feat: Added configurable anchor for infoWindows

Author: LuisThein

example/lib/place_annotation.dart

@@ -93,6 +93,7 @@ class PlaceAnnotationBodyState extends State<PlaceAnnotationBody> {
       ),
       infoWindow: InfoWindow(
           title: annotationIdVal,
+          anchor: Offset(0.5, 0.0),
           snippet: '*',
           onTap: () => print('InfowWindow of id: $annotationId tapped.')),
       onTap: () {
@@ -221,7 +222,7 @@ class PlaceAnnotationBodyState extends State<PlaceAnnotationBody> {
   @override
   Widget build(BuildContext context) {
     _createAnnotationImageFromAsset(context, _devicePixelRatio);
-    _getBytesFromAsset('assets/red_square.png', 10);
+    _getBytesFromAsset('assets/red_square.png', 40);
     return Column(
       mainAxisAlignment: MainAxisAlignment.spaceEvenly,
       crossAxisAlignment: CrossAxisAlignment.stretch,

ios/Classes/Annotations/AnnotationController.swift

@@ -111,6 +111,10 @@ class AnnotationController: NSObject {
     }
 
     private func initInfoWindow(annotation: FlutterAnnotation, annotationView: MKAnnotationView) {
+\(CGFloat(annotation.calloutOffset.y))")
+        let x = self.getInfoWindowXOffset(annotationView: annotationView, annotation: annotation)
+        let y = self.getInfoWindowYOffset(annotationView: annotationView, annotation: annotation)
+        annotationView.calloutOffset = CGPoint(x: x, y: y)
         if #available(iOS 9.0, *) {
             let lines = annotation.subtitle?.split(whereSeparator: \.isNewline)
             if lines != nil {
@@ -186,4 +190,15 @@ class AnnotationController: NSObject {
         annotationView?.image = annotation.icon.image
         return annotationView!
     }
+    
+    private func getInfoWindowXOffset(annotationView: MKAnnotationView, annotation: FlutterAnnotation) -> CGFloat {
+        if annotation.icon.iconType == .PIN {
+            return annotationView.frame.origin.x - (annotationView.frame.origin.x * CGFloat(annotation.calloutOffset.x))
+        }
+        return annotationView.frame.origin.x + (annotationView.frame.width * CGFloat(annotation.calloutOffset.x))
+    }
+    
+    private func getInfoWindowYOffset(annotationView: MKAnnotationView, annotation: FlutterAnnotation) -> CGFloat {
+        return annotationView.frame.height * CGFloat(annotation.calloutOffset.y)
+    }
 }

ios/Classes/Annotations/FlutterAnnotation.swift

@@ -19,6 +19,7 @@ class FlutterAnnotation: NSObject, MKAnnotation {
     var isDraggable: Bool?
     var wasDragged: Bool = false
     var isVisible: Bool? = true
+    var calloutOffset: CalloutOffset = CalloutOffset(x: 0, y: 0)
     var icon: AnnotationIcon = AnnotationIcon.init()
 
     public init(fromDictionary annotationData: Dictionary<String, Any>, registrar: FlutterPluginRegistrar) {
@@ -39,6 +40,10 @@ class FlutterAnnotation: NSObject, MKAnnotation {
         if let iconData: Array<Any> = annotationData["icon"] as? Array<Any> {
             self.icon = FlutterAnnotation.getAnnotationIcon(iconData: iconData, registrar: registrar, annotationId: id)
         }
+        
+        if let calloutOffsetJSON = infoWindow["anchor"] as? Array<Double> {
+            self.calloutOffset = CalloutOffset(x: calloutOffsetJSON[0], y: calloutOffsetJSON[1])
+        }
     }
 
     static private func getAnnotationIcon(iconData: Array<Any>, registrar: FlutterPluginRegistrar, annotationId: String) -> AnnotationIcon {
@@ -69,3 +74,8 @@ class FlutterAnnotation: NSObject, MKAnnotation {
         return !(lhs == rhs)
     }
 }
+
+struct CalloutOffset {
+    let x: Double
+    let y: Double
+}

ios/Classes/MapView/AppleMapController.swift

@@ -93,9 +93,10 @@ public class AppleMapController : NSObject, FlutterPlatformView, MKMapViewDelega
     }
 
     public func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView)  {
-        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(self.calloutTapped(_:)))
-        view.addGestureRecognizer(tapGesture)
         if let annotation :FlutterAnnotation = view.annotation as? FlutterAnnotation  {
+            if annotation.infoWindowConsumesTapEvents {
+                view.addGestureRecognizer(self.onCalloutTapGestureRecognizer!)
+            }
             self.currentlySelectedAnnotation = annotation.id
             self.annotationController.onAnnotationClick(annotation: annotation)
         }