content: /*******************************************************************************
   * Copyright (c) 2000, 2007 IBM Corporation and others.
   * This program and the accompanying materials are made available under the
   * terms of the Eclipse Public License v. 2.0 which is available at
   * http://www.eclipse.org/legal/epl-2.0.
   * 
   * SPDX-License-Identifier: EPL-2.0
   *
   
   *******************************************************************************/
  package org.eclipse.dltk.core;
  
  import java.util.EventObject;
  
  /**
   * A buffer changed event describes how a buffer has changed. These events are
   * used in <code>IBufferChangedListener</code> notifications.
   * <p>
   * For text insertions, <code>getOffset</code> is the offset
   * of the first inserted character, <code>getText</code> is the
   * inserted text, and <code>getLength</code> is 0.
   * </p>
   * <p>
   * For text removals, <code>getOffset</code> is the offset
   * of the first removed character, <code>getText</code> is <code>null</code>,
   * and <code>getLength</code> is the length of the text that was removed.
   * </p>
   * <p>
   * For replacements (including <code>IBuffer.setContents</code>), 
   * <code>getOffset</code> is the offset
   * of the first replaced character, <code>getText</code> is the replacement
   * text, and <code>getLength</code> is the length of the original text
   * that was replaced.
   * </p>
   * <p>
   * When a buffer is closed, <code>getOffset</code> is 0, <code>getLength</code>
   * is 0, and <code>getText</code> is <code>null</code>.
   * </p>
   * <p>
   * This class is not intended to be instantiated or subclassed by clients.
   * Instances of this class are automatically created by the script model.
   * </p>
   *
   * @see IBuffer
   */
  public class BufferChangedEvent extends EventObject {
  
  	/**
  	 * The length of text that has been modified in the buffer.
  	 */
  	private int length;
  
  	/**
  	 * The offset into the buffer where the modification took place.
  	 */
  	private int offset;
  
  	/**
  	 * The text that was modified.
  	 */
  	private String text;
  	
  	private static final long serialVersionUID = 655379473891745999L; // backward compatible
  
  /**
   * Creates a new buffer changed event indicating that the given buffer has changed.
   * 
   * @param buffer the given buffer
   * @param offset the given offset
   * @param length the given length
   * @param text the given text
   */
  public BufferChangedEvent(IBuffer buffer, int offset, int length, String text) {
  	super(buffer);
  	this.offset = offset;
  	this.length = length;
  	this.text = text;
  }
  /**
   * Returns the buffer which has changed.
   *
   * @return the buffer affected by the change
   */
  public IBuffer getBuffer() {
  	return (IBuffer) this.source;
  }
  /**
   * Returns the length of text removed or replaced in the buffer, or
   * 0 if text has been inserted into the buffer.
   *
   * @return the length of the original text fragment modified by the 
   *   buffer change (<code> 0 </code> in case of insertion).
   */
  public int getLength() {
  	return this.length;
  }
  /**
   * Returns the index of the first character inserted, removed, or replaced
   * in the buffer.
   *
   * @return the source offset of the textual manipulation in the buffer
   */
  public int getOffset() {
  	return this.offset;
  }
  /**
   * Returns the text that was inserted, the replacement text,
   * or <code>null</code> if text has been removed.
   *
   * @return the text corresponding to the buffer change (<code> null </code>
   *   in case of deletion).
   */
  public String getText() {
  	return this.text;
  }
  }
  