In my application I have a lot of little UIImageViews and a view off to the side. What I need is that view off to the side to be able to detect which image view was tapped and give me all the information about it (much like with (id)sender) as well as its coordinates. What is the best way to do this?
This is the internal class from my project. I think you get the idea.
As an option you can create protocol for the owner (or delegate).
You can obtain coords using
-[UITouch locationInView: someView]
Here is the code:
#interface _FaceSelectView : UIImageView {
#protected
VIFaceSelectVC* _owner;
}
-(id) initWithOwner:(FaceSelectVC*) owner;
#end
#implementation _FaceSelectView
-(id) initWithOwner:(FaceSelectVC*) owner {
if( self = [super init] ) {
_owner = owner;
self.userInteractionEnabled = YES;
}
return self;
}
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[_owner _touchesBeganIn: self withTouch: (UITouch*)[touches anyObject]];
}
-(void) touchesEnded:(NSSet*) touches withEvent:(UIEvent*) event {
[_owner _touchesEndedIn: self withTouch: (UITouch*)[touches anyObject]];
}
-(void) touchesMoved:(NSSet*) touches withEvent:(UIEvent*) event {
[_owner _touchesMovedIn: self withTouch: (UITouch*)[touches anyObject]];
}
#end
I would subclass UIImageView and add a new property for the target view you would like to message. Then reenable userInteractionEnabled and add a action to touchesUpInside.
In the action method of the custom subclass call a method on the target view in which you also give the object of the custom subview. Basically you use delegation and pass in the delegate call all parameters you need.
Add tag to UIImageView like myUIImageView.tag = intNumber;
and in side touchesBegan or you can call any common method for all your UIImageView and use tag to identify which view is tapped.
Related
I want to be able to recognise ALL touches in an interface, no matter what was touched.
I've tried:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
.. but this just recognises when the user taps on something that doesn't respond to taps (uiimages for instance)
The reason i need this ability is that I want to kick in a slide show if the user doesn't touch the screen for 5 minutes, so I want to reset the timer whenever they touch. It seems wrong to put this reset code in each UI event individually.
There are several possible solutions, but as said #omz - overriding the sendEvent: it is the best one.
#interface YourWindow : UIWindow {
NSDate timeOfLastTouch;
}
#end
#implementation YourWindow
- (void)sendEvent:(UIEvent *)event {
[super sendEvent:event];
NSSet *touches = [event allTouches];
UITouch *touch = [touches anyObject];
if( touch.phase == UITouchPhaseEnded ){
timeOfLastTouch = [NSDate date];
}
}
#end
Do not forget replace UIWindow with YourWindow.
You could subclass UIWindow and override the sendEvent: method.
you could use a tap gesture
In your interface add the UIGestureRecognizerDelegate
#interface ViewController : UIViewController <UIGestureRecognizerDelegate> {
then in your viewDidLoad add this
UITapGestureRecognizer *tapped = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapMethod)];
tapped.delegate=self;
tapped.numberOfTapsRequired = 1;
[self.view addGestureRecognizer:tapped];
then do your timer code in the tapped method
-(void)tapped {
//timer code
}
Make sure you UI elements have setUserInteractionEnabled:YES
You can subclass the UIWindow and override the sendEvent: method like this:
- (void)sendEvent:(UIEvent *)event {
if (event.type == UIEventTypeTouches) {
// You got a touch, do whatever you like
};
[super sendEvent:event]; // Let the window do the propagation of the event
}
As #Alladinian said in one of the comments, iOS Reference Documentation mentions that subclassing UIApplication is the right application and thus, seems preferred to subclassing UIWindow. cf. https://developer.apple.com/library/ios/#documentation/UIKit/Reference/UIApplication_Class/Reference/Reference.html :
You might decide to subclass UIApplication to override sendEvent: or
sendAction:to:from:forEvent: to implement custom event and action
dispatching.
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 implemented gesture recognizer in UIMapView just as described in the accepted answer to this question: How to intercept touches events on a MKMapView or UIWebView objects?
Single touches are recognized correctly. However, when I changed the superclass of my class from UIGestureRecognizer to UIPinchGestureRecognizer in order to recognize map scaling, everything stopped working.
Now TouchesEnded event occurs only when the user double tap the annotation on map (don't know, why!) and doesn't occur when the user pinches the map (zoom in or out doesn't matter).
PS I'm using iOS SDK 4.3 and testing my app in simulator if that matters.
The code of mapViewController.m - viewDidLoad method:
- (void)viewDidLoad
{
[super viewDidLoad];
MapGestureRecognizer *changeMapPositionRecognizer = [[MapGestureRecognizer alloc] init];
changeMapPositionRecognizer.touchesEndedCallback = ^(NSSet * touches, UIEvent * event)
{
...
};
[self.mapView addGestureRecognizer:changeMapPositionRecognizer];
[changeMapPositionRecognizer release];
}
The code of MapGestureRecognizer.h:
#import <UIKit/UIKit.h>
typedef void (^TouchesEventBlock) (NSSet * touches, UIEvent * event);
#interface MapGestureRecognizer : UIPinchGestureRecognizer
#property(nonatomic, copy) TouchesEventBlock touchesEndedCallback;
#end
The code of MapGestureRecognizer.m:
#import "MapGestureRecognizer.h"
#implementation MapGestureRecognizer
#synthesize touchesEndedCallback = _touchesEndedCallback;
- (id)init
{
self = [super init];
if (self) {
self.cancelsTouchesInView = NO;
}
return self;
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
if (self.touchesEndedCallback)
{
self.touchesEndedCallback(touches, event);
NSLog(#"Touches ended, callback done");
}
else
{
NSLog(#"Touches ended, callback skipped");
}
}
- (void) dealloc
{
[super dealloc];
}
#end
What should I correct in to make pinch gesture to be recognized?
I'm not sure why you need to subclass UIPinchGestureRecognizer instead of using it directly as-is.
Also not sure why you need the gesture recognizer to detect map scaling which you could do by using the delegate methods regionWillChangeAnimated and regionDidChangeAnimated and comparing the span before and after. Unless you are trying to detect the scaling as it is happening (and not wanting to wait until user finishes the gesture)
The gesture recognizer may not be getting called because the map view's own pinch gesture recognizer is getting called instead.
To have your recognizer called as well as the map view's, implement the UIGestureRecognizer delegate method shouldRecognizeSimultaneouslyWithGestureRecognizer and return YES:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
shouldRecognizeSimultaneouslyWithGestureRecognizer:
(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
Make sure the gesture recognizer's delegate property is set or that method won't get called either.
I want to add an image view that should be hidden by default, and when the user taps
its location, the image should appear.
For example:
If there is a chocolate bar
and I added a small UIImageView on top of the left bottom piece and set it to be hidden,
when the user taps that piece of chocolate, the new small image view should come and cover
that tapped piece.
This is the code I have
The .h file
#import <UIKit/UIKit.h>
#interface ChompViewController : UIViewController {
int s;
int turn;
IBOutlet UIImageView *sq1;
}
//#property (nonatomic, retain) IBOutlet UIImageView *aq1;
- (IBAction) mainMenu:(id)sender;
#end
The .m file:
#import "ChompViewController.h"
#import "MainMenuViewController.h"
#implementation ChompViewController
// Main Menu button in Start Game view.
- (IBAction) mainMenu:(id)sender {
MainMenuViewController* mainM = [[MainMenuViewController
alloc] initWithNibName:#"MainMenuViewController" bundle:nil];
[self.navigationController pushViewController:mainM animated:YES];
}
// The Game Method.
- (void) startGame {
s=20;
while (s>0) {
// Players' Turn
if (turn = 1) {
turn = 0;
}
// Computers' Turn
else {
turn = 1;
}
}
}
#end
So I want to implement the tap and hide in the two 'if' statements under
- (void) StartGame
I hope you can help me, I really need your help..
Thanks
EDIT:
I have found a method and made some changes and it works, but it works when tapping
any location on the screen and I want it to be triggered when the user taps the exact location of the small UIImageView.
Also, I do not know how to implement this method inside my StartGame method.
This is the code
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
sq1.hidden = NO;
[sq1 release];
}
I know I am asking a lot, I am noob and need some help to improve my knowledge of iPhone development.
===============
EDIT 2..
I have done something else,, but there is something wrong in the code and I do not know what is it..
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
s=20;
turn =1;
while (s>0) {
// Players' Turn
if (turn = 1) {
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:self.view];
if (CGRectContainsPoint(sq1.frame, touchLocation)){
sq1.hidden = YES;
}
turn = 0;
}
// Computers' Turn
else {
//Computer Here
turn = 1;
}
}
}
Now when I touch the imageView, the simulator freezes and quits the app.
Simplest is to place a custom UIButton with no image and no title text (so it's transparent) on top of the hidden UIImageView location and connect the TouchUpInside action of the button to a method that performs
myImageView.hidden = NO.
Right now I can think of two possible ways to do this (probably there are more):
Use the touchesStarted: withEvent: Method and check whether the touch was inside the observed area. If it was, display/unhide the UIImageView
Forget the UIImageView and use transparent UIButtons instead. When the button gets pressed add the image to the instance if UIButton that was pressed.
On UIWebview, how can I detect a touch?
But not when user clicks some URL or touching a control.
Is it possible to handle it?
Use UIGestureRecognizerDelegate method:
Add UIGestureRecognizerDelegate in declaration file (i.e. your .h file)
Step 1: Just set the delegate of gestureRecognizer: (in .m file viewDidLoad)
UITapGestureRecognizer *webViewTapped = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(tapAction:)];
webViewTapped.numberOfTapsRequired = 1;
webViewTapped.delegate = self;
[offScreenWebView addGestureRecognizer:webViewTapped];
[webViewTapped release];
Step 2: Override this function: (in .m file)
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
Step 3: Now implement the tapAction function:
- (void)tapAction:(UITapGestureRecognizer *)sender
{
NSLog(#"touched");
// Get the specific point that was touched
CGPoint point = [sender locationInView:self.view];
}
The accepted answer is great if you only need to detect taps. If you need to detect all touches, the best way is to create a new UIView subclass and place it over the webview. In the subclass you can detect touches using hitTest:
TouchOverlay.h
#class TouchOverlay;
#protocol TouchOverlayDelegate <NSObject>
#optional
- (void)touchOverlayTouched:(TV4TouchOverlay *)touchOverlay;
#end
#interface TouchOverlay : UIView
#property (nonatomic, unsafe_unretained) id <TouchOverlayDelegate> delegate;
#end
Touchoverlay.m
#implementation TouchOverlay
- (id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
return self;
}
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
UIView *hitView = [super hitTest:point withEvent:event];
if (hitView == self) {
if (self.delegate && [self.delegate respondsToSelector:#selector(touchOverlayTouched:)]) {
[self.delegate touchOverlayTouched:self];
}
return nil; // Tell the OS to keep looking for a responder
}
return hitView;
}
#end
Note that the accepted answer above will only capture tap gestures (touchDown and touchUp without a drag in between), and that swipe gestures will be ignored.
For my purposes I needed to be informed of both, and so I added swipe gesture recognizers appropriately. (Note that despite being a bit field, you can't OR together swipe gesture recognizers' direction property, so 4 gesture recognizers are required to detect any swipe).
// Note that despite being a bit field, you can't `OR` together swipe gesture
// recognizers' `direction` property, so 4 gesture recognizers are required
// to detect any swipe
for (NSNumber * swipeDirection in #[#(UISwipeGestureRecognizerDirectionUp), #(UISwipeGestureRecognizerDirectionDown), #(UISwipeGestureRecognizerDirectionLeft), #(UISwipeGestureRecognizerDirectionRight)]) {
UISwipeGestureRecognizer * swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(timerReset:)];
swipe.direction = [swipeDirection integerValue];
swipe.delegate = self;
[rootWebView addGestureRecognizer:swipe];
}
Everything that inherits from UIResponder can handle touches (so does UIWebView). Read the doc:
http://developer.apple.com/library/ios/#documentation/uikit/reference/UIResponder_Class/Reference/Reference.html
You'll have to use:
touchesBegan:withEvent:
Edit: Adding the comment here for clarity-
I believe then there's no clean way of doing it, you can either override the hittest withEvent method like this or do a hack like this: overriding UIView
Do you mean you want to override the options that popup when they hold down on a link? I managed to get one to work with this tutorial/guide but the one posted here is still slightly buggy and needs you to do some fine tuning:
http://www.icab.de/blog/2010/07/11/customize-the-contextual-menu-of-uiwebview/