mainwidget.cpp Example File

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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(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)
  {
      QMessageBox::warning(this, heading, detail, QMessageBox::Close);
  }

  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::audioPositionChanged(qint64 position)
  {
  #ifndef DISABLE_WAVEFORM
      m_waveform->audioPositionChanged(position);
  #else
      Q_UNUSED(position)
  #endif
  }

  void MainWidget::bufferLengthChanged(qint64 length)
  {
      m_progressBar->bufferLengthChanged(length);
  }

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

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

  void MainWidget::showSettingsDialog()
  {
      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()
  {
      m_toneGeneratorDialog->exec();
      if (m_toneGeneratorDialog->result() == QDialog::Accepted) {
          reset();
          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();
          }
      } else {
          updateModeMenu();
      }
  }

  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->bufferLengthChanged(m_engine->bufferLength());

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

      CHECKED_CONNECT(m_engine, SIGNAL(dataLengthChanged(qint64)),
              this, SLOT(updateButtonStates()));

      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(audioPositionChanged(qint64)));

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

  #ifndef DISABLE_WAVEFORM
      CHECKED_CONNECT(m_engine, SIGNAL(bufferChanged(qint64, qint64, const QByteArray &)),
              m_waveform, SLOT(bufferChanged(qint64, qint64, const QByteArray &)));
  #endif
  }

  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->dataLength() &&*/
                                (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;
      updateModeMenu();
  }

  void MainWidget::updateModeMenu()
  {
      m_loadFileAction->setChecked(LoadFileMode == m_mode);
      m_generateToneAction->setChecked(GenerateToneMode == m_mode);
      m_recordAction->setChecked(RecordMode == m_mode);
  }