/*
* Copyright (c) 1997, 2001, 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
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*/
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();
}