Separate an abstract base class from MeterPanel...

... to break its cycle with AudioIO

src/AudioIOBase.cpp

@@ -306,7 +306,7 @@ void AudioIOBase::HandleDeviceChange()
 #endif   // USE_PORTMIXER
 }
 
-void AudioIOBase::SetCaptureMeter(AudacityProject *project, MeterPanel *meter)
+void AudioIOBase::SetCaptureMeter(AudacityProject *project, MeterPanelBase *meter)
 {
    if (( mOwningProject ) && ( mOwningProject != project))
       return;
@@ -320,7 +320,7 @@ void AudioIOBase::SetCaptureMeter(AudacityProject *project, MeterPanel *meter)
       mInputMeter.Release();
 }
 
-void AudioIOBase::SetPlaybackMeter(AudacityProject *project, MeterPanel *meter)
+void AudioIOBase::SetPlaybackMeter(AudacityProject *project, MeterPanelBase *meter)
 {
    if (( mOwningProject ) && ( mOwningProject != project))
       return;

src/AudioIOBase.h

@@ -31,7 +31,7 @@ class AudioIOBase;
 class AudacityProject;
 class AudioIOListener;
 class BoundedEnvelope;
-class MeterPanel;
+class MeterPanelBase;
 using PRCrossfadeData = std::vector< std::vector < float > >;
 
 #define BAD_STREAM_TIME (-DBL_MAX)
@@ -83,7 +83,7 @@ struct AudioIOStartStreamOptions
    {}
 
    AudacityProject *pProject{};
-   MeterPanel *captureMeter{}, *playbackMeter{};
+   MeterPanelBase *captureMeter{}, *playbackMeter{};
    BoundedEnvelope *envelope; // for time warping
    AudioIOListener* listener;
    double rate;
@@ -111,8 +111,8 @@ class AudioIOBase /* not final */
 public:
    static AudioIOBase *Get();
 
-   void SetCaptureMeter(AudacityProject *project, MeterPanel *meter);
+   void SetCaptureMeter(AudacityProject *project, MeterPanelBase *meter);
-   void SetPlaybackMeter(AudacityProject *project, MeterPanel *meter);
+   void SetPlaybackMeter(AudacityProject *project, MeterPanelBase *meter);
 
    /** \brief update state after changing what audio devices are selected
     *
@@ -268,8 +268,8 @@ protected:
 
    PaStream           *mPortStreamV19;
 
-   wxWeakRef<MeterPanel> mInputMeter{};
+   wxWeakRef<MeterPanelBase> mInputMeter{};
-   wxWeakRef<MeterPanel> mOutputMeter{};
+   wxWeakRef<MeterPanelBase> mOutputMeter{};
 
    #if USE_PORTMIXER
    PxMixer            *mPortMixer;

src/ProjectAudioIO.cpp

@@ -55,12 +55,12 @@ bool ProjectAudioIO::IsAudioActive() const
       gAudioIO->IsStreamActive(GetAudioIOToken());
 }
 
-MeterPanel *ProjectAudioIO::GetPlaybackMeter()
+MeterPanelBase *ProjectAudioIO::GetPlaybackMeter()
 {
    return mPlaybackMeter;
 }
 
-void ProjectAudioIO::SetPlaybackMeter(MeterPanel *playback)
+void ProjectAudioIO::SetPlaybackMeter(MeterPanelBase *playback)
 {
    auto &project = mProject;
    mPlaybackMeter = playback;
@@ -71,12 +71,12 @@ void ProjectAudioIO::SetPlaybackMeter(MeterPanel *playback)
    }
 }
 
-MeterPanel *ProjectAudioIO::GetCaptureMeter()
+MeterPanelBase *ProjectAudioIO::GetCaptureMeter()
 {
    return mCaptureMeter;
 }
 
-void ProjectAudioIO::SetCaptureMeter(MeterPanel *capture)
+void ProjectAudioIO::SetCaptureMeter(MeterPanelBase *capture)
 {
    auto &project = mProject;
    mCaptureMeter = capture;

src/ProjectAudioIO.h

@@ -14,7 +14,7 @@ Paul Licameli split from AudacityProject.h
 #include "ClientData.h" // to inherit
 
 class AudacityProject;
-class MeterPanel;
+class MeterPanelBase;
 
 ///\ brief Holds per-project state needed for interaction with AudioIO,
 /// including the audio stream token and pointers to meters
@@ -32,17 +32,17 @@ public:
    bool IsAudioActive() const;
    void SetAudioIOToken(int token);
 
-   MeterPanel *GetPlaybackMeter();
+   MeterPanelBase *GetPlaybackMeter();
-   void SetPlaybackMeter(MeterPanel *playback);
+   void SetPlaybackMeter(MeterPanelBase *playback);
-   MeterPanel *GetCaptureMeter();
+   MeterPanelBase *GetCaptureMeter();
-   void SetCaptureMeter(MeterPanel *capture);
+   void SetCaptureMeter(MeterPanelBase *capture);
 
 private:
    AudacityProject &mProject;
 
    // Project owned meters
-   MeterPanel *mPlaybackMeter{};
+   MeterPanelBase *mPlaybackMeter{};
-   MeterPanel *mCaptureMeter{};
+   MeterPanelBase *mCaptureMeter{};
 
    int  mAudioIOToken{ -1 };
 };

src/toolbars/ControlToolBar.cpp

@@ -893,7 +893,7 @@ void ControlToolBar::StopPlaying(bool stopStream /* = true*/)
    // also clean the MeterQueues
    if( project ) {
       auto &projectAudioIO = ProjectAudioIO::Get( *project );
-      MeterPanel *meter = projectAudioIO.GetPlaybackMeter();
+      auto meter = projectAudioIO.GetPlaybackMeter();
       if( meter ) {
          meter->Clear();
       }

src/widgets/Meter.cpp

@@ -292,7 +292,7 @@ MeterPanel::MeterPanel(AudacityProject *project,
              const wxSize& size /*= wxDefaultSize*/,
              Style style /*= HorizontalStereo*/,
              float fDecayRate /*= 60.0f*/)
-: wxPanelWrapper(parent, id, pos, size, wxTAB_TRAVERSAL | wxNO_BORDER | wxWANTS_CHARS),
+: MeterPanelBase(parent, id, pos, size, wxTAB_TRAVERSAL | wxNO_BORDER | wxWANTS_CHARS),
    mProject(project),
    mQueue(1024),
    mWidth(size.x),
@@ -2151,6 +2151,10 @@ MeterAx::~MeterAx()
 {
 }
 
+MeterPanelBase::~MeterPanelBase()
+{
+}
+
 // Performs the default action. childId is 0 (the action for this object)
 // or > 0 (the action for a child).
 // Return wxACC_NOT_SUPPORTED if there is no default action for this

src/widgets/Meter.h

@@ -87,11 +87,27 @@ class MeterUpdateQueue
 
 class MeterAx;
 
+class MeterPanelBase /* not final */
+   : public wxPanelWrapper
+{
+public:
+   using wxPanelWrapper::wxPanelWrapper;
+   ~MeterPanelBase() override;
+
+   virtual void Clear() = 0;
+   virtual void Reset(double sampleRate, bool resetClipping) = 0;
+   virtual void UpdateDisplay(unsigned numChannels,
+                      int numFrames, float *sampleData) = 0;
+   virtual bool IsMeterDisabled() const = 0;
+   virtual float GetMaxPeak() const = 0;
+private:
+};
+
 /********************************************************************//**
 \brief MeterPanel is a panel that paints the meter used for monitoring
 or playback.
 ************************************************************************/
-class MeterPanel final : public wxPanelWrapper, private PrefsListener
+class MeterPanel final : public MeterPanelBase, private PrefsListener
 {
    DECLARE_DYNAMIC_CLASS(MeterPanel)
 
@@ -121,7 +137,7 @@ class MeterPanel final : public wxPanelWrapper, private PrefsListener
 
    void SetFocusFromKbd() override;
 
-   void Clear();
+   void Clear() override;
 
    Style GetStyle() const { return mStyle; }
    Style GetDesiredStyle() const { return mDesiredStyle; }
@@ -132,7 +148,7 @@ class MeterPanel final : public wxPanelWrapper, private PrefsListener
     * This method is thread-safe!  Feel free to call from a
     * different thread (like from an audio I/O callback).
     */
-   void Reset(double sampleRate, bool resetClipping);
+   void Reset(double sampleRate, bool resetClipping) override;
 
    /** \brief Update the meters with a block of audio data
     *
@@ -157,7 +173,7 @@ class MeterPanel final : public wxPanelWrapper, private PrefsListener
     * The second overload is for ease of use in MixerBoard.
     */
    void UpdateDisplay(unsigned numChannels,
-                      int numFrames, float *sampleData);
+                      int numFrames, float *sampleData) override;
 
    // Vaughan, 2010-11-29: This not currently used. See comments in MixerTrackCluster::UpdateMeter().
    //void UpdateDisplay(int numChannels, int numFrames,
@@ -171,9 +187,9 @@ class MeterPanel final : public wxPanelWrapper, private PrefsListener
     * This method is thread-safe!  Feel free to call from a
     * different thread (like from an audio I/O callback).
     */
-   bool IsMeterDisabled() const;
+   bool IsMeterDisabled() const override;
 
-   float GetMaxPeak() const;
+   float GetMaxPeak() const override;
 
    bool IsClipping() const;