Wave track view type stored in the views not the tracks...

... and some latent support added for multiple views.

Still unsettled is what Nyquist should do with tracks with multiple view types;
for now only pass one of them.

src/WaveTrack.cpp

@@ -97,15 +97,6 @@ WaveTrack::WaveTrack(const std::shared_ptr<DirManager> &projDirManager, sampleFo
       }
    }
 
-   // Force creation always:
-   WaveformSettings &settings = GetIndependentWaveformSettings();
-
-   mDisplay = TracksPrefs::ViewModeChoice();
-   if (mDisplay == WaveTrackViewConstants::obsoleteWaveformDBDisplay) {
-      mDisplay = WaveTrackViewConstants::Waveform;
-      settings.scaleType = WaveformSettings::stLogarithmic;
-   }
-
    mLegacyProjectFileOffset = 0;
 
    mFormat = format;
@@ -161,7 +152,6 @@ void WaveTrack::Init(const WaveTrack &orig)
    mOldGain[1] = 0.0;
    SetDefaultName(orig.GetDefaultName());
    SetName(orig.GetName());
-   mDisplay = orig.mDisplay;
    mDisplayMin = orig.mDisplayMin;
    mDisplayMax = orig.mDisplayMax;
    mSpectrumMin = orig.mSpectrumMin;
@@ -196,7 +186,6 @@ void WaveTrack::Merge(const Track &orig)
 {
    orig.TypeSwitch( [&](const WaveTrack *pwt) {
       const WaveTrack &wt = *pwt;
-      mDisplay = wt.mDisplay;
       mGain    = wt.mGain;
       mPan     = wt.mPan;
       mDisplayMin = wt.mDisplayMin;

src/WaveTrack.h

@@ -17,7 +17,6 @@
 #include <wx/longlong.h>
 
 #include "WaveTrackLocation.h"
-#include "tracks/playabletrack/wavetrack/ui/WaveTrackViewConstants.h"
 
 class ProgressDialog;
 
@@ -523,17 +522,12 @@ private:
    // Set the unique autosave ID
    void SetAutoSaveIdent(int id);
 
-   using WaveTrackDisplay = WaveTrackViewConstants::Display;
-
    int GetLastScaleType() const { return mLastScaleType; }
    void SetLastScaleType() const;
 
    int GetLastdBRange() const { return mLastdBRange; }
    void SetLastdBRange() const;
 
-   WaveTrackDisplay GetDisplay() const { return mDisplay; }
-   void SetDisplay(WaveTrackDisplay display) { mDisplay = display; }
-
    void GetDisplayBounds(float *min, float *max) const;
    void SetDisplayBounds(float min, float max) const;
    void GetSpectrumBounds(float *min, float *max) const;
@@ -568,7 +562,6 @@ private:
    mutable float         mSpectrumMin;
    mutable float         mSpectrumMax;
 
-   WaveTrackDisplay mDisplay;
    mutable int   mLastScaleType; // last scale type choice
    mutable int           mLastdBRange;
    mutable std::vector <Location> mDisplayLocationsCache;

src/commands/SetTrackInfoCommand.cpp

@@ -44,7 +44,8 @@ SetTrackAudioCommand and SetTrackVisualsCommand.
 #include "../prefs/SpectrogramSettings.h"
 #include "../Shuttle.h"
 #include "../ShuttleGui.h"
-#include "../tracks/ui/TrackView.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackView.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackViewConstants.h"
 #include "CommandContext.h"
 
 SetTrackBase::SetTrackBase(){
@@ -353,7 +354,7 @@ bool SetTrackVisualsCommand::ApplyInner(const CommandContext & context, Track *
       TrackView::Get( *t ).SetHeight( mHeight );
 
    if( wt && bHasDisplayType  )
-      wt->SetDisplay(
+      WaveTrackView::Get( *wt ).SetDisplay(
          (mDisplayType == kWaveform) ?
             WaveTrackViewConstants::Waveform
             : WaveTrackViewConstants::Spectrum

src/effects/Effect.cpp

@@ -68,6 +68,8 @@ greater use in future.
 #include "../widgets/ProgressDialog.h"
 #include "../ondemand/ODManager.h"
 #include "TimeWarper.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackView.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackViewConstants.h"
 #include "../widgets/HelpSystem.h"
 #include "../widgets/NumericTextCtrl.h"
 #include "../widgets/AudacityMessageBox.h"
@@ -2360,7 +2362,8 @@ void Effect::Preview(bool dryOnly)
 
       mixLeft->Offset(-mixLeft->GetStartTime());
       mixLeft->SetSelected(true);
-      mixLeft->SetDisplay(WaveTrackViewConstants::NoDisplay);
+      WaveTrackView::Get( *mixLeft )
+         .SetDisplay(WaveTrackViewConstants::NoDisplay);
       auto pLeft = mTracks->Add( mixLeft );
       Track *pRight{};
       if (mixRight) {
@@ -2375,8 +2378,8 @@ void Effect::Preview(bool dryOnly)
          if (src->GetSelected() || mPreviewWithNotSelected) {
             auto dest = src->Copy(mT0, t1);
             dest->SetSelected(src->GetSelected());
-            static_cast<WaveTrack*>(dest.get())
+            WaveTrackView::Get( *static_cast<WaveTrack*>(dest.get()) )
-               ->SetDisplay(WaveTrackViewConstants::NoDisplay);
+               .SetDisplay(WaveTrackViewConstants::NoDisplay);
             mTracks->Add( dest );
          }
       }

src/effects/nyquist/Nyquist.cpp

@@ -73,6 +73,8 @@ effects from this one class.
 #include "../../wxFileNameWrapper.h"
 #include "../../prefs/GUIPrefs.h"
 #include "../../prefs/WaveformSettings.h"
+#include "../../tracks/playabletrack/wavetrack/ui/WaveTrackView.h"
+#include "../../tracks/playabletrack/wavetrack/ui/WaveTrackViewConstants.h"
 #include "../../widgets/NumericTextCtrl.h"
 #include "../../widgets/ProgressDialog.h"
 
@@ -542,7 +544,11 @@ bool NyquistEffect::Init()
 
       for ( auto t :
                TrackList::Get( *project ).Selected< const WaveTrack >() ) {
-         if (t->GetDisplay() != WaveTrackViewConstants::Spectrum ||
+         const auto displays = WaveTrackView::Get(*t).GetDisplays();
+         bool hasSpectral =
+            make_iterator_range( displays.begin(), displays.end())
+               .contains( WaveTrackViewConstants::Spectrum );
+         if ( !hasSpectral ||
              !(t->GetSpectrogramSettings().SpectralSelectionEnabled())) {
             bAllowSpectralEditing = false;
             break;
@@ -1066,7 +1072,12 @@ bool NyquistEffect::ProcessOne()
          [&](const WaveTrack *wt) {
             type = wxT("wave");
             spectralEditp = mCurTrack[0]->GetSpectrogramSettings().SpectralSelectionEnabled()? wxT("T") : wxT("NIL");
-            switch (wt->GetDisplay())
+            // To do: accommodate split views
+            auto viewType = WaveTrackViewConstants::NoDisplay;
+            auto displays = WaveTrackView::Get( *wt ).GetDisplays();
+            if (!displays.empty())
+               viewType = displays[0];
+            switch ( viewType )
             {
             case Waveform:
                view = (mCurTrack[0]->GetWaveformSettings().scaleType == 0) ? wxT("\"Waveform\"") : wxT("\"Waveform (dB)\"");

src/menus/SelectMenus.cpp

@@ -21,6 +21,8 @@
 #include "../commands/CommandManager.h"
 #include "../toolbars/ControlToolBar.h"
 #include "../tracks/ui/SelectHandle.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackView.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackViewConstants.h"
 
 // private helper classes and functions
 namespace {
@@ -33,8 +35,9 @@ void DoNextPeakFrequency(AudacityProject &project, bool up)
    // Find the first selected wave track that is in a spectrogram view.
    const WaveTrack *pTrack {};
    for ( auto wt : tracks.Selected< const WaveTrack >() ) {
-      const int display = wt->GetDisplay();
+      const auto displays = WaveTrackView::Get( *wt ).GetDisplays();
-      if (display == WaveTrackViewConstants::Spectrum) {
+      if ( make_iterator_range( displays.begin(), displays.end() )
+         .contains( WaveTrackViewConstants::Spectrum) ) {
          pTrack = wt;
          break;
       }

src/prefs/SpectrumPrefs.cpp

@@ -31,6 +31,7 @@
 
 #include "../TrackPanel.h"
 #include "../WaveTrack.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackView.h"
 
 #include <algorithm>
 
@@ -48,7 +49,7 @@ SpectrumPrefs::SpectrumPrefs(wxWindow * parent, wxWindowID winid, WaveTrack *wt)
       wt->GetSpectrumBounds(&mOrigMin, &mOrigMax);
       mTempSettings.maxFreq = mOrigMax;
       mTempSettings.minFreq = mOrigMin;
-      mOrigDisplay = mWt->GetDisplay();
+      mOrigPlacements = WaveTrackView::Get( *mWt ).SavePlacements();
    }
    else  {
       mTempSettings = mOrigSettings = SpectrogramSettings::defaults();
@@ -423,7 +424,7 @@ void SpectrumPrefs::Rollback()
    if (mWt && isOpenPage) {
       auto channels = TrackList::Channels(mWt);
       for (auto channel : channels)
-         channel->SetDisplay(mOrigDisplay);
+         WaveTrackView::Get( *channel ).RestorePlacements( mOrigPlacements );
    }
 
    if (isOpenPage) {
@@ -470,7 +471,8 @@ void SpectrumPrefs::Preview()
 
    if (mWt && isOpenPage) {
       for (auto channel : TrackList::Channels(mWt))
-         channel->SetDisplay(WaveTrackViewConstants::Spectrum);
+         WaveTrackView::Get( *channel )
+            .SetDisplay( WaveTrackViewConstants::Spectrum );
    }
 
    if (isOpenPage) {

src/prefs/SpectrumPrefs.h

@@ -23,6 +23,7 @@
 
 #include "../Experimental.h"
 
+#include <vector>
 #include <wx/defs.h>
 
 #include "../tracks/playabletrack/wavetrack/ui/WaveTrackViewConstants.h"
@@ -38,6 +39,7 @@ struct FFTParam;
 class ShuttleGui;
 class SpectrogramSettings;
 class WaveTrack;
+struct WaveTrackSubViewPlacement;
 
 #define SPECTRUM_PREFS_PLUGIN_SYMBOL ComponentInterfaceSymbol{ XO("Spectrum") }
 
@@ -98,7 +100,7 @@ class SpectrumPrefs final : public PrefsPanel
 
    SpectrogramSettings mTempSettings, mOrigSettings;
 
-   WaveTrackViewConstants::Display mOrigDisplay;
+   std::vector<WaveTrackSubViewPlacement> mOrigPlacements;
    float mOrigMin, mOrigMax;
 
    bool mPopulating;

src/prefs/WaveformPrefs.cpp

@@ -27,6 +27,8 @@ Paul Licameli
 #include "../TrackPanel.h"
 #include "../ShuttleGui.h"
 #include "../WaveTrack.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackView.h"
+#include "../tracks/playabletrack/wavetrack/ui/WaveTrackViewConstants.h"
 
 WaveformPrefs::WaveformPrefs(wxWindow * parent, wxWindowID winid, WaveTrack *wt)
 /* i18n-hint: A waveform is a visual representation of vibration */
@@ -184,7 +186,8 @@ bool WaveformPrefs::Commit()
 
    if (mWt && isOpenPage) {
       for (auto channel : TrackList::Channels(mWt))
-         channel->SetDisplay(WaveTrackViewConstants::Waveform);
+         WaveTrackView::Get( *channel )
+            .SetDisplay( WaveTrackViewConstants::Waveform );
    }
 
    if (isOpenPage) {

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

@@ -120,10 +120,6 @@ UIHandlePtr SampleHandle::HitTest
    /// editable sample
    const auto wavetrack = pTrack.get();
 
-   const int displayType = wavetrack->GetDisplay();
-   if (WaveTrackViewConstants::Waveform != displayType)
-      return {};  // Not a wave, so return.
-
    const double tt =
       adjustTime(wavetrack, viewInfo.PositionToTime(state.m_x, rect.x));
    if (!SampleResolutionTest(viewInfo, wavetrack, tt, rect.width))
@@ -178,17 +174,6 @@ namespace {
       (const wxMouseEvent &event,
        const wxRect &rect, const ViewInfo &viewInfo, WaveTrack *wt, int width)
    {
-      //Get out of here if we shouldn't be drawing right now:
-      //If we aren't displaying the waveform, Display a message dialog
-      const int display = wt->GetDisplay();
-      if (WaveTrackViewConstants::Waveform != display)
-      {
-         AudacityMessageBox(_(
-"To use Draw, choose 'Waveform' or 'Waveform (dB)' in the Track Dropdown Menu."),
-                      _("Draw Tool"));
-         return false;
-      }
-
       //If we aren't zoomed in far enough, show a message dialog.
       const double time = adjustTime(wt, viewInfo.PositionToTime(event.m_x, rect.x));
       if (!SampleResolutionTest(viewInfo, wt, time, width))

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

@@ -15,6 +15,7 @@ Paul Licameli split from WaveTrackView.cpp
 
 #include "SpectrumVRulerControls.h"
 #include "WaveTrackView.h"
+#include "WaveTrackViewConstants.h"
 
 #include "../../../../AColor.h"
 #include "../../../../Prefs.h"
@@ -31,6 +32,11 @@ Paul Licameli split from WaveTrackView.cpp
 
 SpectrumView::~SpectrumView() = default;
 
+bool SpectrumView::IsSpectral() const
+{
+   return true;
+}
+
 std::vector<UIHandlePtr> SpectrumView::DetailedHitTest(
    const TrackPanelMouseState &state,
    const AudacityProject *pProject, int currentTool, bool bMultiTool )

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

@@ -28,6 +28,7 @@ public:
 
    std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 
+   bool IsSpectral() const override;
 
 private:
    // TrackPanelDrawable implementation

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

@@ -16,7 +16,7 @@ Paul Licameli split from TrackPanel.cpp
 #include "../../ui/PlayableTrackButtonHandles.h"
 #include "WaveTrackSliderHandles.h"
 
-#include "../../../ui/TrackView.h"
+#include "WaveTrackView.h"
 #include "../../../../AudioIOBase.h"
 #include "../../../../CellularPanel.h"
 #include "../../../../Menus.h"
@@ -599,19 +599,23 @@ void WaveTrackMenuTable::InitMenu(Menu *pMenu, void *pUserData)
 
    std::vector<int> checkedIds;
 
-   const int display = pTrack->GetDisplay();
+   const auto displays = WaveTrackView::Get( *pTrack ).GetDisplays();
-   checkedIds.push_back(
+   for ( auto display : displays ) {
-      display == WaveTrackViewConstants::Waveform
+      checkedIds.push_back(
-         ? (pTrack->GetWaveformSettings().isLinear()
+         display == WaveTrackViewConstants::Waveform
-            ? OnWaveformID : OnWaveformDBID)
+            ? (pTrack->GetWaveformSettings().isLinear()
-         : OnSpectrumID);
+               ? OnWaveformID : OnWaveformDBID)
+            : OnSpectrumID);
+   }
 
    // Bug 1253.  Shouldn't open preferences if audio is busy.
    // We can't change them on the fly yet anyway.
    auto gAudioIO = AudioIOBase::Get();
    const bool bAudioBusy = gAudioIO->IsBusy();
-   pMenu->Enable(OnSpectrogramSettingsID,
+   bool hasSpectrum =
-      (display == WaveTrackViewConstants::Spectrum) && !bAudioBusy);
+      make_iterator_range( displays.begin(), displays.end() )
+         .contains( WaveTrackViewConstants::Spectrum );
+   pMenu->Enable(OnSpectrogramSettingsID, hasSpectrum && !bAudioBusy);
 
    AudacityProject *const project = ::GetActiveProject();
    auto &tracks = TrackList::Get( *project );
@@ -683,9 +687,9 @@ void WaveTrackMenuTable::InitMenu(Menu *pMenu, void *pUserData)
 BEGIN_POPUP_MENU(WaveTrackMenuTable)
    POPUP_MENU_SEPARATOR()
 
-   POPUP_MENU_RADIO_ITEM(OnWaveformID, _("Wa&veform"), OnSetDisplay)
+   POPUP_MENU_CHECK_ITEM(OnWaveformID, _("Wa&veform"), OnSetDisplay)
-   POPUP_MENU_RADIO_ITEM(OnWaveformDBID, _("&Waveform (dB)"), OnSetDisplay)
+   POPUP_MENU_CHECK_ITEM(OnWaveformDBID, _("&Waveform (dB)"), OnSetDisplay)
-   POPUP_MENU_RADIO_ITEM(OnSpectrumID, _("&Spectrogram"), OnSetDisplay)
+   POPUP_MENU_CHECK_ITEM(OnSpectrumID, _("&Spectrogram"), OnSetDisplay)
    POPUP_MENU_ITEM(OnSpectrogramSettingsID, _("S&pectrogram Settings..."), OnSpectrogramSettings)
    POPUP_MENU_SEPARATOR()
 
@@ -702,9 +706,15 @@ BEGIN_POPUP_MENU(WaveTrackMenuTable)
 #endif
 
    WaveTrack *const pTrack = static_cast<WaveTrack*>(mpTrack);
-   if( pTrack && pTrack->GetDisplay() != WaveTrackViewConstants::Spectrum  ){
+   if ( pTrack ) {
-      POPUP_MENU_SEPARATOR()
+      const auto displays = WaveTrackView::Get( *pTrack ).GetDisplays();
-      POPUP_MENU_SUB_MENU(OnWaveColorID, _("&Wave Color"), WaveColorMenuTable)
+      bool hasWaveform =
+         make_iterator_range( displays.begin(), displays.end() )
+            .contains( WaveTrackViewConstants::Waveform );
+      if( hasWaveform ){
+         POPUP_MENU_SEPARATOR()
+         POPUP_MENU_SUB_MENU(OnWaveColorID, _("&Wave Color"), WaveColorMenuTable)
+      }
    }
 
    POPUP_MENU_SEPARATOR()
@@ -723,7 +733,7 @@ void WaveTrackMenuTable::OnSetDisplay(wxCommandEvent & event)
    const auto pTrack = static_cast<WaveTrack*>(mpData->pTrack);
 
    bool linear = false;
-   WaveTrack::WaveTrackDisplay id;
+   WaveTrackView::WaveTrackDisplay id;
    switch (idInt) {
    default:
    case OnWaveformID:
@@ -734,14 +744,16 @@ void WaveTrackMenuTable::OnSetDisplay(wxCommandEvent & event)
       id = Spectrum; break;
    }
 
-   const bool wrongType = pTrack->GetDisplay() != id;
+   const auto displays = WaveTrackView::Get( *pTrack ).GetDisplays();
+   const bool wrongType = !(displays.size() == 1 && displays[0] == id);
    const bool wrongScale =
       (id == Waveform &&
       pTrack->GetWaveformSettings().isLinear() != linear);
    if (wrongType || wrongScale) {
       for (auto channel : TrackList::Channels(pTrack)) {
          channel->SetLastScaleType();
-         channel->SetDisplay(WaveTrack::WaveTrackDisplay(id));
+         WaveTrackView::Get( *channel )
+            .SetDisplay(WaveTrackView::WaveTrackDisplay(id));
          if (wrongScale)
             channel->GetIndependentWaveformSettings().scaleType = linear
                ? WaveformSettings::stLinear
@@ -876,8 +888,8 @@ void WaveTrackMenuTable::OnMergeStereo(wxCommandEvent &)
 
    // Set NEW track heights and minimized state
    auto
-      &view = TrackView::Get( *pTrack ),
+      &view = WaveTrackView::Get( *pTrack ),
-      &partnerView = TrackView::Get( *partner );
+      &partnerView = WaveTrackView::Get( *partner );
    view.SetMinimized(false);
    partnerView.SetMinimized(false);
    int AverageHeight = (view.GetHeight() + partnerView.GetHeight()) / 2;
@@ -886,6 +898,8 @@ void WaveTrackMenuTable::OnMergeStereo(wxCommandEvent &)
    view.SetMinimized(bBothMinimizedp);
    partnerView.SetMinimized(bBothMinimizedp);
 
+   partnerView.RestorePlacements( view.SavePlacements() );
+
    //On Demand - join the queues together.
    if (ODManager::IsInstanceCreated())
       if (!ODManager::Instance()

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

@@ -22,19 +22,57 @@ Paul Licameli split from TrackPanel.cpp
 #include "../../../../TrackPanelMouseEvent.h"
 #include "../../../../ViewInfo.h"
 #include "../../../../prefs/SpectrogramSettings.h"
+#include "../../../../prefs/WaveformSettings.h"
+#include "../../../../prefs/TracksPrefs.h"
 
 #include "../../../ui/TimeShiftHandle.h"
 
+WaveTrackView &WaveTrackView::Get( WaveTrack &track )
+{
+   return static_cast< WaveTrackView& >( TrackView::Get( track ) );
+}
+
+const WaveTrackView &WaveTrackView::Get( const WaveTrack &track )
+{
+   return Get( const_cast<WaveTrack&>( track ) );
+}
+
 WaveTrackView::WaveTrackView( const std::shared_ptr<Track> &pTrack )
    : CommonTrackView{ pTrack }
 {
    WaveTrackSubViews::BuildAll();
+
+   auto display = TracksPrefs::ViewModeChoice();
+
+   // Force creation always:
+   WaveformSettings &settings = static_cast< WaveTrack* >( pTrack.get() )
+      ->GetIndependentWaveformSettings();
+
+   if (display == WaveTrackViewConstants::obsoleteWaveformDBDisplay) {
+      display = WaveTrackViewConstants::Waveform;
+      settings.scaleType = WaveformSettings::stLogarithmic;
+   }
+
+   mPlacements.resize( WaveTrackSubViews::size() );
+
+   SetDisplay( display );
 }
 
 WaveTrackView::~WaveTrackView()
 {
 }
 
+void WaveTrackView::CopyTo( Track &track ) const
+{
+   TrackView::CopyTo( track );
+   auto &other = TrackView::Get( track );
+
+   if ( const auto pOther = dynamic_cast< WaveTrackView* >( &other ) ) {
+      // only one field is important to preserve in undo/redo history
+      pOther->RestorePlacements( SavePlacements() );
+   }
+}
+
 std::vector<UIHandlePtr> WaveTrackView::DetailedHitTest
 (const TrackPanelMouseState &st,
  const AudacityProject *pProject, int currentTool, bool bMultiTool)
@@ -75,23 +113,72 @@ WaveTrackView::DoDetailedHitTest
    return { false, results };
 }
 
-auto WaveTrackView::GetSubViews( const wxRect &rect ) -> Refinement
+auto WaveTrackView::GetDisplays() const -> std::vector<WaveTrackDisplay>
 {
-   auto wt = static_cast<WaveTrack*>( FindTrack().get() );
+   // Collect the display types of visible views and sort them by position
-   auto display = wt->GetDisplay();
+   using Pair = std::pair< int, WaveTrackDisplay >;
-   std::shared_ptr<TrackView> pSubView;
+   std::vector< Pair > pairs;
+   size_t ii = 0;
+   WaveTrackSubViews::ForEach( [&]( const WaveTrackSubView &subView ){
+      auto &placement = mPlacements[ii];
+      if ( placement.fraction > 0 )
+         pairs.emplace_back( placement.index, subView.SubViewType() );
+      ++ii;
+   } );
+   std::sort( pairs.begin(), pairs.end() );
+   std::vector<WaveTrackDisplay> results;
+   for ( const auto &pair : pairs )
+      results.push_back( pair.second );
+   return results;
+}
+
+void WaveTrackView::SetDisplay(WaveTrackDisplay display)
+{
+   size_t ii = 0;
    WaveTrackSubViews::ForEach( [&,display]( WaveTrackSubView &subView ){
       if ( subView.SubViewType() == display )
-         pSubView = subView.shared_from_this();
+         mPlacements[ii] = {  0, 1.0 };
+      else
+         mPlacements[ii] = { -1, 0.0 };
+      ++ii;
    } );
-   if ( !pSubView )
+}
-      return {};
+
-   return {
+auto WaveTrackView::GetSubViews( const wxRect &rect ) -> Refinement
-      {
+{
-         rect.GetTop(),
+   // Collect the visible views
-         pSubView
+   using Pair = std::pair< float, std::shared_ptr< TrackView > >;
-      }
+   std::vector< Pair > pairs( mPlacements.size() );
-   };
+   size_t ii = 0;
+   float total = 0;
+   WaveTrackSubViews::ForEach( [&]( WaveTrackSubView &subView ){
+      const auto &placement = mPlacements[ii];
+      auto index = placement.index;
+      auto fraction = placement.fraction;
+      if ( index >= 0 && fraction > 0.0 )
+         total += fraction,
+         pairs[ index ] = { fraction, subView.shared_from_this() };
+      ++ii;
+   } );
+
+   // Remove views we don't need
+   auto begin = pairs.begin(), end = pairs.end(),
+     newEnd = std::remove_if( begin, end,
+        []( const Pair &item ){ return !item.second; } );
+   pairs.erase( newEnd, end );
+
+   // Assign coordinates
+   Refinement results;
+   results.reserve( pairs.size() );
+   float partial = 0;
+   const auto top = rect.GetTop();
+   const auto height = rect.GetHeight();
+   for ( const auto &pair : pairs ) {
+      results.emplace_back( top + (partial / total) * height, pair.second );
+      partial += pair.first;
+   }
+
+   return results;
 }
 
 void WaveTrackView::DoSetMinimized( bool minimized )

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

@@ -24,6 +24,12 @@ public:
    virtual WaveTrackViewConstants::Display SubViewType() const = 0;
 };
 
+struct WaveTrackSubViewPlacement {
+   int index;
+   float fraction;
+};
+using WaveTrackSubViewPlacements = std::vector< WaveTrackSubViewPlacement >;
+
 class WaveTrackView;
 using WaveTrackSubViews = ClientData::Site<
    WaveTrackView, WaveTrackSubView, ClientData::SkipCopying, std::shared_ptr
@@ -37,10 +43,16 @@ class WaveTrackView final
    WaveTrackView &operator=( const WaveTrackView& ) = delete;
 
 public:
+   static WaveTrackView &Get( WaveTrack &track );
+   static const WaveTrackView &Get( const WaveTrack &track );
+
    explicit
    WaveTrackView( const std::shared_ptr<Track> &pTrack );
    ~WaveTrackView() override;
 
+   // Preserve some view state too for undo/redo purposes
+   void CopyTo( Track &track ) const override;
+
    std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 
    // CommonTrackView implementation
@@ -55,6 +67,16 @@ public:
       const std::shared_ptr<WaveTrack> &wt,
       CommonTrackView &view);
 
+   using WaveTrackDisplay = WaveTrackViewConstants::Display;
+
+   std::vector<WaveTrackDisplay> GetDisplays() const;
+   void SetDisplay(WaveTrackDisplay display);
+
+   const WaveTrackSubViewPlacements &SavePlacements() const
+      { return mPlacements; }
+   void RestorePlacements( const WaveTrackSubViewPlacements &placements )
+      { mPlacements = placements; }
+
 private:
    // TrackPanelDrawable implementation
    void Draw(
@@ -71,6 +93,8 @@ private:
 
 protected:
    void DoSetMinimized( bool minimized ) override;
+
+   WaveTrackSubViewPlacements mPlacements;
 };
 
 // Helper for drawing routines

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

@@ -15,6 +15,7 @@ Paul Licameli split from WaveTrackView.cpp
 
 #include "WaveformVRulerControls.h"
 #include "WaveTrackView.h"
+#include "WaveTrackViewConstants.h"
 
 #include "CutlineHandle.h"
 #include "SampleHandle.h"

src/tracks/ui/CommonTrackView.cpp

@@ -73,7 +73,7 @@ std::vector<UIHandlePtr> CommonTrackView::HitTest
    // Finally, default of all is adjustment of the selection box.
    if ( isMultiTool || currentTool == selectTool ) {
       result = SelectHandle::HitTest(
-         mSelectHandle, st, pProject, FindTrack() );
+         mSelectHandle, st, pProject, shared_from_this() );
       if (result)
          results.push_back(result);
    }

src/tracks/ui/EnvelopeHandle.cpp

@@ -98,12 +98,6 @@ UIHandlePtr EnvelopeHandle::WaveTrackHitTest
    if (!envelope)
       return {};
 
-   const int displayType = wt->GetDisplay();
-   // Not an envelope hit, unless we're using a type of wavetrack display
-   // suitable for envelopes operations, ie one of the Wave displays.
-   if (displayType != WaveTrackViewConstants::Waveform)
-      return {};  // No envelope, not a hit, so return.
-
    // Get envelope point, range 0.0 to 1.0
    const bool dB = !wt->GetWaveformSettings().isLinear();
 
@@ -188,9 +182,6 @@ UIHandle::Result EnvelopeHandle::Click
    if (pTrack)
       result = pTrack->TypeSwitch< decltype(RefreshNone) >(
       [&](WaveTrack *wt) {
-         if (wt->GetDisplay() != WaveTrackViewConstants::Waveform)
-            return Cancelled;
-
          if (!mEnvelope)
             return Cancelled;
 

src/tracks/ui/SelectHandle.cpp

@@ -128,13 +128,16 @@ namespace
    }
 
    // This returns true if we're a spectral editing track.
-   inline bool isSpectralSelectionTrack(const Track *pTrack) {
+   inline bool isSpectralSelectionView(const TrackView *pTrackView) {
-      return pTrack && pTrack->TypeSwitch< bool >( [&](const WaveTrack *wt) {
+      return
-         const SpectrogramSettings &settings = wt->GetSpectrogramSettings();
+        pTrackView &&
-         const int display = wt->GetDisplay();
+        pTrackView->IsSpectral() &&
-         return (display == WaveTrackViewConstants::Spectrum) &&
+        pTrackView->FindTrack() &&
-            settings.SpectralSelectionEnabled();
+        pTrackView->FindTrack()->TypeSwitch< bool >(
-      });
+           [&](const WaveTrack *wt) {
+              const SpectrogramSettings &settings = wt->GetSpectrogramSettings();
+              return settings.SpectralSelectionEnabled();
+           });
    }
 
    enum SelectionBoundary {
@@ -187,7 +190,7 @@ namespace
 
    SelectionBoundary ChooseBoundary
       (const ViewInfo &viewInfo,
-       wxCoord xx, wxCoord yy, const Track *pTrack, const wxRect &rect,
+       wxCoord xx, wxCoord yy, const TrackView *pTrackView, const wxRect &rect,
        bool mayDragWidth, bool onlyWithinSnapDistance,
        double *pPinValue = NULL)
    {
@@ -220,9 +223,11 @@ namespace
       // within the time boundaries
       if (!viewInfo.selectedRegion.isPoint() &&
          t0 <= selend && selend < t1 &&
-         isSpectralSelectionTrack(pTrack)) {
+         isSpectralSelectionView(pTrackView)) {
          // Spectral selection track is always wave
-         const WaveTrack *const wt = static_cast<const WaveTrack*>(pTrack);
+         auto pTrack = pTrackView->FindTrack();
+         const WaveTrack *const wt =
+           static_cast<const WaveTrack*>(pTrack.get());
          const wxInt64 bottomSel = (f0 >= 0)
             ? FrequencyToPosition(wt, f0, rect.y, rect.height)
             : rect.y + rect.height;
@@ -374,7 +379,7 @@ namespace
 UIHandlePtr SelectHandle::HitTest
 (std::weak_ptr<SelectHandle> &holder,
  const TrackPanelMouseState &st, const AudacityProject *pProject,
- const std::shared_ptr<Track> &pTrack)
+ const std::shared_ptr<TrackView> &pTrackView)
 {
    // This handle is a little special because there may be some state to
    // preserve during movement before the click.
@@ -393,13 +398,14 @@ UIHandlePtr SelectHandle::HitTest
 
    const auto &viewInfo = ViewInfo::Get( *pProject );
    auto result = std::make_shared<SelectHandle>(
-      pTrack, oldUseSnap, TrackList::Get( *pProject ), st, viewInfo );
+      pTrackView, oldUseSnap, TrackList::Get( *pProject ), st, viewInfo );
 
    result = AssignUIHandlePtr(holder, result);
 
    //Make sure we are within the selected track
    // Adjusting the selection edges can be turned off in
    // the preferences...
+   auto pTrack = pTrackView->FindTrack();
    if (!pTrack->GetSelected() || !viewInfo.bAdjustSelectionEdges)
    {
       return result;
@@ -438,16 +444,17 @@ UIHandle::Result SelectHandle::NeedChangeHighlight
 }
 
 SelectHandle::SelectHandle
-( const std::shared_ptr<Track> &pTrack, bool useSnap,
+( const std::shared_ptr<TrackView> &pTrackView, bool useSnap,
   const TrackList &trackList,
   const TrackPanelMouseState &st, const ViewInfo &viewInfo )
-   : mpTrack{ pTrack }
+   : mpView{ pTrackView }
    , mSnapManager{ std::make_shared<SnapManager>(&trackList, &viewInfo) }
 {
    const wxMouseState &state = st.state;
    mRect = st.rect;
 
    auto time = std::max(0.0, viewInfo.PositionToTime(state.m_x, mRect.x));
+   auto pTrack = pTrackView->FindTrack();
    mSnapStart = mSnapManager->Snap(pTrack.get(), time, false);
    if (mSnapStart.snappedPoint)
       mSnapStart.outCoord += mRect.x;
@@ -531,8 +538,12 @@ UIHandle::Result SelectHandle::Click
 
    using namespace RefreshCode;
 
+   const auto pView = mpView.lock();
+   if ( !pView )
+      return Cancelled;
+
    wxMouseEvent &event = evt.event;
-   const auto sTrack = TrackList::Get( *pProject ).Lock(mpTrack);
+   const auto sTrack = TrackList::Get( *pProject ).Lock( FindTrack() );
    const auto pTrack = sTrack.get();
    auto &trackPanel = TrackPanel::Get( *pProject );
    auto &viewInfo = ViewInfo::Get( *pProject );
@@ -620,7 +631,8 @@ UIHandle::Result SelectHandle::Click
       double value;
       // Shift-click, choose closest boundary
       SelectionBoundary boundary =
-         ChooseBoundary(viewInfo, xx, event.m_y, pTrack, mRect, false, false, &value);
+         ChooseBoundary(viewInfo, xx, event.m_y,
+            pView.get(), mRect, false, false, &value);
       mSelectionBoundary = boundary;
       switch (boundary) {
          case SBLeft:
@@ -686,7 +698,7 @@ UIHandle::Result SelectHandle::Click
       if (viewInfo.bAdjustSelectionEdges) {
 #ifdef EXPERIMENTAL_SPECTRAL_EDITING
          if (mFreqSelMode == FREQ_SEL_SNAPPING_CENTER &&
-            isSpectralSelectionTrack(pTrack)) {
+            isSpectralSelectionView(pView.get())) {
             // This code is no longer reachable, but it had a place in the
             // spectral selection prototype.  It used to be that you could be
             // in a center-frequency-snapping mode that was not a mouse drag
@@ -714,7 +726,8 @@ UIHandle::Result SelectHandle::Click
             // Not shift-down, choose boundary only within snapping
             double value;
             SelectionBoundary boundary =
-               ChooseBoundary(viewInfo, xx, event.m_y, pTrack, mRect, true, true, &value);
+               ChooseBoundary(viewInfo, xx, event.m_y,
+                  pView.get(), mRect, true, true, &value);
             mSelectionBoundary = boundary;
             switch (boundary) {
             case SBNone:
@@ -766,7 +779,8 @@ UIHandle::Result SelectHandle::Click
       // If we didn't move a selection boundary, start a NEW selection
       selectionState.SelectNone( trackList );
 #ifdef EXPERIMENTAL_SPECTRAL_EDITING
-      StartFreqSelection (viewInfo, event.m_y, mRect.y, mRect.height, pTrack);
+      StartFreqSelection (viewInfo, event.m_y, mRect.y, mRect.height,
+         pView.get());
 #endif
       StartSelection(pProject);
       selectionState.SelectTrack( *pTrack, true, true );
@@ -791,6 +805,10 @@ UIHandle::Result SelectHandle::Drag
 {
    using namespace RefreshCode;
 
+   const auto pView = mpView.lock();
+   if ( !pView )
+      return Cancelled;
+
    auto &viewInfo = ViewInfo::Get( *pProject );
    const wxMouseEvent &event = evt.event;
 
@@ -814,7 +832,7 @@ UIHandle::Result SelectHandle::Drag
    }
 
    // Also fuhggeddaboudit if not in a track.
-   auto pTrack = TrackList::Get( *pProject ).Lock(mpTrack);
+   auto pTrack = TrackList::Get( *pProject ).Lock( FindTrack() );
    if (!pTrack)
       return RefreshNone;
 
@@ -850,7 +868,7 @@ UIHandle::Result SelectHandle::Drag
          if (mFreqSelMode == FREQ_SEL_SNAPPING_CENTER &&
              !viewInfo.selectedRegion.isPoint())
             MoveSnappingFreqSelection
-            (pProject, viewInfo, y, mRect.y, mRect.height, pTrack.get());
+            (pProject, viewInfo, y, mRect.y, mRect.height, pView.get());
          else
    #endif
             if ( TrackList::Get( *pProject ).Lock(mFreqSelTrack) == pTrack )
@@ -883,7 +901,11 @@ HitTestPreview SelectHandle::Preview
       // Moved out of snapping; revert to un-escaped state
       mUseSnap = true;
 
-   auto pTrack = mpTrack.lock();
+   const auto pView = mpView.lock();
+   if ( !pView )
+      return {};
+
+   auto pTrack = FindTrack().lock();
    if (!pTrack)
       return {};
 
@@ -937,7 +959,8 @@ HitTestPreview SelectHandle::Preview
             // choose boundaries only in snapping tolerance,
             // and may choose center.
             SelectionBoundary boundary =
-            ChooseBoundary(viewInfo, xx, state.m_y, pTrack.get(), rect, !bModifierDown, !bModifierDown);
+            ChooseBoundary(viewInfo, xx, state.m_y,
+               pView.get(), rect, !bModifierDown, !bModifierDown);
 
             SetTipAndCursorForBoundary(boundary, !bShiftDown, tip, pCursor);
          }
@@ -949,7 +972,7 @@ HitTestPreview SelectHandle::Preview
       // and drag width.
 #ifdef EXPERIMENTAL_SPECTRAL_EDITING
       if ((mFreqSelMode == FREQ_SEL_SNAPPING_CENTER) &&
-         isSpectralSelectionTrack(pTrack)) {
+         isSpectralSelectionView(pView)) {
          // Not shift-down, but center frequency snapping toggle is on
          tip = _("Click and drag to set frequency bandwidth.");
          pCursor = &*envelopeCursor;
@@ -966,7 +989,8 @@ HitTestPreview SelectHandle::Preview
          const bool bCtrlDown = state.ControlDown();
          const bool bModifierDown = bShiftDown || bCtrlDown;
          SelectionBoundary boundary = ChooseBoundary(
-            viewInfo, xx, state.m_y, pTrack.get(), rect, !bModifierDown, !bModifierDown);
+            viewInfo, xx, state.m_y,
+               pView.get(), rect, !bModifierDown, !bModifierDown);
          SetTipAndCursorForBoundary(boundary, !bShiftDown, tip, pCursor);
       }
 
@@ -1034,6 +1058,15 @@ wxRect SelectHandle::DrawingArea(
       return rect;
 }
 
+std::weak_ptr<Track> SelectHandle::FindTrack()
+{
+   auto pView = mpView.lock();
+   if (!pView)
+      return {};
+   else
+      return pView->FindTrack();
+}
+
 void SelectHandle::Connect(AudacityProject *pProject)
 {
    mTimerHandler = std::make_shared<TimerHandler>( this, pProject );
@@ -1113,7 +1146,7 @@ void SelectHandle::TimerHandler::OnTimer(wxCommandEvent &event)
       }
    }
 
-   auto pTrack = mParent->mpTrack.lock(); // TrackList::Lock() ?
+   auto pTrack = mParent->FindTrack().lock(); // TrackList::Lock() ?
    if (mParent->mAutoScrolling && pTrack) {
       // AS: To keep the selection working properly as we scroll,
       //  we fake a mouse event (remember, this method is called
@@ -1164,7 +1197,7 @@ void SelectHandle::AdjustSelection
 
    auto pTrack = Track::SharedPointer( track );
    if (!pTrack)
-      pTrack = TrackList::Get( *pProject ).Lock(mpTrack);
+      pTrack = TrackList::Get( *pProject ).Lock( FindTrack() );
 
    if (pTrack && mSnapManager.get()) {
       bool rightEdge = (selend > mSelStart);
@@ -1216,15 +1249,15 @@ void SelectHandle::AssignSelection
 
 void SelectHandle::StartFreqSelection(ViewInfo &viewInfo,
    int mouseYCoordinate, int trackTopEdge,
-   int trackHeight, Track *pTrack)
+   int trackHeight, TrackView *pTrackView)
 {
    mFreqSelTrack.reset();
    mFreqSelMode = FREQ_SEL_INVALID;
    mFreqSelPin = SelectedRegion::UndefinedFrequency;
 
-   if (isSpectralSelectionTrack(pTrack)) {
+   if (isSpectralSelectionView(pTrackView)) {
       // Spectral selection track is always wave
-      auto shTrack = pTrack->SharedPointer<const WaveTrack>();
+      auto shTrack = pTrackView->FindTrack()->SharedPointer<const WaveTrack>();
       mFreqSelTrack = shTrack;
       mFreqSelMode = FREQ_SEL_FREE;
       mFreqSelPin =
@@ -1386,11 +1419,12 @@ void SelectHandle::StartSnappingFreqSelection
 void SelectHandle::MoveSnappingFreqSelection
    (AudacityProject *pProject, ViewInfo &viewInfo, int mouseYCoordinate,
     int trackTopEdge,
-    int trackHeight, Track *pTrack)
+    int trackHeight, TrackView *pTrackView)
 {
+   auto pTrack = pTrackView->FindTrack().get();
    if (pTrack &&
       pTrack->GetSelected() &&
-      isSpectralSelectionTrack(pTrack)) {
+      isSpectralSelectionView(pTrackView)) {
       // Spectral selection track is always wave
       WaveTrack *const wt = static_cast<WaveTrack*>(pTrack);
       // PRL:

src/tracks/ui/SelectHandle.h

@@ -21,6 +21,7 @@ class SelectionStateChanger;
 class SnapManager;
 class SpectrumAnalyst;
 class Track;
+class TrackView;
 class TrackList;
 class ViewInfo;
 class WaveTrack;
@@ -32,7 +33,7 @@ class SelectHandle : public UIHandle
 
 public:
    explicit SelectHandle
-      (const std::shared_ptr<Track> &pTrack, bool useSnap,
+      (const std::shared_ptr<TrackView> &pTrackView, bool useSnap,
        const TrackList &trackList,
        const TrackPanelMouseState &st, const ViewInfo &viewInfo);
 
@@ -41,7 +42,7 @@ public:
    static UIHandlePtr HitTest
       (std::weak_ptr<SelectHandle> &holder,
        const TrackPanelMouseState &state, const AudacityProject *pProject,
-       const std::shared_ptr<Track> &pTrack);
+       const std::shared_ptr<TrackView> &pTrackView);
 
    SelectHandle &operator=(const SelectHandle&) = default;
    
@@ -78,6 +79,8 @@ public:
        const SelectHandle &newState);
 
 private:
+   std::weak_ptr<Track> FindTrack();
+
    void Connect(AudacityProject *pProject);
 
    void StartSelection(AudacityProject *pProject);
@@ -89,7 +92,7 @@ private:
 
    void StartFreqSelection
       (ViewInfo &viewInfo, int mouseYCoordinate, int trackTopEdge,
-      int trackHeight, Track *pTrack);
+      int trackHeight, TrackView *pTrackView);
    void AdjustFreqSelection
       (const WaveTrack *wt,
        ViewInfo &viewInfo, int mouseYCoordinate, int trackTopEdge,
@@ -104,7 +107,7 @@ private:
    void MoveSnappingFreqSelection
       (AudacityProject *pProject, ViewInfo &viewInfo, int mouseYCoordinate,
        int trackTopEdge,
-       int trackHeight, Track *pTrack);
+       int trackHeight, TrackView *pTrackView);
 public:
    // This is needed to implement a command assignable to keystrokes
    static void SnapCenterOnce
@@ -124,7 +127,7 @@ private:
    //   (const ViewInfo &viewInfo, double hintFrequency, bool logF);
 
 
-   std::weak_ptr<Track> mpTrack;
+   std::weak_ptr<TrackView> mpView;
    wxRect mRect{};
    SelectedRegion mInitialSelection{};
 

src/tracks/ui/TrackView.cpp

@@ -114,6 +114,11 @@ auto TrackView::GetSubViews( const wxRect &rect ) -> Refinement
    return { { rect.GetTop(), shared_from_this() } };
 }
 
+bool TrackView::IsSpectral() const
+{
+   return false;
+}
+
 void TrackView::DoSetMinimized(bool isMinimized)
 {
    mMinimized = isMinimized;

src/tracks/ui/TrackView.h

@@ -73,6 +73,9 @@ public:
    > >;
    virtual Refinement GetSubViews( const wxRect &rect );
 
+   // default is false
+   virtual bool IsSpectral() const;
+
    virtual void DoSetMinimized( bool isMinimized );
 
 protected: