iOS MapKit: Selected MKAnnotation coordinates.
- by Oh Danny Boy
Using the code at the following tutorial, http://www.zenbrains.com/blog/en/2010/05/detectar-cuando-se-selecciona-una-anotacion-mkannotation-en-mapa-mkmapview/, I was able to add an observer to each MKAnnotation and receive a notification of selected/deselected states.
I am attempting to add a UIView on top of the selection annotation to display relevant information about the location. This information cannot be conveyed in the 2 lines allowed (Title/Subtitle) for the pin's callout.
- (void)observeValueForKeyPath:(NSString *)keyPath
ofObject:(id)object
change:(NSDictionary *)change
context:(void *)context {
Annotation *a = (Annotation *)object;
// Alternatively attempted using:
//Annotation *a = (Annotation *)[mapView.selectedAnnotations objectAtIndex:0];
NSString *action = (NSString *)context;
if ([action isEqualToString:ANNOTATION_SELECTED_DESELECTED]) {
BOOL annotationSelected = [[change valueForKey:@"new"] boolValue];
if (annotationSelected) {
// Actions when annotation selected
CGPoint origin = a.frame.origin;
NSLog(@"origin (%f, %f) ", origin.x, origin.y);
// Test
UIView *v = [[UIView alloc] init];
[v setBackgroundColor:[UIColor orangeColor]];
[v setFrame:CGRectMake(origin.x, origin.y , 300, 300)];
[self.view addSubview:v];
[v release];
}else {
// Accions when annotation deselected
}
}
}
Results using Annotation *a = (Annotation *)object
origin (154373.000000, 197135.000000)
origin (154394.000000, 197152.000000)
origin (154445.000000, 197011.000000)
Results using Annotation *a = (Annotation *)[mapView.selectedAnnotations objectAtIndex:0];
origin (0.000000, 0.000000)
origin (0.000000, 0.000000)
origin (0.000000, 0.000000)
The numbers are large. They are not relative to the view (1024 x 768). I believe they are relative to the entire map. How would I be able to detect the exact coordinates relative to the entire view so that I can appropriately position my view?
