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	/*
	* Copyright (c) 1999, 2003, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package javax.sound.sampled;

	/**
	* The <code>LineEvent</code> class encapsulates information that a line
	* sends its listeners whenever the line opens, closes, starts, or stops.
	* Each of these four state changes is represented by a corresponding
	* type of event. A listener receives the event as a parameter to its
	* {@link LineListener#update update} method. By querying the event,
	* the listener can learn the type of event, the line responsible for
	* the event, and how much data the line had processed when the event occurred.
	*
	* <p>Although this class implements Serializable, attempts to
	* serialize a <code>LineEvent</code> object will fail.
	*
	* @author Kara Kytle
	*
	* @see Line
	* @see LineListener#update
	* @since 1.3
	*
	* @serial exclude
	*/
	public class LineEvent extends java.util.EventObject {

	// INSTANCE VARIABLES

	/**
	* The kind of line event (<code>OPEN</code>, <code>CLOSE</code>,
	* <code>START</code>, or <code>STOP</code>).
	* @see #getType
	* @serial
	*/
	private final Type type;

	/**
	* The media position when the event occurred, expressed in sample frames.
	* Note that this field is only relevant to certain events generated by
	* data lines, such as <code>START</code> and <code>STOP</code>. For
	* events generated by lines that do not count sample frames, and for any
	* other events for which this value is not known, the position value
	* should be {@link AudioSystem#NOT_SPECIFIED}.
	* @serial
	* @see #getFramePosition
	*/
	private final long position;


	/**
	* Constructs a new event of the specified type, originating from the specified line.
	* @param line the source of this event
	* @param type the event type (<code>OPEN</code>, <code>CLOSE</code>, <code>START</code>, or <code>STOP</code>)
	* @param position the number of sample frames that the line had already processed when the event occurred,
	* or {@link AudioSystem#NOT_SPECIFIED}
	*
	* @throws IllegalArgumentException if <code>line</code> is
	* <code>null</code>.
	*/
	public LineEvent(Line line, Type type, long position) {

	super(line);
	this.type = type;
	this.position = position;
	}

	/**
	* Obtains the audio line that is the source of this event.
	* @return the line responsible for this event
	*/
	public final Line getLine() {

	return (Line)getSource();
	}


	/**
	* Obtains the event's type.
	* @return this event's type ({@link Type#OPEN}, {@link Type#CLOSE},
	* {@link Type#START}, or {@link Type#STOP})
	*/
	public final Type getType() {

	return type;
	}

	/**
	* Obtains the position in the line's audio data when the event occurred, expressed in sample frames.
	* For example, if a source line had already played back 14 sample frames at the time it was
	* paused, the pause event would report the line's position as 14. The next frame to be processed
	* would be frame number 14 using zero-based numbering, or 15 using one-based numbering.
	* <p>
	* Note that this field is relevant only to certain events generated by
	* data lines, such as <code>START</code> and <code>STOP</code>. For
	* events generated by lines that do not count sample frames, and for any
	* other events for which this value is not known, the position value
	* should be {@link AudioSystem#NOT_SPECIFIED}.
	*
	* @return the line's position as a sample frame number
	*/
	/*
	* $$kk: 04.20.99: note to myself: should make sure our implementation is consistent with this.
	* which is a reasonable definition....
	*/
	public final long getFramePosition() {

	return position;
	}

	/**
	* Obtains a string representation of the event. The contents of the string may vary
	* between implementations of Java Sound.
	* @return a string describing the event.
	*/
	public String toString() {
	String sType = "";
	if (type != null) sType = type.toString()+" ";
	String sLine;
	if (getLine() == null) {
	sLine = "null";
	} else {
	sLine = getLine().toString();
	}
	return new String(sType + "event from line " + sLine);
	}


	/**
	* The LineEvent.Type inner class identifies what kind of event occurred on a line.
	* Static instances are provided for the common types (OPEN, CLOSE, START, and STOP).
	*
	* @see LineEvent#getType()
	*/
	public static class Type {


	/**
	* Type name.
	*/
	// $$kk: 03.25.99: why can't this be final??
	private /final/ String name;

	/**
	* Constructs a new event type.
	* @param name name of the type
	*/
	protected Type(String name) {
	this.name = name;
	}


	//$$fb 2002-11-26: fix for 4695001: SPEC: description of equals() method contains typo
	/**
	* Indicates whether the specified object is equal to this event type,
	* returning <code>true</code> if the objects are identical.
	* @param obj the reference object with which to compare
	* @return <code>true</code> if this event type is the same as
	* <code>obj</code>; <code>false</code> otherwise
	*/
	public final boolean equals(Object obj) {
	return super.equals(obj);
	}


	/**
	* Finalizes the hashcode method.
	*/
	public final int hashCode() {
	return super.hashCode();
	}


	/**
	* Returns the type name as the string representation.
	*/
	public String toString() {
	return name;
	}


	// LINE EVENT TYPE DEFINES

	/**
	* A type of event that is sent when a line opens, reserving system
	* resources for itself.
	* @see #CLOSE
	* @see Line#open
	*/
	public static final Type OPEN = new Type("Open");


	/**
	* A type of event that is sent when a line closes, freeing the system
	* resources it had obtained when it was opened.
	* @see #OPEN
	* @see Line#close
	*/
	public static final Type CLOSE = new Type("Close");


	/**
	* A type of event that is sent when a line begins to engage in active
	* input or output of audio data in response to a
	* {@link DataLine#start start} request.
	* @see #STOP
	* @see DataLine#start
	*/
	public static final Type START = new Type("Start");


	/**
	* A type of event that is sent when a line ceases active input or output
	* of audio data in response to a {@link DataLine#stop stop} request,
	* or because the end of media has been reached.
	* @see #START
	* @see DataLine#stop
	*/
	public static final Type STOP = new Type("Stop");


	/**
	* A type of event that is sent when a line ceases to engage in active
	* input or output of audio data because the end of media has been reached.
	*/
	/*
	* ISSUE: we may want to get rid of this. Is JavaSound
	* responsible for reporting this??
	*
	* [If it's decided to keep this API, the docs will need to be updated to include mention
	* of EOM events elsewhere.]
	*/
	//public static final Type EOM = new Type("EOM");


	/**
	* A type of event that is sent when a line begins to engage in active
	* input or output of audio data. Examples of when this happens are
	* when a source line begins or resumes writing data to its mixer, and
	* when a target line begins or resumes reading data from its mixer.
	* @see #STOP
	* @see SourceDataLine#write
	* @see TargetDataLine#read
	* @see DataLine#start
	*/
	//public static final Type ACTIVE = new Type("ACTIVE");


	/**
	* A type of event that is sent when a line ceases active input or output
	* of audio data.
	* @see #START
	* @see DataLine#stop
	*/
	//public static final Type INACTIVE = new Type("INACTIVE");

	} // class Type

	} // class LineEvent

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