view/classic/Channel.java

/*
 *   JSampler - a java front-end for LinuxSampler
 *
 *   Copyright (C) 2005 Grigor Kirilov Iliev
 *
 *   This file is part of JSampler.
 *
 *   JSampler is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License version 2
 *   as published by the Free Software Foundation.
 *
 *   JSampler 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 for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with JSampler; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *   MA  02111-1307  USA
 */

package org.jsampler.view.classic;

import java.awt.Color;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;

import java.net.URL;

import java.util.Vector;

import java.util.logging.Level;

import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JSeparator;
import javax.swing.JSlider;
import javax.swing.JToggleButton;

import javax.swing.border.Border;
import javax.swing.border.LineBorder;

import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

import net.sf.juife.JuifeUtils;

import org.jsampler.CC;
import org.jsampler.AudioDeviceModel;
import org.jsampler.MidiDeviceModel;
import org.jsampler.SamplerChannelModel;
import org.jsampler.SamplerModel;

import org.jsampler.event.AudioDeviceListEvent;
import org.jsampler.event.AudioDeviceListListener;
import org.jsampler.event.MidiDeviceListEvent;
import org.jsampler.event.MidiDeviceListListener;
import org.jsampler.event.SamplerChannelAdapter;
import org.jsampler.event.SamplerChannelEvent;
import org.jsampler.event.SamplerChannelListener;

import org.linuxsampler.lscp.AudioOutputDevice;
import org.linuxsampler.lscp.MidiInputDevice;
import org.linuxsampler.lscp.MidiPort;
import org.linuxsampler.lscp.SamplerChannel;
import org.linuxsampler.lscp.SamplerEngine;

import static org.jsampler.view.classic.ClassicI18n.i18n;


/**
 *
 * @author Grigor Iliev
 */
public class Channel extends org.jsampler.view.JSChannel {
        private final static ImageIcon iconMuteOn;
        private final static ImageIcon iconMuteOff;
        private final static ImageIcon iconMutedBySolo;
        
        private final static ImageIcon iconSoloOn;
        private final static ImageIcon iconSoloOff;
        
        private final static ImageIcon iconShowProperties;
        private final static ImageIcon iconHideProperties;
        
        private static Border borderSelected;
        private static Border borderDeselected;
        
        private static Color borderColor;
        
        private final static Vector<PropertyChangeListener> propertyChangeListeners
                = new Vector<PropertyChangeListener>();
        
        static {
                String path = "org/jsampler/view/classic/res/icons/";
                URL url = ClassLoader.getSystemClassLoader().getResource(path + "mute_on.png");
                iconMuteOn = new ImageIcon(url);
                
                url = ClassLoader.getSystemClassLoader().getResource(path + "mute_off.png");
                iconMuteOff = new ImageIcon(url);
                
                url = ClassLoader.getSystemClassLoader().getResource(path + "muted_by_solo.png");
                iconMutedBySolo = new ImageIcon(url);
                
                url = ClassLoader.getSystemClassLoader().getResource(path + "solo_on.png");
                iconSoloOn = new ImageIcon(url);
                
                url = ClassLoader.getSystemClassLoader().getResource(path + "solo_off.png");
                iconSoloOff = new ImageIcon(url);
                
                url = ClassLoader.getSystemClassLoader().getResource(path + "Back16.gif");
                iconShowProperties = new ImageIcon(url);
                
                url = ClassLoader.getSystemClassLoader().getResource(path + "Down16.gif");
                iconHideProperties = new ImageIcon(url);
                
                if(ClassicPrefs.getCustomChannelBorderColor())
                        setBorderColor(ClassicPrefs.getChannelBorderColor());
                else setBorderColor(ClassicPrefs.getDefaultChannelBorderColor());
                
                borderSelected = new LineBorder(getBorderColor(), 2, true);
                borderDeselected = BorderFactory.createEmptyBorder(2, 2, 2, 2);
        }
        
        /**
         * Registers the specified listener for receiving property change events.
         * @param l The <code>PropertyChangeListener</code> to register.
         */
        public void
        addPropertyChangeListener(PropertyChangeListener l) {
                propertyChangeListeners.add(l);
        }
        
        /**
         * Removes the specified listener.
         * @param l The <code>PropertyChangeListener</code> to remove.
         */
        public void
        removePropertyChangeListener(PropertyChangeListener l) {
                propertyChangeListeners.remove(l);
        }
        
        /**
         * Gets the border color that is used when the channel is selected.
         * @return The border color that is used when the channel is selected.
         */
        public static Color
        getBorderColor() { return borderColor; }
        
        /**
         * Sets the border color to be used when the channel is selected.
         * @param c The border color to be used when the channel is selected.
         */
        public static void
        setBorderColor(Color c) {
                if(borderColor != null && borderColor.getRGB() == c.getRGB()) return;
                
                Color oldColor = borderColor;
                borderColor = c;
                borderSelected = new LineBorder(getBorderColor(), 2, true);
                firePropertyChanged("borderColor", oldColor, borderColor);
        }
        
        private static void
        firePropertyChanged(String propertyName, Object oldValue, Object newValue) {
                PropertyChangeEvent e =
                        new PropertyChangeEvent(Channel.class, propertyName, oldValue, newValue);
                
                for(PropertyChangeListener l : propertyChangeListeners) l.propertyChange(e);
        }
        
        
        private final JPanel mainPane = new JPanel();
        private final ChannelProperties propertiesPane;
        private final JButton btnInstr = new JButton(i18n.getLabel("Channel.btnInstr"));
        private final JButton btnMute = new JButton();
        private final JButton btnSolo = new JButton();
        private final JSlider slVolume = new JSlider(0, 100);
        private final JLabel lVolume = new JLabel();
        private final JLabel lStreams = new JLabel("--");
        private final JLabel lVoices = new JLabel("--");
        private final JToggleButton btnProperties = new JToggleButton();
        
        private final EventHandler eventHandler = new EventHandler();
        
        private static int count = 2;
        
        private boolean selected = false;
        
        
        /**
         * Creates a new instance of <code>Channel</code> using the specified
         * non-<code>null</code> channel model.
         * @param model The model to be used by this channel.
         * @throws IllegalArgumentException If the model is <code>null</code>.
         */
        public
        Channel(SamplerChannelModel model) {
                super(model);
                
                setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
                
                mainPane.setLayout(new BoxLayout(mainPane, BoxLayout.Y_AXIS));
                
                JPanel p = new JPanel();
                p.setLayout(new BoxLayout(p, BoxLayout.X_AXIS));
                p.setBorder(BorderFactory.createEmptyBorder(3, 3, 3, 3));
                
                //setToolTipText(" Channel: " + String.valueOf(getChannelID()) + " ");
                
                Dimension d = btnInstr.getPreferredSize();
                btnInstr.setMaximumSize(new Dimension(Short.MAX_VALUE, d.height));
                p.add(btnInstr);
                p.add(Box.createRigidArea(new Dimension(6, 0)));
                
                lStreams.setHorizontalAlignment(JLabel.CENTER);
                lVoices.setHorizontalAlignment(JLabel.CENTER);
                
                JPanel statPane = new JPanel();
                statPane.setBorder(BorderFactory.createLoweredBevelBorder());
                statPane.setLayout(new BoxLayout(statPane, BoxLayout.X_AXIS));
                statPane.add(Box.createRigidArea(new Dimension(6, 0)));
                statPane.add(lStreams);
                statPane.add(new JLabel("/"));
                statPane.add(lVoices);
                statPane.add(Box.createRigidArea(new Dimension(6, 0)));
                
                p.add(statPane);
                
                p.add(Box.createRigidArea(new Dimension(6, 0)));
                
                btnMute.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
                p.add(btnMute);
                p.add(Box.createRigidArea(new Dimension(6, 0)));
                
                btnSolo.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
                p.add(btnSolo);
                p.add(Box.createRigidArea(new Dimension(6, 0)));
                
                JPanel volumePane = new JPanel();
                volumePane.setBorder(BorderFactory.createLoweredBevelBorder());
                volumePane.setLayout(new BoxLayout(volumePane, BoxLayout.X_AXIS));
                volumePane.add(Box.createRigidArea(new Dimension(6, 0)));
                
                d = slVolume.getPreferredSize();
                slVolume.setMaximumSize(new Dimension(d.width > 300 ? d.width : 300, d.height));
                volumePane.add(slVolume);
                
                lVolume.setBorder(BorderFactory.createEmptyBorder(3, 6, 3, 6));
                lVolume.setHorizontalAlignment(lVolume.RIGHT);
                
                // We use this to set the size of the lVolume that will be used in setVolume()
                // to prevent the frequent resizing of lVolume
                lVolume.setText("100%");
                
                volumePane.add(lVolume);
                
                p.add(volumePane);
                p.add(Box.createRigidArea(new Dimension(6, 0)));
                
                btnProperties.setContentAreaFilled(false);
                btnProperties.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
                btnProperties.setIcon(iconShowProperties);
                btnProperties.setSelectedIcon(iconHideProperties);
                p.add(btnProperties);
                
                mainPane.add(p);
                
                propertiesPane = new ChannelProperties(model);
                propertiesPane.setBorder(BorderFactory.createEmptyBorder(0, 3, 3, 3));
                propertiesPane.setVisible(false);
                mainPane.add(propertiesPane);
                add(mainPane);
                
                d = getPreferredSize();
                setMaximumSize(new Dimension(getMaximumSize().width, d.height));
                
                getModel().addSamplerChannelListener(getHandler());
                
                btnInstr.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { loadInstrument(); }
                });
                
                btnMute.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { changeMute(); }
                });
                
                btnSolo.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { changeSolo(); }
                });
                
                slVolume.addChangeListener(new ChangeListener() {
                        public void
                        stateChanged(ChangeEvent e) { setVolume(); }
                });
                
                btnProperties.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) {
                                showProperties(btnProperties.isSelected());
                                
                                String s;
                                if(btnProperties.isSelected()) {
                                        s = i18n.getButtonLabel("Channel.ttHideProps");
                                } else {
                                        s = i18n.getButtonLabel("Channel.ttShowProps");
                                }
                                
                                btnProperties.setToolTipText(s);
                        }
                });
                
                btnProperties.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
                
                String s;
                if(btnProperties.isSelected()) s = i18n.getButtonLabel("Channel.ttHideProps");
                else s = i18n.getButtonLabel("Channel.ttShowProps");
                
                btnProperties.setToolTipText(s);
                
                addPropertyChangeListener(getHandler());
                
                updateChannelInfo();
        }
        
        private EventHandler
        getHandler() { return eventHandler; }
        
        private class EventHandler implements SamplerChannelListener, PropertyChangeListener {
                /**
                 * Invoked when changes are made to a sampler channel.
                 * @param e A <code>SamplerChannelEvent</code> instance
                 * containing event information.
                 */
                public void
                channelChanged(SamplerChannelEvent e) { updateChannelInfo(); }
        
                /**
                 * Invoked when the number of active disk streams has changed.
                 * @param e A <code>SamplerChannelEvent</code> instance
                 * containing event information.
                 */
                public void
                streamCountChanged(SamplerChannelEvent e) {
                        updateStreamCount(getModel().getStreamCount());
                }
        
                /**
                 * Invoked when the number of active voices has changed.
                 * @param e A <code>SamplerChannelEvent</code> instance
                 * containing event information.
                 */
                public void
                voiceCountChanged(SamplerChannelEvent e) {
                        updateVoiceCount(getModel().getVoiceCount());
                }
                
                public void
                propertyChange(PropertyChangeEvent e) {
                        if(e.getPropertyName() == "borderColor") setSelected(isSelected());
                }
        }
        
        /**
         * Determines whether the channel is selected.
         * @return <code>true</code> if the channel is selected, <code>false</code> otherwise.
         */
        public boolean isSelected() { return selected; }
        
        /**
         * Sets the selection state of this channel.
         * This method is invoked when the selection state of the channel has changed.
         * @param select Specifies the new selection state of this channel;
         * <code>true</code> to select the channel, <code>false</code> otherwise.
         */
        public void
        setSelected(boolean select) {
                if(select)  mainPane.setBorder(borderSelected);
                else mainPane.setBorder(borderDeselected);
                
                selected = select;
        }
        
        /** Hides the channel properties. */
        public void
        collapseChannel() { if(btnProperties.isSelected()) btnProperties.doClick(); }
        
        /** Shows the channel properties. */
        public void
        expandChannel() { if(!btnProperties.isSelected()) btnProperties.doClick(); }
        
        /**
         * Updates the channel settings. This method is invoked when changes to the
         * channel were made.
         */
        private void
        updateChannelInfo() {
                SamplerChannel sc = getChannelInfo();
                
                int status = sc.getInstrumentStatus();
                if(status >= 0 && status < 100) {
                        btnInstr.setText(i18n.getLabel("Channel.loadingInstrument", status));
                } else {
                        if(sc.getInstrumentName() != null) btnInstr.setText(sc.getInstrumentName());
                        else btnInstr.setText(i18n.getLabel("Channel.btnInstr"));
                }
                
                updateMute(sc);
                
                if(sc.isSoloChannel()) btnSolo.setIcon(iconSoloOn);
                else btnSolo.setIcon(iconSoloOff);
                
                slVolume.setValue((int)(sc.getVolume() * 100));
                
                boolean b = sc.getEngine() != null;
                slVolume.setEnabled(b);
                btnSolo.setEnabled(b);
                btnMute.setEnabled(b);
        }
        
        /** Invoked when the user clicks the mute button. */
        private void
        changeMute() {
                SamplerChannel sc = getChannelInfo();
                boolean b = true;
                
                /*
                 * Changing the mute button icon now instead of
                 * leaving the work to the notification mechanism of the LinuxSampler.
                 */
                if(sc.isMuted() && !sc.isMutedBySolo()) {
                        b = false;
                        boolean hasSolo = CC.getSamplerModel().hasSoloChannel();
                        
                        if(sc.isSoloChannel() || !hasSolo) btnMute.setIcon(iconMuteOff);
                        else btnMute.setIcon(iconMutedBySolo);
                } else btnMute.setIcon(iconMuteOn);
                
                getModel().setMute(b);
        }
        
        /** Invoked when the user clicks the solo button. */
        private void
        changeSolo() {
                SamplerChannel sc = getChannelInfo();
                boolean b = !sc.isSoloChannel();
                
                /*
                 * Changing the solo button icon (and related) now instead of
                 * leaving the work to the notification mechanism of the LinuxSampler.
                 */
                if(b) {
                        btnSolo.setIcon(iconSoloOn);
                        if(sc.isMutedBySolo()) btnMute.setIcon(iconMuteOff);
                } else {
                        btnSolo.setIcon(iconSoloOff);
                        if(!sc.isMuted() && CC.getSamplerModel().getSoloChannelCount() > 1)
                                btnMute.setIcon(iconMutedBySolo);
                }
                
                getModel().setSolo(b);
        }
        
        /** Invoked when the user changes the volume */
        private void
        setVolume() {
                updateVolume();
                
                if(slVolume.getValueIsAdjusting()) return;
                
                int vol = (int)(getChannelInfo().getVolume() * 100);
                
                if(vol == slVolume.getValue()) return;
                
                /*
                 * If the model's volume is not equal to the slider
                 * value we assume that the change is due to user input.
                 * So we must update the volume at the backend too.
                 */
                float volume = slVolume.getValue();
                volume /= 100;
                getModel().setVolume(volume);
        }
        
        private void
        updateVolume() {
                int volume = slVolume.getValue();
                slVolume.setToolTipText(i18n.getLabel("Channel.volume", volume));
                
                setVolumeLabel(volume);
                
                
        }
        
        private void
        setVolumeLabel(int volume) {
                Dimension d = lVolume.getPreferredSize();
                lVolume.setText(String.valueOf(volume) + '%');
                d = JuifeUtils.getUnionSize(d, lVolume.getPreferredSize());
                lVolume.setMinimumSize(d);
                lVolume.setPreferredSize(d);
                lVolume.setMaximumSize(d);
        }
        
        /**
         * Updates the mute button with the proper icon regarding to information obtained
         * from <code>channel</code>.
         * @param channel A <code>SamplerChannel</code> instance containing the new settings
         * for this channel.
         */
        private void
        updateMute(SamplerChannel channel) {
                if(channel.isMutedBySolo()) btnMute.setIcon(iconMutedBySolo);
                else if(channel.isMuted()) btnMute.setIcon(iconMuteOn);
                else btnMute.setIcon(iconMuteOff);
        }
        
        /**
         * Updates the number of active disk streams.
         * @param count The new number of active disk streams.
         */
        private void
        updateStreamCount(int count) {
                Dimension d = lStreams.getPreferredSize();
                lStreams.setText(count == 0 ? "--" : String.valueOf(count));
                d = JuifeUtils.getUnionSize(d, lStreams.getPreferredSize());
                lStreams.setMinimumSize(d);
                lStreams.setPreferredSize(d);
                lStreams.setMaximumSize(d);
        }
        
        /**
         * Updates the number of active voices.
         * @param count The new number of active voices.
         */
        private void
        updateVoiceCount(int count) {
                Dimension d = lVoices.getPreferredSize();
                lVoices.setText(count == 0 ? "--" : String.valueOf(count));
                d = JuifeUtils.getUnionSize(d, lVoices.getPreferredSize());
                lVoices.setMinimumSize(d);
                lVoices.setPreferredSize(d);
                lVoices.setMaximumSize(d);
        }
        
        private void
        showProperties(boolean show) {propertiesPane.setVisible(show); }
        
        private void
        loadInstrument() {
                InstrumentChooser dlg = new InstrumentChooser(CC.getMainFrame());
                dlg.setVisible(true);
                
                if(!dlg.isCancelled()) {
                        getModel().loadInstrument(dlg.getFileName(), dlg.getInstrumentIndex());
                }
        }
}

class ChannelProperties extends JPanel {
        private final static ImageIcon iconAudioProps;
        
        static {
                String path = "org/jsampler/view/classic/res/icons/";
                URL url = ClassLoader.getSystemClassLoader().getResource(path + "Import16.gif");
                iconAudioProps = new ImageIcon(url);
        }
        
        private final JLabel lMidiDevice =
                new JLabel(i18n.getLabel("ChannelProperties.lMidiDevice"));
        private final JLabel lMidiPort =
                new JLabel(i18n.getLabel("ChannelProperties.lMidiPort"));
        private final JLabel lMidiChannel =
                new JLabel(i18n.getLabel("ChannelProperties.lMidiChannel"));
        
        private final JLabel lAudioDevice =
                new JLabel(i18n.getLabel("ChannelProperties.lAudioDevice"));
        
        private final JComboBox cbEngines = new JComboBox();
        
        private final JComboBox cbMidiDevice = new JComboBox();
        private final JComboBox cbMidiPort = new JComboBox();
        private final JComboBox cbMidiChannel = new JComboBox();
        private final JComboBox cbAudioDevice = new JComboBox();
        
        private final JButton btnAudioProps = new JButton(iconAudioProps);
        
        private SamplerChannelModel channelModel = null;
        
        private boolean update = false;
        
        /**
         * Creates a new instance of <code>ChannelProperties</code> using the specified non-null
         * channel model.
         * @param model The model to be used by this channel properties pane.
         */
        ChannelProperties(SamplerChannelModel model) {
                channelModel = model;
                
                setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
                
                add(new JSeparator());
                
                JPanel enginesPane = new JPanel();
                
                for(SamplerEngine e : CC.getSamplerModel().getEngines()) cbEngines.addItem(e);
                
                //cbEngines.setMaximumSize(cbEngines.getPreferredSize());
                
                enginesPane.add(cbEngines);
                String s = i18n.getLabel("ChannelProperties.enginesPane");
                enginesPane.setBorder(BorderFactory.createTitledBorder(s));
                
                JPanel devicesPane = new JPanel();
                devicesPane.setLayout(new BoxLayout(devicesPane, BoxLayout.X_AXIS));
                
                devicesPane.add(Box.createRigidArea(new Dimension(3, 0)));
                
                devicesPane.add(createMidiPane());
                
                devicesPane.add(Box.createRigidArea(new Dimension(3, 0)));
                
                devicesPane.add(enginesPane);
                
                devicesPane.add(Box.createRigidArea(new Dimension(3, 0)));
                
                JPanel audioPane = createAudioPane();
                Dimension d = audioPane.getPreferredSize();
                d.height = Short.MAX_VALUE;
                
                audioPane.setMaximumSize(d);
                devicesPane.add(audioPane);
                
                add(devicesPane);
                add(Box.createRigidArea(new Dimension(0, 6)));
                
                add(new JSeparator());
                
                cbMidiChannel.addItem("All");
                for(int i = 1; i <= 16; i++) cbMidiChannel.addItem(String.valueOf(i));
                
                cbMidiDevice.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { setMidiDevice(); }
                });
                
                cbMidiPort.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { setMidiPort(); }
                });
                
                cbMidiChannel.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { setMidiChannel(); }
                });
                
                cbEngines.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { setEngineType(); }
                });
                
                cbAudioDevice.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) { setAudioDevice(); }
                });
                
                getModel().addSamplerChannelListener(new SamplerChannelAdapter() {
                        public void
                        channelChanged(SamplerChannelEvent e) { updateChannelProperties(); }
                });
                
                CC.getSamplerModel().addMidiDeviceListListener(getHandler());
                CC.getSamplerModel().addAudioDeviceListListener(getHandler());
                
                btnAudioProps.setToolTipText(i18n.getLabel("ChannelProperties.routing"));
                btnAudioProps.addActionListener(new ActionListener() {
                        public void
                        actionPerformed(ActionEvent e) {
                                SamplerChannel c = getModel().getChannelInfo();
                                new ChannelOutputRoutingDlg(CC.getMainFrame(), c).setVisible(true);
                        
                        }
                });
                
                
                updateMidiDevices();
                updateAudioDevices();
                updateChannelProperties();
        }

        private JPanel
        createMidiPane() {
                JPanel midiPane = new JPanel();
                
                GridBagLayout gridbag = new GridBagLayout();
                GridBagConstraints c = new GridBagConstraints();
                
                midiPane.setLayout(gridbag);
                
                c.gridx = 0;
                c.gridy = 0;
                c.insets = new Insets(3, 3, 3, 3);
                gridbag.setConstraints(lMidiDevice, c);
                midiPane.add(lMidiDevice);
                
                c.gridx = 1;
                c.gridy = 0;
                gridbag.setConstraints(cbMidiDevice, c);
                midiPane.add(cbMidiDevice);
                
                c.gridx = 2;
                c.gridy = 0;
                gridbag.setConstraints(lMidiPort, c);
                midiPane.add(lMidiPort);
                
                c.gridx = 4;
                c.gridy = 0;
                gridbag.setConstraints(lMidiChannel, c);
                midiPane.add(lMidiChannel);
                
                c.gridx = 5;
                c.gridy = 0;
                gridbag.setConstraints(cbMidiChannel, c);
                midiPane.add(cbMidiChannel);
                
                c.gridx = 3;
                c.gridy = 0;
                c.weightx = 1.0;
                c.fill = GridBagConstraints.HORIZONTAL;
                c.insets = new Insets(3, 3, 3, 3);
                gridbag.setConstraints(cbMidiPort, c);
                midiPane.add(cbMidiPort);
                
                String s = i18n.getLabel("ChannelProperties.midiPane");
                midiPane.setBorder(BorderFactory.createTitledBorder(s));
                
                return midiPane;
        }
        
        private JPanel
        createAudioPane() {
                JPanel audioPane = new JPanel();
                
                GridBagLayout gridbag = new GridBagLayout();
                GridBagConstraints c = new GridBagConstraints();
                
                audioPane.setLayout(gridbag);
                
                c.gridx = 0;
                c.gridy = 0;
                c.insets = new Insets(3, 3, 3, 3);
                gridbag.setConstraints(lAudioDevice, c);
                audioPane.add(lAudioDevice);
                
                c.gridx = 1;
                c.gridy = 0;
                gridbag.setConstraints(cbAudioDevice, c);
                audioPane.add(cbAudioDevice);
                
                btnAudioProps.setMargin(new Insets(0, 0, 0, 0));
                c.gridx = 2;
                c.gridy = 0;
                c.insets = new Insets(3, 9, 3, 3);
                gridbag.setConstraints(btnAudioProps, c);
                audioPane.add(btnAudioProps);
                
                String s = i18n.getLabel("ChannelProperties.audioPane");
                audioPane.setBorder(BorderFactory.createTitledBorder(s));
                
                return audioPane;
        }
        
        /**
         * Gets the model that is currently used by this channel properties pane.
         * @return model The <code>SamplerChannelModel</code> instance
         * that provides information about the channel whose settings are
         * represented by this channel properties pane.
         */
        public SamplerChannelModel
        getModel() { return channelModel; }
        
        /**
         * Updates the channel settings. This method is invoked when changes to the
         * channel were made.
         */
        private void
        updateChannelProperties() {
                SamplerModel sm = CC.getSamplerModel();
                SamplerChannel sc = getModel().getChannelInfo();
                
                MidiDeviceModel mm = sm.getMidiDeviceModel(sc.getMidiInputDevice());
                AudioDeviceModel am = sm.getAudioDeviceModel(sc.getAudioOutputDevice());
                
                if(isUpdate()) CC.getLogger().warning("Unexpected update state!");
                
                setUpdate(true);
                
                try {
                        cbMidiDevice.setSelectedItem(mm == null ? null : mm.getDeviceInfo());
                        
                        cbEngines.setSelectedItem(sc.getEngine());
                        
                        cbAudioDevice.setSelectedItem(am == null ? null : am.getDeviceInfo());
                } catch(Exception x) {
                        CC.getLogger().log(Level.WARNING, "Unkown error", x);
                }
                
                setUpdate(false);
        }
        
        /**
         * Updates the MIDI device list.
         */
        private void
        updateMidiDevices() {
                SamplerModel sm = CC.getSamplerModel();
                SamplerChannel sc = getModel().getChannelInfo();
                
                setUpdate(true);
                
                try {
                        cbMidiDevice.removeAllItems();
                
                        for(MidiDeviceModel m : sm.getMidiDeviceModels())
                                cbMidiDevice.addItem(m.getDeviceInfo());
                
                        MidiDeviceModel mm = sm.getMidiDeviceModel(sc.getMidiInputDevice());
                        cbMidiDevice.setSelectedItem(mm == null ? null : mm.getDeviceInfo());
                } catch(Exception x) {
                        CC.getLogger().log(Level.WARNING, "Unkown error", x);
                }
                 
                setUpdate(false);
        }
        
        /**
         * Updates the audio device list.
         */
        private void
        updateAudioDevices() {
                SamplerModel sm = CC.getSamplerModel();
                SamplerChannel sc = getModel().getChannelInfo();
                
                setUpdate(true);
                
                try {
                        cbAudioDevice.removeAllItems();
                
                        for(AudioDeviceModel m : sm.getAudioDeviceModels()) 
                                cbAudioDevice.addItem(m.getDeviceInfo());
                
                        AudioDeviceModel am = sm.getAudioDeviceModel(sc.getAudioOutputDevice());
                        cbAudioDevice.setSelectedItem(am == null ? null : am.getDeviceInfo());
                } catch(Exception x) {
                        CC.getLogger().log(Level.WARNING, "Unkown error", x);
                }
                
                setUpdate(false);
        }
        
        private void
        setMidiDevice() {
                MidiInputDevice mid = (MidiInputDevice)cbMidiDevice.getSelectedItem();
                
                if(!isUpdate()) {
                        if(mid != null) getModel().setMidiInputDevice(mid.getDeviceID());
                        return;
                }
                
                cbMidiPort.removeAllItems();
                
                if(mid == null) {
                        cbMidiPort.setEnabled(false);
                        
                        cbMidiChannel.setSelectedItem(null);
                        cbMidiChannel.setEnabled(false);
                } else {
                        cbMidiPort.setEnabled(true);
                        
                        MidiPort[] ports = mid.getMidiPorts();
                        for(MidiPort port : ports) cbMidiPort.addItem(port);
                        
                        int p = getModel().getChannelInfo().getMidiInputPort();
                        cbMidiPort.setSelectedItem(p >= 0 && p < ports.length ? ports[p] : null);
                        
                        cbMidiChannel.setEnabled(true);
                        int c = getModel().getChannelInfo().getMidiInputChannel();
                        cbMidiChannel.setSelectedItem(c == -1 ? "All" : String.valueOf(c + 1));
                }
                
                
        }
        
        private void
        setMidiPort() {
                if(isUpdate()) return;
                
                getModel().setMidiInputPort(cbMidiPort.getSelectedIndex());
        }
        
        private void
        setMidiChannel() {
                if(isUpdate()) return;
                
                Object o = cbMidiChannel.getSelectedItem();
                if(o == null) return;
                
                int c = o.toString().equals("All") ? -1 : Integer.parseInt(o.toString()) - 1;
                
                getModel().setMidiInputChannel(c);
        }
        
        /** Invoked when the user selects an engine. */
        private void
        setEngineType() {
                Object oldEngine = getModel().getChannelInfo().getEngine();
                SamplerEngine newEngine = (SamplerEngine)cbEngines.getSelectedItem();
                
                if(oldEngine != null) { if(oldEngine.equals(newEngine)) return; }
                else if(newEngine == null) return;
                
                getModel().setEngineType(newEngine.getName());
                
        }
        
        private void
        setAudioDevice() {
                if(isUpdate()) return;
                AudioOutputDevice dev = (AudioOutputDevice)cbAudioDevice.getSelectedItem();
                if(dev != null) getModel().setAudioOutputDevice(dev.getDeviceID());
        }
        
        /**
         * Determines whether the currently processed changes are due to update.
         * @return <code>true</code> if the currently processed changes are due to update and
         * <code>false</code> if the currently processed changes are due to user input.
         */
        private boolean
        isUpdate() { return update; }
        
        /**
         * Sets whether the currently processed changes are due to update.
         * @param b Specify <code>true</code> to indicate that the currently 
         * processed changes are due to update; <code>false</code> 
         * indicates that the currently processed changes are due to user input.
         */
        private void
        setUpdate(boolean b) { update = b; }
        
        private final Handler handler = new Handler();
        
        private Handler
        getHandler() { return handler; }
        
        private class Handler implements MidiDeviceListListener, AudioDeviceListListener {
                /**
                 * Invoked when a new MIDI device is created.
                 * @param e A <code>MidiDeviceListEvent</code>
                 * instance providing the event information.
                 */
                public void
                deviceAdded(MidiDeviceListEvent e) {
                        cbMidiDevice.addItem(e.getMidiDeviceModel().getDeviceInfo());
                }
        
                /**
                 * Invoked when a MIDI device is removed.
                 * @param e A <code>MidiDeviceListEvent</code>
                 * instance providing the event information.
                 */
                public void
                deviceRemoved(MidiDeviceListEvent e) {
                        cbMidiDevice.removeItem(e.getMidiDeviceModel().getDeviceInfo());
                }
                
                /**
                 * Invoked when a new audio device is created.
                 * @param e An <code>AudioDeviceListEvent</code>
                 * instance providing the event information.
                 */
                public void
                deviceAdded(AudioDeviceListEvent e) {
                        cbAudioDevice.addItem(e.getAudioDeviceModel().getDeviceInfo());
                }
        
                /**
                 * Invoked when an audio device is removed.
                 * @param e An <code>AudioDeviceListEvent</code>
                 * instance providing the event information.
                 */
                public void
                deviceRemoved(AudioDeviceListEvent e) {
                        cbAudioDevice.removeItem(e.getAudioDeviceModel().getDeviceInfo());
                }
        }
}