plugins/org.eclipse.app4mc.amalthea.model/src/org/eclipse/app4mc/amalthea/model/AmaltheaExtensions.java

/**
 ********************************************************************************
 * Copyright (c) 2020 Robert Bosch GmbH and others.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Robert Bosch GmbH - initial API and implementation
 ********************************************************************************
 */

package org.eclipse.app4mc.amalthea.model;

import static com.google.common.base.Preconditions.checkArgument;

import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;

import org.eclipse.emf.common.util.EList;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;

/**
 * This class provides static helper methods (extension methods).
 * <p>
 * The methods are called from several generated model objects.
 */
public class AmaltheaExtensions {

	// Suppress default constructor
	private AmaltheaExtensions() {
		throw new IllegalStateException("Utility class");
	}

	private static final String ARG_STRING_MESSAGE = "Argument is null, expected: String";
	private static final String ARG_LIST_MESSAGE = "Argument is null, expected: EList";
	private static final String ARG_LIST_ITEM_MESSAGE = "List argument contains null";

	public static String toPlainString(final @NonNull EList<@NonNull String> segments, final @NonNull String delimiter) {
		checkArgument(segments != null, ARG_LIST_MESSAGE);
		checkArgument(!segments.contains(null), ARG_LIST_ITEM_MESSAGE);
		checkArgument(delimiter != null, ARG_STRING_MESSAGE);

		if (segments.isEmpty()) return "";

		StringBuilder result = new StringBuilder(segments.get(0));
		for (int i = 1; i < segments.size(); i++) {
			result.append(delimiter);
			result.append(segments.get(i));
		}
		return result.toString();
	}

	public static String toEncodedString(final @NonNull EList<@NonNull String> segments) {
		checkArgument(segments != null, ARG_LIST_MESSAGE);
		checkArgument(!segments.contains(null), ARG_LIST_ITEM_MESSAGE);

		if (segments.isEmpty()) return "";

		StringBuilder result = new StringBuilder(encode(segments.get(0)));
		for (int i = 1; i < segments.size(); i++) {
			result.append("/");
			result.append(encode(segments.get(i)));
		}
		return result.toString();
	}

	public static String encode(final @Nullable String str) {
		if (str == null || str.isEmpty()) return "no-name";

		try {
			return URLEncoder.encode(str, StandardCharsets.UTF_8.toString());
		} catch (UnsupportedEncodingException e) {
			throw org.eclipse.xtext.xbase.lib.Exceptions.sneakyThrow(e);
		}
	}
}