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MapLibre Android Java Utilities
package org.maplibre.geojson;
import androidx.annotation.Keep;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.TypeAdapter;
import com.google.gson.reflect.TypeToken;
import com.google.gson.stream.JsonReader;
import com.google.gson.stream.JsonToken;
import com.google.gson.stream.JsonWriter;
import org.maplibre.geojson.gson.GeoJsonAdapterFactory;
import java.io.IOException;
import java.util.Arrays;
import java.util.List;
/**
* A GeoJson object with TYPE "GeometryCollection" is a Geometry object.
*
* A GeometryCollection has a member with the name "geometries". The value of "geometries" is a List
* Each element of this list is a GeoJson Geometry object. It is possible for this list to be empty.
*
* Unlike the other geometry types, a GeometryCollection can be a heterogeneous composition of
* smaller Geometry objects. For example, a Geometry object in the shape of a lowercase roman "i"
* can be composed of one point and one LineString.
*
* GeometryCollections have a different syntax from single TYPE Geometry objects (Point,
* LineString, and Polygon) and homogeneously typed multipart Geometry objects (MultiPoint,
* MultiLineString, and MultiPolygon) but have no different semantics. Although a
* GeometryCollection object has no "coordinates" member, it does have coordinates: the coordinates
* of all its parts belong to the collection. The "geometries" member of a GeometryCollection
* describes the parts of this composition. Implementations SHOULD NOT apply any additional
* semantics to the "geometries" array.
*
* To maximize interoperability, implementations SHOULD avoid nested GeometryCollections.
* Furthermore, GeometryCollections composed of a single part or a number of parts of a single TYPE
* SHOULD be avoided when that single part or a single object of multipart TYPE (MultiPoint,
* MultiLineString, or MultiPolygon) could be used instead.
*
* An example of a serialized GeometryCollections given below:
*
* {
* "TYPE": "GeometryCollection",
* "geometries": [{
* "TYPE": "Point",
* "coordinates": [100.0, 0.0]
* }, {
* "TYPE": "LineString",
* "coordinates": [
* [101.0, 0.0],
* [102.0, 1.0]
* ]
* }]
* }
*
*
* @since 1.0.0
*/
@Keep
public final class GeometryCollection implements Geometry {
private static final String TYPE = "GeometryCollection";
private final String type;
private final BoundingBox bbox;
private final List geometries;
/**
* Create a new instance of this class by passing in a formatted valid JSON String. If you are
* creating a GeometryCollection object from scratch it is better to use one of the other provided
* static factory methods such as {@link #fromGeometries(List)}.
*
* @param json a formatted valid JSON string defining a GeoJson Geometry Collection
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static GeometryCollection fromJson(String json) {
GsonBuilder gson = new GsonBuilder();
gson.registerTypeAdapterFactory(GeoJsonAdapterFactory.create());
gson.registerTypeAdapterFactory(GeometryAdapterFactory.create());
return gson.create().fromJson(json, GeometryCollection.class);
}
/**
* Create a new instance of this class by giving the collection a list of {@link Geometry}.
*
* @param geometries a non-null list of geometry which makes up this collection
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static GeometryCollection fromGeometries(@NonNull List geometries) {
return new GeometryCollection(TYPE, null, geometries);
}
/**
* Create a new instance of this class by giving the collection a list of {@link Geometry}.
*
* @param geometries a non-null list of geometry which makes up this collection
* @param bbox optionally include a bbox definition as a double array
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 1.0.0
*/
public static GeometryCollection fromGeometries(@NonNull List geometries,
@Nullable BoundingBox bbox) {
return new GeometryCollection(TYPE, bbox, geometries);
}
/**
* Create a new instance of this class by giving the collection a single GeoJSON {@link Geometry}.
*
* @param geometry a non-null object of type geometry which makes up this collection
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 3.0.0
*/
public static GeometryCollection fromGeometry(@NonNull Geometry geometry) {
List geometries = Arrays.asList(geometry);
return new GeometryCollection(TYPE, null, geometries);
}
/**
* Create a new instance of this class by giving the collection a single GeoJSON {@link Geometry}.
*
* @param geometry a non-null object of type geometry which makes up this collection
* @param bbox optionally include a bbox definition as a double array
* @return a new instance of this class defined by the values passed inside this static factory
* method
* @since 3.0.0
*/
public static GeometryCollection fromGeometry(@NonNull Geometry geometry,
@Nullable BoundingBox bbox) {
List geometries = Arrays.asList(geometry);
return new GeometryCollection(TYPE, bbox, geometries);
}
/**
* Create a new instance of this class by giving the collection a list of {@link Geometry} and
* bounding box.
*
* @param type type
* @param geometries a non-null list of geometry which makes up this collection
* @param bbox optionally include a bbox definition as a double array
* @since 4.6.0
*/
GeometryCollection(String type, @Nullable BoundingBox bbox, List geometries) {
if (type == null) {
throw new NullPointerException("Null type");
}
this.type = type;
this.bbox = bbox;
if (geometries == null) {
throw new NullPointerException("Null geometries");
}
this.geometries = geometries;
}
/**
* This describes the TYPE of GeoJson this object is, thus this will always return
* {@link GeometryCollection}.
*
* @return a String which describes the TYPE of geometry, for this object it will always return
* {@code GeometryCollection}
* @since 1.0.0
*/
@NonNull
@Override
public String type() {
return type;
}
/**
* A Feature Collection might have a member named {@code bbox} to include information on the
* coordinate range for it's {@link Feature}s. The value of the bbox member MUST be a list of
* size 2*n where n is the number of dimensions represented in the contained feature geometries,
* with all axes of the most southwesterly point followed by all axes of the more northeasterly
* point. The axes order of a bbox follows the axes order of geometries.
*
* @return a list of double coordinate values describing a bounding box
* @since 3.0.0
*/
@Nullable
@Override
public BoundingBox bbox() {
return bbox;
}
/**
* This provides the list of geometry making up this Geometry Collection. Note that if the
* Geometry Collection was created through {@link #fromJson(String)} this list could be null.
* Otherwise, the list can't be null but the size of the list can equal 0.
*
* @return a list of {@link Geometry} which make up this Geometry Collection
* @since 1.0.0
*/
@NonNull
public List geometries() {
return geometries;
}
/**
* This takes the currently defined values found inside this instance and converts it to a GeoJson
* string.
*
* @return a JSON string which represents this GeometryCollection
* @since 1.0.0
*/
@Override
public String toJson() {
GsonBuilder gson = new GsonBuilder();
gson.registerTypeAdapterFactory(GeoJsonAdapterFactory.create());
gson.registerTypeAdapterFactory(GeometryAdapterFactory.create());
return gson.create().toJson(this);
}
/**
* Gson TYPE adapter for parsing Gson to this class.
*
* @param gson the built {@link Gson} object
* @return the TYPE adapter for this class
* @since 3.0.0
*/
public static TypeAdapter typeAdapter(Gson gson) {
return new GeometryCollection.GsonTypeAdapter(gson);
}
@Override
public String toString() {
return "GeometryCollection{"
+ "type=" + type + ", "
+ "bbox=" + bbox + ", "
+ "geometries=" + geometries
+ "}";
}
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (obj instanceof GeometryCollection) {
GeometryCollection that = (GeometryCollection) obj;
return (this.type.equals(that.type()))
&& ((this.bbox == null) ? (that.bbox() == null) : this.bbox.equals(that.bbox()))
&& (this.geometries.equals(that.geometries()));
}
return false;
}
@Override
public int hashCode() {
int hashCode = 1;
hashCode *= 1000003;
hashCode ^= type.hashCode();
hashCode *= 1000003;
hashCode ^= (bbox == null) ? 0 : bbox.hashCode();
hashCode *= 1000003;
hashCode ^= geometries.hashCode();
return hashCode;
}
/**
* TypeAdapter to serialize/deserialize GeometryCollection objects.
*
* @since 4.6.0
*/
static final class GsonTypeAdapter extends TypeAdapter {
private volatile TypeAdapter stringTypeAdapter;
private volatile TypeAdapter boundingBoxTypeAdapter;
private volatile TypeAdapter> listGeometryAdapter;
private final Gson gson;
GsonTypeAdapter(Gson gson) {
this.gson = gson;
}
@Override
public void write(JsonWriter jsonWriter, GeometryCollection object) throws IOException {
if (object == null) {
jsonWriter.nullValue();
return;
}
jsonWriter.beginObject();
jsonWriter.name("type");
if (object.type() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter stringTypeAdapter = this.stringTypeAdapter;
if (stringTypeAdapter == null) {
stringTypeAdapter = gson.getAdapter(String.class);
this.stringTypeAdapter = stringTypeAdapter;
}
stringTypeAdapter.write(jsonWriter, object.type());
}
jsonWriter.name("bbox");
if (object.bbox() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter boundingBoxTypeAdapter = this.boundingBoxTypeAdapter;
if (boundingBoxTypeAdapter == null) {
boundingBoxTypeAdapter = gson.getAdapter(BoundingBox.class);
this.boundingBoxTypeAdapter = boundingBoxTypeAdapter;
}
boundingBoxTypeAdapter.write(jsonWriter, object.bbox());
}
jsonWriter.name("geometries");
if (object.geometries() == null) {
jsonWriter.nullValue();
} else {
TypeAdapter> listGeometryAdapter = this.listGeometryAdapter;
if (listGeometryAdapter == null) {
TypeToken typeToken = TypeToken.getParameterized(List.class, Geometry.class);
listGeometryAdapter =
(TypeAdapter>) gson.getAdapter(typeToken);
this.listGeometryAdapter = listGeometryAdapter;
}
listGeometryAdapter.write(jsonWriter, object.geometries());
}
jsonWriter.endObject();
}
@Override
public GeometryCollection read(JsonReader jsonReader) throws IOException {
if (jsonReader.peek() == JsonToken.NULL) {
jsonReader.nextNull();
return null;
}
jsonReader.beginObject();
String type = null;
BoundingBox bbox = null;
List geometries = null;
while (jsonReader.hasNext()) {
String name = jsonReader.nextName();
if (jsonReader.peek() == JsonToken.NULL) {
jsonReader.nextNull();
continue;
}
switch (name) {
case "type":
TypeAdapter stringTypeAdapter = this.stringTypeAdapter;
if (stringTypeAdapter == null) {
stringTypeAdapter = gson.getAdapter(String.class);
this.stringTypeAdapter = stringTypeAdapter;
}
type = stringTypeAdapter.read(jsonReader);
break;
case "bbox":
TypeAdapter boundingBoxTypeAdapter = this.boundingBoxTypeAdapter;
if (boundingBoxTypeAdapter == null) {
boundingBoxTypeAdapter = gson.getAdapter(BoundingBox.class);
this.boundingBoxTypeAdapter = boundingBoxTypeAdapter;
}
bbox = boundingBoxTypeAdapter.read(jsonReader);
break;
case "geometries":
TypeAdapter> listGeometryAdapter = this.listGeometryAdapter;
if (listGeometryAdapter == null) {
TypeToken typeToken = TypeToken.getParameterized(List.class, Geometry.class);
listGeometryAdapter =
(TypeAdapter>) gson.getAdapter(typeToken);
this.listGeometryAdapter = listGeometryAdapter;
}
geometries = listGeometryAdapter.read(jsonReader);
break;
default:
jsonReader.skipValue();
}
}
jsonReader.endObject();
return new GeometryCollection(type == null ? "GeometryCollection" : type, bbox, geometries);
}
}
}
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