1 /*
2 * Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.awt.event;
27
28 import java.awt.Adjustable;
29 import java.awt.AWTEvent;
30 import java.lang.annotation.Native;
31
32
33 /**
34 * The adjustment event emitted by Adjustable objects like
35 * {@link java.awt.Scrollbar} and {@link java.awt.ScrollPane}.
36 * When the user changes the value of the scrolling component,
37 * it receives an instance of {@code AdjustmentEvent}.
38 * <p>
39 * An unspecified behavior will be caused if the {@code id} parameter
40 * of any particular {@code AdjustmentEvent} instance is not
41 * in the range from {@code ADJUSTMENT_FIRST} to {@code ADJUSTMENT_LAST}.
42 * <p>
43 * The {@code type} of any {@code AdjustmentEvent} instance takes one of the following
44 * values:
45 * <ul>
46 * <li> {@code UNIT_INCREMENT}
47 * <li> {@code UNIT_DECREMENT}
48 * <li> {@code BLOCK_INCREMENT}
49 * <li> {@code BLOCK_DECREMENT}
50 * <li> {@code TRACK}
51 * </ul>
52 * Assigning the value different from listed above will cause an unspecified behavior.
53 * @see java.awt.Adjustable
54 * @see AdjustmentListener
55 *
56 * @author Amy Fowler
57 * @since 1.1
58 */
59 public class AdjustmentEvent extends AWTEvent {
60
61 /**
62 * Marks the first integer id for the range of adjustment event ids.
63 */
64 public static final int ADJUSTMENT_FIRST = 601;
65
66 /**
67 * Marks the last integer id for the range of adjustment event ids.
68 */
69 public static final int ADJUSTMENT_LAST = 601;
70
71 /**
72 * The adjustment value changed event.
73 */
74 public static final int ADJUSTMENT_VALUE_CHANGED = ADJUSTMENT_FIRST; //Event.SCROLL_LINE_UP
75
76 /**
77 * The unit increment adjustment type.
78 */
79 @Native public static final int UNIT_INCREMENT = 1;
80
81 /**
82 * The unit decrement adjustment type.
83 */
84 @Native public static final int UNIT_DECREMENT = 2;
85
86 /**
87 * The block decrement adjustment type.
88 */
89 @Native public static final int BLOCK_DECREMENT = 3;
90
91 /**
92 * The block increment adjustment type.
93 */
94 @Native public static final int BLOCK_INCREMENT = 4;
95
96 /**
97 * The absolute tracking adjustment type.
98 */
99 @Native public static final int TRACK = 5;
100
101 /**
102 * The adjustable object that fired the event.
103 *
104 * @serial
105 * @see #getAdjustable
106 */
107 Adjustable adjustable;
108
109 /**
110 * {@code value} will contain the new value of the
111 * adjustable object. This value will always be in a
112 * range associated adjustable object.
113 *
114 * @serial
115 * @see #getValue
116 */
117 int value;
118
119 /**
120 * The {@code adjustmentType} describes how the adjustable
121 * object value has changed.
122 * This value can be increased/decreased by a block or unit amount
123 * where the block is associated with page increments/decrements,
124 * and a unit is associated with line increments/decrements.
125 *
126 * @serial
127 * @see #getAdjustmentType
128 */
129 int adjustmentType;
130
131
132 /**
133 * The {@code isAdjusting} is true if the event is one
134 * of the series of multiple adjustment events.
135 *
136 * @since 1.4
137 * @serial
138 * @see #getValueIsAdjusting
139 */
140 boolean isAdjusting;
141
142
143 /*
144 * JDK 1.1 serialVersionUID
145 */
146 private static final long serialVersionUID = 5700290645205279921L;
147
148
149 /**
150 * Constructs an {@code AdjustmentEvent} object with the
151 * specified {@code Adjustable} source, event type,
152 * adjustment type, and value.
153 * <p> This method throws an
154 * {@code IllegalArgumentException} if {@code source}
155 * is {@code null}.
156 *
157 * @param source The {@code Adjustable} object where the
158 * event originated
159 * @param id An integer indicating the type of event.
160 * For information on allowable values, see
161 * the class description for {@link AdjustmentEvent}
162 * @param type An integer indicating the adjustment type.
163 * For information on allowable values, see
164 * the class description for {@link AdjustmentEvent}
165 * @param value The current value of the adjustment
166 * @throws IllegalArgumentException if {@code source} is null
167 * @see #getSource()
168 * @see #getID()
169 * @see #getAdjustmentType()
170 * @see #getValue()
171 */
172 public AdjustmentEvent(Adjustable source, int id, int type, int value) {
173 this(source, id, type, value, false);
174 }
175
176 /**
177 * Constructs an {@code AdjustmentEvent} object with the
178 * specified Adjustable source, event type, adjustment type, and value.
179 * <p> This method throws an
180 * {@code IllegalArgumentException} if {@code source}
181 * is {@code null}.
182 *
183 * @param source The {@code Adjustable} object where the
184 * event originated
185 * @param id An integer indicating the type of event.
186 * For information on allowable values, see
187 * the class description for {@link AdjustmentEvent}
188 * @param type An integer indicating the adjustment type.
189 * For information on allowable values, see
190 * the class description for {@link AdjustmentEvent}
191 * @param value The current value of the adjustment
192 * @param isAdjusting A boolean that equals {@code true} if the event is one
193 * of a series of multiple adjusting events,
194 * otherwise {@code false}
195 * @throws IllegalArgumentException if {@code source} is null
196 * @since 1.4
197 * @see #getSource()
198 * @see #getID()
199 * @see #getAdjustmentType()
200 * @see #getValue()
201 * @see #getValueIsAdjusting()
202 */
203 public AdjustmentEvent(Adjustable source, int id, int type, int value, boolean isAdjusting) {
204 super(source, id);
205 adjustable = source;
206 this.adjustmentType = type;
207 this.value = value;
208 this.isAdjusting = isAdjusting;
209 }
210
211 /**
212 * Returns the {@code Adjustable} object where this event originated.
213 *
214 * @return the {@code Adjustable} object where this event originated
215 */
216 public Adjustable getAdjustable() {
217 return adjustable;
218 }
219
220 /**
221 * Returns the current value in the adjustment event.
222 *
223 * @return the current value in the adjustment event
224 */
225 public int getValue() {
226 return value;
227 }
228
229 /**
230 * Returns the type of adjustment which caused the value changed
231 * event. It will have one of the following values:
232 * <ul>
233 * <li>{@link #UNIT_INCREMENT}
234 * <li>{@link #UNIT_DECREMENT}
235 * <li>{@link #BLOCK_INCREMENT}
236 * <li>{@link #BLOCK_DECREMENT}
237 * <li>{@link #TRACK}
238 * </ul>
239 * @return one of the adjustment values listed above
240 */
241 public int getAdjustmentType() {
242 return adjustmentType;
243 }
244
245 /**
246 * Returns {@code true} if this is one of multiple
247 * adjustment events.
248 *
249 * @return {@code true} if this is one of multiple
250 * adjustment events, otherwise returns {@code false}
251 * @since 1.4
252 */
253 public boolean getValueIsAdjusting() {
254 return isAdjusting;
255 }
256
257 public String paramString() {
258 String typeStr;
259 switch(id) {
260 case ADJUSTMENT_VALUE_CHANGED:
261 typeStr = "ADJUSTMENT_VALUE_CHANGED";
262 break;
263 default:
264 typeStr = "unknown type";
265 }
266 String adjTypeStr;
267 switch(adjustmentType) {
268 case UNIT_INCREMENT:
269 adjTypeStr = "UNIT_INCREMENT";
270 break;
271 case UNIT_DECREMENT:
272 adjTypeStr = "UNIT_DECREMENT";
273 break;
274 case BLOCK_INCREMENT:
275 adjTypeStr = "BLOCK_INCREMENT";
276 break;
277 case BLOCK_DECREMENT:
278 adjTypeStr = "BLOCK_DECREMENT";
279 break;
280 case TRACK:
281 adjTypeStr = "TRACK";
282 break;
283 default:
284 adjTypeStr = "unknown type";
285 }
286 return typeStr
287 + ",adjType="+adjTypeStr
288 + ",value="+value
289 + ",isAdjusting="+isAdjusting;
290 }
291 }