Don't hard-code the exhaustive list of sub-view types...

... in Wave track context menu and SetTrackVisualsCommand

Instead, discover them through a registry.

This eliminates some duplication of string constants and prepares for
non-intrusive generalization to more kinds of sub-views.

This makes the command agnostic about which subview types are known, but the
context menu still has special case treatment for Spectrogram Settings and
Wave Colors.

include/audacity/ComponentInterface.h

@@ -87,9 +87,10 @@ public:
 
    const wxString &Internal() const { return mInternal; }
    const TranslatableString &Msgid() const { return mMsgid; }
+   const TranslatableString Stripped() const { return mMsgid.Stripped(); }
    const wxString Translation() const { return mMsgid.Translation(); }
    const wxString StrippedTranslation() const
-      { return mMsgid.Stripped().Translation(); }
+      { return Stripped().Translation(); }
 
    bool empty() const { return mInternal.empty(); }
 

src/commands/SetTrackInfoCommand.cpp

@@ -248,20 +248,6 @@ static const EnumValueSymbol kColourStrings[nColours] =
 };
 
 
-enum kDisplayTypes
-{
-   kWaveform,
-   kSpectrogram,
-   nDisplayTypes
-};
-
-static const EnumValueSymbol kDisplayTypeStrings[nDisplayTypes] =
-{
-   // These are acceptable dual purpose internal/visible names
-   { XO("Waveform") },
-   { XO("Spectrogram") },
-};
-
 enum kScaleTypes
 {
    kLinear,
@@ -292,10 +278,22 @@ static const EnumValueSymbol kZoomTypeStrings[nZoomTypes] =
    { XO("HalfWave") },
 };
 
+static EnumValueSymbols DiscoverSubViewTypes()
+{
+   const auto &types = WaveTrackSubView::AllTypes();
+   return transform_container< EnumValueSymbols >(
+      types, std::mem_fn( &WaveTrackSubView::Type::name ) );
+}
+
 bool SetTrackVisualsCommand::DefineParams( ShuttleParams & S ){ 
    SetTrackBase::DefineParams( S );
    S.OptionalN( bHasHeight         ).Define(     mHeight,         wxT("Height"),     120, 44, 2000 );
-   S.OptionalN( bHasDisplayType    ).DefineEnum( mDisplayType,    wxT("Display"),    kWaveform, kDisplayTypeStrings, nDisplayTypes );
+
+   {
+      auto symbols = DiscoverSubViewTypes();
+      S.OptionalN( bHasDisplayType    ).DefineEnum( mDisplayType,    wxT("Display"),    0, symbols.data(), symbols.size() );
+   }
+
    S.OptionalN( bHasScaleType      ).DefineEnum( mScaleType,      wxT("Scale"),      kLinear,   kScaleTypeStrings, nScaleTypes );
    S.OptionalN( bHasColour         ).DefineEnum( mColour,         wxT("Color"),      kColour0,  kColourStrings, nColours );
    S.OptionalN( bHasVZoom          ).DefineEnum( mVZoom,          wxT("VZoom"),      kReset,    kZoomTypeStrings, nZoomTypes );
@@ -318,8 +316,15 @@ void SetTrackVisualsCommand::PopulateOrExchange(ShuttleGui & S)
       S.Optional( bHasHeight      ).TieNumericTextBox(  XO("Height:"),        mHeight );
       S.Optional( bHasColour      ).TieChoice(          XO("Color:"),         mColour,
          Msgids(  kColourStrings, nColours ) );
-      S.Optional( bHasDisplayType ).TieChoice(          XO("Display:"),       mDisplayType,
-         Msgids( kDisplayTypeStrings, nDisplayTypes ) );
+      
+      {
+         auto symbols = DiscoverSubViewTypes();
+         auto typeNames = transform_container<TranslatableStrings>(
+             symbols, std::mem_fn( &EnumValueSymbol::Stripped ) );
+         S.Optional( bHasDisplayType ).TieChoice(          XO("Display:"),       mDisplayType,
+            typeNames );
+      }
+
       S.Optional( bHasScaleType   ).TieChoice(          XO("Scale:"),         mScaleType,
          Msgids( kScaleTypeStrings, nScaleTypes ) );
       S.Optional( bHasVZoom       ).TieChoice(          XO("VZoom:"),         mVZoom,
@@ -355,10 +360,7 @@ bool SetTrackVisualsCommand::ApplyInner(const CommandContext & context, Track *
 
    if( wt && bHasDisplayType  )
       WaveTrackView::Get( *wt ).SetDisplay(
-         (mDisplayType == kWaveform) ?
-            WaveTrackViewConstants::Waveform
-            : WaveTrackViewConstants::Spectrum
-         );
+         WaveTrackSubView::AllTypes()[ mDisplayType ].id );
    if( wt && bHasScaleType )
       wt->GetIndependentWaveformSettings().scaleType = 
          (mScaleType==kLinear) ? 

src/tracks/playabletrack/wavetrack/ui/SpectrumView.cpp

@@ -30,6 +30,11 @@ Paul Licameli split from WaveTrackView.cpp
 #include <wx/dcmemory.h>
 #include <wx/graphics.h>
 
+static WaveTrackSubView::RegisteredType reg{ {
+   WaveTrackViewConstants::Spectrum,
+   { wxT("Spectrogram"), XO("&Spectrogram") }
+} };
+
 SpectrumView::~SpectrumView() = default;
 
 bool SpectrumView::IsSpectral() const

src/tracks/playabletrack/wavetrack/ui/WaveTrackControls.cpp

@@ -104,6 +104,8 @@ std::vector<UIHandlePtr> WaveTrackControls::HitTest
 }
 
 enum {
+   reserveDisplays = 100,
+
    OnRate8ID = 30000,      // <---
    OnRate11ID,             //    |
    OnRate16ID,             //    |
@@ -123,8 +125,9 @@ enum {
    OnFloatID,              // <---
 
    OnMultiViewID,
-   OnWaveformID,
-   OnSpectrumID,
+
+   OnSetDisplayId, lastDisplayId = (OnSetDisplayId + reserveDisplays - 1),
+
    OnSpectrogramSettingsID,
 
    OnChannelLeftID,
@@ -620,6 +623,16 @@ void WaveTrackMenuTable::InitUserData(void *pUserData)
    mpData = static_cast<PlayableTrackControls::InitMenuData*>(pUserData);
 }
 
+static WaveTrackSubView::Types AllTypes()
+{
+   auto result = WaveTrackSubView::AllTypes();
+   if ( result.size() > reserveDisplays ) {
+      wxASSERT( false );
+      result.resize( reserveDisplays );
+   }
+   return result;
+}
+
 void WaveTrackMenuTable::InitMenu(Menu *pMenu)
 {
    WaveTrack *const pTrack = static_cast<WaveTrack*>(mpData->pTrack);
@@ -631,16 +644,40 @@ void WaveTrackMenuTable::InitMenu(Menu *pMenu)
    if (multiView)
       checkedIds.push_back( OnMultiViewID );
 
+   bool hasSpectrum = false;
    int uniqueDisplay = 0;
+   {
+      // Find the set of type ids of the shown displays, disregarding their
+      // top-to-bottom arrangement
+      auto displays = view.GetDisplays();
+      const auto end = displays.end();
+      auto iter = displays.begin();
+      std::sort( iter, end );
 
-   const auto displays = view.GetDisplays();
-   for ( auto display : displays ) {
-      auto id = (display == WaveTrackViewConstants::Waveform)
-         ? OnWaveformID
-         : OnSpectrumID;
-      checkedIds.push_back( id );
-      if ( displays.size() == 1 )
-         uniqueDisplay = id;
+      // Check the corresponding menu items, and decide which if any has
+      // the unique check
+      int displayId = OnSetDisplayId;
+      int nDisplays = 0;
+      for ( const auto &type : AllTypes() ) {
+         if ( iter != end && *iter == type.id ) {
+            checkedIds.push_back( displayId );
+            uniqueDisplay = displayId;
+            ++iter;
+            ++nDisplays;
+
+            // Unfortunately this special knowledge of the Spectrum view type
+            // remains.  In future, either let a registry system insert this
+            // menu item, or (better) move it to the context menu of the
+            // Spectrum vertical ruler.
+            // (But the latter won't be satisfactory without a means to
+            // open that other context menu with keystrokes only, and that
+            // would require some notion of a focused sub-view.)
+            hasSpectrum = ( type.id == WaveTrackViewConstants::Spectrum );
+         }
+         ++displayId;
+      }
+      if ( nDisplays > 1 )
+         uniqueDisplay = 0;
    }
 
    if ( multiView && uniqueDisplay )
@@ -652,9 +689,6 @@ void WaveTrackMenuTable::InitMenu(Menu *pMenu)
    // We can't change them on the fly yet anyway.
    auto gAudioIO = AudioIOBase::Get();
    const bool bAudioBusy = gAudioIO->IsBusy();
-   bool hasSpectrum =
-      make_iterator_range( displays.begin(), displays.end() )
-         .contains( WaveTrackViewConstants::Spectrum );
    pMenu->Enable(OnSpectrogramSettingsID, hasSpectrum && !bAudioBusy);
 
    AudacityProject *const project = &mpData->project;
@@ -733,13 +767,14 @@ BEGIN_POPUP_MENU(WaveTrackMenuTable)
    if ( WaveTrackSubViews::slots() > 1 )
       POPUP_MENU_CHECK_ITEM(OnMultiViewID, XO("&Multi-view"), OnMultiView)
 
-   if ( view.GetMultiView() ) {
-      POPUP_MENU_CHECK_ITEM(OnWaveformID, XO("Wa&veform"), OnSetDisplay)
-      POPUP_MENU_CHECK_ITEM(OnSpectrumID, XO("&Spectrogram"), OnSetDisplay)
-   }
-   else {
-      POPUP_MENU_RADIO_ITEM(OnWaveformID, XO("Wa&veform"), OnSetDisplay)
-      POPUP_MENU_RADIO_ITEM(OnSpectrumID, XO("&Spectrogram"), OnSetDisplay)
+   int id = OnSetDisplayId;
+   for ( const auto &type : AllTypes() ) {
+      if ( view.GetMultiView() ) {
+         POPUP_MENU_CHECK_ITEM(id++, type.name.Msgid(), OnSetDisplay)
+      }
+      else {
+         POPUP_MENU_RADIO_ITEM(id++, type.name.Msgid(), OnSetDisplay)
+      }
    }
 
    POPUP_MENU_ITEM(OnSpectrogramSettingsID, XO("S&pectrogram Settings..."), OnSpectrogramSettings)
@@ -799,19 +834,12 @@ void WaveTrackMenuTable::OnMultiView(wxCommandEvent & event)
 ///  Set the Display mode based on the menu choice in the Track Menu.
 void WaveTrackMenuTable::OnSetDisplay(wxCommandEvent & event)
 {
-   using namespace WaveTrackViewConstants;
    int idInt = event.GetId();
-   wxASSERT(idInt >= OnWaveformID && idInt <= OnSpectrumID);
+   wxASSERT(idInt >= OnSetDisplayId &&
+            idInt <= lastDisplayId);
    const auto pTrack = static_cast<WaveTrack*>(mpData->pTrack);
 
-   WaveTrackView::Display id;
-   switch (idInt) {
-   default:
-   case OnWaveformID:
-      id = Waveform; break;
-   case OnSpectrumID:
-      id = Spectrum; break;
-   }
+   auto id = AllTypes()[ idInt - OnSetDisplayId ].id;
 
    auto &view = WaveTrackView::Get( *pTrack );
    if ( view.GetMultiView() ) {
@@ -887,7 +915,7 @@ void WaveTrackMenuTable::OnSpectrogramSettings(wxCommandEvent &)
    // factories.push_back(WaveformPrefsFactory( pTrack ));
    factories.push_back(SpectrumPrefsFactory( pTrack ));
    const int page =
-      // (pTrack->GetDisplay() == WaveTrack::Spectrum) ? 1 :
+      // (pTrack->GetDisplay() == WaveTrackViewConstants::Spectrum) ? 1 :
       0;
 
    auto title = XO("%s:").Format( pTrack->GetName() );

src/tracks/playabletrack/wavetrack/ui/WaveTrackView.cpp

@@ -40,6 +40,53 @@ Paul Licameli split from TrackPanel.cpp
 #include "../../../ui/ButtonHandle.h"
 #include "../../../../TrackInfo.h"
 
+namespace {
+   class Registry {
+   public:
+      using Type = WaveTrackSubView::Type;
+      using Types = std::vector< Type >;
+
+      void Append( Type type )
+      {
+         types.emplace_back( std::move( type ) );
+         sorted = false;
+      }
+
+      Types &Get()
+      {
+         if ( !sorted ) {
+            auto begin = types.begin(), end = types.end();
+            std::sort( begin, end );
+            // We don't want duplicate ids!
+            wxASSERT( end == std::adjacent_find( begin, end ) );
+            sorted = true;
+         }
+         return types;
+      }
+
+   private:
+      Types types;
+      bool sorted = false;
+   };
+
+   Registry &GetRegistry()
+   {
+      static Registry result;
+      return result;
+   }
+}
+
+WaveTrackSubView::RegisteredType::RegisteredType( Type type )
+{
+   GetRegistry().Append( std::move( type ) );
+}
+
+// static
+auto WaveTrackSubView::AllTypes() -> const Types &
+{
+   return GetRegistry().Get();
+}
+
 namespace {
 
 using WaveTrackSubViewPtrs = std::vector< std::shared_ptr< WaveTrackSubView > >;

src/tracks/playabletrack/wavetrack/ui/WaveTrackView.h

@@ -13,16 +13,39 @@ Paul Licameli split from class WaveTrack
 
 #include "../../../ui/CommonTrackView.h"
 #include "../../../../ClientData.h"
+#include "audacity/ComponentInterface.h"
 namespace WaveTrackViewConstants{ enum Display : int; }
 
 class CutlineHandle;
+class TranslatableString;
 class WaveTrack;
 class WaveTrackView;
 
 class WaveTrackSubView : public CommonTrackView
 {
 public:
+
    using Display = WaveTrackViewConstants::Display;
+   struct Type {
+      // Identifies the type session-wide, and determines relative position in
+      // menus listing all types
+      Display id;
+      // The translation is suitable for the track control panel drop-down,
+      // and it may contain a menu accelerator
+      EnumValueSymbol name;
+
+      bool operator < ( const Type &other ) const { return id < other.id; }
+      bool operator == ( const Type &other ) const { return id == other.id; }
+   };
+   using Types = std::vector< Type >;
+
+   // Typically a file scope statically constructed object
+   struct RegisteredType {
+      RegisteredType( Type type );
+   };
+
+   // Discover all registered types
+   static const Types &AllTypes();
 
    explicit
    WaveTrackSubView( WaveTrackView &waveTrackView );

src/tracks/playabletrack/wavetrack/ui/WaveformView.cpp

@@ -36,6 +36,11 @@ Paul Licameli split from WaveTrackView.cpp
 #include <wx/graphics.h>
 #include <wx/dc.h>
 
+static WaveTrackSubView::RegisteredType reg{ {
+   WaveTrackViewConstants::Waveform,
+   { wxT("Waveform"), XO("Wa&veform") }
+} };
+
 WaveformView::~WaveformView() = default;
 
 std::vector<UIHandlePtr> WaveformView::DetailedHitTest(