[android] - zoom to at least 2 when tracking is enabled (#7795)

* [android] - zoom to at least 2 when tracking is enabled, introduce interface for zoom invalidation, simplify example

* fixup unit test, added test for new interface + focal point interface

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapView.java

@@ -132,10 +132,13 @@ public class MapView extends FrameLayout {
     // callback for registering touch listeners
     RegisterTouchListener registerTouchListener = new RegisterTouchListener();
 
+    // callback for zooming in the camera
+    CameraZoomInvalidator zoomInvalidator = new CameraZoomInvalidator();
+
     // setup components for MapboxMap creation
     Projection proj = new Projection(nativeMapView);
     UiSettings uiSettings = new UiSettings(proj, focalPoint, compassView, attrView, view.findViewById(R.id.logoView));
-    TrackingSettings trackingSettings = new TrackingSettings(myLocationView, uiSettings, focalPoint);
+    TrackingSettings trackingSettings = new TrackingSettings(myLocationView, uiSettings, focalPoint, zoomInvalidator);
     MyLocationViewSettings myLocationViewSettings = new MyLocationViewSettings(myLocationView, proj, focalPoint);
     MarkerViewManager markerViewManager = new MarkerViewManager((ViewGroup) findViewById(R.id.markerViewContainer));
     AnnotationManager annotations = new AnnotationManager(nativeMapView, this, markerViewManager);
@@ -970,6 +973,16 @@ public class MapView extends FrameLayout {
     }
   }
 
+  private class CameraZoomInvalidator implements TrackingSettings.CameraZoomInvalidator {
+    @Override
+    public void zoomTo(double zoomLevel) {
+      double currentZoomLevel = mapboxMap.getCameraPosition().zoom;
+      if (currentZoomLevel < zoomLevel) {
+        mapboxMap.getTransform().setZoom(zoomLevel);
+      }
+    }
+  }
+
   private static class MapCallback implements OnMapChangedListener {
 
     private final MapboxMap mapboxMap;

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/TrackingSettings.java

@@ -2,7 +2,6 @@ package com.mapbox.mapboxsdk.maps;
 
 import android.Manifest;
 import android.content.pm.PackageManager;
-import android.graphics.PointF;
 import android.location.Location;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
@@ -28,6 +27,7 @@ public final class TrackingSettings {
   private final MyLocationView myLocationView;
   private final UiSettings uiSettings;
   private final FocalPointChangeListener focalPointChangedListener;
+  private final CameraZoomInvalidator zoomInvalidator;
   private LocationListener myLocationListener;
 
   private boolean myLocationEnabled;
@@ -38,10 +38,11 @@ public final class TrackingSettings {
   private MapboxMap.OnMyBearingTrackingModeChangeListener onMyBearingTrackingModeChangeListener;
 
   TrackingSettings(@NonNull MyLocationView myLocationView, UiSettings uiSettings,
-                   FocalPointChangeListener focalPointChangedListener) {
+                   FocalPointChangeListener focalPointChangedListener, CameraZoomInvalidator zoomInvalidator) {
     this.myLocationView = myLocationView;
     this.focalPointChangedListener = focalPointChangedListener;
     this.uiSettings = uiSettings;
+    this.zoomInvalidator = zoomInvalidator;
   }
 
   void initialise(MapboxMapOptions options) {
@@ -92,8 +93,8 @@ public final class TrackingSettings {
     myLocationView.setMyLocationTrackingMode(myLocationTrackingMode);
 
     if (myLocationTrackingMode == MyLocationTracking.TRACKING_FOLLOW) {
-      focalPointChangedListener.onFocalPointChanged(new PointF(myLocationView.getCenterX(),
-        myLocationView.getCenterY()));
+      zoomInvalidator.zoomTo(2.0);
+      focalPointChangedListener.onFocalPointChanged(myLocationView.getCenter());
     } else {
       focalPointChangedListener.onFocalPointChanged(null);
     }
@@ -343,4 +344,8 @@ public final class TrackingSettings {
   void onStop() {
     myLocationView.onStop();
   }
+
+  interface CameraZoomInvalidator {
+    void zoomTo(double zoomLevel);
+  }
 }

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/Transform.java

@@ -186,6 +186,10 @@ final class Transform implements MapView.OnMapChangedListener {
     }
   }
 
+  void setZoom(double zoom) {
+    mapView.setZoom(zoom);
+  }
+
   // Direction
   double getBearing() {
     double direction = -mapView.getBearing();

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/widgets/MyLocationView.java

@@ -308,7 +308,7 @@ public class MyLocationView extends View {
   public void setTilt(@FloatRange(from = 0, to = 60.0f) double tilt) {
     this.tilt = tilt;
     if (myLocationTrackingMode == MyLocationTracking.TRACKING_FOLLOW) {
-      mapboxMap.getUiSettings().setFocalPoint(new PointF(getCenterX(), getCenterY()));
+      mapboxMap.getUiSettings().setFocalPoint(getCenter());
     }
     invalidate();
   }
@@ -529,11 +529,15 @@ public class MyLocationView extends View {
     directionAnimator.start();
   }
 
-  public float getCenterX() {
+  public PointF getCenter() {
+    return new PointF(getCenterX(), getCenterY());
+  }
+
+  private float getCenterX() {
     return (getX() + getMeasuredWidth()) / 2 + contentPaddingX - projectedX;
   }
 
-  public float getCenterY() {
+  private float getCenterY() {
     return (getY() + getMeasuredHeight()) / 2 + contentPaddingY - projectedY;
   }
 

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/widgets/MyLocationViewSettings.java

@@ -1,6 +1,5 @@
 package com.mapbox.mapboxsdk.maps.widgets;
 
-import android.graphics.PointF;
 import android.graphics.drawable.Drawable;
 import android.support.annotation.ColorInt;
 import android.support.annotation.IntRange;
@@ -289,8 +288,7 @@ public class MyLocationViewSettings {
 
   private void invalidateFocalPointForTracking(MyLocationView myLocationView) {
     if (!(myLocationView.getMyLocationTrackingMode() == MyLocationTracking.TRACKING_NONE)) {
-      focalPointChangeListener.onFocalPointChanged(new PointF(myLocationView.getCenterX(),
-        myLocationView.getCenterY()));
+      focalPointChangeListener.onFocalPointChanged(myLocationView.getCenter());
     } else {
       focalPointChangeListener.onFocalPointChanged(null);
     }