Adding Shifter implementation (#922)

* Adding Shifter implementation

* bumped @SInCE annotations to 4.1.1

* javadoc writing update

* checkstyle line spacing fix

* updated @SInCE and modified BBox Test

Author: osana

services-geojson/src/main/java/com/mapbox/geojson/Point.java

@@ -17,9 +17,9 @@
 import com.mapbox.geojson.gson.BoundingBoxSerializer;
 import com.mapbox.geojson.gson.CoordinateTypeAdapter;
 import com.mapbox.geojson.gson.GeoJsonAdapterFactory;
+import com.mapbox.geojson.shifter.CoordinateShifterManager;
 
 import java.io.Serializable;
-import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -97,7 +97,8 @@ public static Point fromLngLat(
     @FloatRange(from = MIN_LONGITUDE, to = MAX_LONGITUDE) double longitude,
     @FloatRange(from = MIN_LATITUDE, to = MAX_LATITUDE) double latitude) {
 
-    List<Double> coordinates = Arrays.asList(longitude, latitude);
+    List<Double> coordinates =
+      CoordinateShifterManager.getCoordinateShifter().shiftLonLat(longitude, latitude);
     return new AutoValue_Point(TYPE, null, coordinates);
   }
 
@@ -121,7 +122,8 @@ public static Point fromLngLat(
     @FloatRange(from = MIN_LATITUDE, to = MAX_LATITUDE) double latitude,
     @Nullable BoundingBox bbox) {
 
-    List<Double> coordinates = Arrays.asList(longitude, latitude);
+    List<Double> coordinates =
+      CoordinateShifterManager.getCoordinateShifter().shiftLonLat(longitude, latitude);
     return new AutoValue_Point(TYPE, bbox, coordinates);
   }
 
@@ -146,9 +148,9 @@ public static Point fromLngLat(
     @FloatRange(from = MIN_LATITUDE, to = MAX_LATITUDE) double latitude,
     double altitude) {
 
-    List<Double> coordinates = Double.isNaN(altitude)
-            ? Arrays.asList(longitude, latitude) :
-            Arrays.asList(longitude, latitude, altitude);
+    List<Double> coordinates =
+      CoordinateShifterManager.getCoordinateShifter().shiftLonLatAlt(longitude, latitude, altitude);
+
     return new AutoValue_Point(TYPE, null, coordinates);
   }
 
@@ -174,9 +176,8 @@ public static Point fromLngLat(
     @FloatRange(from = MIN_LATITUDE, to = MAX_LATITUDE) double latitude,
     double altitude, @Nullable BoundingBox bbox) {
 
-    List<Double> coordinates = Double.isNaN(altitude)
-            ? Arrays.asList(longitude, latitude) :
-            Arrays.asList(longitude, latitude, altitude);
+    List<Double> coordinates =
+      CoordinateShifterManager.getCoordinateShifter().shiftLonLatAlt(longitude, latitude, altitude);
     return new AutoValue_Point(TYPE, bbox, coordinates);
   }
 

services-geojson/src/main/java/com/mapbox/geojson/gson/BoundingBoxSerializer.java

@@ -7,8 +7,10 @@
 import com.google.gson.JsonSerializer;
 import com.mapbox.geojson.BoundingBox;
 import com.mapbox.geojson.Point;
+import com.mapbox.geojson.shifter.CoordinateShifterManager;
 
 import java.lang.reflect.Type;
+import java.util.List;
 
 /**
  * Serializer used for converting the {@link BoundingBox} object inside a GeoJson object to a JSON
@@ -43,18 +45,23 @@ public JsonElement serialize(BoundingBox src, Type typeOfSrc, JsonSerializationC
 
     // Southwest
     Point point = src.southwest();
-    bbox.add(new JsonPrimitive(point.longitude()));
-    bbox.add(new JsonPrimitive(point.latitude()));
+    List<Double> unshiftedCoordinates =
+            CoordinateShifterManager.getCoordinateShifter().unshiftPoint(point);
+
+    bbox.add(new JsonPrimitive(unshiftedCoordinates.get(0)));
+    bbox.add(new JsonPrimitive(unshiftedCoordinates.get(1)));
     if (point.hasAltitude()) {
-      bbox.add(new JsonPrimitive(point.altitude()));
+      bbox.add(new JsonPrimitive(unshiftedCoordinates.get(2)));
     }
 
     // Northeast
     point = src.northeast();
-    bbox.add(new JsonPrimitive(point.longitude()));
-    bbox.add(new JsonPrimitive(point.latitude()));
+    unshiftedCoordinates =
+            CoordinateShifterManager.getCoordinateShifter().unshiftPoint(point);
+    bbox.add(new JsonPrimitive(unshiftedCoordinates.get(0)));
+    bbox.add(new JsonPrimitive(unshiftedCoordinates.get(1)));
     if (point.hasAltitude()) {
-      bbox.add(new JsonPrimitive(point.altitude()));
+      bbox.add(new JsonPrimitive(unshiftedCoordinates.get(2)));
     }
 
     return bbox;

services-geojson/src/main/java/com/mapbox/geojson/gson/CoordinateTypeAdapter.java

@@ -4,6 +4,8 @@
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
 
+import com.mapbox.geojson.shifter.CoordinateShifterManager;
+
 import java.io.IOException;
 import java.math.BigDecimal;
 import java.math.RoundingMode;
@@ -21,11 +23,15 @@ public void write(JsonWriter out, List<Double> value) throws IOException {
 
     out.beginArray();
 
-    BigDecimal lon = BigDecimal.valueOf(value.get(0));
+    // Unshift coordinates
+    List<Double> unshiftedCoordinates =
+            CoordinateShifterManager.getCoordinateShifter().unshiftPoint(value);
+
+    BigDecimal lon = BigDecimal.valueOf(unshiftedCoordinates.get(0));
     String lonString = lon.setScale(7, RoundingMode.HALF_UP)
             .stripTrailingZeros().toPlainString();
 
-    BigDecimal lat = BigDecimal.valueOf(value.get(1));
+    BigDecimal lat = BigDecimal.valueOf(unshiftedCoordinates.get(1));
     String latString = lat.setScale(7, RoundingMode.HALF_UP)
             .stripTrailingZeros().toPlainString();
 
@@ -34,7 +40,7 @@ public void write(JsonWriter out, List<Double> value) throws IOException {
 
     // Includes altitude
     if (value.size() > 2) {
-      out.value(value.get(2));
+      out.value(unshiftedCoordinates.get(2));
     }
     out.endArray();
   }
@@ -48,6 +54,11 @@ public List<Double> read(JsonReader in) throws IOException {
     }
     in.endArray();
 
-    return coordinates;
+    if (coordinates.size() > 2) {
+      return CoordinateShifterManager.getCoordinateShifter()
+              .shiftLonLatAlt(coordinates.get(0), coordinates.get(1), coordinates.get(2));
+    }
+    return CoordinateShifterManager.getCoordinateShifter()
+            .shiftLonLat(coordinates.get(0), coordinates.get(1));
   }
 }

services-geojson/src/main/java/com/mapbox/geojson/gson/PointSerializer.java

@@ -6,10 +6,12 @@
 import com.google.gson.JsonSerializationContext;
 import com.google.gson.JsonSerializer;
 import com.mapbox.geojson.Point;
+import com.mapbox.geojson.shifter.CoordinateShifterManager;
 
 import java.lang.reflect.Type;
 import java.math.BigDecimal;
 import java.math.RoundingMode;
+import java.util.List;
 
 /**
  * Required to handle the special case where the altitude might be a Double.NaN, which isn't a valid
@@ -44,11 +46,15 @@ public PointSerializer() {
   public JsonElement serialize(Point src, Type typeOfSrc, JsonSerializationContext context) {
     JsonArray rawCoordinates = new JsonArray();
 
-    BigDecimal lon = BigDecimal.valueOf(src.longitude());
+    // Unshift coordinates
+    List<Double> unshiftedCoordinates =
+            CoordinateShifterManager.getCoordinateShifter().unshiftPoint(src);
+
+    BigDecimal lon = BigDecimal.valueOf(unshiftedCoordinates.get(0));
     String lonString = lon.setScale(7, RoundingMode.HALF_UP)
       .stripTrailingZeros().toPlainString();
 
-    BigDecimal lat = BigDecimal.valueOf(src.latitude());
+    BigDecimal lat = BigDecimal.valueOf(unshiftedCoordinates.get(1));
     String latString = lat.setScale(7, RoundingMode.HALF_UP)
             .stripTrailingZeros().toPlainString();
 
@@ -57,7 +63,7 @@ public JsonElement serialize(Point src, Type typeOfSrc, JsonSerializationContext
 
     // Includes altitude
     if (src.hasAltitude()) {
-      rawCoordinates.add(new JsonPrimitive(src.altitude()));
+      rawCoordinates.add(new JsonPrimitive(unshiftedCoordinates.get(2)));
     }
 
     return rawCoordinates;

services-geojson/src/main/java/com/mapbox/geojson/shifter/CoordinateShifter.java

@@ -0,0 +1,57 @@
+package com.mapbox.geojson.shifter;
+
+import com.mapbox.geojson.Point;
+
+import java.util.List;
+
+/**
+ * ShifterManager allows the movement of all Point objects according to a custom algorithm.
+ * Once set, it will be applied to all Point objects created through this method.
+ *
+ * @since 4.2.0
+ */
+public interface CoordinateShifter {
+
+  /**
+   * Shifted coordinate values according to its algorithm.
+   *
+   * @param lon unshifted longitude
+   * @param lat unshifted latitude
+   * @return shifted longitude, shifted latitude in the form of a List of Double values
+   * @since 4.2.0
+   */
+  List<Double> shiftLonLat(double lon, double lat);
+
+  /**
+   * Shifted coordinate values according to its algorithm.
+   *
+   * @param lon unshifted longitude
+   * @param lat unshifted latitude
+   * @param altitude  unshifted altitude
+   * @return shifted longitude, shifted latitude, shifted altitude in the form of a
+   *         List of Double values
+   * @since 4.2.0
+   */
+  List<Double> shiftLonLatAlt(double lon, double lat, double altitude);
+
+  /**
+   * Unshifted coordinate values according to its algorithm.
+   *
+   * @param shiftedPoint shifted point
+   * @return unshifted longitude, shifted latitude,
+   *         and altitude (if present) in the form of List of Double
+   * @since 4.2.0
+   */
+  List<Double> unshiftPoint(Point shiftedPoint);
+
+
+  /**
+   * Unshifted coordinate values according to its algorithm.
+   *
+   * @param shiftedCoordinates shifted point
+   * @return unshifted longitude, shifted latitude,
+   *         and altitude (if present) in the form of List of Double
+   * @since 4.2.0
+   */
+  List<Double> unshiftPoint(List<Double> shiftedCoordinates);
+}

services-geojson/src/main/java/com/mapbox/geojson/shifter/CoordinateShifterManager.java

@@ -0,0 +1,61 @@
+package com.mapbox.geojson.shifter;
+
+import com.mapbox.geojson.Point;
+
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * CoordinateShifterManager keeps track of currently set CoordinateShifter.
+ *
+ * @since 4.2.0
+ */
+public final class CoordinateShifterManager {
+
+  private static final CoordinateShifter DEFAULT = new CoordinateShifter() {
+    @Override
+    public List<Double> shiftLonLat(double lon, double lat) {
+      return Arrays.asList(lon, lat);
+    }
+
+    @Override
+    public List<Double> shiftLonLatAlt(double lon, double lat, double alt) {
+      return Double.isNaN(alt)
+              ? Arrays.asList(lon, lat) :
+              Arrays.asList(lon, lat, alt);
+    }
+
+    @Override
+    public List<Double> unshiftPoint(Point point) {
+      return point.coordinates();
+    }
+
+    @Override
+    public List<Double> unshiftPoint(List<Double> coordinates) {
+      return coordinates;
+    }
+  };
+
+  private static volatile CoordinateShifter coordinateShifter = DEFAULT;
+
+  /**
+   * Currently set CoordinateShifterManager.
+   *
+   * @return Currently set CoordinateShifterManager
+   * @since 4.2.0
+   */
+  public static CoordinateShifter getCoordinateShifter() {
+    return coordinateShifter;
+  }
+
+  /**
+   * Sets CoordinateShifterManager.
+   *
+   * @param coordinateShifter CoordinateShifterManager to be set
+   * @since 4.2.0
+   */
+  public static void setCoordinateShifter(CoordinateShifter coordinateShifter) {
+    CoordinateShifterManager.coordinateShifter =
+      coordinateShifter == null ? DEFAULT : coordinateShifter;
+  }
+}

services-geojson/src/main/java/com/mapbox/geojson/shifter/package-info.java

@@ -0,0 +1,4 @@
+/**
+ * Contains Utility for universally applying a shifting algorithm to all Geometry types.
+ */
+package com.mapbox.geojson.shifter;