/******************************************************************************* * Copyright (c) 2000, 2003 IBM Corporation and others. * All rights reserved. This program and the accompanying materials  * are made available under the terms of the Common Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/cpl-v10.html *  * Contributors: *     IBM Corporation - initial API and implementation *******************************************************************************/package org.eclipse.swt.widgets;import org.eclipse.swt.*;import org.eclipse.swt.internal.SWTEventListener;/** * Instances of this class implement a simple * look up mechanism that maps an event type * to a listener.  Muliple listeners for the * same event type are supported. */class EventTable {	int [] types;	Listener [] listeners;	int level;	public void hook (int eventType, Listener listener) {	if (types == null) types = new int [4];	if (listeners == null) listeners = new Listener [4];	int length = types.length, index = length - 1;	while (index >= 0) {		if (types [index] != 0) break;		--index;	}	index++;	if (index == length) {		if (level == 0) {			index = 0;			for (int i=0; i<types.length; i++) {				if (types [i] != 0) {					types [index] = types [i];					listeners [index] = listeners [i];					index++;				}			}			for (int i=index; i<types.length; i++) {				types [i] = 0;				listeners [i] = null;			}		}		if (index == length) {			int [] newTypes = new int [length + 4];			System.arraycopy (types, 0, newTypes, 0, length);			types = newTypes;			Listener [] newListeners = new Listener [length + 4];			System.arraycopy (listeners, 0, newListeners, 0, length);			listeners = newListeners;		}	}	types [index] = eventType;	listeners [index] = listener;}public boolean hooks (int eventType) {	if (types == null) return false;	for (int i=0; i<types.length; i++) {		if (types [i] == eventType) return true;	}	return false;}public void sendEvent (Event event) {	if (types == null) return;	level++;	try {		for (int i=0; i<types.length; i++) {			if (event.type == SWT.None) return;			if (types [i] == event.type) {				Listener listener = listeners [i];				if (listener != null) listener.handleEvent (event);			}		}	} finally {		--level;	}}public int size () {	if (types == null) return 0;	int count = 0;	for (int i=0; i<types.length; i++) {		if (types [i] != 0) count++;	}	return count;}void remove (int index) {	if (level == 0) {		int end = types.length - 1;		System.arraycopy (types, index + 1, types, index, end - index);		System.arraycopy (listeners, index + 1, listeners, index, end - index);		index = end;	}	types [index] = 0;	listeners [index] = null;}public void unhook (int eventType, Listener listener) {	if (types == null) return;	for (int i=0; i<types.length; i++) {		if (types [i] == eventType && listeners [i] == listener) {			remove (i);			return;		}	}}public void unhook (int eventType, SWTEventListener listener) {	if (types == null) return;	for (int i=0; i<types.length; i++) {		if (types [i] == eventType) {			if (listeners [i] instanceof TypedListener) {				TypedListener typedListener = (TypedListener) listeners [i];				if (typedListener.getEventListener () == listener) {					remove (i);					return;				}			}		}	}}}