Let's say we have a view controller with one sub view. the subview takes up the center of the screen with 100 px margins on all sides. We then add a bunch of little stuff to click on inside that subview. We are only using the subview to take advantage of the new frame ( x=0, y=0 inside the subview is actually 100,100 in the parent view).
Then, imagine that we have something behind the subview, like a menu. I want the user to be able to select any of the "little stuff" in the subview, but if there is nothing there, I want touches to pass through it (since the background is clear anyway) to the buttons behind it.
How can I do this? It looks like touchesBegan goes through, but buttons don't work.
Create a custom view for your container and override the pointInside: message to return false when the point isn't within an eligible child view, like this:
Swift:
class PassThroughView: UIView {
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
for subview in subviews {
if !subview.isHidden && subview.isUserInteractionEnabled && subview.point(inside: convert(point, to: subview), with: event) {
return true
}
}
return false
}
}
Objective C:
#interface PassthroughView : UIView
#end
#implementation PassthroughView
-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
for (UIView *view in self.subviews) {
if (!view.hidden && view.userInteractionEnabled && [view pointInside:[self convertPoint:point toView:view] withEvent:event])
return YES;
}
return NO;
}
#end
Using this view as a container will allow any of its children to receive touches but the view itself will be transparent to events.
I also use
myView.userInteractionEnabled = NO;
No need to subclass. Works fine.
From Apple:
Event forwarding is a technique used by some applications. You forward touch events by invoking the event-handling methods of another responder object. Although this can be an effective technique, you should use it with caution. The classes of the UIKit framework are not designed to receive touches that are not bound to them .... If you want to conditionally forward touches to other responders in your application, all of these responders should be instances of your own subclasses of UIView.
Apples Best Practise:
Do not explicitly send events up the responder chain (via nextResponder); instead, invoke the superclass implementation and let the UIKit handle responder-chain traversal.
instead you can override:
-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
in your UIView subclass and return NO if you want that touch to be sent up the responder chain (I.E. to views behind your view with nothing in it).
A far simpler way is to "Un-Check" User Interaction Enabled in the interface builder. "If you are using a storyboard"
Lately I wrote a class that will help me with just that. Using it as a custom class for a UIButton or UIView will pass touch events that were executed on a transparent pixel.
This solution is a somewhat better than the accepted answer because you can still click a UIButton that is under a semi transparent UIView while the non transparent part of the UIView will still respond to touch events.
As you can see in the GIF, the Giraffe button is a simple rectangle but touch events on transparent areas are passed on to the yellow UIButton underneath.
Link to class
Top voted solution was not fully working for me, I guess it was because I had a TabBarController into the hierarchy (as one of the comments points out) it was in fact passing along touches to some parts of the UI but it was messing with my tableView's ability to intercept touch events, what finally did it was overriding hitTest in the view I want to ignore touches and let the subviews of that view handle them
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
UIView *view = [super hitTest:point withEvent:event];
if (view == self) {
return nil; //avoid delivering touch events to the container view (self)
}
else{
return view; //the subviews will still receive touch events
}
}
Building on what John posted, here is an example that will allow touch events to pass through all subviews of a view except for buttons:
-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
// Allow buttons to receive press events. All other views will get ignored
for( id foundView in self.subviews )
{
if( [foundView isKindOfClass:[UIButton class]] )
{
UIButton *foundButton = foundView;
if( foundButton.isEnabled && !foundButton.hidden && [foundButton pointInside:[self convertPoint:point toView:foundButton] withEvent:event] )
return YES;
}
}
return NO;
}
Swift 3
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
for subview in subviews {
if subview.frame.contains(point) {
return true
}
}
return false
}
According to the 'iPhone Application Programming Guide':
Turning off delivery of touch events.
By default, a view receives touch
events, but you can set its userInteractionEnabled property to NO
to turn off delivery of events. A view also does not receive events if it’s hidden
or if it’s transparent.
http://developer.apple.com/iphone/library/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/EventHandling/EventHandling.html
Updated: Removed example - reread the question...
Do you have any gesture processing on the views that may be processing the taps before the button gets it? Does the button work when you don't have the transparent view over it?
Any code samples of non-working code?
As far as I know, you are supposed to be able to do this by overriding the hitTest: method. I did try it but could not get it to work properly.
In the end I created a series of transparent views around the touchable object so that they did not cover it. Bit of a hack for my issue this worked fine.
Taking tips from the other answers and reading up on Apple's documentation, I created this simple library for solving your problem:
https://github.com/natrosoft/NATouchThroughView
It makes it easy to draw views in Interface Builder that should pass touches through to an underlying view.
I think method swizzling is overkill and very dangerous to do in production code because you are directly messing with Apple's base implementation and making an application-wide change that could cause unintended consequences.
There is a demo project and hopefully the README does a good job explaining what to do. To address the OP, you would change the clear UIView that contains the buttons to class NATouchThroughView in Interface Builder. Then find the clear UIView that overlays the menu that you want to be tap-able. Change that UIView to class NARootTouchThroughView in Interface Builder. It can even be the root UIView of your view controller if you intend those touches to pass through to the underlying view controller. Check out the demo project to see how it works. It's really quite simple, safe, and non-invasive
I created a category to do this.
a little method swizzling and the view is golden.
The header
//UIView+PassthroughParent.h
#interface UIView (PassthroughParent)
- (BOOL) passthroughParent;
- (void) setPassthroughParent:(BOOL) passthroughParent;
#end
The implementation file
#import "UIView+PassthroughParent.h"
#implementation UIView (PassthroughParent)
+ (void)load{
Swizz([UIView class], #selector(pointInside:withEvent:), #selector(passthroughPointInside:withEvent:));
}
- (BOOL)passthroughParent{
NSNumber *passthrough = [self propertyValueForKey:#"passthroughParent"];
if (passthrough) return passthrough.boolValue;
return NO;
}
- (void)setPassthroughParent:(BOOL)passthroughParent{
[self setPropertyValue:[NSNumber numberWithBool:passthroughParent] forKey:#"passthroughParent"];
}
- (BOOL)passthroughPointInside:(CGPoint)point withEvent:(UIEvent *)event{
// Allow buttons to receive press events. All other views will get ignored
if (self.passthroughParent){
if (self.alpha != 0 && !self.isHidden){
for( id foundView in self.subviews )
{
if ([foundView alpha] != 0 && ![foundView isHidden] && [foundView pointInside:[self convertPoint:point toView:foundView] withEvent:event])
return YES;
}
}
return NO;
}
else {
return [self passthroughPointInside:point withEvent:event];// Swizzled
}
}
#end
You will need to add my Swizz.h and Swizz.m
located Here
After that, you just Import the UIView+PassthroughParent.h in your {Project}-Prefix.pch file, and every view will have this ability.
every view will take points, but none of the blank space will.
I also recommend using a clear background.
myView.passthroughParent = YES;
myView.backgroundColor = [UIColor clearColor];
EDIT
I created my own property bag, and that was not included previously.
Header file
// NSObject+PropertyBag.h
#import <Foundation/Foundation.h>
#interface NSObject (PropertyBag)
- (id) propertyValueForKey:(NSString*) key;
- (void) setPropertyValue:(id) value forKey:(NSString*) key;
#end
Implementation File
// NSObject+PropertyBag.m
#import "NSObject+PropertyBag.h"
#implementation NSObject (PropertyBag)
+ (void) load{
[self loadPropertyBag];
}
+ (void) loadPropertyBag{
#autoreleasepool {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
Swizz([NSObject class], NSSelectorFromString(#"dealloc"), #selector(propertyBagDealloc));
});
}
}
__strong NSMutableDictionary *_propertyBagHolder; // Properties for every class will go in this property bag
- (id) propertyValueForKey:(NSString*) key{
return [[self propertyBag] valueForKey:key];
}
- (void) setPropertyValue:(id) value forKey:(NSString*) key{
[[self propertyBag] setValue:value forKey:key];
}
- (NSMutableDictionary*) propertyBag{
if (_propertyBagHolder == nil) _propertyBagHolder = [[NSMutableDictionary alloc] initWithCapacity:100];
NSMutableDictionary *propBag = [_propertyBagHolder valueForKey:[[NSString alloc] initWithFormat:#"%p",self]];
if (propBag == nil){
propBag = [NSMutableDictionary dictionary];
[self setPropertyBag:propBag];
}
return propBag;
}
- (void) setPropertyBag:(NSDictionary*) propertyBag{
if (_propertyBagHolder == nil) _propertyBagHolder = [[NSMutableDictionary alloc] initWithCapacity:100];
[_propertyBagHolder setValue:propertyBag forKey:[[NSString alloc] initWithFormat:#"%p",self]];
}
- (void)propertyBagDealloc{
[self setPropertyBag:nil];
[self propertyBagDealloc];//Swizzled
}
#end
Try set a backgroundColor of your transparentView as UIColor(white:0.000, alpha:0.020). Then you can get touch events in touchesBegan/touchesMoved methods. Place the code below somewhere your view is inited:
self.alpha = 1
self.backgroundColor = UIColor(white: 0.0, alpha: 0.02)
self.isMultipleTouchEnabled = true
self.isUserInteractionEnabled = true
Try this
class PassthroughToWindowView: UIView {
override func test(_ point: CGPoint, with event: UIEvent?) -> UIView? {
var view = super.hitTest(point, with: event)
if view != self {
return view
}
while !(view is PassthroughWindow) {
view = view?.superview
}
return view
}
}
I use that instead of override method point(inside: CGPoint, with: UIEvent)
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
guard self.point(inside: point, with: event) else { return nil }
return self
}
If you can't bother to use a category or subclass UIView, you could also just bring the button forward so that it is in front of the transparent view. This won't always be possible depending on your application, but it worked for me. You can always bring the button back again or hide it.
Related
Below is what I want to make
What I have is ScrollView001 & ScrollView002. Layout is as below.
- View
- ScrollView001
- ScrollView002
ScrollView002, takes full screen so ScrollView001 is obviously below ScrollView002.
I am doing this for some effect i.e. when I scroll ScrollView002, I want to scroll ScrollView001 but with lower speed, which I have done successfully but the problem is when I try to click on Car for Gallery, its not clicking. If I hide ScrollView002 simply, gallery is working as usual.
Any idea how can I make underlying view as clickable?
For Gallery, what I have used is UICollectionView.
Edit 1
After scrolling, I want somewhat like below.
Fahim Parkar,
Not sure this is what you want or have I understood you wrong :) I believe you can makeuse of hitTest: to solve it :)
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *hitView = [super hitTest:point withEvent:event];
if (hitView && CGRectContainsPoint(ScrollView001.frame, point)) {
return ScrollView001;
}
return hitView;
}
How it Works
Whenever you tap on screen scorllView002 covering whole screen captures the touch :) Hence hitTest of ScrollView002 gets called :) If by anyway you can access the ScrollView001 (that should be easy as they are in same ViewController) you can verify if the touch point is inside ScrollView001, If yes you can return the touchView as ScrollView001.
As a result ScrollView001 will get touch rather then ScrollView002 :)
EDIT
As you have mentioned you did try my method and it still din work for you :) I decided to give a shot myself and realized it works absolutely fine. Please have a look :)
I believe this is what your situation :) I have added two scrollViews on top of each other. Small scrollView (myScrollView) being below the bigger fullscreen scrollView (TestScrollView).
Now when I tap on the screen there is no way myScrollView getting touch :)
But thats what we need so here is what I did :)
I created a subclass of ScrollView called TestScrollView and set the same for the top scrollView :)
TestScrollView.swift
import UIKit
class TestScrollView: UIScrollView {
var scrollViewBehind : UIView!
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
override func drawRect(rect: CGRect) {
// Drawing code
}
*/
override func hitTest(point: CGPoint, withEvent event: UIEvent?) -> UIView? {
let hitView = super.hitTest(point, withEvent: event)
if hitView != nil && CGRectContainsPoint(scrollViewBehind.frame,point) {
return scrollViewBehind
}
return hitView;
}
}
I have created a variable called scrollViewBehind to hold the reference of smallerScrollView which is behind it in storyboard (I am very much aware that holding a reference like this to view behind is not a great design :) But I believe it is good enough to explain the logic )
This is my ViewController code :)
import UIKit
class ViewController: UIViewController,UIGestureRecognizerDelegate {
#IBOutlet var myScrollView: UIScrollView!
#IBOutlet var testScrollView: TestScrollView!
override func viewDidLoad() {
super.viewDidLoad()
testScrollView.scrollViewBehind = myScrollView
let tap = UITapGestureRecognizer(target: self, action: Selector("handleTap"))
tap.delegate = self
myScrollView .addGestureRecognizer(tap)
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func handleTap(){
print("Me tapped")
}
}
EDIT
As per our discussion, I realized that you have a collectionView as a subView on smaller ScrollView which itself is behind the full screen scrollView :)
I have kept the answer above as it is in Swift and it also explains how to handle hitTest to handover the control to scrollView below from the scrollView above. Though it does not completely solve your question, might give a solution enough to somebody else :)
Now as per your question, when user taps, the scrollView above captures the touch and the touch should be forwarded to collectionView on top of smaller scrollView :)
So following the same approach explained above :) I created a subclass of ScrollView lets call TestScrollView (Answer is in objective C as per your requirement)
TestScrollView.h
#import <UIKit/UIKit.h>
#interface TestScrollView : UIScrollView
#property (nonatomic,strong) UICollectionView *collectionViewBehind;
#property (nonatomic,strong) UIScrollView *scrollViewBehind;
#end
TestScrollView.m
#import "TestScrollView.h"
#implementation TestScrollView
/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
// Drawing code
}
*/
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
UIView *hitView = [super hitTest:point withEvent:event];
CGPoint myPoint = [self convertPoint:point toView:self.scrollViewBehind];
if (hitView != nil && CGRectContainsPoint(self.scrollViewBehind.frame,point)) {
return self.collectionViewBehind;
}
return hitView;
}
#end
If you notice properly TestScrollView has two properties namely collectionViewBehind and scrollViewBehind this is to hold the reference of below scrollView and collectionView :)
What hitTest does is already explained above. Though, all it does is it checks the touch point if touch point is inside scrollView it returns the collectionView. What taht does is it transfers the touch event to collectionView.
Now go to storyboard select the topScrollView and set its class as TestScrollView.
In ViewController which loads these scrollViews add,
#import "ViewController.h"
#import "TestScrollView.h"
#interface ViewController ()<UICollectionViewDelegate,UICollectionViewDataSource,UIGestureRecognizerDelegate>
#property (strong, nonatomic) IBOutlet TestScrollView *testScrollView;
#property (strong, nonatomic) IBOutlet UICollectionView *collectionView;
#property (strong, nonatomic) IBOutlet UIScrollView *scrollView;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.testScrollView.collectionViewBehind = self.collectionView;
self.testScrollView.scrollViewBehind = self.scrollView;
self.collectionView.delegate = self;
self.collectionView.dataSource = self;
[self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:#"test"];
UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
tapGesture.numberOfTapsRequired = 1;
tapGesture.delegate = self;
[self.collectionView addGestureRecognizer:tapGesture];
// Do any additional setup after loading the view, typically from a nib.
}
Yes, If you have noticed you noticed it right I am adding a TapGesture recognizer to UICollectionView. Though we managed to handover the touch to UICollectionView we noticed that didSelectItemAtIndexPath was never triggered. So this is a small work around.
Though adding GestureRecognizer to collectionView is not much advisable here in this case it is still ok as we are only overriding single tap leaving all other gestures unaltered.
So now whenever user taps the scrollView above gestureRecognizer of UICollectionView triggers and calls our selector :) Now all you have to do is to figure out which cell was tapped and select it programmatically :)
-(void)handleTap:(UIGestureRecognizer *)recognizer {
[self collectionView:self.collectionView didSelectItemAtIndexPath:[self.collectionView indexPathForItemAtPoint:[recognizer locationInView:self.collectionView]]];
}
Finally enjoy the control at
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
NSLog(#"Hi indexPath tapped is %#",indexPath);
}
Finally here is a link to the project : https://github.com/sandeeplearner/UnderlayingClickableViews
Try this
Take button as background for your car then imageview for car so that it can be clickable.. i think there i is no need to make view cickable
You should add tapgesturerecognizer on upper scrollview, then you can handle tap something like,
- (void)handleTap:(UITapGestureRecognizer *)recognizer {
// First get the tap gesture recognizers's location in the entire
// view's window
CGPoint tapPoint = [recognizer locationInView:self.view];
// Then see if it falls within one of your below images' frames
for (UIImageView* image in relevantImages) {
// If the image's coordinate system isn't already equivalent to
// self.view, convert it so it has the same coordinate system
// as the tap.
CGRect imageFrameInSuperview = [image.superview convertRect:image toView:self.view]
// If the tap in fact lies inside the image bounds,
// perform the appropriate action.
if (CGRectContainsPoint(imageFrameInSuperview, tapPoint)) {
// Perhaps call a method here to react to the image tap
[self reactToImageTap:image];
break;
}
}
}
You can consider your car or instead of imageview in your case.
Hope this will help :)
I have custom view in my application which can be scrolled by the user. This view, however, does not inherit from UIScrollView. Now I want the user to be able to scroll this view to the top, just as any other scrollable view allows. I figured that there is no direct way to do so.
Google turned up one solution: http://cocoawithlove.com/2009/05/intercepting-status-bar-touches-on.html This no longer works on iOS 4.x. That's a no-go.
I had the idea of creating a scrollview and keeping it around somewhere, just to catch it's notifications and then forward them to my control. This is not a nice way to solve my problem, so I am looking for "cleaner" solutions. I like the general approach of the aforementioned link to subclass UIApplication. But what API can give me reliable info?
Are there any thoughts, help, etc...?
Edit: Another thing I don't like about my current solution is that it only works as long as the current view does not have any scroll views. The scroll-to-top gesture works only if exactly one scroll view is around. As soon as the dummy is added (see my answer below for details) to a view with another scrollview, the gesture is completely disabled. Another reason to look for a better solution...
Finally, i've assembled the working solution from answers here. Thank you guys.
Declare notification name somewhere (e.g. AppDelegate.h):
static NSString * const kStatusBarTappedNotification = #"statusBarTappedNotification";
Add following lines to your AppDelegate.m:
#pragma mark - Status bar touch tracking
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesBegan:touches withEvent:event];
CGPoint location = [[[event allTouches] anyObject] locationInView:[self window]];
CGRect statusBarFrame = [UIApplication sharedApplication].statusBarFrame;
if (CGRectContainsPoint(statusBarFrame, location)) {
[self statusBarTouchedAction];
}
}
- (void)statusBarTouchedAction {
[[NSNotificationCenter defaultCenter] postNotificationName:kStatusBarTappedNotification
object:nil];
}
Observe notification in the needed controller (e.g. in viewWillAppear):
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(statusBarTappedAction:)
name:kStatusBarTappedNotification
object:nil];
Remove observer properly (e.g. in viewDidDisappear):
[[NSNotificationCenter defaultCenter] removeObserver:self name:kStatusBarTappedNotification object:nil];
Implement notification-handling callback:
- (void)statusBarTappedAction:(NSNotification*)notification {
NSLog(#"StatusBar tapped");
//handle StatusBar tap here.
}
Hope it will help.
Swift 3 update
Tested and works on iOS 9+.
Declare notification name somewhere:
let statusBarTappedNotification = Notification(name: Notification.Name(rawValue: "statusBarTappedNotification"))
Track status bar touches and post notification. Add following lines to your AppDelegate.swift:
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesBegan(touches, with: event)
let statusBarRect = UIApplication.shared.statusBarFrame
guard let touchPoint = event?.allTouches?.first?.location(in: self.window) else { return }
if statusBarRect.contains(touchPoint) {
NotificationCenter.default.post(statusBarTappedNotification)
}
}
Observe notification where necessary:
NotificationCenter.default.addObserver(forName: statusBarTappedNotification.name, object: .none, queue: .none) { _ in
print("status bar tapped")
}
So this is my current solution, which works amazingly well. But please come with other ideas, as I don't really like it...
Add a scrollview somewhere in your view. Maybe hide it or place it below some other view etc.
Set its contentSize to be larger than the bounds
Set a non-zero contentOffset
In your controller implement a delegate of the scrollview like shown below.
By always returning NO, the scroll view never scrolls up and one gets a notification whenever the user hits the status bar. The problem is, however, that this does not work with a "real" content scroll view around. (see question)
- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView
{
// Do your action here
return NO;
}
Adding this to your AppDelegate.swift will do what you want:
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
super.touchesBegan(touches, withEvent: event)
let events = event!.allTouches()
let touch = events!.first
let location = touch!.locationInView(self.window)
let statusBarFrame = UIApplication.sharedApplication().statusBarFrame
if CGRectContainsPoint(statusBarFrame, location) {
NSNotificationCenter.defaultCenter().postNotificationName("statusBarSelected", object: nil)
}
}
Now you can subscribe to the event where ever you need:
NSNotificationCenter.defaultCenter().addObserverForName("statusBarSelected", object: nil, queue: nil) { event in
// scroll to top of a table view
self.tableView!.setContentOffset(CGPointZero, animated: true)
}
Thanks Max, your solution worked for me after spending ages looking.
For information :
dummyScrollView = [[UIScrollView alloc] init];
dummyScrollView.delegate = self;
[view addSubview:dummyScrollView];
[view sendSubviewToBack:dummyScrollView];
then
dummyScrollView.contentSize = CGSizeMake(view.frame.size.width, view.frame.size.height+200);
// scroll it a bit, otherwise scrollViewShouldScrollToTop not called
dummyScrollView.contentOffset = CGPointMake(0, 1);
//delegate :
- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)scrollView
{
// DETECTED! - do what you need to
NSLog(#"scrollViewShouldScrollToTop");
return NO;
}
Note that I had a UIWebView also which I had to hack a bit with a solution I found somewhere :
- (void)webViewDidFinishLoad:(UIWebView *)wv
{
[super webViewDidFinishLoad:wv];
UIScrollView *scroller = (UIScrollView *)[[webView subviews] objectAtIndex:0];
if ([scroller respondsToSelector:#selector(setScrollEnabled:)])
scroller.scrollEnabled = NO;
}
Found a much better solution which is iOS7 compatible here :http://ruiaureliano.tumblr.com/post/37260346960/uitableview-tap-status-bar-to-scroll-up
Add this method to your AppDelegate:
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesBegan:touches withEvent:event];
CGPoint location = [[[event allTouches] anyObject] locationInView:[self window]];
if (CGRectContainsPoint([UIApplication sharedApplication].statusBarFrame, location)) {
NSLog(#"STATUS BAR TAPPED!");
}
}
I implemented this by adding a clear UIView over the status bar and then intercepting the touch events
First in your Application delegate application:didFinishLaunchingWithOptions: add these 2 lines of code:
self.window.backgroundColor = [UIColor clearColor];
self.window.windowLevel = UIWindowLevelStatusBar+1.f;
Then in the view controller you wish to intercept status bar taps (or in the application delegate) add the following code
UIView* statusBarInterceptView = [[[UIView alloc] initWithFrame:[UIApplication sharedApplication].statusBarFrame] autorelease];
statusBarInterceptView.backgroundColor = [UIColor clearColor];
UITapGestureRecognizer* tapRecognizer = [[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(statusBarClicked)] autorelease];
[statusBarInterceptView addGestureRecognizer:tapRecognizer];
[[[UIApplication sharedApplication].delegate window] addSubview:statusBarInterceptView];
In the statusBarClicked selector, do what you need to do, in my case I posted a notification to the notification center so that other view controllers can respond to the status bar tap.
Use an invisible UIScrollView. Tested at iOS 10 & Swift 3.
override func viewDidLoad() {
let scrollView = UIScrollView()
scrollView.bounds = view.bounds
scrollView.contentOffset.y = 1
scrollView.contentSize.height = view.bounds.height + 1
scrollView.delegate = self
view.addSubview(scrollView)
}
func scrollViewShouldScrollToTop(_ scrollView: UIScrollView) -> Bool {
debugPrint("status bar tapped")
return false
}
You can track status bar tap by using following code:
[[NSNotificationCenter defaultCenter] addObserverForName:#"_UIApplicationSystemGestureStateChangedNotification"
object:nil
queue:nil
usingBlock:^(NSNotification *note) {
NSLog(#"Status bar pressed!");
}];
One way, might not be the best, could be to put a clear UIView on top of the status bar and intercept the touches of the UIView, might help you out if nothing else comes up...
If you're just trying to have a UIScrollView scroll to the top when the status bar is tapped, it's worth noting that this is the default behavior IF your view controller has exactly one UIScrollView in its subviews that has scrollsToTop set to YES.
So I just had to go and find any other UIScrollView (or subclasses: UITableView, UICollectionView, and set scrollsToTop to be NO.
To be fair, I found this info in the post that was linked to in the original question, but it's also dismissed as no longer working so I skipped it and only found the relevant piece on a subsequent search.
For iOS 13 this has worked for me, Objective-C category of UIStatusBarManager
#implementation UIStatusBarManager (CAPHandleTapAction)
-(void)handleTapAction:(id)arg1 {
// Your code here
}
#end
I've googled on how to dismiss keyboard when touching a blank area in UITableView in iOS, and there're several ways to solve this. Like using delegate, UITapGestureRecognizer, - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event and - (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event.
I decide to take hitTest by subclassing the corresponding UIView class and override this method like this:
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *result = [super hitTest:point withEvent:event];
[self endEditing:YES];
return result;
}
This really works, will dismiss the virtual keyboard when I touch / scroll / swipe / pinch ... somewhere else, but another problem shows up.
The keyboard is active or shown when I touch one UITextField object, then I touch the same UITextField object, here is the problem, the keyboard try to dismiss but not completely, in the middle of somewhere it begin to show up, doing this kind of weird animation. Most of the case in our APPs, the keyboard should stay still when we touch the same UITextField object. Is there a nice and simple way to solve this problem?
Solved:
Finally, I figure it out myself. Thanks to #Wain, thanks to #Wain's hint. I do check the result before I invoke [self endEditing:YES];. Here is the modified code:
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *result = [super hitTest:point withEvent:event];
// You can change the following condition to meet your own needs
if (![result isMemberOfClass:[UITextField class]] && ![result isMemberOfClass:[UITextView class]]) {
[self endEditing:YES];
}
return result;
}
As per #iBCode answer, if I select same text field multiple times then keyboard automatically hide and show immediately, to avoid that I have added one more condition and added code below in swift languagge
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
if let resultView = super.hitTest(point, with: event) {
if resultView.isMember(of: UITextField.self) ||
resultView.isKind(of: UITextField.self) ||
resultView.isMember(of: UITextView.self) ||
resultView.isKind(of: UITextView.self) {
return resultView
}
if !resultView.isMember(of: UITextField.self) && !resultView.isMember(of: UITextView.self) {
endEditing(true)
}
return resultView
}
return nil
}
Check the class of the result so that you can limit when you end editing. If the hit target was an editable class (like a text field, or a switch) then don't end the editing session.
I have a custom subclass of MKPinAnnotationView that displays a custom call out. I want to handle touch events inside that annotation.
I have a working solution (below) but it just doesn't feel right. I have a rule of thumb that whenever I use performSelector: .. withDelay: I'm fighting the system rather than working with it.
Does anyone have a good, clean workaround for the aggressive event handling of MKMapView and annotation selection handling?
My current solution:
(All code from my annotation selection class)
I do my own hit testing (without this my gesture recognisers don't fire as the Map View consumes the events:
- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent*)event; {
// To enable our gesture recogniser to fire. we have to hit test and return the correct view for events inside the callout.
UIView* hitView = nil;
if (self.selected) {
// check if we tpped inside the custom view
if (CGRectContainsPoint(self.customView.frame, point))
hitView = self.customView;
}
if(hitView) {
// If we are performing a gesture recogniser (and hence want to consume the action)
// we need to turn off selections for the annotation temporarily
// the are re-enabled in the gesture recogniser.
self.selectionEnabled = NO;
// *1* The re-enable selection a moment later
[self performSelector:#selector(enableAnnotationSelection) withObject:nil afterDelay:kAnnotationSelectionDelay];
} else {
// We didn't hit test so pass up the chain.
hitView = [super hitTest:point withEvent:event];
}
return hitView;
}
Note that I also turn off selections so that in my overridden setSelected I can ignore the deselection.
- (void)setSelected:(BOOL)selected animated:(BOOL)animated; {
// If we have hit tested positive for one of our views with a gesture recogniser, temporarily
// disable selections through _selectionEnabled
if(!_selectionEnabled){
// Note that from here one, we are out of sync with the enclosing map view
// we're just displaying out callout even though it thinks we've been deselected
return;
}
if(selected) {
// deleted code to set up view here
[self addSubview:_customView];
_mainTapGestureRecogniser = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(calloutTapped:)];
[_customView addGestureRecognizer: _mainTapGestureRecogniser];
} else {
self.selected = NO;
[_customView removeFromSuperview];
}
}
It's the line commented 1 that I don't like but it's also pretty hairy at the end of theta delayed fire. I have to walk back up the superview chain to get to the mapView so that I can convince it the selection is still in place.
// Locate the mapview so that we can ensure it has the correct annotation selection state after we have ignored selections.
- (void)enableAnnotationSelection {
// This reenables the seelction state and resets the parent map view's idea of the
// correct selection i.e. us.
MKMapView* map = [self findMapView];
[map selectAnnotation:self.annotation animated:NO];
_selectionEnabled = YES;
}
with
-(MKMapView*)findMapView; {
UIView* view = [self superview];
while(!_mapView) {
if([view isKindOfClass:[MKMapView class]]) {
_mapView = (MKMapView*)view;
} else if ([view isKindOfClass:[UIWindow class]]){
return nil;
} else{
view = [view superview];
if(!view)
return nil;
}
}
return _mapView;
}
This all seems to work without and downside (like flicker I've seen from other solutions. It's relatively straightforward but it doesn't feel right.
Anyone have a better solution?
I don't think you need to monkey with the map view's selection tracking. If I'm correctly interpreting what you want, you should be able to accomplish it with just the hitTest:withEvent: override and canShowCallout set to NO. In setSelected: perform your callout appearance/disappearance animation accordingly. You should also override setHighlighted: and adjust the display of your custom callout if visible.
The following code expresses my problem:
(It's self-contained in that you could create a Xcode project with an empty template, replace the contents of the main.m file, delete the AppDelegate.h/.m files and build it)
//
// main.m
// CollectionViewProblem
//
#import <UIKit/UIKit.h>
#interface Cell : UICollectionViewCell
#property (nonatomic, strong) UIButton *button;
#property (nonatomic, strong) UILabel *label;
#end
#implementation Cell
- (id)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame])
{
self.label = [[UILabel alloc] initWithFrame:self.bounds];
self.label.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
self.label.backgroundColor = [UIColor greenColor];
self.label.textAlignment = NSTextAlignmentCenter;
self.button = [UIButton buttonWithType:UIButtonTypeInfoLight];
self.button.frame = CGRectMake(-frame.size.width/4, -frame.size.width/4, frame.size.width/2, frame.size.width/2);
self.button.backgroundColor = [UIColor redColor];
[self.button addTarget:self action:#selector(buttonClicked:) forControlEvents:UIControlEventTouchUpInside];
[self.contentView addSubview:self.label];
[self.contentView addSubview:self.button];
}
return self;
}
// Overriding this because the button's rect is partially outside the parent-view's bounds:
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
if ([super pointInside:point withEvent:event])
{
NSLog(#"inside cell");
return YES;
}
if ([self.button
pointInside:[self convertPoint:point
toView:self.button] withEvent:nil])
{
NSLog(#"inside button");
return YES;
}
return NO;
}
- (void)buttonClicked:(UIButton *)sender
{
NSLog(#"button clicked!");
}
#end
#interface ViewController : UICollectionViewController
#end
#implementation ViewController
// (1a) viewdidLoad:
- (void)viewDidLoad
{
[super viewDidLoad];
[self.collectionView registerClass:[Cell class] forCellWithReuseIdentifier:#"ID"];
}
// collection view data source methods ////////////////////////////////////
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 100;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
Cell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"ID" forIndexPath:indexPath];
cell.label.text = [NSString stringWithFormat:#"%d", indexPath.row];
return cell;
}
///////////////////////////////////////////////////////////////////////////
// collection view delegate methods ////////////////////////////////////////
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"cell #%d was selected", indexPath.row);
}
////////////////////////////////////////////////////////////////////////////
#end
#interface AppDelegate : UIResponder <UIApplicationDelegate>
#property (strong, nonatomic) UIWindow *window;
#end
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
ViewController *vc = [[ViewController alloc] initWithCollectionViewLayout:layout];
layout.itemSize = CGSizeMake(128, 128);
layout.minimumInteritemSpacing = 64;
layout.minimumLineSpacing = 64;
layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
layout.sectionInset = UIEdgeInsetsMake(32, 32, 32, 32);
self.window.rootViewController = vc;
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}
#end
int main(int argc, char *argv[])
{
#autoreleasepool {
return UIApplicationMain(argc, argv, nil, NSStringFromClass([AppDelegate class]));
}
}
Basically I'm creating a Springboard-type UI using collection views. My UICollectionViewCell subclass (Cell) has a button which lies partially outside the cell's contentView (i.e. its superview's) bounds.
The problem is that clicking on any part of the button outside of the contentView bounds (basically 3/4th of the button) doesn't invoke the button action. Only when clicking on the portion of the button that overlaps the contentView is the button's action method called.
I've even overridden -pointInside:withEvent: method in Cell so that touches in the button will be acknowledged. But that hasn't helped with the button clicking problem.
I'm guessing it might be something to do with how collectionView handles touches, but I don't know what. I know that UICollectionView is a UIScrollView subclass and I've actually tested that overriding -pointInside:withEvent: on a view (made subview to a scroll view) containing a partially overlapping button solves the button clicking problem, but it hasn't worked here.
Any help?
** Added:
For the record, my current solution to the problem involves insetting a smaller subview to contentView which gives the cell its appearance. The delete button is added to the contentView such that its rect actually lies within the bounds of contentView but only partially overlaps the visible part of the cell (i.e. the inset subview). So I've got the effect I wanted, and the button is working properly. But I'm still curious about the problem with the original implementation above.
The problem appears to be with hitTest/pointInside. I'm guessing the cell is returning NO from pointInside if the touch is on the part of the button that is outside the cell and thus the button doesn't get hit tested. To fix this you have to override pointInside on your UICollectionViewCell subclass to take the button into account. You also need to override hitTest to return the button if the touch is inside the button. Here are example implementations assuming your button is in a property in the UICollectionViewCell subclass called deleteButton.
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
UIView *view = [self.deleteButton hitTest:[self.deleteButton convertPoint:point fromView:self] withEvent:event];
if (view == nil) {
view = [super hitTest:point withEvent:event];
}
return view;
}
-(BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
if ([super pointInside:point withEvent:event]) {
return YES;
}
//Check to see if it is within the delete button
return !self.deleteButton.hidden && [self.deleteButton pointInside:[self.deleteButton convertPoint:point fromView:self] withEvent:event];
}
Note that because hitTest and pointInside expect the point to be in the coordinate space of the receiver you have to remember to convert the point before calling those methods on the button.
In Interface Builder do you have set the object as UICollectionViewCell? Because erroneously one time I set a UIView and after assign to it the correct UICollectionViewCell class...but doing this things (buttons, labels, ecc.) are not added tor the contentView so they don't respond as they would...
So, remind in IB to take the UICollectionViewCell Object when drawing the interface :)
Swift version:
override func hitTest(point: CGPoint, withEvent event: UIEvent?) -> UIView? {
//From higher z- order to lower except base view;
for (var i = subviews.count-2; i >= 0 ; i--){
let newPoint = subviews[i].convertPoint(point, fromView: self)
let view = subviews[i].hitTest(newPoint, withEvent: event)
if view != nil{
return view
}
}
return super.hitTest(point, withEvent: event)
}
that's it ... for all subViews
I am successfully receiving touches to a button created as follows in the subclassed UICollectionViewCell.m file;
- (id)initWithCoder:(NSCoder *)aDecoder
{
self = [super initWithCoder:aDecoder];
if (self)
{
// Create button
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
button.frame = CGRectMake(0, 0, 100, 100); // position in the parent view and set the size of the button
[button setTitle:#"Title" forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:#"animage.png"] forState:UIControlStateNormal];
[button addTarget:self action:#selector(button:) forControlEvents:UIControlEventTouchUpInside];
// add to contentView
[self.contentView addSubview:button];
}
return self;
}
I added the button in code after realising that buttons added in Storyboard did not work, not sure if this is fixed in latest Xcode.
Hope that helps.
I see two swift conversions of the original answer that aren't exactly swift conversions. So I just want to give the Swift 4 conversion of the original answer so everyone who wants to can use it. You can just paste the code into your subclassed UICollectionViewCell. Just make sure that you change closeButton with your own button.
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
var view = closeButton.hitTest(closeButton.convert(point, from: self), with: event)
if view == nil {
view = super.hitTest(point, with: event)
}
return view
}
override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
if super.point(inside: point, with: event) {
return true
}
return !closeButton.isHidden && closeButton.point(inside: closeButton.convert(point, from: self), with: event)
}
As accepted answer requested, we should make a hitTest in order to recieve touches inside the cell. Here is the Swift 4 code for hit test:
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
for i in (0..<subviews.count-1).reversed() {
let newPoint = subviews[i].convert(point, from: self)
if let view = subviews[i].hitTest(newPoint, with: event) {
return view
}
}
return super.hitTest(point, with: event)
}
I had a similar problem trying to place a deletion button outside the bounds of a uicollectionview cell and it didn't seam to respond to tap events.
the way i solved it was to place a UITapGestureRecognizer on the collection and when a tap happend preform the following code
//this works also on taps outside the cell bouns, im guessing by getting the closest cell to the point of click.
NSIndexPath* tappedCellPath = [self.collectionView indexPathForItemAtPoint:[tapRecognizer locationInView:self.collectionView]];
if(tappedCellPath) {
UICollectionViewCell *tappedCell = [self.collectionView cellForItemAtIndexPath:tappedCellPath];
CGPoint tapInCellPoint = [tapRecognizer locationInView:tappedCell];
//if the tap was outside of the cell bounds then its in negative values and it means the delete button was tapped
if (tapInCellPoint.x < 0) [self deleteCell:tappedCell];
}
Honus has the best answer here in my opinion. In fact the only one that worked for me so I've been answering other similar questions and sending them this way:
I spent hours scouring the web for a solution to my UIButton's inside UICollectionView's not working. Driving me nuts until I finally found a solution that works for me. And I believe it's also the proper way to go: hacking the hit tests. It's a solution that can go a lot deeper (pun intended) than fixing the UICollectionView Button issues as well, as it can help you get the click event to any button buried under other views that are blocking your events from getting through:
UIButton in cell in collection view not receiving touch up inside event
Since that SO answer was in Objective C, I followed the clues from there to find a swift solution:
http://khanlou.com/2018/09/hacking-hit-tests/
--
When I would disable user interaction on the cell, or any other variety of answers I tried, nothing worked.
The beauty of the solution I posted above is that you can leave your addTarget's and selector functions how you are used to doing them since they were most likey never the problem. You need only override one function to help the touch event make it to its destination.
Why the solution works:
For the first few hours I figured the gesture wasn't being registered properly with my addTarget calls. It turns out the targets were registering fine. The touch events were simply never reaching my buttons.
The reality seems to be from any number of SO posts and articles I read, that UICollectionView Cells were meant to house one action, not multiple for a variety of reasons. So you were only supposed to be using the built in selection actions. With that in mind, I believe the proper way around this limitation is not to hack UICollectionView to disable certain aspects of scrolling or user interaction. UICollectionView is only doing its job. The proper way is to hack the hit tests to intercept the tap before it gets to UICollectionView and figure out which items they were tapping on. Then you simply send a touch event to the button they were tapping on, and let your normal stuff do the work.
My final solution (from the khanlou.com article) is to put my addTarget declaration and my selector function wherever I like (in the cell class or the cellForItemAt override), and in the cell class overriding the hitTest function.
In my cell class I have:
#objc func didTapMyButton(sender:UIButton!) {
print("Tapped it!")
}
and
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
guard isUserInteractionEnabled else { return nil }
guard !isHidden else { return nil }
guard alpha >= 0.01 else { return nil }
guard self.point(inside: point, with: event) else { return nil }
// add one of these blocks for each button in our collection view cell we want to actually work
if self.myButton.point(inside: convert(point, to: myButton), with: event) {
return self.myButton
}
return super.hitTest(point, with: event)
}
And in my cell class init I have:
self.myButton.addTarget(self, action: #selector(didTapMyButton), for: .touchUpInside)
I found this from here py4u.net
tried the solution that was at the very bottom. (the whole stuff was collected from this page, as I understand)
In my case the colution also worked. and then I just checked wether the User Interaction Enabled checkmark is checked on Collection view in xib and in it's contentView. Guess what. the contentView`s UserInteraction was disabled.
Enabling it fixed the issue with button's touchUpInside event and there was no need to override hitTest method.
You might not have to override hit test or do any of the complicated solutions above.
This issue can also be caused if you are using a custom button with lots of subviews.
What happens is when the button is hit tested, one of its subviews is being returned.
A cleaner solution here is just to set userInteractionEnabled = false on all of your button's subviews.
That way, hit testing your button will only ever return the button itself and none of the views on it.