/* * 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; }