/* EventListenerList.java -- Copyright (C) 2002 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath 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 for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. */ package javax.swing.event; // Imports import java.io.Serializable; import java.util.EventListener; /** * EventListenerList * @author Andrew Selkirk */ public class EventListenerList extends Object implements Serializable { //------------------------------------------------------------- // Variables -------------------------------------------------- //------------------------------------------------------------- /** * Listener list */ protected Object[] listenerList = null; //------------------------------------------------------------- // Initialization --------------------------------------------- //------------------------------------------------------------- /** * EventListenerList constructor */ public EventListenerList() { listenerList = new Object[0]; } // EventListenerList() //------------------------------------------------------------- // Methods ---------------------------------------------------- //------------------------------------------------------------- /** * Add Listener * @param t Class type * @param listener Listener to add */ public void add(Class t, EventListener listener) { // Variables Object[] list; int index; Class checkClass; EventListener checkListener; // Create New list in anticipation that listener is not present list = new Object[listenerList.length + 2]; // Search through list looking for listener for (index = 0; index < listenerList.length; index += 2) { checkClass = (Class) listenerList[index]; checkListener = (EventListener) listenerList[index + 1]; if (checkClass.equals(t) == true && checkListener.equals(listener) == true) { return; } // if } // for // Add Listener list[listenerList.length] = t; list[listenerList.length + 1] = listener; // Replace Listener List listenerList = list; } // add() /** * Get the total number of listeners * @return Count of listeners */ public int getListenerCount() { return (int) listenerList.length / 2; } // getListenerCount /** * Get the number of listeners of a particular type * @param t Class type to count * @returns Count of the specified listeners */ public int getListenerCount(Class t) { // Variables int index; int count; String name; // Loop through entire list count = 0; name = t.getName(); for (index = 0; index < listenerList.length; index += 2) { if (((Class) listenerList[index]).getName().equals(name) == true) { count += 1; } } // for: index // Return Count return count; } // getListenerCount() /** * Get a list of listenerType/listener pairs * @returns Listener list */ public Object[] getListenerList() { return listenerList; } // getListenerList() /** * Get list of listeners of a particular type * @param c Class type * @returns List of listeners of the specified type */ public EventListener[] getListeners(Class c) { // Variables int count; EventListener[] list; String name; int index; // Get count of listeners count = getListenerCount(c); // Create Event Listener list list = new EventListener[count]; // Construct List count = 0; name = c.getName(); for (index = 0; index < listenerList.length; index += 2) { if (((Class) listenerList[index]).getName().equals(name) == true) { list[count] = (EventListener) listenerList[index]; count += 1; } // if } // for: index // Return List return list; } // getListeners() /** * Remove a listener * @param t Class type * @param listener Listener to be removed */ public void remove(Class t, EventListener listener) { // Variables Object[] list; int index; Class checkClass; EventListener checkListener; int pointer; boolean found; // Create New list in anticipation that listener is not present if (listenerList.length == 0) { return; } // if list = new Object[listenerList.length - 2]; // Search through list looking for listener pointer = 0; found = false; for (index = 0; index < listenerList.length - 2; index += 2) { checkClass = (Class) listenerList[index]; checkListener = (EventListener) listenerList[index + 1]; if (checkClass.equals(t) == false || checkListener.equals(listener) == false) { list[pointer] = checkClass; list[pointer + 1] = checkListener; pointer += 2; } else { found = true; } // if } // for // Replace Listener List if (found == true) { listenerList = list; } // if } // remove() /** * Get a string representation * @returns String representation */ public String toString() { return null; // TODO } // toString() } // EventListenerList