How to detect touch on UIWebView - iphone

Question

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?

Answer 1

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];
}

Answer 2

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

Answer 3

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];
}

Answer 4

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

Answer 5

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/