I have a UIScrollView with subviews and a UITapGestureRecognizer.
I create the recognizer like this:
UITapGestureRecognizer *tgr = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapGestureRecognized:)];
[self addGestureRecognizer:tgr];
The view property of UITapGestureRecognizer points to the scroll view itself even if the user touched a different view. I need to know if touch went down on the scroll view directly.
Paul's suggestions are good, but if you don't want (or can't) subclass or become the delegate of the recognizer, there's another way.
You can ask the gesture recognizer for its locationInView: and then retrieve the view which that point is on top of with your scrollView's hitTest:withEvent: method (defined on UIView). Something like:
CGPoint location = [recognizer locationInView:scrollView];
UIView *touchedView = [scrollView hitTest:location withEvent:nil];
You can become either subclass UITapGestureRecognizer and add a new ivar to hold this info by overriding the touchesBegan:withEvent: method something like this
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
/*
* If you wanted you could store a set of all the views to allow
* for multiple touches
*/
self.touchedView = [touches.anyObject view];
[super touchesBegan:touches withEvent:event];
}
Or if you like you can become the delegate for UITapGestureRecognizer and store the tapped view as a property in your class by implementing gestureRecognizer:shouldReceiveTouch:
Related
I am new to iOS. Not sure if there is a possiblity to bring the following logic.
1. UITabBarController has three UIViewController.
2. While Swipping horizontally in the second UIViewController, i want to move
to the third UIViewController.
Is it possible?. if so, kindly advice how to achieve the same.
In the Second ViewController add the following lines in ViewDidLoad
UISwipeGestureRecognizer *swipeRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(gotoNextPage:)];
[self.view addGestureRecognizer:swipeRecognizer];
[swipeRecognizer release];
And add method
-(void)gotoNextPage:(id)sender {
[self.tabBarController setSelectedViewController:thirdViewController];
}
You can use Touch Delegate Method i am doing to pop to previous view
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint startPosoition = [touch previousLocationInView:self.view];
CGPoint endPosition = [touch locationInView:self.view];
if (endPosition.x - startPosoition.x > 20)
{
[self.navigationController popViewControllerAnimated:YES];
} else
{
}
}
Yes that can be done. For 1. I assume you know how to setup a tabbar based app with viewcontrollers. For 2. Implement the swipe gesture recognizer on your second view controller's view and in the gesture handler do: [self.yourTabBarController setSelectedIndex:2];
Use this code;
UISwipeGestureRecognizer *swipeGestureNextPage = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(loadPreviousPageClicked)];
swipeGestureNextPage.direction = UISwipeGestureRecognizerDirectionRight;
[self.view addGestureRecognizer:swipeGestureNextPage];
-(void)loadPreviousPageClicked
{
//use navigation controller here accordingly
}
Thats it.
In my iPhone app I have one messaging screen. I have added UITapGestureRecognizer on the UIViewController and also I have a UITableview on the screen. I want to select the UITableViewCell but I can't select the UITableView because of UITapGestureRecognizer. When I touch the screen, only the tap gesture action is called but UITableView delegate didSelectRowAtIndexPath: is not called. Could anyone please help me to work on both tap gesture and UITableView:didSelectRowAtIndexPath:. Thanks in advance.
While I prefer Matt Meyer's suggestion or my other suggestion of using a custom gesture recognizer, another solution, not involving custom gesture recognizers, would be to have your tap gesture recognizer identify whether you tapped on a cell in your tableview, and if so, manually invoke didSelectRowAtIndexPath, e.g.:
- (void)handleTap:(UITapGestureRecognizer *)sender
{
CGPoint location = [sender locationInView:self.view];
if (CGRectContainsPoint([self.view convertRect:self.tableView.frame fromView:self.tableView.superview], location))
{
CGPoint locationInTableview = [self.tableView convertPoint:location fromView:self.view];
NSIndexPath *indexPath = [self.tableView indexPathForRowAtPoint:locationInTableview];
if (indexPath)
[self tableView:self.tableView didSelectRowAtIndexPath:indexPath];
return;
}
// otherwise proceed with the rest of your tap handling logic
}
This is suboptimal because if you're doing anything sophisticated with your tableview (e.g. in cell editing, custom controls, etc.), you lose that behavior, but if you're just looking to receive the didSelectRowAtIndexPath, then this might do the job. The other two approaches (separate views or the custom gesture recognizer) let you retain the full tableview functionality, but this could work if you just need something simple and you don't need the rest of the tableview's built-in capabilities.
You can use the TagGesture delegate:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
if ([touch.view isDescendantOfView:yourTableView]) {
return NO;
}
return YES;
}
Hope this helps.
An easier way to do this is to have two views: one containing the view that you want the tap gesture to be on, and one containing the tableview. You can attach the UITapGestureRecognizer to the view you want it to work on, and then it won't block your UITableView.
Assuming you want the tap gesture to work everywhere except over the tableview, you could subclass the tap gesture recognizer, creating a recognizer that will ignore any subviews included in an array of excludedViews, preventing them from generating a successful gesture (thus passing it on to didSelectRowAtIndexPath or whatever):
#import <UIKit/UIGestureRecognizerSubclass.h>
#interface MyTapGestureRecognizer : UITapGestureRecognizer
#property (nonatomic, strong) NSMutableArray *excludedViews;
#end
#implementation MyTapGestureRecognizer
#synthesize excludedViews = _excludedViews;
- (id)initWithTarget:(id)target action:(SEL)action
{
self = [super initWithTarget:target action:action];
if (self)
{
_excludedViews = [[NSMutableArray alloc] init];
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
CGPoint location = [[touches anyObject] locationInView:self.view];
for (UIView *excludedView in self.excludedViews)
{
CGRect frame = [self.view convertRect:excludedView.frame fromView:excludedView.superview];
if (CGRectContainsPoint(frame, location))
self.state = UIGestureRecognizerStateFailed;
}
}
#end
And then, when you want to use it, just specify what controls you want to exclude:
MyTapGestureRecognizer *tap = [[MyTapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
[tap.excludedViews addObject:self.tableView];
[self.view addGestureRecognizer:tap];
Note: I already read some questions about the UIScrollView sending touches to the subviews (this included and although I have up voted, it's not working as I intended anymore).
What I have: I have a UIScrollView with a Custom UIView (let's call it A) inside which covers the entire UIScrollView. I am also allowed to put other custom UIViews inside the A.
On the code I am doing this:
[scrollView setDelaysContentTouches:YES];
scrollView.canCancelContentTouches = NO;
What is happening: At the moment my only issue is that, if I want to move a subview inside A, I have to touch it, wait, and then move it. Exactly as stated here:
Now, the behaviour changes depending on the "length in time" of the
first touch on the UIView. If it's short, then the relative dragging
is managed as it was a scroll for the UIScrollView. If it's long, then
I'm getting the touchesMoved: events inside my UIView.
What I want: The subviews inside A should always receive priority and I shouldn't have to touch and wait. If I touch A and not a subview of it, I want the UIScrollView to receive the touches, like panning and moving around (the contentSize is bigger than the frame).
Edit 1.0
The only reason for me to have this A view inside a generic UIScrollView, is because I want to be able to zoom in/out on the A view. So I am doing the following:
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return customView; // this is the A view
}
In the beginning I didn't had the A view inside the UIScrollView and the only thing I did was adding the A as a subView of my UIViewController's root view and everything went well. If there is another way to enable zoom in/out I will gladly accept the answer.
Note: Thank you all for your contributions, specially to Aaron Hayman.
I was able to figure it out by doing the following on the UIScrollView sub-class I had:
-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
CGPoint pointOfContact = [gestureRecognizer locationInView:self];
// The view with a tag of 200 is my A view.
return (![[self hitTest:pointOfContact withEvent:nil] isEqual:[self viewWithTag:200]]);
}
I haven't tested this, but I believe how you are handling the touch events in View A (or it's subviews) will determine how touch events are passed on. Specifically, if you're trying to use the methods: touchesBegan, touchesMoves, touchesEnded, etc instead of a UIGestureRecognizer you won't receive the touches in the way you want. Apple design the UIGestureRecognizer to handle problems like the one you're facing. Specifically, the UIScrollView uses UIPanGestureRecognizer to handle the scrolling. If you add a UIPanGestureRecognizer to each of the subviews of View A any "panning" that occurs on one of those subviews should be sent to that subview instead of the UIScrollView. However, if you're simply using the "raw" touches methods, the UIPanGestureRecognizer in UIScrollView will never be cancelled.
In general, it's almost always best to use a UIGestureRecognizer instead of processing the touches directly in the view. If you need touches processed in a way that no standard UIGestureRecognizer can provide, subclass UIGestureRecognizer and process the touches there. That way you get all the the functionality of a UIGestureRecognizer along with your own custom touch processing. I really think Apple intended for UIGestureRecognizer to replace most (if not all) of the custom touch processing code that developers use on UIView. It allows for code-reuse and it's a lot easier to deal with when mitigating what code processes what touch event.
Jacky, I needed a similar thing: Within a building plan (your A, in my case a subclass of UIScrollView), let the user place and resize objects (call them Bs). Here's a sketch of what it took me to get at this behavior:
In the superview's (A) initWithFrame: method, set these two:
self.canCancelContentTouches = YES;
self.delaysContentTouches = NO;
This will ensure taps on B are immediately routed to the Bs.
In the embedded B, stop the superview A from cancelling taps, so it does not interfere with a gesture started on the B.
In the touchesBegan: method, search the view hierarchy upwards (using superview property of the views) until you find a UIScrollView, and set its canCancelContentTouches to NO. Remember the superview you changed, and restore this property in the touchesEnded and touchesCancelled methods of B.
I'd be interested whether this works for you as well. Good Luck!
nobi
I think you had better use "touchesBegan,touchesMoved,touchesEnded" to pass the event.
you can do like this:
you should make a mainView . It has 2 property. One is yourScrollView A , and One is yourCustomView.
`[yourScrollView addSubviews:yourCustomView];
[mainView addSubviews:yourScrollView];`
and then write your touches method in the mainView.m like this (ignor the scrollView statment)
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
if ([[touches allObjects] isKindOfClass:[yourCustomView class]])
{
//do whatever you want
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
if ([[touches allObjects] isKindOfClass:[yourCustomView class]])
{
//do whatever you want
}
}
The last step: pass the event to the subview of the scrollView(your A).
#import "yourScrollView.h"
#implementation yourScrollView
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code.
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
[super touchesBegan:touches withEvent:event];
if(!self.dragging)
[[self nextResponder] touchesBegan:touches withEvent:event];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
[super touchesMoved:touches withEvent:event];
if(!self.dragging)
[[self nextResponder] touchesMoved:touches withEvent:event];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
[super touchesEnded:touches withEvent:event];
if(!self.dragging)
[[self nextResponder] touchesEnded:touches withEvent:event];
}
- (void)dealloc {
[super dealloc];
}
#end
wish to help you
I have a UIView with 4 buttons on it and another UIView on top of the buttons view. The top most view contains a UIImageView with a UITapGestureRecognizer on it.
The behavoir I am trying to create is that when the user taps the UIImageView it toggles between being small in the bottom right hand corner of the screen and animating to become larger. When it is large I want the buttons on the bottom view to be disabled and when it is small and in the bottom right hand corner I want the touches to be passed through to the buttons and for them to work as normal. I am almost there but I cannot get the touches to pass through to the buttons unless I disable the UserInteractions of the top view.
I have this in my initWithFrame: of the top view:
// Add a gesture recognizer to the image view
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(imageTapped:)];
tapGestureRecognizer.cancelsTouchesInView = NO;
[imageView addGestureRecognizer:tapGestureRecognizer];
[tapGestureRecognizer release];
and I this is my imageTapped: method:
- (void) imageTapped:(UITapGestureRecognizer *) gestureRecognizer {
// Toggle between expanding and contracting the image
if (expanded) {
[self contractAnimated:YES];
expanded = NO;
gestureRecognizer.cancelsTouchesInView = NO;
self.userInteractionEnabled = NO;
self.exclusiveTouch = NO;
}
else {
[self expandAnimated:YES];
expanded = YES;
gestureRecognizer.cancelsTouchesInView = NO;
self.userInteractionEnabled = YES;
self.exclusiveTouch = YES;
}
}
With the above code, when the image is large the buttons are inactive, when I touch the image it shrinks and the buttons become active. However, the small image doesn't receive the touches and therefore wont expand.
If I set self.userInteractionEnabled = YES in both cases, then the image expands and contracts when touched but the buttons never receive touches and act as though disabled.
Is there away to get the image to expand and contract when touched but for the buttons underneath to only receive touches if the image is in its contracted state? Am I doing something stupid here and missing something obvious?
I am going absolutely mad trying to get this to work so any help would be appreciated,
Dave
UPDATE:
For further testing I overrode the touchesBegan: and touchesCancelled: methods and called their super implementations on my view containing the UIImageView. With the code above, the touchesCancelled: is never called and the touchesBegan: is always called.
So it would appear that the view is getting the touches, they are just not passed to the view underneath.
UPDATE
Is this because of the way the responder chain works? My view hierarchy looks like this:
VC - View1
-View2
-imageView1 (has tapGestureRecogniser)
-imageView2
-View3
-button1
-button2
I think the OS first does a hitTest as says View2 is in front so should get all the touches and these are never passed on to View3 unless userInteractions is set to NO for View2, in which case the imageView1 is also prevented from receiving touches. Is this how it works and is there a way for View2 to pass through it's touches to View3?
The UIGestureRecognizer is a red herring I think. In the end to solve this I overrode the pointInside:withEvent: method of my UIView:
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
BOOL pointInside = NO;
if (CGRectContainsPoint(imageView.frame, point) || expanded) pointInside = YES;
return pointInside;
}
This causes the view to trap all touches if you touch either the imageView or if its expanded flag is set. If it is not expanded then only trap the touches if they are on the imageView.
By returning NO, the top level VC's View queries the rest of its view hierarchy looking for a hit.
Select your View in Storyboard or XIB and...
Or in Swift
view.isUserInteractionEnabled = false
Look into the UIGestureRecognizerDelegate Protocol. Specifically, gestureRecognizer:shouldReceiveTouch:
You'll want to make each UIGestureRecognizer a property of your UIViewController,
// .h
#property (nonatomic, strong) UITapGestureRecognizer *lowerTap;
// .m
#synthesize lowerTap;
// When you are adding the gesture recognizer to the image view
self.lowerTap = tapGestureRecognizer
Make sure you make your UIViewController a delegate,
[self.lowerTap setDelegate: self];
Then, you'd have something like this,
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch {
if (expanded && gestureRecognizer == self.lowerTap) {
return NO;
}
else {
return YES;
}
}
Of course, this isn't exact code. But this is the general pattern you'd want to follow.
I have a another solution. I have two views, let's call them CustomSubView that were overlapping and they should both receive the touches. So I have a view controller and a custom UIView class, lets call it ViewControllerView that I set in interface builder, then I added the two views that should receive the touches to that view.
So I intercepted the touches in ViewControllerView by overwriting hitTest:
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
return self;
}
Then I overwrote in ViewControllerView:
- (void)touchesBegan:(NSSet *)touches
withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
for (UIView *subview in [self.subviews reverseObjectEnumerator])
{
if ([subview isKindOfClass:[CustomSubView class]])
{
[subview touchesBegan:touches withEvent:event];
}
}
}
Do the exact same with touchesMoved touchesEnded and touchesCancelled.
#Magic Bullet Dave's solution but in Swift
Swift 3
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
var pointInside = false
if commentTextField.frame.contains(point) {
pointInside = true
} else {
commentTextField.resignFirstResponder()
}
return pointInside
}
I use it in my CameraOverlayView for ImagePickerViewController.cameraOverlay to give user ability to comment while taking new photo
I want to catch both mouse down and mouse up using gesture recognizer. However, when the mouse down is caught, mouse up is never caught.
Here's what I did:
First create a custom MouseGestureRecognizer:
#implementation MouseGestureRecognizer
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesBegan:touches withEvent:event];
self.state = UIGestureRecognizerStateRecognized;
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesEnded:touches withEvent:event];
self.state = UIGestureRecognizerStateRecognized;
}
#end
Then bind the recognizer to a view in view controller:
UIGestureRecognizer *recognizer = [MouseGestureRecognizer alloc] initWithTarget:self action:#selector(handleGesture:)];
[self.view addGestureRecognizer:recognizer];
When I click mouse in the view, the touchesBegan is called, but touchesEnded is never called. Is it because of the UIGestureRecognizerStateRecognized?
Maybe you can use a UILongPressGestureRecognizer instead with minimumPressDuration set to 0.
From UIGestureRecognizer class reference for reset method:
The runtime calls this method (reset) after
the gesture-recognizer state has been
set to UIGestureRecognizerStateEnded
or UIGestureRecognizerStateRecognized. (...) After this
method is called, the runtime ignores
all remaining active touches; that is,
the gesture recognizer receives no
further updates for touches that have
begun but haven't ended.
So, yes, it's because you're setting the state to UIGestureRecognizerStateRecognized in touchesBegan.
EDIT
As a workaround, you can make two recognizers, one for touchesBegan and the other for touchesEnded, and then add both of them to the target view:
UIGestureRecognizer *recognizer1 = [TouchDownGestureRecognizer alloc] initWithTarget:self action:#selector(handleGesture:)];
UIGestureRecognizer *recognizer2 = [TouchUpGestureRecognizer alloc] initWithTarget:self action:#selector(handleGesture:)];
[self.view addGestureRecognizer:recognizer1];
[self.view addGestureRecognizer:recognizer2];