org.eclipse.swt.widgets.EventTable Maven / Gradle / Ivy

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/*******************************************************************************
 * Copyright (c) 2000, 2024 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.widgets;


import java.util.*;

import org.eclipse.swt.*;
import org.eclipse.swt.internal.*;

/**
 * Instances of this class implement a simple
 * look up mechanism that maps an event type
 * to a listener.  Multiple listeners for the
 * same event type are supported.
 */

class EventTable {
	int [] types;
	Listener [] listeners;
	int level;
	static final int GROW_SIZE = 4;

public Listener [] getListeners (int eventType) {
	if (types == null) return new Listener [0];
	int count = 0;
	for (int type : types) {
		if (type == eventType) count++;
	}
	if (count == 0) return new Listener [0];
	Listener [] result = new Listener [count];
	count = 0;
	for (int i=0; i= 0) {
		if (types [index] != 0) break;
		--index;
	}
	index++;
	if (index == length) {
		int [] newTypes = new int [length + GROW_SIZE];
		System.arraycopy (types, 0, newTypes, 0, length);
		types = newTypes;
		Listener [] newListeners = new Listener [length + GROW_SIZE];
		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 type : types) {
		if (type == eventType) return true;
	}
	return false;
}

public void sendEvent (Event event) {
	if (types == null) return;
	level += level >= 0 ? 1 : -1;
	try (ExceptionStash exceptions = new ExceptionStash ()) {
		for (int i=0; i= 0 ? 1 : -1;
		if (compact && level == 0) {
			int index = 0;
			for (int i=0; i 0) level = -level;
	}
	types [index] = 0;
	listeners [index] = null;
}

public void unhook (int eventType, Listener listener) {
	if (types == null) return;
	for (int i=0; i