I have a touchesBegan: method which works fine. However I recently added a UIView (a button) to my UIViewController and now the button isn't registering taps, however my touchesBegan: method is.
How can I tell my touchesBegan: method to avoid the button?
Here is my current touchesBegan: method:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"touches began");
UITouch *touch = [touches anyObject];
switch ([touch tapCount])
{
case 1:
break;
case 2:
if(something)
[doing something];
break;
default:
break;
}
}
Make sure that the button is in front ([self.view bringSubviewToFront: myButton]). Then you can ask the touch in which in view it occurred:
if ([touch.view isEqualTo: myButton]) {
NSLog(#"touch was on button");
}
I had the same problem. When I moved my button to the front (in code via UIViewController.bringSubviewToFront) the touchesBegan no longer was fired when I clicked on the button. I'm running Xcode 4.2, in the simulator.
Related
I have a custom scrollView with the following method implemented:
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
//if not dragging send it on up the chain
if(!self.dragging){
[self.nextResponder touchesEnded:touches withEvent:event];
}else {
[super touchesEnded:touches withEvent:event];
}
}
And in My View Controller I have the following method:
-(void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event {
NSLog(#"TOUCH");
//---get all touches on the screen---
NSSet *allTouches = [event allTouches];
//---compare the number of touches on the screen---
switch ([allTouches count])
{
//---single touch---
case 1: {
//---get info of the touch---
UITouch *touch = [[allTouches allObjects] objectAtIndex:0];
//---compare the touches---
switch ([touch tapCount])
{
//---single tap---
case 1: {
NSLog(#"Single");
[self mySingleTapMethod];
} break;
//---double tap---
case 2: {
[self myDoubleTapMethod];
} break;
}
} break;
}
}
under iOS 4, this works perfectly, touches on the scrollview are recognized and the touchesEnded gets called in my view controller and all is right with the world. Under iOS 5x, however, the touchesEnded never gets fired. Does anyone know what the heck is going on/wrong?
Found the Answer here, basically if you want to do what I am doing you need to pass the touchesBegan up the chain as well.. because if a viewController didn't see the touchesBegan it won't get the TouchesEnded... So I modified the custom ScrollView to throw up the touchesBegan and everything now works fine in 5.0
Reference:
UIView touch handling behavior changed with Xcode 4.2?
I'm posting this message because I've been reading the forum and I haven't been able to find a similar problem. I need to be able to discriminate taps and double taps (this is a standard thing) BUT my problem is that for whatever reasons I have a Scroll View inside another ScrollView. So, I had to sub-class my ScrollView in order to get touchedBegin method called.
I have a class called PhotoViewController (a sub-class of BaseViewController) this class contains another class called CustomScrollView (a subclass of ScrollView). I needed to sub-class this CustomScrollView from ScrollView in order to override the touchesBegin method, and to be able to capture the touches made by the user.
I tried calling the touchesBegin method from CustomScrollView using something like return [super touchesBegan:touches withEvent:event] inside the touchesBegin method, but when the touchesBegin method inside PhotoViewController gets called it's parameters are empty (and I can't discriminate if the user made a single or double tap, which is exactly what I need)
I have a class, called PhotoViewController:
#class PhotoViewController
#interface PhotoViewController : BaseViewController <UIScrollViewDelegate> {
CustomScrollView* myScrollView;
}
#implementation PhotoViewController
...
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
NSUInteger tapCount = [touch tapCount];
switch (tapCount) {
case 1:
[self performSelector:#selector(singleTapMethod) withObject:nil afterDelay:.4];
break;
case 2:
[NSObject cancelPreviousPerformRequestsWithTarget:self selector:#selector(singleTapMethod) object:nil];
[self performSelector:#selector(doubleTapMethod) withObject:nil afterDelay:.4];
break;
default:
break;
}
}
the class CustomScrollView is (CustomScrollView.h):
#interface CustomScrollViewPhoto : UIScrollView {
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
#end
and it's implementation is this(CustomScrollView.m):
#implementation CustomScrollViewPhoto
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[self.superview touchesBegan:[NSSet set] withEvent:event];
return [super touchesBegan:touches withEvent:event];
}
Am I going in the wrong direction with what I want to do? Maybe, I should capture the taps/double taps inside the CustomScrollView class(this works fine!), and from there using a #selector or something call the appropiate methods in PhotoViewController?
Thanks for reading!
I think you're going the wrong route (only slightly!). I do a very similar thing in a photo viewer and I capture the touches in the CustomScrollView. You shouldn't need to do anything in PhotoViewController.
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesEnded:touches withEvent:event];
UITouch *touch = [touches anyObject];
if(touch.tapCount == 2)
{
if (self.zoomScale == self.minimumZoomScale)
{
//Zoom where the user has clicked from
CGPoint pos = [touch locationInView:self];
[self zoomToRect:CGRectMake((pos.x - 5.0)/self.zoomScale, (pos.y-5.0)/self.zoomScale, 10.0, 10.0) animated:YES];
}
else
{
//Zoom back out to full size
[self setZoomScale:self.minimumZoomScale animated:YES];
}
}
}
I wish to drag from one subview to another within my application (and connect them with a line), and so I need to keep track of the current view being touched by the user.
I thought that I could achieve this by simply calling [UITouch view] in the touchesMoved method, but after a quick look at the docs I've found out that [UITouch view] only returns the view in which the initial touch occurred.
Does anyone know how I can detect the view being touched while the drag is in progress?
And my way:
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
if ([self pointInside:[touch locationInView:self] withEvent:event]) {
[self sendActionsForControlEvents:UIControlEventTouchUpInside];
} else {
[self sendActionsForControlEvents:UIControlEventTouchUpOutside];
}
}
After a bit more research I found the answer.
Originally, I was checking for the view like so:
if([[touch view] isKindOfClass:[MyView* class]])
{
//hurray.
}
But, as explained in my question, the [touch view] returns the view in which the original touch occurred. This can be solved by replacing the code above with the following:
if([[self hitTest:[touch locationInView:self] withEvent:event] isKindOfClass:[MyView class]])
{
//hurrraaay! :)
}
Hope this helps
UIView is subclass of UIResponder. So you can override touches ended/ began methods in your custom class, that inherits from UIView. Than you should add delegate to that class and define protocol for it. In the methods
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
or whatever interactions you need just send appropriate message to object's delegate also passing this object. E.g.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[delegate touchesBeganInView: self withEvent: event];
}
HI . i am trying to move an UIImageView object with UITouch and have problem with the code how can i implement UITouch to detect only my UIImageView object ?
**imageA it my UIImageView
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *toucheA = [[event allTouches] anyObject];
if ([toucheA view] == imageA) {
CGPoint location = [toucheA locationInView:self];
imageA.center = location;
}
}
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
[self touchesBegan:touches withEvent:event];
CGPoint postion = imageA.center;
imageA.center = postion;
postion.y = 230;
imageA.center = postion;
}
but doesn't work !
I think you can make a custom UIImageView by subclassing and receive touch event you want inside the custom view.
Generally, the top most view will receiver the touch event. If the view process the touch event and doesn't pass the event to another view, then the others view behind it are impossible to receive any touch event. If the view cannot deal with the touch event, it will pass that by calling super's method.
I'm wondering how to track touches anywhere on the iPhone screen and still have UIButtons respond to taps.
I subclassed a UIView, made it full screen and the highest view in the hierarchy, and overrode its pointInside:withEvent method. If I return YES, I'm able to track touches anywhere on the screen but the buttons don't respond (likely because the view is instructed to handle and terminate the touch). If I return NO, the touch passes through the view and the buttons respond, but I'm not able to track touches.
Do I need to subclass UIButton or is this possible through the responder chain? What am I doing wrong?
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event{
return NO;
}
//only works if pointInside:withEvent: returns YES.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
NSLog(#"began");
[self.nextResponder touchesBegan:touches withEvent:event];
}
//only works if pointInside:withEvent: returns YES.
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
NSLog(#"end");
[self.nextResponder touchesEnded:touches withEvent:event];
}
Rather then having extra view you can subclass your applications main window and track touches (and other events in it)
#interface MyAppWindow : UIWindow
...
#implementation MyAppWindow
- (void)sendEvent:(UIEvent*)event {
[super sendEvent:event];
if (event.type == UIEventTypeTouches){
// Do something here
}
return;
}
Then set your application window type to MyAppWindow (I did that in MainWindow.xib in IB)