Source code: org/eclipse/swt/widgets/EventTable.java
1 /*******************************************************************************
2 * Copyright (c) 2000, 2003 IBM Corporation and others.
3 * All rights reserved. This program and the accompanying materials
4 * are made available under the terms of the Common Public License v1.0
5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/cpl-v10.html
7 *
8 * Contributors:
9 * IBM Corporation - initial API and implementation
10 *******************************************************************************/
11 package org.eclipse.swt.widgets;
12
13
14 import org.eclipse.swt.*;
15 import org.eclipse.swt.internal.SWTEventListener;
16
17 /**
18 * Instances of this class implement a simple
19 * look up mechanism that maps an event type
20 * to a listener. Muliple listeners for the
21 * same event type are supported.
22 */
23
24 class EventTable {
25 int [] types;
26 Listener [] listeners;
27 int level;
28
29 public void hook (int eventType, Listener listener) {
30 if (types == null) types = new int [4];
31 if (listeners == null) listeners = new Listener [4];
32 int length = types.length, index = length - 1;
33 while (index >= 0) {
34 if (types [index] != 0) break;
35 --index;
36 }
37 index++;
38 if (index == length) {
39 if (level == 0) {
40 index = 0;
41 for (int i=0; i<types.length; i++) {
42 if (types [i] != 0) {
43 types [index] = types [i];
44 listeners [index] = listeners [i];
45 index++;
46 }
47 }
48 for (int i=index; i<types.length; i++) {
49 types [i] = 0;
50 listeners [i] = null;
51 }
52 }
53 if (index == length) {
54 int [] newTypes = new int [length + 4];
55 System.arraycopy (types, 0, newTypes, 0, length);
56 types = newTypes;
57 Listener [] newListeners = new Listener [length + 4];
58 System.arraycopy (listeners, 0, newListeners, 0, length);
59 listeners = newListeners;
60 }
61 }
62 types [index] = eventType;
63 listeners [index] = listener;
64 }
65
66 public boolean hooks (int eventType) {
67 if (types == null) return false;
68 for (int i=0; i<types.length; i++) {
69 if (types [i] == eventType) return true;
70 }
71 return false;
72 }
73
74 public void sendEvent (Event event) {
75 if (types == null) return;
76 level++;
77 try {
78 for (int i=0; i<types.length; i++) {
79 if (event.type == SWT.None) return;
80 if (types [i] == event.type) {
81 Listener listener = listeners [i];
82 if (listener != null) listener.handleEvent (event);
83 }
84 }
85 } finally {
86 --level;
87 }
88 }
89
90 public int size () {
91 if (types == null) return 0;
92 int count = 0;
93 for (int i=0; i<types.length; i++) {
94 if (types [i] != 0) count++;
95 }
96 return count;
97 }
98
99 void remove (int index) {
100 if (level == 0) {
101 int end = types.length - 1;
102 System.arraycopy (types, index + 1, types, index, end - index);
103 System.arraycopy (listeners, index + 1, listeners, index, end - index);
104 index = end;
105 }
106 types [index] = 0;
107 listeners [index] = null;
108 }
109
110 public void unhook (int eventType, Listener listener) {
111 if (types == null) return;
112 for (int i=0; i<types.length; i++) {
113 if (types [i] == eventType && listeners [i] == listener) {
114 remove (i);
115 return;
116 }
117 }
118 }
119
120 public void unhook (int eventType, SWTEventListener listener) {
121 if (types == null) return;
122 for (int i=0; i<types.length; i++) {
123 if (types [i] == eventType) {
124 if (listeners [i] instanceof TypedListener) {
125 TypedListener typedListener = (TypedListener) listeners [i];
126 if (typedListener.getEventListener () == listener) {
127 remove (i);
128 return;
129 }
130 }
131 }
132 }
133 }
134
135 }