Successful Swipe in UITextView?

Question

Has anyone been able to implement a successful swipe gesture on a UITableView? By default this is not possible due to the scrolling nature of the control. I've tried subclassing UITextView and implementing the swipe function in the instance methods, but no dice.

My UITextView has scrolling disabled - Unless there is another way to implement multiline text?

[Edit] What I should say is input multiline text[/Edit]

Answer 1

Here is a subclass of a UITextView that will detect a swipes gesture...

Is this what you are looking for?

#import <UIKit/UIKit.h>

#define kMinimumGestureLength   25
#define kMaximumVariance        5

@interface SwipeableTextView : UITextView {
    CGPoint gestureStartPoint;
}

@end

@implementation SwipeableTextView

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesBegan:touches withEvent:event];

    UITouch *touch =[touches anyObject];
    gestureStartPoint = [touch locationInView:self];

}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesMoved:touches withEvent:event];

    UITouch *touch = [touches anyObject];
    CGPoint currentPosition = [touch locationInView:self];

    CGFloat deltaX = fabsf(gestureStartPoint.x - currentPosition.x);
    CGFloat deltaY = fabsf(gestureStartPoint.y - currentPosition.y);

    if (deltaX >= kMinimumGestureLength && deltaY <= kMaximumVariance) {
        NSLog(@"Horizontal swipe detected");
    }

}

@end

Answer 2

An even better solution, I have found, is to simply pass touches back to the superview:

@interface SwipeableTextView : UITextView {
}

@end

@implementation SwipeableTextView

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesBegan:touches withEvent:event];

    [self.superview touchesBegan:touches withEvent:event];

}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesMoved:touches withEvent:event];

    [self.superview touchesMoved:touches withEvent:event];
}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesEnded:touches withEvent:event];

    [self.superview touchesEnded:touches withEvent:event];
} 

@end

Answer 3

Add a transparent UIView on top of the UITextView and use it to handle the swipe, and send the touchesBegan/Moved/Ended/Canceled: messages to the text view to preserve normal interaction.

Answer 4

I took Ross's code and added a few things that helped me. In particular, this code won't respond to the swipe until it stops. It also prevents a swipe from reversing direction partway through.

#import <UIKit/UIKit.h>

#define kMinimumGestureLength   25
#define kMaximumVariance        5

typedef enum swipeDirection {
    kSwipeNone,
    kSwipeLeft,
    kSwipeRight
} tSwipeDirection;

@interface SwipeableTextView : UITextView {
    CGPoint gestureStartPoint;
    tSwipeDirection swipeDirection;
}

@end

@implementation SwipeableTextView

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesBegan:touches withEvent:event];

    swipeDirection = kSwipeNone;
    UITouch *touch =[touches anyObject];
    gestureStartPoint = [touch locationInView:self];

}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
    [super touchesMoved:touches withEvent:event];

    UITouch *touch = [touches anyObject];
    CGPoint currentPosition = [touch locationInView:self];

    CGFloat deltaX = fabsf(gestureStartPoint.x - currentPosition.x);
    CGFloat deltaY = fabsf(gestureStartPoint.y - currentPosition.y);

    // Check if we already started a swipe in a particular direction
    // Don't let the user reverse once they get going
    if (deltaX >= kMinimumGestureLength && deltaY <= kMaximumVariance &&
        swipeDirection == kSwipeNone) {
        if (gestureStartPoint.x < currentPosition.x) {
            swipeDirection = kSwipeRight;
        }
        else {
            swipeDirection = kSwipeLeft;
        }
    }
}

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
    if (swipeDirection == kSwipeRight) {
        NSLog(@"Swipe right");
    }
    else if (swipeDirection == kSwipeLeft) {
        NSLog(@"Swipe left");
    }
    [super touchesEnded:touches withEvent:event];
} 

@end

Answer 5

Usually you implement the touch responding events in a UITableViewCell, which can recognize the swipe and do something. UITableViews inherit from UIScrollView which does not like having touch events overridden.

Answer 6

You could also use a two finger swipe. When I get home I can elaborate with some code but that was what I have used