[LLP] move camera and puck immediately when starting to track and displacement is big

Author: Łukasz Paczos

app/src/androidTest/java/com/mapbox/mapboxsdk/plugins/locationlayer/LocationLayerPluginTest.kt

@@ -1063,6 +1063,30 @@ class LocationLayerPluginTest {
     executePluginTest(pluginAction, PluginGenerationUtil.getLocationLayerPluginProvider(activityRule.activity))
   }
 
+  @Test
+  fun cameraPositionSnappedToTargetIfExceedsThreshold() {
+    val pluginAction = object : GenericPluginAction.OnPerformGenericPluginAction<LocationLayerPlugin> {
+      override fun onGenericPluginAction(plugin: LocationLayerPlugin, mapboxMap: MapboxMap,
+                                         uiController: UiController, context: Context) {
+        val target = LatLng(51.0, 17.0)
+        assertTrue(target.distanceTo(LatLng(location)) > LocationLayerConstants.INSTANT_LOCATION_TRANSITION_THRESHOLD)
+
+        plugin.cameraMode = CameraMode.NONE
+        plugin.forceLocationUpdate(location)
+        plugin.isLocationLayerEnabled = true
+        mapboxMap.moveCamera(CameraUpdateFactory.newLatLng(target))
+        mapboxMap.moveCamera(CameraUpdateFactory.bearingTo(90.0))
+        plugin.cameraMode = CameraMode.TRACKING_GPS
+
+        assertEquals(location.bearing.toDouble(), mapboxMap.cameraPosition.bearing, 0.1)
+        assertEquals(location.latitude, mapboxMap.cameraPosition.target.latitude, 0.1)
+        assertEquals(location.longitude, mapboxMap.cameraPosition.target.longitude, 0.1)
+      }
+    }
+
+    executePluginTest(pluginAction, PluginGenerationUtil.getLocationLayerPluginProvider(activityRule.activity))
+  }
+
   @Test
   fun onPluginInitialized_defaultCompassEngineIsProvided() {
     val pluginAction = object : GenericPluginAction.OnPerformGenericPluginAction<LocationLayerPlugin> {

plugin-locationlayer/src/main/java/com/mapbox/mapboxsdk/plugins/locationlayer/LocationLayerConstants.java

@@ -25,6 +25,9 @@ final class LocationLayerConstants {
   // Default animation duration for tilting while tracking.
   static final long DEFAULT_TRACKING_TILT_ANIMATION_DURATION = 1250;
 
+  // Threshold value to perform immediate camera/layer position update.
+  static final double INSTANT_LOCATION_TRANSITION_THRESHOLD = 500_000;
+
   // Sources
   static final String LOCATION_SOURCE = "mapbox-location-source";
   static final String PROPERTY_GPS_BEARING = "mapbox-property-gps-bearing";

plugin-locationlayer/src/main/java/com/mapbox/mapboxsdk/plugins/locationlayer/LocationLayerPlugin.java

@@ -269,8 +269,8 @@ public boolean isLocationLayerEnabled() {
    */
   public void setCameraMode(@CameraMode.Mode int cameraMode) {
     boolean isGpsNorth = cameraMode == CameraMode.TRACKING_GPS_NORTH;
-    pluginAnimatorCoordinator.resetAllCameraAnimations(mapboxMap.getCameraPosition(), isGpsNorth);
     locationLayerCamera.setCameraMode(cameraMode);
+    pluginAnimatorCoordinator.resetAllCameraAnimations(mapboxMap.getCameraPosition(), isGpsNorth);
   }
 
   /**

plugin-locationlayer/src/main/java/com/mapbox/mapboxsdk/plugins/locationlayer/PluginAnimatorCoordinator.java

@@ -7,6 +7,7 @@
 import android.os.SystemClock;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.v4.view.animation.FastOutSlowInInterpolator;
 import android.view.animation.LinearInterpolator;
 
 import com.mapbox.mapboxsdk.camera.CameraPosition;
@@ -21,6 +22,7 @@
 import static com.mapbox.mapboxsdk.plugins.locationlayer.LocationLayerConstants.ACCURACY_RADIUS_ANIMATION_DURATION;
 import static com.mapbox.mapboxsdk.plugins.locationlayer.LocationLayerConstants.COMPASS_UPDATE_RATE_MS;
 import static com.mapbox.mapboxsdk.plugins.locationlayer.LocationLayerConstants.MAX_ANIMATION_DURATION_MS;
+import static com.mapbox.mapboxsdk.plugins.locationlayer.LocationLayerConstants.INSTANT_LOCATION_TRANSITION_THRESHOLD;
 import static com.mapbox.mapboxsdk.plugins.locationlayer.LocationLayerConstants.TRANSITION_ANIMATION_DURATION_MS;
 import static com.mapbox.mapboxsdk.plugins.locationlayer.PluginAnimator.ANIMATOR_CAMERA_COMPASS_BEARING;
 import static com.mapbox.mapboxsdk.plugins.locationlayer.PluginAnimator.ANIMATOR_CAMERA_GPS_BEARING;
@@ -82,7 +84,9 @@ void feedNewLocation(@NonNull Location newLocation, @NonNull CameraPosition curr
     updateLayerAnimators(previousLayerLatLng, targetLatLng, previousLayerBearing, targetLayerBearing);
     updateCameraAnimators(previousCameraLatLng, previousCameraBearing, targetLatLng, targetCameraBearing);
 
-    playLocationAnimators(getAnimationDuration());
+    boolean snap = immediateAnimation(previousCameraLatLng, targetLatLng, currentCameraPosition.zoom)
+      || immediateAnimation(previousLayerLatLng, targetLatLng, currentCameraPosition.zoom);
+    playLocationAnimators(snap ? 0 : getAnimationDuration());
 
     previousLocation = newLocation;
   }
@@ -289,32 +293,34 @@ private void playCameraLocationAnimators(long duration) {
     locationAnimators.add(animatorMap.get(ANIMATOR_CAMERA_GPS_BEARING));
     AnimatorSet locationAnimatorSet = new AnimatorSet();
     locationAnimatorSet.playTogether(locationAnimators);
-    locationAnimatorSet.setInterpolator(new LinearInterpolator());
+    locationAnimatorSet.setInterpolator(new FastOutSlowInInterpolator());
     locationAnimatorSet.setDuration(duration);
     locationAnimatorSet.start();
   }
 
   void resetAllCameraAnimations(CameraPosition currentCameraPosition, boolean isGpsNorth) {
     resetCameraCompassAnimation(currentCameraPosition);
-    resetCameraLocationAnimations(currentCameraPosition, isGpsNorth);
-    playCameraLocationAnimators(TRANSITION_ANIMATION_DURATION_MS);
+    boolean snap = resetCameraLocationAnimations(currentCameraPosition, isGpsNorth);
+    playCameraLocationAnimators(snap ? 0 : TRANSITION_ANIMATION_DURATION_MS);
   }
 
-  private void resetCameraLocationAnimations(CameraPosition currentCameraPosition, boolean isGpsNorth) {
-    resetCameraLatLngAnimation(currentCameraPosition);
+  private boolean resetCameraLocationAnimations(CameraPosition currentCameraPosition, boolean isGpsNorth) {
     resetCameraGpsBearingAnimation(currentCameraPosition, isGpsNorth);
+    return resetCameraLatLngAnimation(currentCameraPosition);
   }
 
-  private void resetCameraLatLngAnimation(CameraPosition currentCameraPosition) {
+  private boolean resetCameraLatLngAnimation(CameraPosition currentCameraPosition) {
     CameraLatLngAnimator animator = (CameraLatLngAnimator) animatorMap.get(ANIMATOR_CAMERA_LATLNG);
     if (animator == null) {
-      return;
+      return false;
     }
 
     LatLng currentTarget = animator.getTarget();
     LatLng previousCameraTarget = currentCameraPosition.target;
     createNewAnimator(ANIMATOR_CAMERA_LATLNG,
       new CameraLatLngAnimator(previousCameraTarget, currentTarget, cameraListeners));
+
+    return immediateAnimation(previousCameraTarget, currentTarget, currentCameraPosition.zoom);
   }
 
   private void resetCameraGpsBearingAnimation(CameraPosition currentCameraPosition, boolean isGpsNorth) {
@@ -377,4 +383,13 @@ private void cancelAnimator(@PluginAnimator.Type int animatorType) {
   void setTrackingAnimationDurationMultiplier(float trackingAnimationDurationMultiplier) {
     this.durationMultiplier = trackingAnimationDurationMultiplier;
   }
+
+  private boolean immediateAnimation(LatLng current, LatLng target, double zoom) {
+    // TODO: 02/10/2018 calculate the value based on the projection
+    double distance = current.distanceTo(target);
+    if (zoom > 10) {
+      distance *= zoom;
+    }
+    return distance > INSTANT_LOCATION_TRANSITION_THRESHOLD;
+  }
 }

plugin-locationlayer/src/main/java/com/mapbox/mapboxsdk/plugins/locationlayer/Utils.java

@@ -85,8 +85,7 @@ static float calculateZoomLevelRadius(@NonNull MapboxMap mapboxMap, @Nullable Lo
     if (location == null) {
       return 0;
     }
-    double metersPerPixel = mapboxMap.getProjection().getMetersPerPixelAtLatitude(
-      location.getLatitude());
+    double metersPerPixel = mapboxMap.getProjection().getMetersPerPixelAtLatitude(location.getLatitude());
     return (float) (location.getAccuracy() * (1 / metersPerPixel));
   }