mainwidget.h Example File

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 #ifndef MAINWIDGET_H
 #define MAINWIDGET_H

 #include <QWidget>
 #include <QIcon>
 #include <QtMultimedia/qaudio.h>

 class Engine;
 class FrequencySpectrum;
 class ProgressBar;
 class Spectrograph;
 class Waveform;
 class LevelMeter;
 class SettingsDialog;
 class ToneGeneratorDialog;

 QT_FORWARD_DECLARE_CLASS(QAudioFormat)
 QT_FORWARD_DECLARE_CLASS(QLabel)
 QT_FORWARD_DECLARE_CLASS(QPushButton)
 QT_FORWARD_DECLARE_CLASS(QMenu)
 QT_FORWARD_DECLARE_CLASS(QAction)

 /**
  * Main application widget, responsible for connecting the various UI
  * elements to the Engine.
  */
 class MainWidget : public QWidget {
     Q_OBJECT
 public:
     MainWidget(QWidget *parent = 0);
     ~MainWidget();

     // QObject
     void timerEvent(QTimerEvent *event);

 public slots:
     void stateChanged(QAudio::Mode mode, QAudio::State state);
     void formatChanged(const QAudioFormat &format);
     void spectrumChanged(qint64 position, qint64 length,
                          const FrequencySpectrum &spectrum);
     void infoMessage(const QString &message, int timeoutMs);
     void errorMessage(const QString &heading, const QString &detail);
     void audioPositionChanged(qint64 position);
     void bufferLengthChanged(qint64 length);

 private slots:
     void showFileDialog();
     void showSettingsDialog();
     void showToneGeneratorDialog();
     void initializeRecord();
     void updateModeMenu();
     void updateButtonStates();

 private:
     void createUi();
     void createMenus();
     void connectUi();
     void reset();

     enum Mode {
         NoMode,
         RecordMode,
         GenerateToneMode,
         LoadFileMode
     };

     void setMode(Mode mode);

 private:
     Mode                    m_mode;

     Engine*                 m_engine;

 #ifndef DISABLE_WAVEFORM
     Waveform*               m_waveform;
 #endif
     ProgressBar*            m_progressBar;
     Spectrograph*           m_spectrograph;
     LevelMeter*             m_levelMeter;

     QPushButton*            m_modeButton;
     QPushButton*            m_recordButton;
     QIcon                   m_recordIcon;
     QPushButton*            m_pauseButton;
     QIcon                   m_pauseIcon;
     QPushButton*            m_playButton;
     QIcon                   m_playIcon;
     QPushButton*            m_settingsButton;
     QIcon                   m_settingsIcon;

     QLabel*                 m_infoMessage;
     int                     m_infoMessageTimerId;

     SettingsDialog*         m_settingsDialog;
     ToneGeneratorDialog*    m_toneGeneratorDialog;

     QMenu*                  m_modeMenu;
     QAction*                m_loadFileAction;
     QAction*                m_generateToneAction;
     QAction*                m_recordAction;

 };

 #endif // MAINWIDGET_H