org.opensearch.geometry.GeometryVisitor Maven / Gradle / Ivy
/*
* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch licenses this file to you under
* the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*/
package org.opensearch.geometry;
import org.opensearch.geometry.utils.WellKnownText;
/**
* Support class for creating Geometry Visitors.
*
* This is an implementation of the Visitor pattern. The basic idea is to simplify adding new operations on Geometries, without
* constantly modifying and adding new functionality to the Geometry hierarchy and keeping it as lightweight as possible.
*
* It is a more object-oriented alternative to structures like this:
*
* if (obj instanceof This) {
* doThis((This) obj);
* } elseif (obj instanceof That) {
* doThat((That) obj);
* ...
* } else {
* throw new IllegalArgumentException("Unknown object " + obj);
* }
*
*
* The Visitor Pattern replaces this structure with Interface inheritance making it easier to identify all places that are using this
* structure, and making a shape a compile-time failure instead of runtime.
*
* See {@link WellKnownText#toWKT(Geometry, StringBuilder)} for an example of how this interface is used.
*
* @see Visitor Pattern
*/
public interface GeometryVisitor {
T visit(Circle circle) throws E;
T visit(GeometryCollection collection) throws E;
T visit(Line line) throws E;
T visit(LinearRing ring) throws E;
T visit(MultiLine multiLine) throws E;
T visit(MultiPoint multiPoint) throws E;
T visit(MultiPolygon multiPolygon) throws E;
T visit(Point point) throws E;
T visit(Polygon polygon) throws E;
T visit(Rectangle rectangle) throws E;
}