How to subclass a UITextView: Implement a horizontal swipe

I'm trying to implement a horizontal scroll on an UITextView. I found this explained here.

However, I don't understand how I can 'subclass' a UITextView. The code which is given and which I tried to implement is the following:

@interface SwipeableTextView : UITextView {
}

@end

@implementation SwipeableTextView

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

    [self.superview touchesBegan:touches开发者_开发问答 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

Apparently, this is supposed to override a normal UITextView which I can then call by referring to SwipeableTextView (e.g. SwipeableTextView.text = @"Some Text";). My question is, where do I put this piece of code? In my .m or .h file? I tried to put it beneath the implementation section of my m file, but this won't work as I already have an @interface and @implementation section. Any help would be very much appreciated.

EDIT: This works now:

//
//  SwipeTextView.h
//  Swipes
//

#import <Foundation/Foundation.h>

@interface SwipeTextView : UITextView {
    CGPoint     gestureStartPoint;
}

@property CGPoint gestureStartPoint;


@end

M File

//
//  SwipeTextView.m
//  Swipes
//

#import "SwipeTextView.h"
#define kMinimumGestureLength    10
#define kMaximumVariance         5

@implementation SwipeTextView
@synthesize gestureStartPoint;

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

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

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

}

- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {

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

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

    CGFloat deltaXX = (gestureStartPoint.x - currentPosition.x); // positive = left, negative = right
    //CGFloat deltaYY = (gestureStartPoint.y - currentPosition.y); // positive = up, negative = down

    CGFloat deltaX = fabsf(gestureStartPoint.x - currentPosition.x); // will always be positive
    CGFloat deltaY = fabsf(gestureStartPoint.y - currentPosition.y); // will always be positive

    if (deltaX >= kMinimumGestureLength && deltaY <= kMaximumVariance) {
        if (deltaXX > 0) {
            NSLog (@"Horizontal Left swipe detected");
        }
        else {
            NSLog(@"Horizontal Right swipe detected");
        }

    }

}

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

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




@end

And finally, this is how I create the subclass of this custom UITextView in my ViewController:

// UITextView
CGRect aFrame = CGRectMake(0, 100, 320, 200);
aSwipeTextView = [[SwipeTextView alloc] initWithFrame:aFrame];
aSwipeTextView.text = @"Some sample text. Some sample text. Some sample text.";
[self.view addSubview:aSwipeTextView];

Ok this is what you do.

When you want to subclass an object you create .h and .m files for it so.

Create a file called SwipeableTextView.h and insert this code inside:

#import <Foundation/Foundation.h>

    @interface SwipeableTextView : UITextView {

    }

@end

Then create a file SwipeableTextView.m and inser this into it:

#import "SwipeableTextView.h"

@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

To use this new sublass in your project do the following.

import the header:

#import "SwipeableTextView.h"

and then instead creating the UITextView normaly you would create SwipeableTextView like this:

SwipeableTextView *sTextView = [[SwipeableTextView alloc] init];

That's it. Hope it helps.