text: /****************************************************************************
  **
  ** Copyright (C) 2015 The Qt Company Ltd.
  ** Contact: http://www.qt.io/licensing/
  **
  ** This file is part of the examples of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** You may use this file under the terms of the BSD license as follows:
  **
  ** "Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
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  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  ****************************************************************************/
  
  #ifndef MAINWIDGET_H
  #define MAINWIDGET_H
  
  #include <QAudio>
  #include <QIcon>
  #include <QWidget>
  
  class Engine;
  class FrequencySpectrum;
  class LevelMeter;
  class ProgressBar;
  class SettingsDialog;
  class Spectrograph;
  class ToneGeneratorDialog;
  class Waveform;
  
  QT_BEGIN_NAMESPACE
  class QAction;
  class QAudioFormat;
  class QLabel;
  class QMenu;
  class QPushButton;
  QT_END_NAMESPACE
  
  /**
   * Main application widget, responsible for connecting the various UI
   * elements to the Engine.
   */
  class MainWidget : public QWidget
  {
      Q_OBJECT
  
  public:
      explicit 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
  