Swift 2 MapKit Annotations - How to group annotations? - ios

Question

I have close to 8.000 annotations in my map and I'd like to group them depending of the zoom that the user do in the app.
All the latitudes and longitudes are already into the CoreData as Double.
Case I have two different annotation images in the same point, I'd like to show two groups, one with the cross and one with the heart.
When the user click over the annotation and if this annotation is a grouped annotation, I'd like to show to the user how many annotations has at this location, "forcing" the user to zoom in to see the annotations individually.
Bellow are the images of my app and the current annotations.
Thank you!

Answer 1

I already got it.
var zoomLevel = Double()
var iphoneScaleFactorLatitude = Double()
var iphoneScaleFactorLongitude = Double()
var CanUpdateMap: Bool = false
static func getLatitudeLongitudeLimitsFromMap(mapView: MKMapView) -> [String: Double] {
var coord = [String: Double]()
let MinLat: Double = mapView.region.center.latitude - (mapView.region.span.latitudeDelta / 2)
let MaxLat: Double = mapView.region.center.latitude + (mapView.region.span.latitudeDelta / 2)
let MinLon: Double = mapView.region.center.longitude - (mapView.region.span.longitudeDelta / 2)
let MaxLon: Double = mapView.region.center.longitude + (mapView.region.span.longitudeDelta / 2)
coord["MinLat"] = MinLat
coord["MaxLat"] = MaxLat
coord["MinLon"] = MinLon
coord["MaxLon"] = MaxLon
return coord
}
func LoadMap(mapView: MKMapView) {
// Get the limits after move or resize the map
let coord: [String: Double] = getLatitudeLongitudeLimitsFromMap(mapView)
let MinLat: Double = coord["MinLat"]! as Double
let MaxLat: Double = coord["MaxLat"]! as Double
let MinLon: Double = coord["MinLon"]! as Double
let MaxLon: Double = coord["MaxLon"]! as Double
var arrAnnotations = [MKAnnotation]()
let FilterMinLat = arrDicListPinsWithLatitudeLongitude.filter({
if let item = $0["Latitude"] as? Double {
return item > MinLat
} else {
return false
}
})
let FilterMaxLat = FilterMinLat.filter({
if let item = $0["Latitude"] as? Double {
return item < MaxLat
} else {
return false
}
})
let FilterMinLon = FilterMaxLat.filter({
if let item = $0["Longitude"] as? Double {
return item > MinLon
} else {
return false
}
})
let FilterMaxLon = FilterMinLon.filter({
if let item = $0["Longitude"] as? Double {
return item < MaxLon
} else {
return false
}
})
for Item in FilterMaxLon {
let dic:[String:AnyObject] = Item
var Name = String()
var Address = String()
var IconPNG = String()
if let Latitude = dic["Latitude"] as? Double {
if let Longitude = dic["Longitude"] as? Double {
if let item = dic["Name"] {
Name = item as! String
}
if let item = dic["Address"] {
Address = item as! String
}
if let item = dic["TypeID"] as? Int {
if item == 11 {
IconPNG = "icon-cross.png"
} else {
IconPNG = "icon-heart.png"
}
}
arrAnnotations.append(CreateAnnotation(Address, Title: Name, Latitude: Latitude, Longitude: Longitude, IconPNG: IconPNG))
}
}
}
}
// Show in the map only the annotations from that specific region
iphoneScaleFactorLatitude = mapView.region.center.latitude
iphoneScaleFactorLongitude = mapView.region.center.longitude
if zoomLevel != mapView.region.span.longitudeDelta {
filterAnnotations(arrAnnotations)
zoomLevel = mapView.region.span.longitudeDelta
CanUpdateMap = true
}
}
func filterAnnotations(arrAnnotations: [MKAnnotation]) {
let latDelta: Double = 0.04 / iphoneScaleFactorLatitude
let lonDelta: Double = 0.04 / iphoneScaleFactorLongitude
var shopsToShow = [AnyObject]()
var arrAnnotationsNew = [MKAnnotation]()
for var i = 0; i < arrAnnotations.count; i++ {
let checkingLocation: MKAnnotation = arrAnnotations[i]
let latitude: Double = checkingLocation.coordinate.latitude
let longitude: Double = checkingLocation.coordinate.longitude
var found: Bool = false
for tempPlacemark: MKAnnotation in shopsToShow as! [MKAnnotation] {
if fabs(tempPlacemark.coordinate.latitude - latitude) < fabs(latDelta) && fabs(tempPlacemark.coordinate.longitude - longitude) < fabs(lonDelta) {
found = true
}
}
if !found {
shopsToShow.append(checkingLocation)
arrAnnotationsNew.append(checkingLocation)
}
}
// Clean the map
for item: MKAnnotation in self.mapRedes.annotations {
myMap.removeAnnotation(item)
}
// Add new annotations to the map
for item: MKAnnotation in arrAnnotationsNew {
myMap.addAnnotation(item)
}
}
func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
// This validation should be added, because it will find all the annotations before the map resize
if CanUpdateMap == true {
LoadMap(mapView)
}
}

Answer 2

Just a correction to my code:
//....
func LoadMap(mapView: MKMapView) {
//....
// Show in the map only the annotations from that specific region
iphoneScaleFactorLatitude = Double(mapView.bounds.size.width / 30) // 30 = width of the annotation
iphoneScaleFactorLongitude = Double(mapView.bounds.size.height / 30) // 30 = height of the annotation
//....
}
func filterAnnotations(mapView: MKMapView, arrAnnotations: [MKAnnotation]) {
let latDelta: Double = mapView.region.span.longitudeDelta / iphoneScaleFactorLatitude
let lonDelta: Double = mapView.region.span.longitudeDelta / iphoneScaleFactorLongitude
//....
}
//....