Replace virtual with override wherever possible; eliminate needless virtual...

... for functions in final classes.

override is like const -- it's not necessary, but it helps the compiler to
catch mistakes.

There may be some overriding functions not explicitly declared virtual and I did
not identify such cases, in which I might also add override.

src/prefs/BatchPrefs.h

@@ -25,7 +25,7 @@ class BatchPrefs final : public PrefsPanel
 public:
    BatchPrefs(wxWindow * parent);
    ~BatchPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
 private:
    void Populate();
@@ -37,6 +37,6 @@ private:
 class BatchPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/DevicePrefs.h

@@ -28,7 +28,7 @@ class DevicePrefs final : public PrefsPanel
  public:
    DevicePrefs(wxWindow * parent);
    virtual ~DevicePrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -57,7 +57,7 @@ class DevicePrefs final : public PrefsPanel
 class DevicePrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 
 #endif

src/prefs/DirectoriesPrefs.h

@@ -23,8 +23,8 @@ class DirectoriesPrefs final : public PrefsPanel
  public:
    DirectoriesPrefs(wxWindow * parent);
    ~DirectoriesPrefs();
-   virtual bool Apply();
-   virtual bool Validate();
+   bool Apply() override;
+   bool Validate() override;
 
  private:
    void Populate();
@@ -41,6 +41,6 @@ class DirectoriesPrefs final : public PrefsPanel
 class DirectoriesPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/EffectsPrefs.h

@@ -27,7 +27,7 @@ class EffectsPrefs final : public PrefsPanel
  public:
    EffectsPrefs(wxWindow * parent);
    ~EffectsPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -37,6 +37,6 @@ class EffectsPrefs final : public PrefsPanel
 class EffectsPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/ExtImportPrefs.h

@@ -47,7 +47,7 @@ class ExtImportPrefs final : public PrefsPanel
  public:
    ExtImportPrefs(wxWindow * parent);
    ~ExtImportPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
    void OnPluginKeyDown(wxListEvent& event);
    void OnPluginBeginDrag(wxListEvent& event);
@@ -111,6 +111,6 @@ class ExtImportPrefs final : public PrefsPanel
 class ExtImportPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/GUIPrefs.h

@@ -27,7 +27,7 @@ class GUIPrefs final : public PrefsPanel
  public:
    GUIPrefs(wxWindow * parent);
    ~GUIPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
    static void GetRangeChoices(wxArrayString *pChoices, wxArrayString *pCodes);
 
@@ -48,6 +48,6 @@ class GUIPrefs final : public PrefsPanel
 class GUIPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/ImportExportPrefs.h

@@ -26,7 +26,7 @@ class ImportExportPrefs final : public PrefsPanel
  public:
    ImportExportPrefs(wxWindow * parent);
    ~ImportExportPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -36,6 +36,6 @@ class ImportExportPrefs final : public PrefsPanel
 class ImportExportPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/KeyConfigPrefs.h

@@ -39,8 +39,8 @@ class KeyConfigPrefs final : public PrefsPanel
 public:
    KeyConfigPrefs(wxWindow * parent);
    ~KeyConfigPrefs();
-   virtual bool Apply();
-   virtual void Cancel();
+   bool Apply() override;
+   void Cancel() override;
 
 private:
    void Populate();
@@ -107,8 +107,8 @@ class KeyConfigPrefs final : public PrefsPanel
  public:
    KeyConfigPrefs(wxWindow * parent);
    ~KeyConfigPrefs();
-   virtual bool Apply();
-   virtual void Cancel();
+   bool Apply() override;
+   void Cancel() override;
 
  private:
    void Populate();
@@ -151,6 +151,6 @@ class KeyConfigPrefs final : public PrefsPanel
 class KeyConfigPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/LibraryPrefs.h

@@ -27,7 +27,7 @@ class LibraryPrefs final : public PrefsPanel
  public:
    LibraryPrefs(wxWindow * parent);
    ~LibraryPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -49,6 +49,6 @@ class LibraryPrefs final : public PrefsPanel
 class LibraryPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/MidiIOPrefs.h

@@ -31,8 +31,8 @@ class MidiIOPrefs final : public PrefsPanel
  public:
    MidiIOPrefs(wxWindow * parent);
    virtual ~MidiIOPrefs();
-   virtual bool Apply();
-   virtual bool Validate();
+   bool Apply() override;
+   bool Validate() override;
 
  private:
    void Populate();
@@ -65,7 +65,7 @@ class MidiIOPrefs final : public PrefsPanel
 class MidiIOPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif
 

src/prefs/ModulePrefs.h

@@ -36,7 +36,7 @@ class ModulePrefs final : public PrefsPanel
  public:
    ModulePrefs(wxWindow * parent);
    ~ModulePrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
    static int GetModuleStatus( const wxString &fname );
    static void SetModuleStatus( const wxString &fname, int iStatus );
@@ -53,6 +53,6 @@ class ModulePrefs final : public PrefsPanel
 class ModulePrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/MousePrefs.h

@@ -24,7 +24,7 @@ class MousePrefs final : public PrefsPanel
  public:
    MousePrefs(wxWindow * parent);
    ~MousePrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -41,6 +41,6 @@ class MousePrefs final : public PrefsPanel
 class MousePrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/PlaybackPrefs.h

@@ -25,7 +25,7 @@ class PlaybackPrefs final : public PrefsPanel
  public:
    PlaybackPrefs(wxWindow * parent);
    virtual ~PlaybackPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -35,7 +35,7 @@ class PlaybackPrefs final : public PrefsPanel
 class PlaybackPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 
 #endif

src/prefs/PrefsDialog.cpp

@@ -85,8 +85,8 @@ public:
       , mTitlePrefix(titlePrefix)
    {;};
    ~wxTreebookExt(){;};
-   virtual int ChangeSelection(size_t n);
-   virtual int SetSelection(size_t n);
+   int ChangeSelection(size_t n) override;
+   int SetSelection(size_t n) override;
    const wxString mTitlePrefix;
 };
 

src/prefs/PrefsDialog.h

@@ -53,7 +53,7 @@ class PrefsDialog /* not final */ : public wxDialog
    virtual ~PrefsDialog();
 
    // Defined this so a protected virtual can be invoked after the constructor
-   virtual int ShowModal();
+   int ShowModal() override;
 
    void OnCategoryChange(wxCommandEvent & e);
    void OnOK(wxCommandEvent & e);
@@ -91,8 +91,8 @@ class GlobalPrefsDialog final : public PrefsDialog
 public:
    GlobalPrefsDialog(wxWindow * parent, Factories &factories = DefaultFactories());
    virtual ~GlobalPrefsDialog();
-   virtual long GetPreferredPage();
-   virtual void SavePreferredPage();
+   long GetPreferredPage() override;
+   void SavePreferredPage() override;
 };
 
 #endif

src/prefs/PrefsPanel.h

@@ -52,6 +52,7 @@ class PrefsPanel /* not final */ : public wxPanel
 
    virtual ~PrefsPanel();
 
+   // NEW virtuals
    virtual bool Apply() = 0;
 
    // If it returns True, the Apply button is added below the panel

src/prefs/ProjectsPrefs.h

@@ -26,7 +26,7 @@ class ProjectsPrefs final : public PrefsPanel
  public:
    ProjectsPrefs(wxWindow * parent);
    ~ProjectsPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -36,6 +36,6 @@ class ProjectsPrefs final : public PrefsPanel
 class ProjectsPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/QualityPrefs.h

@@ -29,7 +29,7 @@ class QualityPrefs final : public PrefsPanel
    QualityPrefs(wxWindow * parent);
    virtual ~QualityPrefs();
 
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -56,6 +56,6 @@ class QualityPrefs final : public PrefsPanel
 class QualityPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/RecordingPrefs.h

@@ -26,7 +26,7 @@ class RecordingPrefs final : public PrefsPanel
  public:
    RecordingPrefs(wxWindow * parent);
    virtual ~RecordingPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -43,6 +43,6 @@ class RecordingPrefs final : public PrefsPanel
 class RecordingPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/SpectrogramSettings.cpp

@@ -146,7 +146,7 @@ const wxArrayString &SpectrogramSettings::GetScaleNames()
 {
    class ScaleNamesArray final : public TranslatableStringArray
    {
-      virtual void Populate()
+      void Populate() override
       {
          // Keep in correspondence with enum SpectrogramSettings::ScaleType:
          mContents.Add(_("Linear"));
@@ -171,7 +171,7 @@ const wxArrayString &SpectrogramSettings::GetAlgorithmNames()
 {
    class AlgorithmNamesArray final : public TranslatableStringArray
    {
-      virtual void Populate()
+      void Populate() override
       {
          // Keep in correspondence with enum SpectrogramSettings::Algorithm:
          mContents.Add(_("Frequencies"));

src/prefs/SpectrumPrefs.h

@@ -43,9 +43,9 @@ class SpectrumPrefs final : public PrefsPanel
  public:
    SpectrumPrefs(wxWindow * parent, WaveTrack *wt);
    virtual ~SpectrumPrefs();
-   virtual bool Apply();
-   virtual bool ShowsApplyButton();
-   virtual bool Validate();
+   bool Apply() override;
+   bool ShowsApplyButton() override;
+   bool Validate() override;
 
  private:
    void Populate(int windowSize);
@@ -100,7 +100,7 @@ class SpectrumPrefsFactory final : public PrefsPanelFactory
 {
 public:
    explicit SpectrumPrefsFactory(WaveTrack *wt = 0);
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 
 private:
    WaveTrack *const mWt;

src/prefs/ThemePrefs.h

@@ -26,7 +26,7 @@ class ThemePrefs final : public PrefsPanel
  public:
    ThemePrefs(wxWindow * parent);
    ~ThemePrefs(void);
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -44,6 +44,6 @@ class ThemePrefs final : public PrefsPanel
 class ThemePrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/TracksPrefs.h

@@ -27,7 +27,7 @@ class TracksPrefs final : public PrefsPanel
  public:
    TracksPrefs(wxWindow * parent);
    ~TracksPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -42,6 +42,6 @@ class TracksPrefs final : public PrefsPanel
 class TracksPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/WarningsPrefs.h

@@ -26,7 +26,7 @@ class WarningsPrefs final : public PrefsPanel
  public:
    WarningsPrefs(wxWindow * parent);
    ~WarningsPrefs();
-   virtual bool Apply();
+   bool Apply() override;
 
  private:
    void Populate();
@@ -36,6 +36,6 @@ class WarningsPrefs final : public PrefsPanel
 class WarningsPrefsFactory final : public PrefsPanelFactory
 {
 public:
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 };
 #endif

src/prefs/WaveformPrefs.h

@@ -25,9 +25,9 @@ class WaveformPrefs final : public PrefsPanel
 public:
    WaveformPrefs(wxWindow * parent, WaveTrack *wt);
    virtual ~WaveformPrefs();
-   virtual bool Apply();
-   virtual bool ShowsApplyButton();
-   virtual bool Validate();
+   bool Apply() override;
+   bool ShowsApplyButton() override;
+   bool Validate() override;
 
 private:
    void Populate();
@@ -60,7 +60,7 @@ class WaveformPrefsFactory final : public PrefsPanelFactory
 {
 public:
    explicit WaveformPrefsFactory(WaveTrack *wt = 0);
-   virtual PrefsPanel *Create(wxWindow *parent);
+   PrefsPanel *Create(wxWindow *parent) override;
 
 private:
    WaveTrack *const mWt;

src/prefs/WaveformSettings.cpp

@@ -151,7 +151,7 @@ const wxArrayString &WaveformSettings::GetScaleNames()
 {
    class ScaleNamesArray final : public TranslatableStringArray
    {
-      virtual void Populate()
+      void Populate() override
       {
          // Keep in correspondence with enum WaveTrack::WaveTrackDisplay:
          mContents.Add(_("Linear"));