Question

I tried to implement this:

UICRouteOverlayMapView

.h file
@protocol DrawingDataDelegate <NSObject>
@required
-(void) drawingSuccessful:(BOOL)done;
@end

@interface UICRouteOverlayMapView : UIView {
    id <DrawingDataDelegate> delegate;
}

- (id)initWithMapView:(MKMapView *)mapView;

@property (nonatomic, retain) id <DrawingDataDelegate> delegate;
@end

 .m file
@implementation UICRouteOverlayMapView
@synthesize delegate;

- (void)drawRect:(CGRect)rect {
         NSLog(@"mesagge");
        if ([self.delegate respondsToSelector:@selector(drawingSuccessful:)]) {
            [self.delegate drawingSuccessful:YES];
        }
    }

The class that adopts the protocol:

.h file
#import "UICRouteOverlayMapView.h"

@class  UICRouteOverlayMapView;

@interface ItineraireViewController : UIViewController <MKMapViewDelegate, UICGDirectionsDelegate, CLLocationManagerDelegate, 
           DrawingDataDelegate> {

               UICRouteOverlayMapView *routeOverlayMapView;
}

    .m file
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    routeOverlayMapView = [[UICRouteOverlayMapView alloc] init];
    routeOverlayMapView.delegate = self;
}

-(void) drawingSuccessful:(BOOL)done{
    NSLog(@"it's done");
}

Now, what am I doing wrong cause the method drawingSuccessful never gets called?

I know for sure that the method

- (void)drawRect:(CGRect)rect {
         NSLog(@"mesagge");
        if ([self.delegate respondsToSelector:@selector(drawingSuccessful:)]) {
            [self.delegate drawingSuccessful:YES];
        }
    }

is called because this gets displayed NSLog(@"mesagge");.Please help

I did debug and set breakpoint at this line:

   if ([self.delegate respondsToSelector:@selector(drawingSuccessful:)])

and I noticed that this is not a valid condition…it never enters the brackets…so this
it is not compiled [self.delegate drawingSuccessful:YES]; .
So, what is wrong?

Answer 1

Does the route overlay map view already appear in your nib? In your view didLoad you are creating a new instance of it, setting it’s delegate, and then…nothing. You would normally be adding it to your subview, unless, as I say, it already exists in your nib file.

If it does, either set an outlet in UICRouteOverlayMapView and connect the delegate in interface builder, or within your viewDidLoad, set the delegate on whatever instance variable you are using to represent the actual map view.

It may just be a matter of removing this line:

 routeOverlayMapView = [[UICRouteOverlayMapView alloc] init];

If routeOverlayMapView is already pointing at your real view.

You are probably not entering that last if statement because your delegate is nil. The statement itself is redundant anyway since the method is required in your protocol.