iOS Custom MKAnnotation object resembling MKUserLocation animation - iphone

Question

I want to drop MKAnnotationView pins on a map and have the pins be animated much like the MKUserLocation animates (the blue dot with circular waves coming out)
How do you achieve this type of animation? What steps do I need to take?
Thanks!

Answer 1

Animate it like any UIView!
subclass MKAnnotationView for custom content. don't go via repeated addAnnotation calls to animate it! that is wrong
you can treat the anotationView just like any other view..
here is some code that has a blinking animation of images -- this code should get you started.
(not pretty but the exact stuff you will need for your case!)
#import "DDViewController.h"
#import <MapKit/MapKit.h>
#import <QuartzCore/QuartzCore.h>
#interface DummyAnnotation : NSObject<MKAnnotation>
#end
#implementation DummyAnnotation
- (CLLocationCoordinate2D)coordinate { return CLLocationCoordinate2DMake(51, 10); }
- (NSString *)title { return #"Dummy"; }
#end
#interface DummyAnnotationView : MKAnnotationView
#end
#implementation DummyAnnotationView
- (id)initWithAnnotation:(id <MKAnnotation>)annotation reuseIdentifier:(NSString *)reuseIdentifier {
self = [super initWithAnnotation:annotation reuseIdentifier:reuseIdentifier];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectZero];
imageView.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth;
imageView.animationImages = #[[UIImage imageNamed:#"1.gif"],[UIImage imageNamed:#"2.gif"]];
imageView.animationDuration = 5;
[imageView startAnimating];
[self addSubview:imageView];
return self;
}
#end
#interface DDViewController() <MKMapViewDelegate>
#end
#implementation DDViewController
- (MKMapView*)mapView {
return (MKMapView*)self.view;
}
- (void)viewDidLoad
{
[super viewDidLoad];
//init a region
MKCoordinateRegion region = MKCoordinateRegionMake(CLLocationCoordinate2DMake(51.0, 10.0), MKCoordinateSpanMake(2.0, 2.0));
[self.mapView setRegion:region animated:NO];
//add a dumy pin
DummyAnnotation *ann = [[DummyAnnotation alloc] init];
[self.mapView addAnnotation:ann];
}
- (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation {
if([annotation isKindOfClass:[DummyAnnotation class]]) {
DummyAnnotationView *view = (id)[mapView dequeueReusableAnnotationViewWithIdentifier:#"animated"];
if(!view)
view =[[DummyAnnotationView alloc ] initWithAnnotation:annotation reuseIdentifier:#"animated"];
view.bounds = CGRectMake(0, 0, 59, 59);
view.backgroundColor = [UIColor purpleColor];
//
//Animate it like any UIView!
//
CABasicAnimation *theAnimation;
//within the animation we will adjust the "opacity"
//value of the layer
theAnimation=[CABasicAnimation animationWithKeyPath:#"opacity"];
//animation lasts 0.4 seconds
theAnimation.duration=0.4;
//and it repeats forever
theAnimation.repeatCount= HUGE_VALF;
//we want a reverse animation
theAnimation.autoreverses=YES;
//justify the opacity as you like (1=fully visible, 0=unvisible)
theAnimation.fromValue=[NSNumber numberWithFloat:1.0];
theAnimation.toValue=[NSNumber numberWithFloat:0.1];
//Assign the animation to your UIImage layer and the
//animation will start immediately
[view.layer addAnimation:theAnimation forKey:#"animateOpacity"];
return view;
}
return nil;
}
//---
#end
uploaded the working sample to my dropbox (it will go away eventually but the code above is all but the image resources and the default boilerplate code of an iOS app) :: https://dl.dropbox.com/u/3753090/test.zip