Hello Angelo,

I think this code might help you:

@protocol BackgroundObjDelegate <NSObject>
@optional

- (void)showText:(NSString*)text;

@end

@interface BackgroundObj : NSObject
{
       id<BackgroundObjDelegate> _delegate;
}

@property(assign) id<BackgroundObjDelegate> delegate

- (void) sayHi;

@end

@implementation BackgroundObj

@synthesize delegate=_delegate;

- (void) sayHi
{
       if ([_delegate respondsToSelector:@selector(showText:)])
           [_delegate showText:@"Hi"];
}

@end

Then, you could implement your delegate class, for example:

@interface ForegroundObj : NSObject <BackgroundObjDelegate>
{
     // Insert your instance variables
}

- (void)showText:(NSString*)text;

@end

@implementation ForegroundObj

- (id)init
{
        if (![super init])
             return nil;

        BackgroundObj *obj = [[BackgroundObj alloc] init];
        obj.delegate = self;        // set the background object delegate

        return self;
}

- (void)showText:(NSString*)text
{
        // Insert your code
}

@end

If you have any questions, just ask, and please read Apple Docs, since
it's already quite complete in explaining these.

Regards,

Jesse
-------------------------------------------------------------------------------------------------
barablu (www.barablu.com), iPhone developer (http://jessearm.blogspot.com)

2008/6/10 Angelo Chen <[EMAIL PROTECTED]>:
> Hi,
>
> I have a code like this:
>
> @interface BackgroundObj : NSObject
> {
>        Controller *mc;
> }
>
> - (void) sayHi;
>
>
> @implementation BackgroundObj
>
> - (void) sayHi
> {
>        [mc showText:@"Hi"];
> }
> @end
>
> As you can see, the code is hard coded to use class Controller, can not be 
> used with any other object, I'd like to add a delegate which will have a 
> showText method, sayHi method will just call the delegate instead of hard 
> coded Controller, any idea how to add delegates to this object? or, any 
> tutorials for this? Thanks,
>
> Angelo
>
>
>
>
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