J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1999-2003 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.sound.sampled; |
| 27 | |
| 28 | /** |
| 29 | * The <code>LineEvent</code> class encapsulates information that a line |
| 30 | * sends its listeners whenever the line opens, closes, starts, or stops. |
| 31 | * Each of these four state changes is represented by a corresponding |
| 32 | * type of event. A listener receives the event as a parameter to its |
| 33 | * {@link LineListener#update update} method. By querying the event, |
| 34 | * the listener can learn the type of event, the line responsible for |
| 35 | * the event, and how much data the line had processed when the event occurred. |
| 36 | * |
| 37 | * <p>Although this class implements Serializable, attempts to |
| 38 | * serialize a <code>LineEvent</code> object will fail. |
| 39 | * |
| 40 | * @author Kara Kytle |
| 41 | * |
| 42 | * @see Line |
| 43 | * @see LineListener#update |
| 44 | * @since 1.3 |
| 45 | * |
| 46 | * @serial exclude |
| 47 | */ |
| 48 | public class LineEvent extends java.util.EventObject { |
| 49 | |
| 50 | // INSTANCE VARIABLES |
| 51 | |
| 52 | /** |
| 53 | * The kind of line event (<code>OPEN</code>, <code>CLOSE</code>, |
| 54 | * <code>START</code>, or <code>STOP</code>). |
| 55 | * @see #getType |
| 56 | * @serial |
| 57 | */ |
| 58 | private final Type type; |
| 59 | |
| 60 | /** |
| 61 | * The media position when the event occurred, expressed in sample frames. |
| 62 | * Note that this field is only relevant to certain events generated by |
| 63 | * data lines, such as <code>START</code> and <code>STOP</code>. For |
| 64 | * events generated by lines that do not count sample frames, and for any |
| 65 | * other events for which this value is not known, the position value |
| 66 | * should be {@link AudioSystem#NOT_SPECIFIED}. |
| 67 | * @serial |
| 68 | * @see #getFramePosition |
| 69 | */ |
| 70 | private final long position; |
| 71 | |
| 72 | |
| 73 | /** |
| 74 | * Constructs a new event of the specified type, originating from the specified line. |
| 75 | * @param line the source of this event |
| 76 | * @param type the event type (<code>OPEN</code>, <code>CLOSE</code>, <code>START</code>, or <code>STOP</code>) |
| 77 | * @param position the number of sample frames that the line had already processed when the event occurred, |
| 78 | * or {@link AudioSystem#NOT_SPECIFIED} |
| 79 | * |
| 80 | * @throws IllegalArgumentException if <code>line</code> is |
| 81 | * <code>null</code>. |
| 82 | */ |
| 83 | public LineEvent(Line line, Type type, long position) { |
| 84 | |
| 85 | super(line); |
| 86 | this.type = type; |
| 87 | this.position = position; |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * Obtains the audio line that is the source of this event. |
| 92 | * @return the line responsible for this event |
| 93 | */ |
| 94 | public final Line getLine() { |
| 95 | |
| 96 | return (Line)getSource(); |
| 97 | } |
| 98 | |
| 99 | |
| 100 | /** |
| 101 | * Obtains the event's type. |
| 102 | * @return this event's type ({@link Type#OPEN}, {@link Type#CLOSE}, |
| 103 | * {@link Type#START}, or {@link Type#STOP}) |
| 104 | */ |
| 105 | public final Type getType() { |
| 106 | |
| 107 | return type; |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Obtains the position in the line's audio data when the event occurred, expressed in sample frames. |
| 112 | * For example, if a source line had already played back 14 sample frames at the time it was |
| 113 | * paused, the pause event would report the line's position as 14. The next frame to be processed |
| 114 | * would be frame number 14 using zero-based numbering, or 15 using one-based numbering. |
| 115 | * <p> |
| 116 | * Note that this field is relevant only to certain events generated by |
| 117 | * data lines, such as <code>START</code> and <code>STOP</code>. For |
| 118 | * events generated by lines that do not count sample frames, and for any |
| 119 | * other events for which this value is not known, the position value |
| 120 | * should be {@link AudioSystem#NOT_SPECIFIED}. |
| 121 | * |
| 122 | * @return the line's position as a sample frame number |
| 123 | */ |
| 124 | /* |
| 125 | * $$kk: 04.20.99: note to myself: should make sure our implementation is consistent with this. |
| 126 | * which is a reasonable definition.... |
| 127 | */ |
| 128 | public final long getFramePosition() { |
| 129 | |
| 130 | return position; |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * Obtains a string representation of the event. The contents of the string may vary |
| 135 | * between implementations of Java Sound. |
| 136 | * @return a string describing the event. |
| 137 | */ |
| 138 | public String toString() { |
| 139 | String sType = ""; |
| 140 | if (type != null) sType = type.toString()+" "; |
| 141 | String sLine; |
| 142 | if (getLine() == null) { |
| 143 | sLine = "null"; |
| 144 | } else { |
| 145 | sLine = getLine().toString(); |
| 146 | } |
| 147 | return new String(sType + "event from line " + sLine); |
| 148 | } |
| 149 | |
| 150 | |
| 151 | /** |
| 152 | * The LineEvent.Type inner class identifies what kind of event occurred on a line. |
| 153 | * Static instances are provided for the common types (OPEN, CLOSE, START, and STOP). |
| 154 | * |
| 155 | * @see LineEvent#getType() |
| 156 | */ |
| 157 | public static class Type { |
| 158 | |
| 159 | |
| 160 | /** |
| 161 | * Type name. |
| 162 | */ |
| 163 | // $$kk: 03.25.99: why can't this be final?? |
| 164 | private /*final*/ String name; |
| 165 | |
| 166 | /** |
| 167 | * Constructs a new event type. |
| 168 | * @param name name of the type |
| 169 | */ |
| 170 | protected Type(String name) { |
| 171 | this.name = name; |
| 172 | } |
| 173 | |
| 174 | |
| 175 | //$$fb 2002-11-26: fix for 4695001: SPEC: description of equals() method contains typo |
| 176 | /** |
| 177 | * Indicates whether the specified object is equal to this event type, |
| 178 | * returning <code>true</code> if the objects are identical. |
| 179 | * @param obj the reference object with which to compare |
| 180 | * @return <code>true</code> if this event type is the same as |
| 181 | * <code>obj</code>; <code>false</code> otherwise |
| 182 | */ |
| 183 | public final boolean equals(Object obj) { |
| 184 | return super.equals(obj); |
| 185 | } |
| 186 | |
| 187 | |
| 188 | /** |
| 189 | * Finalizes the hashcode method. |
| 190 | */ |
| 191 | public final int hashCode() { |
| 192 | return super.hashCode(); |
| 193 | } |
| 194 | |
| 195 | |
| 196 | /** |
| 197 | * Returns the type name as the string representation. |
| 198 | */ |
| 199 | public String toString() { |
| 200 | return name; |
| 201 | } |
| 202 | |
| 203 | |
| 204 | // LINE EVENT TYPE DEFINES |
| 205 | |
| 206 | /** |
| 207 | * A type of event that is sent when a line opens, reserving system |
| 208 | * resources for itself. |
| 209 | * @see #CLOSE |
| 210 | * @see Line#open |
| 211 | */ |
| 212 | public static final Type OPEN = new Type("Open"); |
| 213 | |
| 214 | |
| 215 | /** |
| 216 | * A type of event that is sent when a line closes, freeing the system |
| 217 | * resources it had obtained when it was opened. |
| 218 | * @see #OPEN |
| 219 | * @see Line#close |
| 220 | */ |
| 221 | public static final Type CLOSE = new Type("Close"); |
| 222 | |
| 223 | |
| 224 | /** |
| 225 | * A type of event that is sent when a line begins to engage in active |
| 226 | * input or output of audio data in response to a |
| 227 | * {@link DataLine#start start} request. |
| 228 | * @see #STOP |
| 229 | * @see DataLine#start |
| 230 | */ |
| 231 | public static final Type START = new Type("Start"); |
| 232 | |
| 233 | |
| 234 | /** |
| 235 | * A type of event that is sent when a line ceases active input or output |
| 236 | * of audio data in response to a {@link DataLine#stop stop} request, |
| 237 | * or because the end of media has been reached. |
| 238 | * @see #START |
| 239 | * @see DataLine#stop |
| 240 | */ |
| 241 | public static final Type STOP = new Type("Stop"); |
| 242 | |
| 243 | |
| 244 | /** |
| 245 | * A type of event that is sent when a line ceases to engage in active |
| 246 | * input or output of audio data because the end of media has been reached. |
| 247 | */ |
| 248 | /* |
| 249 | * ISSUE: we may want to get rid of this. Is JavaSound |
| 250 | * responsible for reporting this?? |
| 251 | * |
| 252 | * [If it's decided to keep this API, the docs will need to be updated to include mention |
| 253 | * of EOM events elsewhere.] |
| 254 | */ |
| 255 | //public static final Type EOM = new Type("EOM"); |
| 256 | |
| 257 | |
| 258 | /** |
| 259 | * A type of event that is sent when a line begins to engage in active |
| 260 | * input or output of audio data. Examples of when this happens are |
| 261 | * when a source line begins or resumes writing data to its mixer, and |
| 262 | * when a target line begins or resumes reading data from its mixer. |
| 263 | * @see #STOP |
| 264 | * @see SourceDataLine#write |
| 265 | * @see TargetDataLine#read |
| 266 | * @see DataLine#start |
| 267 | */ |
| 268 | //public static final Type ACTIVE = new Type("ACTIVE"); |
| 269 | |
| 270 | |
| 271 | /** |
| 272 | * A type of event that is sent when a line ceases active input or output |
| 273 | * of audio data. |
| 274 | * @see #START |
| 275 | * @see DataLine#stop |
| 276 | */ |
| 277 | //public static final Type INACTIVE = new Type("INACTIVE"); |
| 278 | |
| 279 | } // class Type |
| 280 | |
| 281 | } // class LineEvent |