Handling touches within UIScrollview

I have a view that contains a UIScrollView. The UIScrollView contains an UIImageView (only one for now but there will be more latter). I want to be able to drag the UIImageView out of the UIScrollView and into the superview.

I have reviewed every similar question and example I can find online and still cant get my head around how this works.

At first I couldn't get touches to register all whithin the scrollview. After a lot of searching I have found a way to get touchesbegan to register as follows:

First I created a new view based project and in the auto-created "ViewController.h" I created an IBOutlet named slider.

Then in the auto-created "ViewController.m" I created the UIScrollview.

In IB I added a UIScrollView to the storyboard then connected it to the "slider" IBOutlet.

Next I added class file to the projects. This new class is a subclass os UIImageView. I named this class "DragableImage" In the

Then in IB I dropped an image into the UIScrollview clicked on it and changed the class to "DragableImage"

In the DragableImage.m I voided touches began and simply told it to become hidden if clicked.

This works and the touch registers and makes the image disappear but how do I now add the new image to the main view and have it follow my finger?

This is what I have in the way of code:

ViewController.h

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController {

    IBOutlet UIScrollView *slider;
}

@end

ViewController.m

#import "ViewController.h"


@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad
{
    [slider setScrollEnabled:YES];
    [slider setContentSize:CGSizeMake(306, 1560)];
    [slider setShowsVerticalScrollIndicator:NO];
    slider.canCancelContentTouches = NO; 
    slider.delaysContentTouches = NO;

    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (BOOL)shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)interfaceOrientation
{
    return YES;
}

@end

DragableImage.h

#import <UIKit/UIKit.h>

@interface DragableImage : UIImageView

@end

DragableImage.m

@implementation DragableImage

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

    self.hidden = YES;
}

@end

How to make this work?

Solution

There is one obvious problem that can arise here. Namely, how to tell the difference between dragging to scroll and dragging an image. The way I would handle this is to setup a tap and hold gesture recognizer (http://developer.apple.com/library/ios/#documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/GestureRecognizers/GestureRecognizers.html).

Once you detect a hold you could set it up so that further touches/gestures get routed to you drag and drop code. You can find a nice tutorial for that here: http://www.ancientprogramming.com/2012/04/05/drag-and-drop-between-multiple-uiviews-in-ios/