[android] Tidy up annotations API

Make unimplemented properties package private.
Make annotations object properties immutable.
Make InfoWindow and Circle classes package private.
Remove no longer needed casts from Options classes.
Added a few missing get/add methods to annotations classes for consistency.
Mininal version of #2546 suitable for v2.1.0 release.

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/Annotation.java

@@ -9,23 +9,26 @@ public abstract class Annotation implements Comparable<Annotation> {
      *
      * Internal C++ id is stored as unsigned int.
      */
-    protected long id = -1; // -1 unless added to a MapView
-    protected MapView mapView;
+    private long id = -1; // -1 unless added to a MapView
+    private MapView mapView;
 
-    float alpha = 1.0f;
-    boolean visible = true;
+    private float alpha = 1.0f;
+    private boolean visible = true;
 
-    public Annotation() {}
+    protected Annotation() {}
 
     public float getAlpha() {
         return alpha;
     }
 
+    /**
+     * Do not use this method. Used internally by the SDK.
+     */
     public long getId() {
         return id;
     }
 
-    public boolean isVisible() {
+    boolean isVisible() {
         return visible;
     }
 
@@ -34,19 +37,29 @@ public void remove() {
         mapView.removeAnnotation(this);
     }
 
-    public void setAlpha(float alpha) {
+    void setAlpha(float alpha) {
         this.alpha = alpha;
     }
 
+    /**
+     * Do not use this method. Used internally by the SDK.
+     */
     public void setId(long id) {
         this.id = id;
     }
 
+    /**
+     * Do not use this method. Used internally by the SDK.
+     */
     public void setMapView(MapView mapView) {
         this.mapView = mapView;
     }
 
-    public void setVisible(boolean visible) {
+    protected MapView getMapView() {
+        return mapView;
+    }
+
+    void setVisible(boolean visible) {
         this.visible = visible;
     }
 

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/Circle.java

@@ -11,13 +11,13 @@
  * https://github.com/mapbox/mapbox-gl-native/issues/1882
  * https://github.com/mapbox/mapbox-gl-native/issues/1726
  */
-public class Circle extends Annotation {
+class Circle extends Annotation {
 
-    LatLng center;
-    int fillColor = Color.BLACK;
-    double radius;
-    int strokeColor = Color.BLACK;
-    float strokeWidth = 10; // Google Maps API defaults to 10
+    private LatLng center;
+    private int fillColor = Color.BLACK;
+    private double radius;
+    private int strokeColor = Color.BLACK;
+    private float strokeWidth = 10; // Google Maps API defaults to 10
 
     public LatLng getCenter() {
         return center;
@@ -44,23 +44,23 @@ public float getStrokeWidth() {
         return strokeWidth;
     }
 
-    public void setCenter(LatLng center) {
+    void setCenter(LatLng center) {
         this.center = center;
     }
 
-    public void setFillColor(int color) {
+    void setFillColor(int color) {
         fillColor = color;
     }
 
-    public void setRadius(double radius) {
+    void setRadius(double radius) {
         this.radius = radius;
     }
 
-    public void setStrokeColor (int color) {
+    void setStrokeColor (int color) {
         strokeColor = color;
     }
 
-    public void setStrokeWidth (float width) {
+    void setStrokeWidth (float width) {
         strokeWidth = width;
     }
 

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/CircleOptions.java

@@ -9,68 +9,73 @@
  * https://github.com/mapbox/mapbox-gl-native/issues/1882
  * https://github.com/mapbox/mapbox-gl-native/issues/1726
  */
-public class CircleOptions {
+class CircleOptions {
 
     private Circle circle;
 
     public CircleOptions() {
         circle = new Circle();
     }
     public CircleOptions center(LatLng center) {
-        circle.center = center;
+        circle.setCenter(center);;
         return this;
     }
 
     public CircleOptions fillColor(int color) {
-        circle.fillColor = color;
+        circle.setFillColor(color);
         return this;
     }
 
     public LatLng getCenter() {
-        return circle.center;
+        return circle.getCenter();
     }
 
     public int getFillColor() {
-        return circle.fillColor;
+        return circle.getFillColor();
     }
 
     public double getRadius() {
-        return circle.radius;
+        return circle.getRadius();
     }
 
     public int getStrokeColor () {
-        return circle.strokeColor;
+        return circle.getStrokeColor();
     }
 
     public float getStrokeWidth() {
-        return circle.strokeWidth;
+        return circle.getStrokeWidth();
     }
 
-    public CircleOptions radius (double radius) {
-        circle.radius = radius;
+    public CircleOptions radius(double radius) {
+        circle.setRadius(radius);
         return this;
     }
 
     public CircleOptions strokeColor(int color) {
-        circle.strokeColor = color;
+        circle.setStrokeColor(color);
         return this;
     }
 
     public CircleOptions strokeWidth (float width) {
-        circle.strokeWidth = width;
+        circle.setStrokeWidth(width);
         return this;
     }
 
     public CircleOptions alpha(float alpha) {
-        circle.alpha = alpha;
+        circle.setAlpha(alpha);
         return this;
     }
 
     public float getAlpha() {
-        return circle.alpha;
+        return circle.getAlpha();
     }
 
-    public boolean isVisible() {
-        return circle.visible;
+    private CircleOptions visible(boolean visible) {
+        circle.setVisible(visible);
+        return this;
+    }
+
+    private boolean isVisible() {
+        return circle.isVisible();
     }
 }

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/InfoWindow.java

@@ -16,7 +16,7 @@
 /**
  * A tooltip view
  */
-public final class InfoWindow {
+final class InfoWindow {
 
     private Marker boundMarker;
     private MapView mMapView;

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/InfoWindowTipView.java

@@ -8,7 +8,7 @@
 import android.util.AttributeSet;
 import android.view.View;
 
-public final class InfoWindowTipView extends View {
+final class InfoWindowTipView extends View {
 
     private Paint mPaint;
     private Path mPath;

android/java/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/annotations/InfoWindowView.java

@@ -7,7 +7,7 @@
 
 import com.mapbox.mapboxsdk.R;
 
-public class InfoWindowView extends RelativeLayout{
+class InfoWindowView extends RelativeLayout{
 
     private InfoWindowTipView mTipView;