I have a PageControl and each page (ViewController) has different number of imageviews (UIImageView), which are created dynamically.
Each imageview is assigned a gesture recognizer (tapped or move). Since these are inside a PageControl, I would like to enable/disable the gesture recognizer so it won't interfere with the swipe to page events.
I know that there's a removeGestureRecognizer method, but I don't want to remove and attach that each time. Is there an equivalent for just enabling and disabling?
Thanks
You can use enable or disable properties of the UIGestureRecognizer like :
swipeGestureRecognizer.enabled = NO;
or you can use the gesture recognizer method return null if you don't want touches
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldReceiveTouch:(UITouch *)touch;
If you want to disable all the gestures at the same time, you can do like
imageView.userIntractionEnabled = NO;
if you want to disable only one gesture recognizer, then
NSArray *gestures = imageView.gestureRecognizers;
for(UIGestureRecognizer *gesture in gestures)
{
if([gesture isKindOfClass: [UITapGestureRecognizer class]])
{
gesture.enabled = NO;
}
Can you disable userInteractionEnabled for that UIImageView ? You could do it in Interface Builder if you are doing it that way or you could programatically set this like so - imageView.userInteractionEnabled = NO; Hope this helps...
Related
I have added UIPanGestureRecognizer on the view of my UIViewController.
In this view (a calculator) are some UIButton triggered by the event .TouchUpInside.
The problem comes if I tap on the button and make a small pan at the same time (which might happen if you tap quickly a button and are moving to the next one at the same time). Then the pan gesture is triggered. I would like to avoid it when there is a tap on a button. But I would like to allow it if the tap takes too long (let say 0.3s is enough to trigger the pan gesture).
How can I achieve that?
Set the property cancelsTouchesInView of your gesture recognizer to NO.
Then your button should work properly.
You can use the delegate method like this-
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch{
if ([touch.view isKindOfClass:[UIButton class]]) {
return NO;
}
return YES;
}
There is a dirty solution. You can just grab it in a UIScrollView
I want the ability to change how the playback controls are presented while using the new AVPlayerViewController in AVKit. Basically, I want to overide the single finger tap gesture to do something else, and replace that gesture with a double finger tap. I am subclassing AVPlayerViewController to add this functionality.
I can add the double finger tap easily by creating a new UITapGestureRecognizer, but doing so with a single tap does nothing, as the playback controls still appear and my custom gesture method is not called. I assume because the AVPlayerViewController has a gesture with priority that is called instead.
I setup the gestures like normal...
// singleFingerTap: will never fire...
UITapGestureRecognizer *singleFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleFingerTap:)];
singleFingerTap.numberOfTouchesRequired = 1;
singleFingerTap.delegate = self;
[self.view addGestureRecognizer:singleFingerTap];
// doubleFingerTap: will work correctly...
UITapGestureRecognizer *doubleFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(doubleFingerTap:)];
doubleFingerTap.numberOfTouchesRequired = 2;
doubleFingerTap.delegate = self;
[self.view addGestureRecognizer:doubleFingerTap];
Any thoughts on how to achieve this without accessing private properties? Is it even permitted? I know I can create my own view controller with an instance of AVPlayer and then create my own playback controls, but I'm hoping I can use the lightweight AVKit player here with a few simple modifications.
I've tried looping through the gestures in AVPlayerViewController's view and removing them, but the gestureRecognizers property was empty. Even if I could do this, I wouldn't know how to add back the gesture to display the playback controls on a double finger tap instead of the single finger tap.
Any suggestions would be much appreciated! Especially whether this is possible/allowed or not. Thanks!
EDIT:
I have found a way to explicitly unblock the player's private gesture that was blocking my own gesture.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
id firstGesture = gestureRecognizer;
id secondGesture = otherGestureRecognizer;
if ([firstGesture isKindOfClass:[UITapGestureRecognizer class]] && [secondGesture isKindOfClass:[UITapGestureRecognizer class]]) {
UITapGestureRecognizer *tapGesture = firstGesture;
UITapGestureRecognizer *otherTapGesture = secondGesture;
if (tapGesture.numberOfTapsRequired == otherTapGesture.numberOfTapsRequired && tapGesture.numberOfTouches == otherTapGesture.numberOfTouches) {
// Disable the single tap that shows the playback controls...
return YES;
}
}
return NO;
}
This effectively prevents the playback controls from appearing on a tap, and my singleTapGesture: fires as expected. However, I now have the issue of getting the playback controls to appear on a different gesture. Is it possible to reroute the private gesture, or simulate the private gesture programmatically?
Why not just check/modify the target/remove the default gesture recognizers first?
You can access them with the standard UIView's gestureRecognizers.
The gestures recognizers may be buried inside a private subview.
Another solution would be to set userInteractionEnabled to NO and add your gesture recognizers to the superview or to a "overlay" transparent view.
Is there any way to get UITapGestureRecognizer to run on touch began?
I can't use touchesBegan because I am using a UITableView and the super view steals the event essentially.
I just want to detect when the screen is first touched. Why is this so difficult? Maybe I need a different solution than using tapgesturerecognizer?
You can use state property of UIGestureRecognizer to identify various states of any gesture -
#property(nonatomic,readonly) UIGestureRecognizerState state; // the current state of the gesture recognizer
So when the gesture begin, use something like this in your registered handler method -
if (gestureRecognizer.state == UIGestureRecognizerStateBegan) {
// Do your stuff
}
You can add a tap gesture recognizer to the tableView in viewDidLoad like this:
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapGestureRecognized:)];
[self.tableView addGestureRecognizer:tapGestureRecognizer];
Then implement this method:
- (void)tapGestureRecognized:(UITapGestureRecognizer *)tapGestureRecognizer {
NSLog(#"tap gesture recognized");
}
Just tested this out, and works fine. For every tap i get the log message on my console. Note that this prevents the tableview from receiving the taps, other gestures will just be handled by the table view as usual.
You need to set delaysContentTouches = NO
If I have a scrollView with a subview and the subview has a pan gesture recognizer, the scrollView's pan gesture override's the subview's pan. What I want is the opposite, I think, so that is I drag a subview it will pan within the scroll view, yet if I touch another area the scroll view will pan as normal. Is there an easy way to set that up?
Here's what works for me:
UIPanGestureRecognizer *subviewPanRecognizer = [[UIPanGestureRecognizer alloc]
initWithTarget:self action:#selector(panSubview:)];
[subview addGestureRecognizer:subviewPanRecognizer];
// play nice with subview's pan gesture
[scrollView.panGestureRecognizer
requireGestureRecognizerToFail:subviewPanRecognizer];
Set canCancelContentTouches property of UIScrollView to false if you don't want to scroll on touching subviews.
Original answer
Overwrite these two delegate below,
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
return YES;
}
This will allow you to recognize both gestures, the default return is NO, so we need to overwrite it and return YES.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer{
if ([gestureRecognizer isKindOfClass:[UITapGestureRecognizer class]]) {
if ([otherGestureRecognizer isKindOfClass:[UIPanGestureRecognizer class]]) {
return NO;
}else{
return YES;
}
}
return YES;
}
In this delegate you can do anything as you wish, as it's name the gestureRecoginzer will be required to fail by the otherGestureRecognizer, all you need to do is to judge what kind of these two gestures and return YES or NO.
I have a simple MapKit app working fine in iOS. It has annotation and when the user clicks on them, the little gray default popup is displayed with the title / subtitle. I even added a UIButton view into it.
So the problem is, I have a search bar above my map. I wanted to resignFirstResponder from the search box whenever the user clicks on the MapView, so I added a simple tap gesture responder. Worked great except now the little gray detail popups no longer show up (only the annotation pins)! I can still tap, zoom, move around etc. Just no popups.
UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapped:)];
tap.cancelsTouchesInView = NO;
tap.delaysTouchesBegan = NO;
tap.delaysTouchesEnded = NO;
[mapView addGestureRecognizer:tap];
-(IBAction)tapped:(UITapGestureRecognizer *)geture {
[searchBar resignFirstResponder];
}
Is it possible to have the best of both worlds?
I used a delegate method similar to the following to arbitrate between touches that should go to my custom view's pan gesture recognizer and touches that should go to the scroll view that contained my custom view. Something like it might work for you.
// the following UIGestureRecognizerDelegate method returns YES by default.
// we modify it so that the tap gesture recognizer only returns YES if
// the search bar is first responder; otherwise it returns NO.
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
if ((gestureRecognizer == self.tapGestureRecognizer) &&
(gestureRecognizer.view == self.mapView) &&
[searchBar isFirstResponder])
{
return YES; // return YES so that the tapGestureRecognizer can deal with the tap and resign first responder
}
else
{
return NO; // return NO so that the touch is sent up the responder chain for the map view to deal with it
}
}