DualOscilloscope.java

package com.jsyn.examples;

import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;

import javax.swing.JApplet;
import javax.swing.JComboBox;

import com.jsyn.JSyn;
import com.jsyn.Synthesizer;
import com.jsyn.devices.AudioDeviceFactory;
import com.jsyn.devices.AudioDeviceManager;
import com.jsyn.scope.AudioScope;
import com.jsyn.swing.JAppletFrame;
import com.jsyn.unitgen.ChannelIn;
import com.jsyn.unitgen.PassThrough;

/**
 * Two channel oscilloscope that demonstrates the use of audio input.
 * 
 * @author Phil Burk (C) 2012 Mobileer Inc
 * 
 */
public class DualOscilloscope extends JApplet
{
	private static final long serialVersionUID = -2704222221111608377L;
	private Synthesizer synth;
	private ChannelIn channel1;
	private ChannelIn channel2;
	private PassThrough pass1;
	private PassThrough pass2;
	private AudioScope scope;
	private AudioDeviceManager audioManager;
	private int defaultInputId;
	private ArrayList<String> deviceNames = new ArrayList<String>();
	private ArrayList<Integer> deviceMaxInputs = new ArrayList<Integer>();
	private ArrayList<Integer> deviceIds = new ArrayList<Integer>();
	private int defaultSelection;
	private JComboBox<String> deviceComboBox;


	public void init()
	{
		audioManager = AudioDeviceFactory.createAudioDeviceManager( true );
		synth = JSyn.createSynthesizer( audioManager );

		int numDevices = audioManager.getDeviceCount();
		defaultInputId = audioManager.getDefaultInputDeviceID();
		for( int i = 0; i < numDevices; i++ )
		{
			int maxInputs = audioManager.getMaxInputChannels( i );
			if( maxInputs > 0 )
			{
				String deviceName = audioManager.getDeviceName( i );
				String itemName = maxInputs + ", " + deviceName + " (#" + i + ")";
				if( i == defaultInputId )
				{
					defaultSelection = deviceNames.size();
					itemName += " (Default)";
				}
				deviceNames.add( itemName );
				deviceMaxInputs.add( maxInputs );
				deviceIds.add( i );
			}
		}

		synth.add( channel1 = new ChannelIn() );
		channel1.setChannelIndex( 0 );
		synth.add( channel2 = new ChannelIn() );
		channel2.setChannelIndex( 1 );

		// Use PassThrough so we can easily disconnect input channels from the scope.
		synth.add( pass1 = new PassThrough() );
		synth.add( pass2 = new PassThrough() );

		setupGUI();
	}

	private void setupGUI()
	{
		setLayout( new BorderLayout() );

		deviceComboBox = new JComboBox<String>( deviceNames.toArray( new String[0] ) );
		deviceComboBox.setSelectedIndex( defaultSelection );
		add( deviceComboBox, BorderLayout.NORTH );
		deviceComboBox.addActionListener( new ActionListener(){

			public void actionPerformed( ActionEvent e )
			{
				stopAudio();
				int itemIndex = deviceComboBox.getSelectedIndex();
				startAudio( itemIndex );
			}} );

		scope = new AudioScope( synth );
		
		scope.addProbe( pass1.output );
		scope.addProbe( pass2.output );
		
		scope.setTriggerMode( AudioScope.TriggerMode.NORMAL );
		scope.getView().setControlsVisible( true );
		add( scope.getView(), BorderLayout.CENTER );
		validate();
	}

	protected void startAudio( int itemIndex )
	{
		// Both stereo.
		int numInputChannels = deviceMaxInputs.get( itemIndex );
		if( numInputChannels > 2 ) numInputChannels = 2;
		int inputDeviceIndex = deviceIds.get( itemIndex );
		synth.start( 44100, inputDeviceIndex,
				numInputChannels, AudioDeviceManager.USE_DEFAULT_DEVICE,
				0 );

		channel1.output.connect( pass1.input );
		// Only connect second channel if more than one input channel.
		if( numInputChannels > 1 )
		{
			channel2.output.connect( pass2.input );
		}
		
		// We only need to start the LineOut. It will pull data from the
		// channels.
		scope.start();
	}

	public void start()
	{
		startAudio( defaultSelection );
	}

	public void stopAudio()
	{
		pass1.input.disconnectAll();
		pass2.input.disconnectAll();
		scope.stop();
		synth.stop();
	}
	
	public void stop()
	{
		stopAudio();
	}

	/* Can be run as either an application or as an applet. */
	public static void main( String args[] )
	{
		DualOscilloscope applet = new DualOscilloscope();
		JAppletFrame frame = new JAppletFrame( "Dual Oscilloscope", applet );
		frame.setSize( 640, 400 );
		frame.setVisible( true );
		frame.test();
	}

}