Is there any method to reset the queue used in dequeueReusableAnnotationViewWithIdentifier? - ios

Question

I add custom annotation in a mapview. Based on the internal model of the app the annotations can change color and title (although position may not change). I am using dequeueReusableAnnotationViewWithIdentifierin the method
- (MKAnnotationView *)mapView:(MKMapView *) viewForAnnotation:(id <MKAnnotation>)
The strange thing is that when the model changes the annotations are "refreshed" to use the correct title and color (I just use removeAnnotations: and add the new ones), but later when playing with the map some old annotations with wrong color are dequeued. I use a different identifier each time the model changes.
here is the code:
- (MKAnnotationView *)mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>)annotation{
// in case it's the user location, we already have an annotation, so just return nil
if ([annotation isKindOfClass:[MKUserLocation class]]){
return nil;
}
if ([annotation isKindOfClass:[APGSAnnotation class]]){
APGSAnnotation *gsn = (APGSAnnotation*) annotation;
NSString *GSAnnotationIdentifier = [NSString stringWithFormat:#"gid_%lu_%#", (unsigned long)gsn.gs.gID, self.car.energyType];
MKAnnotationView *markerView = [theMapView dequeueReusableAnnotationViewWithIdentifier:GSAnnotationIdentifier];
if (markerView == nil) {
MKAnnotationView *annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:GSAnnotationIdentifier];
annotationView.canShowCallout = YES;
annotationView.image = [self customizeAnnotationImage:gsn.gs];
annotationView.opaque = NO;
UIImageView *sfIconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:gsn.logo]];
annotationView.leftCalloutAccessoryView = sfIconView;
// http://stackoverflow.com/questions/8165262/mkannotation-image-offset-with-custom-pin-image
annotationView.centerOffset = CGPointMake(0,-annotationView.image.size.height/2);
UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
[rightButton addTarget:nil action:nil forControlEvents:UIControlEventTouchUpInside];
annotationView.rightCalloutAccessoryView = rightButton;
return annotationView;
}else{
markerView.annotation = annotation;
return markerView;
}
}
return nil;
}
and the customize method
- (UIImage*)customizeAnnotationImage:(APGS*)gs{
UIImage *markerImage;
if (gs.gID == self.best.gID) {
markerImage = [UIImage imageNamed:#"marker_red.png"];
}else if (gs.type == k1){
markerImage = [UIImage imageNamed:#"marker_blue.png"];
}else if (gs.type == k2){
markerImage = [UIImage imageNamed:#"marker_green.png"];
}else if (gs.type == k3){
markerImage = [UIImage imageNamed:#"marker_purple.png"];
}else if (gs.type == k4){
markerImage = [UIImage imageNamed:#"marker_brown.png"];
}
UIImage *logoImage = [UIImage imageNamed:gs.logo];
// size the flag down to the appropriate size
CGRect resizeRect;
resizeRect.size = markerImage.size;
CGSize maxSize = CGRectInset(self.view.bounds, kAnnotationPadding, kAnnotationPadding).size;
maxSize.height -= self.navigationController.navigationBar.frame.size.height + kCallOutHeight;
if (resizeRect.size.width > maxSize.width)
resizeRect.size = CGSizeMake(maxSize.width, resizeRect.size.height / resizeRect.size.width * maxSize.width);
if (resizeRect.size.height > maxSize.height)
resizeRect.size = CGSizeMake(resizeRect.size.width / resizeRect.size.height * maxSize.height, maxSize.height);
resizeRect.origin = CGPointMake(0.0, 0.0);
float initialWidth = resizeRect.size.width;
UIGraphicsBeginImageContextWithOptions(resizeRect.size, NO, 0.0f);
[markerImage drawInRect:resizeRect];
resizeRect.size.width = resizeRect.size.width/2;
resizeRect.size.height = resizeRect.size.height/2;
resizeRect.origin.x = resizeRect.origin.x + (initialWidth - resizeRect.size.width)/2;
resizeRect.origin.y = resizeRect.origin.y + kLogoHeightPadding;
[logoImage drawInRect:resizeRect];
// Create string drawing context
UIFont *font = [UIFont fontWithName:#"DBLCDTempBlack" size:11.2];
NSString * num = [NSString stringWithFormat:#"%4.3f",[gs getL]];
NSDictionary *textAttributes = #{NSFontAttributeName: font,
NSForegroundColorAttributeName: [UIColor whiteColor]};
CGSize textSize = [num sizeWithAttributes:textAttributes];
NSStringDrawingContext *drawingContext = [[NSStringDrawingContext alloc] init];
//adjust center
if (resizeRect.size.width - textSize.width > 0) {
resizeRect.origin.x += (resizeRect.size.width - textSize.width)/2;
}else{
resizeRect.origin.x -= (resizeRect.size.width - textSize.width)/2;
}
resizeRect.origin.y -= kTextPadding;
[num drawWithRect:resizeRect
options:NSStringDrawingUsesLineFragmentOrigin
attributes:textAttributes
context:drawingContext];
UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return resizedImage;
}
Based on car type the annotations should change color.

Answer 1

Based on the title, the answer is NO :)
Normally you would dequeue the view and reset all relevant properties of the view
workaround:
What you can consider is: if the views would change too much, you could switch to a different reusingIdentifier, thereby switching the queue and 'circumventing' the cached views