysContentTouches:NO];
break;
}
}
For iOS 6-:
In iOS6, the cell.subviews has a UITableViewCellContentView class which is not a scrollView subclass and so all it takes is setting one parameter for the tableView alone.
So, in -viewDidLoad or anywhere appropriate, this is all that you need:
[yourTableViewObject setDelaysContentTouches:NO];
PS: By doing this, it will mess up with the scrolling of the tableView so use your better judgement.
UITapGestureRecognizer is applied to both UIImageView and its subview (UITextView). However, when I tap on subview, the receiver becomes subview and its parent view (i.e. UIImageView + UITextView). It should however be only subview because that was the one I tapped. I was assuming nested gestures would react first but apparently parent receives the fist tap and then it goes to child.
So, there are different solutions out there for various scenarios (not similar to mine but rather buttons inside scroll view conflict). How can I easily fix my issue without possible subclassing and for iOS 6+ support? I tried delaying touch on start for UIGestureRecognizer on UIImageView and I tried setting cancelsTouchesInView to NO - all with no luck.
Try the following code:
conform the <UIGestureRecognizerDelegate> to your class.
set yourGesture.delegate = self;
then add this delegate Method:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
// return YES (the default) to allow the gesture recognizer to examine the touch object, NO to prevent the gesture recognizer from seeing this touch object.
if([touch.view isKindOfClass: [UITextView class]] == YES)] {
return YES;
}
else {
return NO;
}
}
Hope it will solve your issue. Enjoy Coding..!!!!
That's exactly what is it supposed to do.
View hierarchy is like a tree structure and its traversal during a touch gesture starts from the root node. It is very likely for your parent view to receive gesture first and then its subviews. The traversal skips the nodes for which
userInteractionEnabled = NO.
since, you don't have any code I can't help you to play with this flag. A more general solution is to always set gesture only for your parentView and in the gesture delegates check the coordinates if it belongs to any one of the subview and if yes then call your gesture method for your subview.
Not a clean approach but works. !!
you should implement the UIGestureRecognizer delegate methods and apply the correct policy to the gesture, when multiple gesture are recognized