iPhone - Gestures on UIPickerView and UIWebView

Question

I'm making an iPhone app in which the user can do gestures (left and right swipes) to flick through tabs. My problem is that some of the pages have views such as the pickerview, webview, textfields and buttons. The swipes don't work on these. Is there any way to have global gestures?

For reference, my gesture code example:

//Swipe between tabs
#define mindrag 100
CGPoint mystartTouchPosition;
BOOL isProcessingListMove;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    CGPoint newTouchPosition = [touch locationInView:self.view];
    if(mystartTouchPosition.x != newTouchPosition.x || mystartTouchPosition.y != newTouchPosition.y) {
        isProcessingListMove = NO;
    }
    mystartTouchPosition = [touch locationInView:self.view];
    [super touchesBegan:touches withEvent:event];
}

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
{
    UITouch *touch = touches.anyObject;
    CGPoint currentTouchPosition = [touch locationInView:self.view];

    // If the swipe tracks correctly.
    double diffx = mystartTouchPosition.x - currentTouchPosition.x + 0.1; // adding 0.1 to avoid division by zero
    double diffy = mystartTouchPosition.y - currentTouchPosition.y + 0.1; // adding 0.1 to avoid division by zero

    if(abs(diffx / diffy) > 2.5 && abs(diffx) > mindrag)
    {
        // It appears to be a swipe.
        if(isProcessingListMove) {
            // ignore move, we're currently processing the swipe
            return;
        }

        if (mystartTouchPosition.x < currentTouchPosition.x) {
            isProcessingListMove = YES;
            self.tabBarController.selectedViewController = [self.tabBarController.viewControllers objectAtIndex:1];
            return;
        }
        else {
            isProcessingListMove = YES;

            self.tabBarController.selectedViewController = [self.tabBarController.viewControllers objectAtIndex:3];

            return;
        }
    }
    else if(abs(diffy / diffx) > 1)
    {
        isProcessingListMove = YES;
        [super touchesMoved:touches withEvent:event];
    }
}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
{
    isProcessingListMove = NO;
    [super touchesEnded:touches withEvent:event];
}
// End of swipe

Any input is appreciated.

Answer 1

You can subclass UIImagePickerController and UIWebView and add these gesture capturing views to them, so long as you gesture detection can still pass touches to the underlying views of course.