Recognise all touches in interface - iphone

Question

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.

Answer 1

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.

Answer 2

You could subclass UIWindow and override the sendEvent: method.

Answer 3

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

Answer 4

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
}

Answer 5

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.