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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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.
*
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package javax.swing.event;
import javax.swing.undo.*;
import javax.swing.text.*;
/**
* Interface for document change notifications. This provides
* detailed information to Document observers about how the
* Document changed. It provides high level information such
* as type of change and where it occurred, as well as the more
* detailed structural changes (What Elements were inserted and
* removed).
*
* @author Timothy Prinzing
* @see javax.swing.text.Document
* @see DocumentListener
*/
public interface DocumentEvent {
/**
* Returns the offset within the document of the start
* of the change.
*
* @return the offset >= 0
*/
public int getOffset();
/**
* Returns the length of the change.
*
* @return the length >= 0
*/
public int getLength();
/**
* Gets the document that sourced the change event.
*
* @return the document
*/
public Document getDocument();
/**
* Gets the type of event.
*
* @return the type
*/
public EventType getType();
/**
* Gets the change information for the given element.
* The change information describes what elements were
* added and removed and the location. If there were
* no changes, null is returned.
* <p>
* This method is for observers to discover the structural
* changes that were made. This means that only elements
* that existed prior to the mutation (and still exist after
* the mutatino) need to have ElementChange records.
* The changes made available need not be recursive.
* <p>
* For example, if the an element is removed from it's
* parent, this method should report that the parent
* changed and provide an ElementChange implementation
* that describes the change to the parent. If the
* child element removed had children, these elements
* do not need to be reported as removed.
* <p>
* If an child element is insert into a parent element,
* the parent element should report a change. If the
* child element also had elements inserted into it
* (grandchildren to the parent) these elements need
* not report change.
*
* @param elem the element
* @return the change information, or null if the
* element was not modified
*/
public ElementChange getChange(Element elem);
/**
* Enumeration for document event types
*/
public static final class EventType {
private EventType(String s) {
typeString = s;
}
/**
* Insert type.
*/
public static final EventType INSERT = new EventType("INSERT");
/**
* Remove type.
*/
public static final EventType REMOVE = new EventType("REMOVE");
/**
* Change type.
*/
public static final EventType CHANGE = new EventType("CHANGE");
/**
* Converts the type to a string.
*
* @return the string
*/
public String toString() {
return typeString;
}
private String typeString;
}
/**
* Describes changes made to a specific element.
*/
public interface ElementChange {
/**
* Returns the element represented. This is the element
* that was changed.
*
* @return the element
*/
public Element getElement();
/**
* Fetches the index within the element represented.
* This is the location that children were added
* and/or removed.
*
* @return the index >= 0
*/
public int getIndex();
/**
* Gets the child elements that were removed from the
* given parent element. The element array returned is
* sorted in the order that the elements used to lie in
* the document, and must be contiguous.
*
* @return the child elements
*/
public Element[] getChildrenRemoved();
/**
* Gets the child elements that were added to the given
* parent element. The element array returned is in the
* order that the elements lie in the document, and must
* be contiguous.
*
* @return the child elements
*/
public Element[] getChildrenAdded();
}
}