trunk/src/qsamplerChannel.cpp

// qsamplerChannel.cpp
//
/****************************************************************************
   Copyright (C) 2004-2007, rncbc aka Rui Nuno Capela. All rights reserved.
   Copyright (C) 2007, Christian Schoenebeck

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.

   This program 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 this program; if not, write to the Free Software Foundation, Inc.,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

*****************************************************************************/

#include "qsamplerUtilities.h"
#include "qsamplerAbout.h"
#include "qsamplerChannel.h"

#include "qsamplerMainForm.h"
#include "qsamplerChannelForm.h"

#include <qfileinfo.h>
#include <qcombobox.h>

#ifdef CONFIG_LIBGIG
#include "gig.h"
#endif

#define QSAMPLER_INSTRUMENT_MAX 100

#define UNICODE_RIGHT_ARROW     QChar(char(0x92), char(0x21))

using namespace QSampler;

//-------------------------------------------------------------------------
// qsamplerChannel - Sampler channel structure.
//

// Constructor.
qsamplerChannel::qsamplerChannel ( int iChannelID )
{
        m_iChannelID = iChannelID;

//  m_sEngineName       = noEngineName();
//  m_sInstrumentName   = noInstrumentName();
//  m_sInstrumentFile   = m_sInstrumentName;
        m_iInstrumentNr     = -1;
        m_iInstrumentStatus = -1;
        m_sMidiDriver       = "ALSA";
        m_iMidiDevice       = -1;
        m_iMidiPort         = -1;
        m_iMidiChannel      = -1;
        m_iMidiMap          = -1;
        m_sAudioDriver      = "ALSA";
        m_iAudioDevice      = -1;
        m_fVolume           = 0.0;
        m_bMute             = false;
        m_bSolo             = false;
}

// Default destructor.
qsamplerChannel::~qsamplerChannel (void)
{
}


// Create a new sampler channel, if not already.
bool qsamplerChannel::addChannel (void)
{
        MainForm* pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL)
                return false;

        // Are we a new channel?
        if (m_iChannelID < 0) {
                m_iChannelID = ::lscp_add_channel(pMainForm->client());
                if (m_iChannelID < 0) {
                        appendMessagesClient("lscp_add_channel");
                        appendMessagesError(
                                QObject::tr("Could not add channel.\n\nSorry."));
                }   // Otherwise it's created...
                else appendMessages(QObject::tr("added."));
        }

        // Return whether we're a valid channel...
        return (m_iChannelID >= 0);
}


// Remove sampler channel.
bool qsamplerChannel::removeChannel (void)
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL)
                return false;

        // Are we an existing channel?
        if (m_iChannelID >= 0) {
                if (::lscp_remove_channel(pMainForm->client(), m_iChannelID) != LSCP_OK) {
                        appendMessagesClient("lscp_remove_channel");
                        appendMessagesError(QObject::tr("Could not remove channel.\n\nSorry."));
                } else {
                        // Otherwise it's removed.
                        appendMessages(QObject::tr("removed."));
                        m_iChannelID = -1;
                }
        }

        // Return whether we've removed the channel...
        return (m_iChannelID < 0);
}


// Channel-ID (aka Sammpler-Channel) accessors.
int qsamplerChannel::channelID (void) const
{
        return m_iChannelID;
}

void qsamplerChannel::setChannelID ( int iChannelID )
{
        m_iChannelID = iChannelID;
}


// Readable channel name.
QString qsamplerChannel::channelName (void) const
{
        return (m_iChannelID < 0 ? QObject::tr("New Channel") : QObject::tr("Channel %1").arg(m_iChannelID));
}


// Engine name accessors.
const QString& qsamplerChannel::engineName (void) const
{
        return m_sEngineName;
}

bool qsamplerChannel::loadEngine ( const QString& sEngineName )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_sEngineName == sEngineName)
                return true;

        if (::lscp_load_engine(pMainForm->client(), sEngineName.latin1(), m_iChannelID) != LSCP_OK) {
                appendMessagesClient("lscp_load_engine");
                return false;
        }

        appendMessages(QObject::tr("Engine: %1.").arg(sEngineName));

        m_sEngineName = sEngineName;
        return true;
}


// Instrument filename accessor.
const QString& qsamplerChannel::instrumentFile (void) const
{
        return m_sInstrumentFile;
}

// Instrument index accessor.
int qsamplerChannel::instrumentNr (void) const
{
        return m_iInstrumentNr;
}

// Instrument name accessor.
const QString& qsamplerChannel::instrumentName (void) const
{
        return m_sInstrumentName;
}

// Instrument status accessor.
int qsamplerChannel::instrumentStatus (void) const
{
        return m_iInstrumentStatus;
}

// Instrument file loader.
bool qsamplerChannel::loadInstrument ( const QString& sInstrumentFile, int iInstrumentNr )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (!isInstrumentFile(sInstrumentFile))
                return false;
        if (m_iInstrumentStatus == 100 && m_sInstrumentFile == sInstrumentFile && m_iInstrumentNr == iInstrumentNr)
                return true;

        if (
                ::lscp_load_instrument_non_modal(
                        pMainForm->client(),
                        qsamplerUtilities::lscpEscapePath(sInstrumentFile).latin1(),
                        iInstrumentNr, m_iChannelID
                ) != LSCP_OK
        ) {
                appendMessagesClient("lscp_load_instrument");
                return false;
        }

        appendMessages(QObject::tr("Instrument: \"%1\" (%2).")
                .arg(sInstrumentFile).arg(iInstrumentNr));

        return setInstrument(sInstrumentFile, iInstrumentNr);
}


// Special instrument file/name/number settler.
bool qsamplerChannel::setInstrument ( const QString& sInstrumentFile, int iInstrumentNr )
{
        m_sInstrumentFile = sInstrumentFile;
        m_iInstrumentNr = iInstrumentNr;
#ifdef CONFIG_INSTRUMENT_NAME
        m_sInstrumentName = QString::null;  // We'll get it, maybe later, on channel_info...
#else
        m_sInstrumentName = getInstrumentName(sInstrumentFile, iInstrumentNr, true);
#endif
        m_iInstrumentStatus = 0;

        return true;
}


// MIDI driver type accessors (DEPRECATED).
const QString& qsamplerChannel::midiDriver (void) const
{
        return m_sMidiDriver;
}

bool qsamplerChannel::setMidiDriver ( const QString& sMidiDriver )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_sMidiDriver == sMidiDriver)
                return true;

        if (::lscp_set_channel_midi_type(pMainForm->client(), m_iChannelID, sMidiDriver.latin1()) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_midi_type");
                return false;
        }

        appendMessages(QObject::tr("MIDI driver: %1.").arg(sMidiDriver));

        m_sMidiDriver = sMidiDriver;
        return true;
}


// MIDI device accessors.
int qsamplerChannel::midiDevice (void) const
{
        return m_iMidiDevice;
}

bool qsamplerChannel::setMidiDevice ( int iMidiDevice )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_iMidiDevice == iMidiDevice)
                return true;

        if (::lscp_set_channel_midi_device(pMainForm->client(), m_iChannelID, iMidiDevice) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_midi_device");
                return false;
        }

        appendMessages(QObject::tr("MIDI device: %1.").arg(iMidiDevice));

        m_iMidiDevice = iMidiDevice;
        return true;
}


// MIDI port number accessor.
int qsamplerChannel::midiPort (void) const
{
        return m_iMidiPort;
}

bool qsamplerChannel::setMidiPort ( int iMidiPort )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_iMidiPort == iMidiPort)
                return true;

        if (::lscp_set_channel_midi_port(pMainForm->client(), m_iChannelID, iMidiPort) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_midi_port");
                return false;
        }

        appendMessages(QObject::tr("MIDI port: %1.").arg(iMidiPort));

        m_iMidiPort = iMidiPort;
        return true;
}


// MIDI channel accessor.
int qsamplerChannel::midiChannel (void) const
{
        return m_iMidiChannel;
}

bool qsamplerChannel::setMidiChannel ( int iMidiChannel )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_iMidiChannel == iMidiChannel)
                return true;

        if (::lscp_set_channel_midi_channel(pMainForm->client(), m_iChannelID, iMidiChannel) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_midi_channel");
                return false;
        }

        appendMessages(QObject::tr("MIDI channel: %1.").arg(iMidiChannel));

        m_iMidiChannel = iMidiChannel;
        return true;
}


// MIDI instrument map accessor.
int qsamplerChannel::midiMap (void) const
{
        return m_iMidiMap;
}

bool qsamplerChannel::setMidiMap ( int iMidiMap )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_iMidiMap == iMidiMap)
                return true;
#ifdef CONFIG_MIDI_INSTRUMENT
        if (::lscp_set_channel_midi_map(pMainForm->client(), m_iChannelID, iMidiMap) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_midi_map");
                return false;
        }
#endif
        appendMessages(QObject::tr("MIDI map: %1.").arg(iMidiMap));

        m_iMidiMap = iMidiMap;
        return true;
}


// Audio device accessor.
int qsamplerChannel::audioDevice (void) const
{
        return m_iAudioDevice;
}

bool qsamplerChannel::setAudioDevice ( int iAudioDevice )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_iAudioDevice == iAudioDevice)
                return true;

        if (::lscp_set_channel_audio_device(pMainForm->client(), m_iChannelID, iAudioDevice) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_audio_device");
                return false;
        }

        appendMessages(QObject::tr("Audio device: %1.").arg(iAudioDevice));

        m_iAudioDevice = iAudioDevice;
        return true;
}


// Audio driver type accessors (DEPRECATED).
const QString& qsamplerChannel::audioDriver (void) const
{
        return m_sAudioDriver;
}

bool qsamplerChannel::setAudioDriver ( const QString& sAudioDriver )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_sAudioDriver == sAudioDriver)
                return true;

        if (::lscp_set_channel_audio_type(pMainForm->client(), m_iChannelID, sAudioDriver.latin1()) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_audio_type");
                return false;
        }

        appendMessages(QObject::tr("Audio driver: %1.").arg(sAudioDriver));

        m_sAudioDriver = sAudioDriver;
        return true;
}


// Channel volume accessors.
float qsamplerChannel::volume (void) const
{
        return m_fVolume;
}

bool qsamplerChannel::setVolume ( float fVolume )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && m_fVolume == fVolume)
                return true;

        if (::lscp_set_channel_volume(pMainForm->client(), m_iChannelID, fVolume) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_volume");
                return false;
        }

        appendMessages(QObject::tr("Volume: %1.").arg(fVolume));

        m_fVolume = fVolume;
        return true;
}


// Sampler channel mute state.
bool qsamplerChannel::channelMute (void) const
{
        return m_bMute;
}

bool qsamplerChannel::setChannelMute ( bool bMute )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && ((m_bMute && bMute) || (!m_bMute && !bMute)))
                return true;

#ifdef CONFIG_MUTE_SOLO
        if (::lscp_set_channel_mute(pMainForm->client(), m_iChannelID, bMute) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_mute");
                return false;
        }
        appendMessages(QObject::tr("Mute: %1.").arg((int) bMute));
        m_bMute = bMute;
        return true;
#else
        return false;
#endif
}


// Sampler channel solo state.
bool qsamplerChannel::channelSolo (void) const
{
        return m_bSolo;
}

bool qsamplerChannel::setChannelSolo ( bool bSolo )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 && ((m_bSolo && bSolo) || (!m_bSolo && !bSolo)))
                return true;

#ifdef CONFIG_MUTE_SOLO
        if (::lscp_set_channel_solo(pMainForm->client(), m_iChannelID, bSolo) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_solo");
                return false;
        }
        appendMessages(QObject::tr("Solo: %1.").arg((int) bSolo));
        m_bSolo = bSolo;
        return true;
#else
        return false;
#endif
}


// Audio routing accessors.
int qsamplerChannel::audioChannel ( int iAudioOut ) const
{
        return m_audioRouting[iAudioOut];
}

bool qsamplerChannel::setAudioChannel ( int iAudioOut, int iAudioIn )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;
        if (m_iInstrumentStatus == 100 &&
                        m_audioRouting[iAudioOut] == iAudioIn)
                return true;

        if (::lscp_set_channel_audio_channel(pMainForm->client(),
                        m_iChannelID, iAudioOut, iAudioIn) != LSCP_OK) {
                appendMessagesClient("lscp_set_channel_audio_channel");
                return false;
        }

        appendMessages(QObject::tr("Audio Channel: %1 -> %2.")
                .arg(iAudioOut).arg(iAudioIn));

        m_audioRouting[iAudioOut] = iAudioIn;
        return true;
}

// The audio routing map itself.
const qsamplerChannelRoutingMap& qsamplerChannel::audioRouting (void) const
{
        return m_audioRouting;
}


// Istrument name remapper.
void qsamplerChannel::updateInstrumentName (void)
{
#ifndef CONFIG_INSTRUMENT_NAME
        m_sInstrumentName = getInstrumentName(m_sInstrumentFile,
                m_iInstrumentNr, (options() && options()->bInstrumentNames));
#endif
}


// Update whole channel info state.
bool qsamplerChannel::updateChannelInfo (void)
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;

        // Read channel information.
        lscp_channel_info_t *pChannelInfo = ::lscp_get_channel_info(pMainForm->client(), m_iChannelID);
        if (pChannelInfo == NULL) {
                appendMessagesClient("lscp_get_channel_info");
                appendMessagesError(QObject::tr("Could not get channel information.\n\nSorry."));
                return false;
        }

#ifdef CONFIG_INSTRUMENT_NAME
        // We got all actual instrument datum...
        m_sInstrumentFile =
                qsamplerUtilities::lscpEscapedPathToPosix(pChannelInfo->instrument_file);
        m_iInstrumentNr   = pChannelInfo->instrument_nr;
        m_sInstrumentName =
                qsamplerUtilities::lscpEscapedTextToRaw(pChannelInfo->instrument_name);
#else
        // First, check if intrument name has changed,
        // taking care that instrument name lookup might be expensive,
        // so we better make it only once and when really needed...
        if ((m_sInstrumentFile != pChannelInfo->instrument_file) ||
                (m_iInstrumentNr   != pChannelInfo->instrument_nr)) {
                m_sInstrumentFile = pChannelInfo->instrument_file;
                m_iInstrumentNr   = pChannelInfo->instrument_nr;
                updateInstrumentName();
        }
#endif
        // Cache in other channel information.
        m_sEngineName       = pChannelInfo->engine_name;
        m_iInstrumentStatus = pChannelInfo->instrument_status;
        m_iMidiDevice       = pChannelInfo->midi_device;
        m_iMidiPort         = pChannelInfo->midi_port;
        m_iMidiChannel      = pChannelInfo->midi_channel;
#ifdef CONFIG_MIDI_INSTRUMENT
        m_iMidiMap          = pChannelInfo->midi_map;
#endif
        m_iAudioDevice      = pChannelInfo->audio_device;
        m_fVolume           = pChannelInfo->volume;
#ifdef CONFIG_MUTE_SOLO
        m_bMute             = pChannelInfo->mute;
        m_bSolo             = pChannelInfo->solo;
#endif
        // Some sanity checks.
        if (m_sEngineName == "NONE" || m_sEngineName.isEmpty())
                m_sEngineName = QString::null;
        if (m_sInstrumentFile == "NONE" || m_sInstrumentFile.isEmpty()) {
                m_sInstrumentFile = QString::null;
                m_sInstrumentName = QString::null;
        }

        // Time for device info grabbing...
        lscp_device_info_t *pDeviceInfo;
        const QString sNone = QObject::tr("(none)");
        // Audio device driver type.
        pDeviceInfo = ::lscp_get_audio_device_info(pMainForm->client(), m_iAudioDevice);
        if (pDeviceInfo == NULL) {
                appendMessagesClient("lscp_get_audio_device_info");
                m_sAudioDriver = sNone;
        } else {
                m_sAudioDriver = pDeviceInfo->driver;
        }
        // MIDI device driver type.
        pDeviceInfo = ::lscp_get_midi_device_info(pMainForm->client(), m_iMidiDevice);
        if (pDeviceInfo == NULL) {
                appendMessagesClient("lscp_get_midi_device_info");
                m_sMidiDriver = sNone;
        } else {
                m_sMidiDriver = pDeviceInfo->driver;
        }

        // Set the audio routing map.
        m_audioRouting.clear();
#ifdef CONFIG_AUDIO_ROUTING
        int *piAudioRouting = pChannelInfo->audio_routing;
        for (int i = 0; piAudioRouting && piAudioRouting[i] >= 0; i++)
                m_audioRouting[i] = piAudioRouting[i];
#else
        char **ppszAudioRouting = pChannelInfo->audio_routing;
        for (int i = 0; ppszAudioRouting && ppszAudioRouting[i]; i++)
                m_audioRouting[i] = ::atoi(ppszAudioRouting[i]);
#endif

        return true;
}


// Reset channel method.
bool qsamplerChannel::channelReset (void)
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;

        if (::lscp_reset_channel(pMainForm->client(), m_iChannelID) != LSCP_OK) {
                appendMessagesClient("lscp_reset_channel");
                return false;
        }

        appendMessages(QObject::tr("reset."));

        return true;
}


// Spawn instrument editor method.
bool qsamplerChannel::editChannel (void)
{
#ifdef CONFIG_EDIT_INSTRUMENT

        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;
        if (pMainForm->client() == NULL || m_iChannelID < 0)
                return false;

        if (::lscp_edit_channel_instrument(pMainForm->client(), m_iChannelID)
                != LSCP_OK) {
                appendMessagesClient("lscp_edit_channel_instrument");
                appendMessagesError(QObject::tr(
                        "Could not launch an appropriate instrument editor "
                        "for the given instrument!\n"
                        "Make sure you have an appropriate "
                        "instrument editor like 'gigedit' installed\n"
                        "and that it placed its mandatory DLL file "
                        "into the sampler's plugin directory.")
                );
                return false;
        }

        appendMessages(QObject::tr("edit instrument."));

        return true;

#else

        appendMessagesError(QObject::tr(
                "Sorry, QSampler was compiled for a version of liblscp "
                "which lacks this feature.\n"
                "You may want to update liblscp and recompile QSampler afterwards.")
        );

        return false;

#endif
}


// Channel setup dialog form.
bool qsamplerChannel::channelSetup ( QWidget *pParent )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm == NULL)
                return false;

        bool bResult = false;

        appendMessages(QObject::tr("setup..."));

        ChannelForm *pChannelForm = new ChannelForm(pParent);
        if (pChannelForm) {
                pChannelForm->setup(this);
                bResult = pChannelForm->exec();
                delete pChannelForm;
        }

        return bResult;
}


// Redirected messages output methods.
void qsamplerChannel::appendMessages( const QString& s ) const
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm)
                pMainForm->appendMessages(channelName() + ' ' + s);
}

void qsamplerChannel::appendMessagesColor( const QString& s,
        const QString& c ) const
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm)
                pMainForm->appendMessagesColor(channelName() + ' ' + s, c);
}

void qsamplerChannel::appendMessagesText( const QString& s ) const
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm)
                pMainForm->appendMessagesText(channelName() + ' ' + s);
}

void qsamplerChannel::appendMessagesError( const QString& s ) const
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm)
                pMainForm->appendMessagesError(channelName() + "\n\n" + s);
}

void qsamplerChannel::appendMessagesClient( const QString& s ) const
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm)
                pMainForm->appendMessagesClient(channelName() + ' ' + s);
}


// Context menu event handler.
void qsamplerChannel::contextMenuEvent( QContextMenuEvent *pEvent )
{
        MainForm *pMainForm = MainForm::getInstance();
        if (pMainForm)
                pMainForm->contextMenuEvent(pEvent);
}


// FIXME: Check whether a given file is an instrument file.
bool qsamplerChannel::isInstrumentFile ( const QString& sInstrumentFile )
{
        bool bResult = false;

        QFile file(sInstrumentFile);
        if (file.open(IO_ReadOnly)) {
                char achHeader[16];
                if (file.readBlock(achHeader, 16)) {
                        bResult = (::memcmp(&achHeader[0], "RIFF", 4)     == 0
                                        && ::memcmp(&achHeader[8], "DLS LIST", 8) == 0);
                }
                file.close();
        }

        return bResult;
}


// Retrieve the instrument list of a instrument file (.gig).
QStringList qsamplerChannel::getInstrumentList( const QString& sInstrumentFile,
        bool bInstrumentNames )
{
        QString sInstrumentName = QFileInfo(sInstrumentFile).fileName();
        QStringList instlist;

        if (isInstrumentFile(sInstrumentFile)) {
#ifdef CONFIG_LIBGIG
                if (bInstrumentNames) {
                        RIFF::File *pRiff = new RIFF::File(sInstrumentFile.latin1());
                        gig::File  *pGig  = new gig::File(pRiff);
                        gig::Instrument *pInstrument = pGig->GetFirstInstrument();
                        while (pInstrument) {
                                instlist.append((pInstrument->pInfo)->Name.c_str());
                                pInstrument = pGig->GetNextInstrument();
                        }
                        delete pGig;
                        delete pRiff;
                }
                else
#endif
                for (int iInstrumentNr = 0; iInstrumentNr < QSAMPLER_INSTRUMENT_MAX; iInstrumentNr++)
                        instlist.append(sInstrumentName + " [" + QString::number(iInstrumentNr) + "]");
        }
        else instlist.append(noInstrumentName());

        return instlist;
}


// Retrieve the spacific instrument name of a instrument file (.gig), given its index.
QString qsamplerChannel::getInstrumentName( const QString& sInstrumentFile,
        int iInstrumentNr, bool bInstrumentNames )
{
        QString sInstrumentName;

        if (isInstrumentFile(sInstrumentFile)) {
                sInstrumentName = QFileInfo(sInstrumentFile).fileName();
#ifdef CONFIG_LIBGIG
                if (bInstrumentNames) {
                        RIFF::File *pRiff = new RIFF::File(sInstrumentFile.latin1());
                        gig::File  *pGig  = new gig::File(pRiff);
                        int iIndex = 0;
                        gig::Instrument *pInstrument = pGig->GetFirstInstrument();
                        while (pInstrument) {
                                if (iIndex == iInstrumentNr) {
                                        sInstrumentName = (pInstrument->pInfo)->Name.c_str();
                                        break;
                                }
                                iIndex++;
                                pInstrument = pGig->GetNextInstrument();
                        }
                        delete pGig;
                        delete pRiff;
                }
                else
#endif
                sInstrumentName += " [" + QString::number(iInstrumentNr) + "]";
        }
        else sInstrumentName = noInstrumentName();

        return sInstrumentName;
}


// Common invalid name-helpers.
QString qsamplerChannel::noEngineName (void)
{
        return QObject::tr("(No engine)");
}

QString qsamplerChannel::noInstrumentName (void)
{
        return QObject::tr("(No instrument)");
}

QString qsamplerChannel::loadingInstrument (void) {
        return QObject::tr("(Loading instrument...)");
}


//-------------------------------------------------------------------------
// ChannelRoutingModel - data model for audio routing (used for QTableView)
//

ChannelRoutingModel::ChannelRoutingModel(QObject* parent) : QAbstractTableModel(parent), pDevice(NULL) {
}

int ChannelRoutingModel::rowCount(const QModelIndex& /*parent*/) const {
    return routing.size();
}

int ChannelRoutingModel::columnCount(const QModelIndex& /*parent*/) const {
    return 1;
}

Qt::ItemFlags ChannelRoutingModel::flags(const QModelIndex& /*index*/) const {
    return Qt::ItemIsSelectable | Qt::ItemIsEditable | Qt::ItemIsEnabled;
}

bool ChannelRoutingModel::setData(const QModelIndex& index, const QVariant& value, int /*role*/) {
    if (!index.isValid()) {
        return false;
    }

    routing[index.row()] = value.toInt();

    emit dataChanged(index, index);
    return true;
}

QVariant ChannelRoutingModel::data(const QModelIndex &index, int role) const {
    if (!index.isValid())
        return QVariant();
    if (role != Qt::DisplayRole)
        return QVariant();
    if (index.column() != 0)
        return QVariant();

    ChannelRoutingItem item;

    // The common device port item list.
    qsamplerDevicePortList& ports = pDevice->ports();
    qsamplerDevicePort* pPort;
    for (pPort = ports.first(); pPort; pPort = ports.next()) {
        item.options.append(
            pDevice->deviceTypeName()
            + ' ' + pDevice->driverName()
            + ' ' + pPort->portName()
        );
    }

    item.selection = routing[index.row()];

    return QVariant::fromValue(item);
}

QVariant ChannelRoutingModel::headerData(int section, Qt::Orientation orientation, int role) const {
    if (role != Qt::DisplayRole) return QVariant();

    switch (orientation) {
        case Qt::Horizontal:
            return UNICODE_RIGHT_ARROW + QObject::tr(" Device Channel");
        case Qt::Vertical:
            return QObject::tr("Sampler Channel ") +
                   QString::number(section) + " " + UNICODE_RIGHT_ARROW;
        default:
            return QVariant();
    }
}

void ChannelRoutingModel::refresh ( qsamplerDevice *pDevice,
        const qsamplerChannelRoutingMap& routing )
{
    this->pDevice = pDevice;
    this->routing = routing;
    // inform the outer world (QTableView) that our data changed
    QAbstractTableModel::reset();
}


//-------------------------------------------------------------------------
// ChannelRoutingDelegate - table cell renderer for audio routing
//

ChannelRoutingDelegate::ChannelRoutingDelegate(QObject *parent) : QItemDelegate(parent) {
}

QWidget* ChannelRoutingDelegate::createEditor(QWidget *parent,
        const QStyleOptionViewItem & option ,
        const QModelIndex& index) const
{
    if (!index.isValid()) {
        return NULL;
    }

    if (index.column() != 0) {
        return NULL;
    }

    ChannelRoutingItem item = index.model()->data(index, Qt::DisplayRole).value<ChannelRoutingItem>();

    QComboBox* pComboBox = new QComboBox(parent);
    pComboBox->addItems(item.options);
    pComboBox->setCurrentIndex(item.selection);
    pComboBox->setEnabled(true);
    pComboBox->setGeometry(option.rect);
    return pComboBox;
}

void ChannelRoutingDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const {
    ChannelRoutingItem item = index.model()->data(index, Qt::DisplayRole).value<ChannelRoutingItem>();
    QComboBox* comboBox = static_cast<QComboBox*>(editor);
    comboBox->setCurrentIndex(item.selection);
}

void ChannelRoutingDelegate::setModelData(QWidget* editor, QAbstractItemModel* model, const QModelIndex& index) const {
    QComboBox* comboBox = static_cast<QComboBox*>(editor);
    model->setData(index, comboBox->currentIndex());
}

void ChannelRoutingDelegate::updateEditorGeometry(QWidget *editor,
        const QStyleOptionViewItem &option, const QModelIndex &/* index */) const
{
    editor->setGeometry(option.rect);
}

// end of qsamplerChannel.cpp