1 /*******************************************************************************
2 * Copyright (c) 2000, 2011 IBM Corporation and others.
4 * This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License 2.0
6 * which accompanies this distribution, and is available at
7 * https://www.eclipse.org/legal/epl-2.0/
9 * SPDX-License-Identifier: EPL-2.0
12 * IBM Corporation - initial API and implementation
13 *******************************************************************************/
14 package org.eclipse.swt.widgets;
17 import org.eclipse.swt.*;
18 import org.eclipse.swt.internal.*;
21 * Instances of this class implement a simple
22 * look up mechanism that maps an event type
23 * to a listener. Multiple listeners for the
24 * same event type are supported.
29 Listener [] listeners;
31 static final int GROW_SIZE = 4;
33 public Listener [] getListeners (int eventType) {
34 if (types == null) return new Listener [0];
36 for (int i=0; i<types.length; i++) {
37 if (types [i] == eventType) count++;
39 if (count == 0) return new Listener [0];
40 Listener [] result = new Listener [count];
42 for (int i=0; i<types.length; i++) {
43 if (types [i] == eventType) {
44 result [count++] = listeners [i];
50 public void hook (int eventType, Listener listener) {
51 if (types == null) types = new int [GROW_SIZE];
52 if (listeners == null) listeners = new Listener [GROW_SIZE];
53 int length = types.length, index = length - 1;
55 if (types [index] != 0) break;
59 if (index == length) {
60 int [] newTypes = new int [length + GROW_SIZE];
61 System.arraycopy (types, 0, newTypes, 0, length);
63 Listener [] newListeners = new Listener [length + GROW_SIZE];
64 System.arraycopy (listeners, 0, newListeners, 0, length);
65 listeners = newListeners;
67 types [index] = eventType;
68 listeners [index] = listener;
71 public boolean hooks (int eventType) {
72 if (types == null) return false;
73 for (int i=0; i<types.length; i++) {
74 if (types [i] == eventType) return true;
79 public void sendEvent (Event event) {
80 if (types == null) return;
81 level += level >= 0 ? 1 : -1;
83 for (int i=0; i<types.length; i++) {
84 if (event.type == SWT.None) return;
85 if (types [i] == event.type) {
86 Listener listener = listeners [i];
87 if (listener != null) {
89 listener.handleEvent (event);
90 } catch (RuntimeException runtimeException) {
91 Display display = Display.getCurrent ();
93 if (display == null) {
94 throw runtimeException;
97 display.getRuntimeExceptionHandler ().accept (runtimeException);
98 } catch (Error error) {
99 Display display = Display.getCurrent ();
101 if (display == null) {
105 display.getErrorHandler ().accept (error);
111 boolean compact = level < 0;
112 level -= level >= 0 ? 1 : -1;
113 if (compact && level == 0) {
115 for (int i=0; i<types.length; i++) {
116 if (types [i] != 0) {
117 types [index] = types [i];
118 listeners [index] = listeners [i];
122 for (int i=index; i<types.length; i++) {
124 listeners [i] = null;
131 if (types == null) return 0;
133 for (int i=0; i<types.length; i++) {
134 if (types [i] != 0) count++;
139 void remove (int index) {
141 int end = types.length - 1;
142 System.arraycopy (types, index + 1, types, index, end - index);
143 System.arraycopy (listeners, index + 1, listeners, index, end - index);
146 if (level > 0) level = -level;
149 listeners [index] = null;
152 public void unhook (int eventType, Listener listener) {
153 if (types == null) return;
154 for (int i=0; i<types.length; i++) {
155 if (types [i] == eventType && listeners [i] == listener) {
162 public void unhook (int eventType, SWTEventListener listener) {
163 if (types == null) return;
164 for (int i=0; i<types.length; i++) {
165 if (types [i] == eventType) {
166 if (listeners [i] instanceof TypedListener) {
167 TypedListener typedListener = (TypedListener) listeners [i];
168 if (typedListener.getEventListener () == listener) {