| /* |
| * Copyright (c) 2010, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package jdk.javadoc.internal.doclets.toolkit; |
| |
| import java.io.IOException; |
| import java.io.StringWriter; |
| import java.io.Writer; |
| import java.util.Objects; |
| |
| /** |
| * A class to create content for javadoc output pages. |
| * |
| * <p><b>This is NOT part of any supported API. |
| * If you write code that depends on this, you do so at your own risk. |
| * This code and its internal interfaces are subject to change or |
| * deletion without notice.</b> |
| * |
| * @author Bhavesh Patel |
| */ |
| public abstract class Content { |
| |
| /** |
| * Returns a string representation of the content. |
| * |
| * @return string representation of the content |
| */ |
| @Override |
| public String toString() { |
| StringWriter out = new StringWriter(); |
| try { |
| write(out, true); |
| } catch (IOException e) { |
| // cannot happen from StringWriter |
| throw new AssertionError(e); |
| } |
| return out.toString(); |
| } |
| |
| /** |
| * Adds content to the existing content. |
| * |
| * @param content content that needs to be added |
| */ |
| public abstract void addContent(Content content); |
| |
| /** |
| * Adds a string content to the existing content. |
| * |
| * @param stringContent the string content to be added |
| */ |
| public abstract void addContent(CharSequence stringContent); |
| |
| /** |
| * Writes content to a writer. |
| * |
| */ |
| public abstract boolean write(Writer writer, boolean atNewline) throws IOException ; |
| |
| /** |
| * Returns true if the content is empty. |
| * |
| * @return true if no content to be displayed else return false |
| */ |
| public abstract boolean isEmpty(); |
| |
| /** |
| * Returns true if the content is valid. |
| * |
| * @return true if the content is valid else return false |
| */ |
| public boolean isValid() { |
| return !isEmpty(); |
| } |
| |
| /** |
| * Return the number of characters of plain text content in this object |
| * (optional operation.) |
| * @return the number of characters of plain text content in this |
| */ |
| public int charCount() { |
| return 0; |
| } |
| |
| /** |
| * Checks for null values. |
| * |
| * @param t reference type to check for null values |
| * @return the reference type if not null or else throws a null pointer exception |
| */ |
| protected static <T> T nullCheck(T t) { |
| return Objects.requireNonNull(t); |
| } |
| } |