Qt Reference Documentation

mainwidget.cpp Example File

demos/spectrum/app/mainwidget.cpp
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 #include "engine.h"
 #include "levelmeter.h"
 #include "mainwidget.h"
 #include "waveform.h"
 #include "progressbar.h"
 #include "settingsdialog.h"
 #include "spectrograph.h"
 #include "tonegeneratordialog.h"
 #include "utils.h"

 #include <QLabel>
 #include <QPushButton>
 #include <QHBoxLayout>
 #include <QVBoxLayout>
 #include <QStyle>
 #include <QMenu>
 #include <QFileDialog>
 #include <QTimerEvent>
 #include <QMessageBox>

 const int NullTimerId = -1;

 MainWidget::MainWidget(QWidget *parent)
     :   QWidget(parent)
     ,   m_mode(NoMode)
     ,   m_engine(new Engine(this))
 #ifndef DISABLE_WAVEFORM
     ,   m_waveform(new Waveform(m_engine->buffer(), this))
 #endif
     ,   m_progressBar(new ProgressBar(this))
     ,   m_spectrograph(new Spectrograph(this))
     ,   m_levelMeter(new LevelMeter(this))
     ,   m_modeButton(new QPushButton(this))
     ,   m_recordButton(new QPushButton(this))
     ,   m_pauseButton(new QPushButton(this))
     ,   m_playButton(new QPushButton(this))
     ,   m_settingsButton(new QPushButton(this))
     ,   m_infoMessage(new QLabel(tr("Select a mode to begin"), this))
     ,   m_infoMessageTimerId(NullTimerId)
     ,   m_settingsDialog(new SettingsDialog(
             m_engine->availableAudioInputDevices(),
             m_engine->availableAudioOutputDevices(),
             this))
     ,   m_toneGeneratorDialog(new ToneGeneratorDialog(this))
     ,   m_modeMenu(new QMenu(this))
     ,   m_loadFileAction(0)
     ,   m_generateToneAction(0)
     ,   m_recordAction(0)
 {
     m_spectrograph->setParams(SpectrumNumBands, SpectrumLowFreq, SpectrumHighFreq);

     createUi();
     connectUi();
 }

 MainWidget::~MainWidget()
 {

 }

 //-----------------------------------------------------------------------------
 // Public slots
 //-----------------------------------------------------------------------------

 void MainWidget::stateChanged(QAudio::Mode mode, QAudio::State state)
 {
     Q_UNUSED(mode);

     updateButtonStates();

     if (QAudio::ActiveState != state && QAudio::SuspendedState != state) {
         m_levelMeter->reset();
         m_spectrograph->reset();
     }
 }

 void MainWidget::formatChanged(const QAudioFormat &format)
 {
    infoMessage(formatToString(format), NullMessageTimeout);

 #ifndef DISABLE_WAVEFORM
     if (QAudioFormat() != format) {
         m_waveform->initialize(format, WaveformTileLength,
                                WaveformWindowDuration);
     }
 #endif
 }

 void MainWidget::spectrumChanged(qint64 position, qint64 length,
                                  const FrequencySpectrum &spectrum)
 {
     m_progressBar->windowChanged(position, length);
     m_spectrograph->spectrumChanged(spectrum);
 }

 void MainWidget::infoMessage(const QString &message, int timeoutMs)
 {
     m_infoMessage->setText(message);

     if (NullTimerId != m_infoMessageTimerId) {
         killTimer(m_infoMessageTimerId);
         m_infoMessageTimerId = NullTimerId;
     }

     if (NullMessageTimeout != timeoutMs)
         m_infoMessageTimerId = startTimer(timeoutMs);
 }

 void MainWidget::errorMessage(const QString &heading, const QString &detail)
 {
 #ifdef Q_OS_SYMBIAN
     const QString message = heading + "\n" + detail;
     QMessageBox::warning(this, "", message, QMessageBox::Close);
 #else
     QMessageBox::warning(this, heading, detail, QMessageBox::Close);
 #endif
 }

 void MainWidget::timerEvent(QTimerEvent *event)
 {
     Q_ASSERT(event->timerId() == m_infoMessageTimerId);
     Q_UNUSED(event) // suppress warnings in release builds
     killTimer(m_infoMessageTimerId);
     m_infoMessageTimerId = NullTimerId;
     m_infoMessage->setText("");
 }

 void MainWidget::positionChanged(qint64 positionUs)
 {
 #ifndef DISABLE_WAVEFORM
     qint64 positionBytes = audioLength(m_engine->format(), positionUs);
     m_waveform->positionChanged(positionBytes);
 #else
     Q_UNUSED(positionUs)
 #endif
 }

 void MainWidget::bufferDurationChanged(qint64 durationUs)
 {
     m_progressBar->bufferDurationChanged(durationUs);
 }

 //-----------------------------------------------------------------------------
 // Private slots
 //-----------------------------------------------------------------------------

 void MainWidget::dataDurationChanged(qint64 duration)
 {
 #ifndef DISABLE_WAVEFORM
     const qint64 dataLength = audioLength(m_engine->format(), duration);
     m_waveform->dataLengthChanged(dataLength);
 #else
     Q_UNUSED(duration)
 #endif

     updateButtonStates();
 }

 void MainWidget::showFileDialog()
 {
     reset();
     const QString dir;
     const QStringList fileNames = QFileDialog::getOpenFileNames(this, tr("Open WAV file"), dir, "*.wav");
     if (fileNames.count()) {
         setMode(LoadFileMode);
         m_engine->loadFile(fileNames.front());
         updateButtonStates();
     }
 }

 void MainWidget::showSettingsDialog()
 {
     reset();
     m_settingsDialog->exec();
     if (m_settingsDialog->result() == QDialog::Accepted) {
         m_engine->setAudioInputDevice(m_settingsDialog->inputDevice());
         m_engine->setAudioOutputDevice(m_settingsDialog->outputDevice());
         m_engine->setWindowFunction(m_settingsDialog->windowFunction());
     }
 }

 void MainWidget::showToneGeneratorDialog()
 {
     reset();
     m_toneGeneratorDialog->exec();
     if (m_toneGeneratorDialog->result() == QDialog::Accepted) {
         setMode(GenerateToneMode);
         const qreal amplitude = m_toneGeneratorDialog->amplitude();
         if (m_toneGeneratorDialog->isFrequencySweepEnabled()) {
             m_engine->generateSweptTone(amplitude);
         } else {
             const qreal frequency = m_toneGeneratorDialog->frequency();
             const Tone tone(frequency, amplitude);
             m_engine->generateTone(tone);
             updateButtonStates();
         }
     }
 }

 void MainWidget::initializeRecord()
 {
     reset();
     setMode(RecordMode);
     if (m_engine->initializeRecord())
         updateButtonStates();
 }

 //-----------------------------------------------------------------------------
 // Private functions
 //-----------------------------------------------------------------------------

 void MainWidget::createUi()
 {
     createMenus();

     setWindowTitle(tr("Spectrum Analyser"));

     QVBoxLayout *windowLayout = new QVBoxLayout(this);

     m_infoMessage->setSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed);
     m_infoMessage->setAlignment(Qt::AlignHCenter);
     windowLayout->addWidget(m_infoMessage);

 #ifdef SUPERIMPOSE_PROGRESS_ON_WAVEFORM
     QScopedPointer<QHBoxLayout> waveformLayout(new QHBoxLayout);
     waveformLayout->addWidget(m_progressBar);
     m_progressBar->setMinimumHeight(m_waveform->minimumHeight());
     waveformLayout->setMargin(0);
     m_waveform->setLayout(waveformLayout.data());
     waveformLayout.take();
     windowLayout->addWidget(m_waveform);
 #else
 #ifndef DISABLE_WAVEFORM
     windowLayout->addWidget(m_waveform);
 #endif // DISABLE_WAVEFORM
     windowLayout->addWidget(m_progressBar);
 #endif // SUPERIMPOSE_PROGRESS_ON_WAVEFORM

     // Spectrograph and level meter

     QScopedPointer<QHBoxLayout> analysisLayout(new QHBoxLayout);
     analysisLayout->addWidget(m_spectrograph);
     analysisLayout->addWidget(m_levelMeter);
     windowLayout->addLayout(analysisLayout.data());
     analysisLayout.take();

     // Button panel

     const QSize buttonSize(30, 30);

     m_modeButton->setText(tr("Mode"));

     m_recordIcon = QIcon(":/images/record.png");
     m_recordButton->setIcon(m_recordIcon);
     m_recordButton->setEnabled(false);
     m_recordButton->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
     m_recordButton->setMinimumSize(buttonSize);

     m_pauseIcon = style()->standardIcon(QStyle::SP_MediaPause);
     m_pauseButton->setIcon(m_pauseIcon);
     m_pauseButton->setEnabled(false);
     m_pauseButton->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
     m_pauseButton->setMinimumSize(buttonSize);

     m_playIcon = style()->standardIcon(QStyle::SP_MediaPlay);
     m_playButton->setIcon(m_playIcon);
     m_playButton->setEnabled(false);
     m_playButton->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
     m_playButton->setMinimumSize(buttonSize);

     m_settingsIcon = QIcon(":/images/settings.png");
     m_settingsButton->setIcon(m_settingsIcon);
     m_settingsButton->setEnabled(true);
     m_settingsButton->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
     m_settingsButton->setMinimumSize(buttonSize);

     QScopedPointer<QHBoxLayout> buttonPanelLayout(new QHBoxLayout);
     buttonPanelLayout->addStretch();
     buttonPanelLayout->addWidget(m_modeButton);
     buttonPanelLayout->addWidget(m_recordButton);
     buttonPanelLayout->addWidget(m_pauseButton);
     buttonPanelLayout->addWidget(m_playButton);
     buttonPanelLayout->addWidget(m_settingsButton);

     QWidget *buttonPanel = new QWidget(this);
     buttonPanel->setSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed);
     buttonPanel->setLayout(buttonPanelLayout.data());
     buttonPanelLayout.take(); // ownership transferred to buttonPanel

     QScopedPointer<QHBoxLayout> bottomPaneLayout(new QHBoxLayout);
     bottomPaneLayout->addWidget(buttonPanel);
     windowLayout->addLayout(bottomPaneLayout.data());
     bottomPaneLayout.take(); // ownership transferred to windowLayout

     // Apply layout

     setLayout(windowLayout);
 }

 void MainWidget::connectUi()
 {
     CHECKED_CONNECT(m_recordButton, SIGNAL(clicked()),
             m_engine, SLOT(startRecording()));

     CHECKED_CONNECT(m_pauseButton, SIGNAL(clicked()),
             m_engine, SLOT(suspend()));

     CHECKED_CONNECT(m_playButton, SIGNAL(clicked()),
             m_engine, SLOT(startPlayback()));

     CHECKED_CONNECT(m_settingsButton, SIGNAL(clicked()),
             this, SLOT(showSettingsDialog()));

     CHECKED_CONNECT(m_engine, SIGNAL(stateChanged(QAudio::Mode,QAudio::State)),
             this, SLOT(stateChanged(QAudio::Mode,QAudio::State)));

     CHECKED_CONNECT(m_engine, SIGNAL(formatChanged(const QAudioFormat &)),
             this, SLOT(formatChanged(const QAudioFormat &)));

     m_progressBar->bufferDurationChanged(m_engine->bufferDuration());

     CHECKED_CONNECT(m_engine, SIGNAL(bufferDurationChanged(qint64)),
             this, SLOT(bufferDurationChanged(qint64)));

     CHECKED_CONNECT(m_engine, SIGNAL(dataDurationChanged(qint64)),
             this, SLOT(dataDurationChanged(qint64)));

     CHECKED_CONNECT(m_engine, SIGNAL(recordPositionChanged(qint64)),
             m_progressBar, SLOT(recordPositionChanged(qint64)));

     CHECKED_CONNECT(m_engine, SIGNAL(playPositionChanged(qint64)),
             m_progressBar, SLOT(playPositionChanged(qint64)));

     CHECKED_CONNECT(m_engine, SIGNAL(recordPositionChanged(qint64)),
             this, SLOT(positionChanged(qint64)));

     CHECKED_CONNECT(m_engine, SIGNAL(playPositionChanged(qint64)),
             this, SLOT(positionChanged(qint64)));

     CHECKED_CONNECT(m_engine, SIGNAL(levelChanged(qreal, qreal, int)),
             m_levelMeter, SLOT(levelChanged(qreal, qreal, int)));

     CHECKED_CONNECT(m_engine, SIGNAL(spectrumChanged(qint64, qint64, const FrequencySpectrum &)),
             this, SLOT(spectrumChanged(qint64, qint64, const FrequencySpectrum &)));

     CHECKED_CONNECT(m_engine, SIGNAL(infoMessage(QString, int)),
             this, SLOT(infoMessage(QString, int)));

     CHECKED_CONNECT(m_engine, SIGNAL(errorMessage(QString, QString)),
             this, SLOT(errorMessage(QString, QString)));

     CHECKED_CONNECT(m_spectrograph, SIGNAL(infoMessage(QString, int)),
             this, SLOT(infoMessage(QString, int)));
 }

 void MainWidget::createMenus()
 {
     m_modeButton->setMenu(m_modeMenu);

     m_generateToneAction = m_modeMenu->addAction(tr("Play generated tone"));
     m_recordAction = m_modeMenu->addAction(tr("Record and play back"));
     m_loadFileAction = m_modeMenu->addAction(tr("Play file"));

     m_loadFileAction->setCheckable(true);
     m_generateToneAction->setCheckable(true);
     m_recordAction->setCheckable(true);

     connect(m_loadFileAction, SIGNAL(triggered(bool)), this, SLOT(showFileDialog()));
     connect(m_generateToneAction, SIGNAL(triggered(bool)), this, SLOT(showToneGeneratorDialog()));
     connect(m_recordAction, SIGNAL(triggered(bool)), this, SLOT(initializeRecord()));
 }

 void MainWidget::updateButtonStates()
 {
     const bool recordEnabled = ((QAudio::AudioOutput == m_engine->mode() ||
                                 (QAudio::ActiveState != m_engine->state() &&
                                  QAudio::IdleState != m_engine->state())) &&
                                 RecordMode == m_mode);
     m_recordButton->setEnabled(recordEnabled);

     const bool pauseEnabled = (QAudio::ActiveState == m_engine->state() ||
                                QAudio::IdleState == m_engine->state());
     m_pauseButton->setEnabled(pauseEnabled);

     const bool playEnabled = (m_engine->dataDuration() &&
                               (QAudio::AudioOutput != m_engine->mode() ||
                                (QAudio::ActiveState != m_engine->state() &&
                                 QAudio::IdleState != m_engine->state())));
     m_playButton->setEnabled(playEnabled);
 }

 void MainWidget::reset()
 {
 #ifndef DISABLE_WAVEFORM
     m_waveform->reset();
 #endif
     m_engine->reset();
     m_levelMeter->reset();
     m_spectrograph->reset();
     m_progressBar->reset();
 }

 void MainWidget::setMode(Mode mode)
 {

     m_mode = mode;
     m_loadFileAction->setChecked(LoadFileMode == mode);
     m_generateToneAction->setChecked(GenerateToneMode == mode);
     m_recordAction->setChecked(RecordMode == mode);
 }
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