/*
 
* 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;

/**
 
* A target data line is a type of <code>{@link DataLine}</code> from which
 
* audio data can be read.
  
The most common example is a data line that gets
 
* its data from an audio capture device.
  
(The device is implemented as a
 
* mixer that writes to the target data line.)
 
* <p>
 
* Note that the naming convention for this interface reflects the relationship
 
* between the line and its mixer.
  
From the perspective of an application,
 
* a target data line may act as a source for audio data.
 
* <p>
 
* The target data line can be obtained from a mixer by invoking the
 
* <code>{@link Mixer#getLine getLine}</code>
 
* method of <code>Mixer</code> with an appropriate
 
* <code>{@link DataLine.Info}</code> object.
 
* <p>
 
* The <code>TargetDataLine</code> interface provides a method for reading the
 
* captured data from the target data line's buffer.Applications
 
* that record audio should read data from the target data line quickly enough
 
* to keep the buffer from overflowing, which could cause discontinuities in
 
* the captured data that are perceived as clicks.
  
Applications can use the
 
* <code>{@link DataLine#available available}</code> method defined in the
 
* <code>DataLine</code> interface to determine the amount of data currently
 
* queued in the data line's buffer.
  
If the buffer does overflow,
 
* the oldest queued data is discarded and replaced by new data.
 
*
 
* @author Kara Kytle
 
* @see Mixer
 
* @see DataLine
 
* @see SourceDataLine
 
* @since 1.3
 
*/

public interface TargetDataLine extends DataLine {


    
/**
     
* Opens the line with the specified format and requested buffer size,
     
* causing the line to acquire any required system resources and become
     
* operational.
     
* <p>
     
* The buffer size is specified in bytes, but must represent an integral
     
* number of sample frames.
  
Invoking this method with a requested buffer
     
* size that does not meet this requirement may result in an
     
* IllegalArgumentException.
  
The actual buffer size for the open line may
     
* differ from the requested buffer size.
  
The value actually set may be
     
* queried by subsequently calling <code>{@link DataLine#getBufferSize}</code>
     
* <p>
     
* If this operation succeeds, the line is marked as open, and an
     
* <code>{@link LineEvent.Type#OPEN OPEN}</code> event is dispatched to the
     
* line's listeners.
     
* <p>
     
* Invoking this method on a line that is already open is illegal
     
* and may result in an <code>IllegalStateException</code>.
     
* <p>
     
* Some lines, once closed, cannot be reopened.
  
Attempts
     
* to reopen such a line will always result in a
     
* <code>LineUnavailableException</code>.
     
*
     
* @param format the desired audio format
     
* @param bufferSize the desired buffer size, in bytes.
     
* @throws LineUnavailableException if the line cannot be
     
* opened due to resource restrictions
     
* @throws IllegalArgumentException if the buffer size does not represent
     
* an integral number of sample frames,
     
* or if <code>format</code> is not fully specified or invalid
     
* @throws IllegalStateException if the line is already open
     
* @throws SecurityException if the line cannot be
     
* opened due to security restrictions
     
*
     
* @see #open(AudioFormat)
     
* @see Line#open
     
* @see Line#close
     
* @see Line#isOpen
     
* @see LineEvent
     
*/

    
public void open(AudioFormat format, int bufferSize) throws LineUnavailableException;


    
/**
     
* Opens the line with the specified format, causing the line to acquire any
     
* required system resources and become operational.
     
*
     
* <p>
     
* The implementation chooses a buffer size, which is measured in bytes but
     
* which encompasses an integral number of sample frames.
  
The buffer size
     
* that the system has chosen may be queried by subsequently calling <code>{@link DataLine#getBufferSize}</code>
     
* <p>
     
* If this operation succeeds, the line is marked as open, and an
     
* <code>{@link LineEvent.Type#OPEN OPEN}</code> event is dispatched to the
     
* line's listeners.
     
* <p>
     
* Invoking this method on a line that is already open is illegal
     
* and may result in an <code>IllegalStateException</code>.
     
* <p>
     
* Some lines, once closed, cannot be reopened.
  
Attempts
     
* to reopen such a line will always result in a
     
* <code>LineUnavailableException</code>.
     
*
     
* @param format the desired audio format
     
* @throws LineUnavailableException if the line cannot be
     
* opened due to resource restrictions
     
* @throws IllegalArgumentException if <code>format</code>
     
* is not fully specified or invalid
     
* @throws IllegalStateException if the line is already open
     
* @throws SecurityException if the line cannot be
     
* opened due to security restrictions
     
*
     
* @see #open(AudioFormat, int)
     
* @see Line#open
     
* @see Line#close
     
* @see Line#isOpen
     
* @see LineEvent
     
*/

    
public void open(AudioFormat format) throws LineUnavailableException;


    
/**
     
* Reads audio data from the data line's input buffer.
   
The requested
     
* number of bytes is read into the specified array, starting at
     
* the specified offset into the array in bytes.
  
This method blocks until
     
* the requested amount of data has been read.
  
However, if the data line
     
* is closed, stopped, drained, or flushed before the requested amount has
     
* been read, the method no longer blocks, but returns the number of bytes
     
* read thus far.
     
* <p>
     
* The number of bytes that can be read without blocking can be ascertained
     
* using the <code>{@link DataLine#available available}</code> method of the
     
* <code>DataLine</code> interface.
  
(While it is guaranteed that
     
* this number of bytes can be read without blocking, there is no guarantee
     
* that attempts to read additional data will block.)
     
* <p>
     
* The number of bytes to be read must represent an integral number of
     
* sample frames, such that:
     
* <br>
     
* <center><code>[ bytes read ] % [frame size in bytes ] == 0</code></center>
     
* <br>
     
* The return value will always meet this requirement.
  
A request to read a
     
* number of bytes representing a non-integral number of sample frames cannot
     
* be fulfilled and may result in an IllegalArgumentException.
     
*
     
* @param b a byte array that will contain the requested input data when
     
* this method returns
     
* @param off the offset from the beginning of the array, in bytes
     
* @param len the requested number of bytes to read
     
* @return the number of bytes actually read
     
* @throws IllegalArgumentException if the requested number of bytes does
     
* not represent an integral number of sample frames.
     
* or if <code>len</code> is negative.
     
* @throws ArrayIndexOutOfBoundsException if <code>off</code> is negative,
     
* or <code>off+len</code> is greater than the length of the array
     
* <code>b</code>.
     
*
     
* @see SourceDataLine#write
     
* @see DataLine#available
     
*/

    
public int read(byte[] b, int off, int len);

    
/**
     
* Obtains the number of sample frames of audio data that can be read from
     
* the target data line without blocking.
  
Note that the return value
     
* measures sample frames, not bytes.
     
* @return the number of sample frames currently available for reading
     
* @see SourceDataLine#availableWrite
     
*/

    
//public int availableRead();
}