Java tutorial
/* * Copyright (c) 1997, 2013, 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 javax.swing.text; /** * Interface to describe a structural piece of a document. It * is intended to capture the spirit of an SGML element. * * @author Timothy Prinzing */ public interface Element { /** * Fetches the document associated with this element. * * @return the document */ public Document getDocument(); /** * Fetches the parent element. If the element is a root level * element returns <code>null</code>. * * @return the parent element */ public Element getParentElement(); /** * Fetches the name of the element. If the element is used to * represent some type of structure, this would be the type * name. * * @return the element name */ public String getName(); /** * Fetches the collection of attributes this element contains. * * @return the attributes for the element */ public AttributeSet getAttributes(); /** * Fetches the offset from the beginning of the document * that this element begins at. If this element has * children, this will be the offset of the first child. * As a document position, there is an implied forward bias. * * @return the starting offset >= 0 and < getEndOffset(); * @see Document * @see AbstractDocument */ public int getStartOffset(); /** * Fetches the offset from the beginning of the document * that this element ends at. If this element has * children, this will be the end offset of the last child. * As a document position, there is an implied backward bias. * <p> * All the default <code>Document</code> implementations * descend from <code>AbstractDocument</code>. * <code>AbstractDocument</code> models an implied break at the end of * the document. As a result of this, it is possible for this to * return a value greater than the length of the document. * * @return the ending offset > getStartOffset() and * <= getDocument().getLength() + 1 * @see Document * @see AbstractDocument */ public int getEndOffset(); /** * Gets the child element index closest to the given offset. * The offset is specified relative to the beginning of the * document. Returns <code>-1</code> if the * <code>Element</code> is a leaf, otherwise returns * the index of the <code>Element</code> that best represents * the given location. Returns <code>0</code> if the location * is less than the start offset. Returns * <code>getElementCount() - 1</code> if the location is * greater than or equal to the end offset. * * @param offset the specified offset >= 0 * @return the element index >= 0 */ public int getElementIndex(int offset); /** * Gets the number of child elements contained by this element. * If this element is a leaf, a count of zero is returned. * * @return the number of child elements >= 0 */ public int getElementCount(); /** * Fetches the child element at the given index. * * @param index the specified index >= 0 * @return the child element */ public Element getElement(int index); /** * Is this element a leaf element? An element that * <i>may</i> have children, even if it currently * has no children, would return <code>false</code>. * * @return true if a leaf element else false */ public boolean isLeaf(); }