Replace MGLAnnotation image on didSelectAnnotation:

[hshah2811]

In Earlier Mapbox version 1.X, we do have RMMarker.replaceUIImage(Image) API to change the annotation image on marker/annotation selection.

But in new 2.0+ versions, i cann't see any API available on MGLAnnotation to replace the existing annotation image.

Requirement is: I want to change annotation/marker image when user taps/select on any annotation/marker in the map.

CODE:

Assigning non-selected image to all markers during map load.

- (MGLAnnotationImage *)mapView:(MGLMapView *)mapView imageForAnnotation:(LocationBasedObjectAnnotation *)annotation {
    UIImage * image = [UIImage imageNamed:@"nonSelectedImage"];
    NSString * reuseIdentifier = NSStringFromClass(annotation.class);
    return [MGLAnnotationImage annotationImageWithImage:image reuseIdentifier:reuseIdentifier];
}

Once user taps:

- (MGLAnnotiation*) mapView:(MGLMapView*)mapView didSelectAnnotation:(MGLAnnotation*)annotation
{
    //No API to change image of selected annotation 
}

[incanus]

This will rely on #1688.

[incanus]

Refs #1980

[hshah2811]

May i know when can we expect this fix?

[incanus]

@hshah2811 That (#1688) is of a class of bug/enhancement we are trying to get into this week's release, but it may not quite make it. Stay tuned — on a short timeline.

[minikin]

I also looking forward to fix this bug/enhancement. Thank you.

[RomainQuidet]

FYI I'm working on it. Will send a pull request soon

[RomainQuidet]

Code is working, cleaning up and pull request coming soon

[RomainQuidet]

Pull request sent : (#3146)
Just get your annotationImage and update the image property

[friedbunny]

Fixed by #3146.

[minikin]

@RomainQuidet Could you give me an example how to change an image(MGLAnnotationImage) for selected annotation in didSelectAnnotation? I can't figure out ...
Thank you in advance.

[RomainQuidet]

@minikin : I'm doing this on my sample

- (void)mapView:(MFMapView *)mapView didSelectAnnotation:(nonnull id<MGLAnnotation>)annotation
{
    // set selected annotation image
    MGLAnnotationImage *annoImage = [self.annotationImages objectForKey:annotation.title];
    annoImage.image = [UIImage imageNamed:@"marker-green"];
}

[minikin]

@RomainQuidet Thank you very much!
Just one question: How do you define annotationImages ?
I do like this :
var annotationImages = [String:MGLAnnotationImage]() also tried var annotationImages = [String:AnuObject]() but I can't call objectForKey

I tried like that : annotationImages["\(annotation.title!!)"]?.image = UIImage(named: "selectedPin")! in didSelectAnnotation but in this case all annotations change images...

I would appreciate any advice. Thanks.

[RomainQuidet]

@minikin MGLAnnotationImages are objects in the mapBox SDK with a designated initializer
+ (instancetype)annotationImageWithImage:(UIImage *)image reuseIdentifier:(NSString *)reuseIdentifier;
(in ObjC)

[minikin]

@RomainQuidet Thank you.
If I understand you correctly I need to do like this:

   let annotationImage = self.mapView.dequeueReusableAnnotationImageWithIdentifier("nonSelectedImage")

       let annoImage = annotationImage?.valueForKey(annotation.title!!) as! MGLAnnotationImage

      annoImage.image = UIImage(named: "selectedPin")!

I have an error :

[< UIImage 0x7f91060f0cd0 > valueForUndefinedKey:]: this class is not key value coding-compliant for the key Antalia.

objc[54908]: pthread_rwlock_rdlock failed (11)

ps: annotation.title!!- looks weird

[minikin]

@1ec5 maybe you can help me? Thanks!

[1ec5]

@minikin, please contact our Support staff, and we’d be happy to assist you further.

[alexagat]

I am still facing an issue trying to change an annotation image on the fly (without removing and adding all annotations).

I create a dictionary of annotation titles to annotations - [String : MGLAnnotationImage]
var annotationsTitlesAndImages: [String:MGLAnnotationImage] = [:]

I populate this dictionary with all my MGLAnnotationImages within the imageForAnnotation function

func mapView(mapView: MGLMapView, imageForAnnotation annotation: MGLAnnotation) -> MGLAnnotationImage? {
    let annotationImage = MGLAnnotationImage(image: UIImage(named: "map-pin")!, reuseIdentifier: "map-pin")
    annotationsTitlesAndImages[annotation.title!!] = annotationImage
    return annotationImage
}

I try and update the annotation's image in the didSelectAnnotation function

func mapView(mapView: MGLMapView, didSelectAnnotation annotation: MGLAnnotation) {
    annotationsTitlesAndImages[annotation.title!!]!.image = UIImage(named: "map-pin-active")!
}

With a breakpoint set on the annotationsTitlesAndImages[annotation.title!!]!.image line above, I see this code in the framework being run:

- (void)setImage:(UIImage *)image {
    _image = image;
    [self.delegate annotationImageNeedsRedisplay:self];
}

...but the image doesn't update.

Any insight?

[RomainQuidet]

replacing the image property of annotationImage should do the job. But I've seen yesterday an error saying
{Map}[Sprite]: Can't change sprite dimensions for 'com.mapbox.sprites.4'

I'll check that.

[Ramshandilya]

@alexagat Were you able to find a way to change image of an annotation? (without removing & adding)

[1ec5]

@alexagat @Ramshandilya, if setting the MGLAnnotationImage’s image property doesn’t work following #3146, it definitely should work following #3835 (which no longer causes the annotation to be removed and readded). Please try it out in the v3.3.0 alphas and let us know if it isn’t working as expected. Thanks!