Redo aup3 import more simply; fix cut, copy, import of TimeTrack

src/CommonCommandFlags.cpp

@@ -41,16 +41,16 @@ cycles.
 
 */
 
-// Really means, some track is selected, that isn't a time track
+// Strong predicate excludes tracks that do not support basic editing.
-bool TracksSelectedPred( const AudacityProject &project )
+bool EditableTracksSelectedPred( const AudacityProject &project )
 {
    auto range = TrackList::Get( project ).Selected()
      - []( const Track *pTrack ){
-        return track_cast<const TimeTrack*>( pTrack ); };
+        return !pTrack->SupportsBasicEditing(); };
    return !range.empty();
 };
 
-// This predicate includes time tracks too.
+// Weaker predicate.
 bool AnyTracksSelectedPred( const AudacityProject &project )
 {
    auto range = TrackList::Get( project ).Selected();
@@ -177,8 +177,8 @@ const ReservedCommandFlag&
       CommandFlagOptions{}.DisableDefaultMessage()
    }; return flag; }
 const ReservedCommandFlag&
-   TracksSelectedFlag() { static ReservedCommandFlag flag{
+   EditableTracksSelectedFlag() { static ReservedCommandFlag flag{
-      TracksSelectedPred, // exclude TimeTracks
+      EditableTracksSelectedPred,
       { []( const TranslatableString &Name ){ return
          // i18n-hint: %s will be replaced by the name of an action, such as "Remove Tracks".
          XO("\"%s\" requires one or more tracks to be selected.").Format( Name );
@@ -186,7 +186,7 @@ const ReservedCommandFlag&
    }; return flag; }
 const ReservedCommandFlag&
    AnyTracksSelectedFlag() { static ReservedCommandFlag flag{
-      AnyTracksSelectedPred, // Allow TimeTracks
+      AnyTracksSelectedPred,
       { []( const TranslatableString &Name ){ return
          // i18n-hint: %s will be replaced by the name of an action, such as "Remove Tracks".
          XO("\"%s\" requires one or more tracks to be selected.").Format( Name );

src/CommonCommandFlags.h

@@ -15,7 +15,7 @@ Paul Licameli split from Menus.cpp
 
 #include "commands/CommandFlag.h"
 
-bool TracksSelectedPred( const AudacityProject &project );
+bool EditableTracksSelectedPred( const AudacityProject &project );
 bool AudioIOBusyPred( const AudacityProject &project );
 bool TimeSelectedPred( const AudacityProject &project );
 extern const CommandFlagOptions &cutCopyOptions();
@@ -27,7 +27,7 @@ extern AUDACITY_DLL_API const ReservedCommandFlag
    &TimeSelectedFlag(), // This is equivalent to check if there is a valid selection, so it's used for Zoom to Selection too
    &WaveTracksSelectedFlag(),
    &TracksExistFlag(),
-   &TracksSelectedFlag(),
+   &EditableTracksSelectedFlag(),
    &AnyTracksSelectedFlag(),
    &TrackPanelHasFocus();  //lll
 

src/LabelTrack.cpp

@@ -85,6 +85,13 @@ LabelTrack::LabelTrack(const LabelTrack &orig) :
    }
 }
 
+Track::Holder LabelTrack::PasteInto( AudacityProject & ) const
+{
+   auto pNewTrack = std::make_shared<LabelTrack>();
+   pNewTrack->Paste(0.0, this);
+   return pNewTrack;
+}
+
 template<typename IntervalType>
 static IntervalType DoMakeInterval(const LabelStruct &label, size_t index)
 {

src/LabelTrack.h

@@ -155,6 +155,8 @@ public:
    int FindNextLabel(const SelectedRegion& currentSelection);
    int FindPrevLabel(const SelectedRegion& currentSelection);
 
+   Track::Holder PasteInto( AudacityProject & ) const override;
+
    struct IntervalData final : Track::IntervalData {
       size_t index;
       explicit IntervalData(size_t index) : index{index} {};

src/NoteTrack.cpp

@@ -683,6 +683,13 @@ QuantizedTimeAndBeat NoteTrack::NearestBeatTime( double time ) const
    return { seq_time + GetOffset(), beat };
 }
 
+Track::Holder NoteTrack::PasteInto( AudacityProject & ) const
+{
+   auto pNewTrack = std::make_shared<NoteTrack>();
+   pNewTrack->Paste(0.0, this);
+   return pNewTrack;
+}
+
 auto NoteTrack::GetIntervals() const -> ConstIntervals
 {
    ConstIntervals results;

src/NoteTrack.h

@@ -185,6 +185,8 @@ public:
          mVisibleChannels = CHANNEL_BIT(c);
    }
 
+   Track::Holder PasteInto( AudacityProject & ) const override;
+
    ConstIntervals GetIntervals() const override;
    Intervals GetIntervals() override;
 

src/ProjectFileIO.cpp

@@ -27,7 +27,6 @@ Paul Licameli split from AudacityProject.cpp
 #include "SampleBlock.h"
 #include "Tags.h"
 #include "TempDirectory.h"
-#include "TimeTrack.h"
 #include "ViewInfo.h"
 #include "WaveTrack.h"
 #include "widgets/AudacityMessageBox.h"
@@ -1677,357 +1676,6 @@ bool ProjectFileIO::WriteDoc(const char *table,
    return true;
 }
 
-// Importing an AUP3 project into an AUP3 project is a bit different than
-// normal importing since we need to copy data from one DB to the other
-// while adjusting the sample block IDs to represent the newly assigned
-// IDs.
-bool ProjectFileIO::ImportProject(const FilePath &fileName)
-{
-   // Get access to the current project file
-   auto db = DB();
-
-   bool success = false;
-   bool restore = true;
-   int rc = SQLITE_OK;
-
-   // Ensure the inbound database gets detached
-   auto detach = finally([&]
-   {
-      // If this DETACH fails, subsequent project imports will fail until Audacity
-      // is relaunched.
-      auto result = sqlite3_exec(db, "DETACH DATABASE inbound;", nullptr, nullptr, nullptr);
-
-      // Only capture the error if there wasn't a previous error
-      if (result != SQLITE_OK && (rc == SQLITE_DONE || rc == SQLITE_OK))
-      {
-         SetDBError(
-            XO("Failed to detach project during import")
-         );
-      }
-   });
-
-   // Attach the inbound project file
-   wxString sql;
-   sql.Printf("ATTACH DATABASE 'file:%s?immutable=1&mode=ro' AS inbound;", fileName);
-
-   rc = sqlite3_exec(db, sql, nullptr, nullptr, nullptr);
-   if (rc != SQLITE_OK)
-   {
-      SetDBError(
-         XO("Unable to attach %s project file").Format(fileName)
-      );
-
-      return false;
-   }
-
-   // We need either the autosave or project docs from the inbound AUP3
-   wxMemoryBuffer buffer;
-
-   // Get the autosave doc, if any
-   if (!GetBlob("SELECT dict || doc FROM inbound.project WHERE id = 1;", buffer))
-   {
-      // Error already set
-      return false;
-   }
-
-   // If we didn't have an autosave doc, load the project doc instead
-   if (buffer.GetDataLen() == 0)
-   {
-      if (!GetBlob("SELECT dict || doc FROM inbound.autosave WHERE id = 1;", buffer))
-      {
-         // Error already set
-         return false;
-      }
-
-      // Missing both the autosave and project docs. This can happen if the
-      // system were to crash before the first autosave into a temporary file.
-      if (buffer.GetDataLen() == 0)
-      {
-         SetError(XO("Unable to load project or autosave documents"));
-         return false;
-      }
-   }
-
-   wxString project;
-
-   project = ProjectSerializer::Decode(buffer);
-   if (project.size() == 0)
-   {
-      SetError(XO("Unable to decode project document"));
-
-      return false;
-   }
-
-   // Parse the project doc
-   wxStringInputStream in(project);
-   wxXmlDocument doc;
-   if (!doc.Load(in))
-   {
-      SetError(XO("Unable to parse the project document"));
-
-      return false;
-   }
-
-   // Get the root ("project") node
-   wxXmlNode *root = doc.GetRoot();
-   if (!root->GetName().IsSameAs(wxT("project")))
-   {
-      SetError(XO("Missing root node in project document"));
-
-      return false;
-   }
-
-   // Soft delete all non-essential attributes to prevent updating the active
-   // project. This takes advantage of the knowledge that when a project is
-   // parsed, unrecognized attributes are simply ignored.
-   //
-   // This is necessary because we don't want any of the active project settings
-   // to be modified by the inbound project.
-   for (wxXmlAttribute *attr = root->GetAttributes(); attr; attr = attr->GetNext())
-   {
-      wxString name = attr->GetName();
-      if (!name.IsSameAs(wxT("version")) && !name.IsSameAs(wxT("audacityversion")))
-      {
-         attr->SetName(name + wxT("_deleted"));
-      }
-   }
-
-   // Recursively find and collect all waveblock nodes
-   std::vector<wxXmlNode *> blocknodes;
-   std::function<void(wxXmlNode *)> findblocks = [&](wxXmlNode *node)
-   {
-      while (node)
-      {
-         if (node->GetName().IsSameAs(wxT("waveblock")))
-         {
-            blocknodes.push_back(node);
-         }
-         else
-         {
-            findblocks(node->GetChildren());
-         }
-
-         node = node->GetNext();
-      }
-   };
-
-   // Get access to the active tracklist
-   auto pProject = &mProject;
-   auto &tracklist = TrackList::Get(*pProject);
-
-   // Search for a timetrack and remove it if the project already has one
-   if (*tracklist.Any<TimeTrack>().begin())
-   {
-      // Find a timetrack and remove it if it exists
-      for (wxXmlNode *node = doc.GetRoot()->GetChildren(); node; node = node->GetNext())
-      {
-         if (node->GetName().IsSameAs(wxT("timetrack")))
-         {
-            AudacityMessageBox(
-               XO("The active project already has a time track and one was encountered in the project being imported, bypassing imported time track."),
-               XO("Project Import"),
-               wxOK | wxICON_EXCLAMATION | wxCENTRE,
-               &GetProjectFrame(*pProject));
-
-            root->RemoveChild(node);
-            break;
-         }
-      }
-   }
-
-   // Find all waveblocks in all wavetracks
-   for (wxXmlNode *node = doc.GetRoot()->GetChildren(); node; node = node->GetNext())
-   {
-      if (node->GetName().IsSameAs(wxT("wavetrack")))
-      {
-         findblocks(node->GetChildren());
-      }
-   }
-
-   {
-      // Cleanup...
-      sqlite3_stmt *stmt = nullptr;
-      auto cleanup = finally([&]
-      {
-         // Ensure the prepared statement gets cleaned up
-         if (stmt)
-         {
-            // Ignore the return code since it will have already been captured below.
-            sqlite3_finalize(stmt);
-         }
-      });
-
-      // Prepare the statement to copy the sample block from the inbound project to the
-      // active project.  All columns other than the blockid column get copied.
-      wxString columns(wxT("sampleformat, summin, summax, sumrms, summary256, summary64k, samples"));
-      sql.Printf("INSERT INTO main.sampleblocks (%s)"
-                 "   SELECT %s"
-                 "   FROM inbound.sampleblocks"
-                 "   WHERE blockid = ?;",
-                 columns,
-                 columns);
-
-      rc = sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr);
-      if (rc != SQLITE_OK)
-      {
-         SetDBError(
-            XO("Unable to prepare project file command:\n\n%s").Format(sql)
-         );
-         return false;
-      }
-
-      /* i18n-hint: This title appears on a dialog that indicates the progress
-         in doing something.*/
-      ProgressDialog progress(XO("Progress"), XO("Importing project"), pdlgHideStopButton);
-      ProgressResult result = ProgressResult::Success;
-
-      wxLongLong_t count = 0;
-      wxLongLong_t total = blocknodes.size();
-
-      rc = sqlite3_exec(db, "BEGIN;", nullptr, nullptr, nullptr);
-      if (rc != SQLITE_OK)
-      {
-         SetDBError(
-            XO("Unable to start a transaction during import")
-         );
-         return false;
-      }
-
-      // Copy all the sample blocks from the inbound project file into
-      // the active one, while remembering which were copied.
-      for (auto node : blocknodes)
-      {
-         // Find the blockid attribute...it should always be there
-         wxXmlAttribute *attr = node->GetAttributes();
-         while (attr && !attr->GetName().IsSameAs(wxT("blockid")))
-         {
-            attr = attr->GetNext();
-         }
-         wxASSERT(attr != nullptr);
-
-         // And get the blockid
-         SampleBlockID blockid;
-         attr->GetValue().ToLongLong(&blockid);
-
-         if ( blockid <= 0 )
-            // silent block
-            continue;
-
-         // Bind statement parameters
-         rc = sqlite3_bind_int64(stmt, 1, blockid);
-         if (rc != SQLITE_OK)
-         {
-            SetDBError(
-               XO("Failed to bind SQL parameter")
-            );
-
-            break;
-         }
-
-         // Process it
-         rc = sqlite3_step(stmt);
-         if (rc != SQLITE_DONE)
-         {
-            SetDBError(
-               XO("Failed to import sample block.\nThe following command failed:\n\n%s").Format(sql)
-            );
-
-            break;
-         }
-
-         // Replace the original blockid with the new one
-         attr->SetValue(wxString::Format(wxT("%lld"), sqlite3_last_insert_rowid(db)));
-
-         // Reset the statement for the next iteration
-         if (sqlite3_reset(stmt) != SQLITE_OK)
-         {
-            THROW_INCONSISTENCY_EXCEPTION;
-         }
-
-         // Remember that we copied this node in case the user cancels
-         result = progress.Update(++count, total);
-         if (result != ProgressResult::Success)
-         {
-            break;
-         }
-      }
-
-      // Bail if the import was cancelled or failed. If the user stopped the
-      // import or it completed, then we continue on.
-      if (rc != SQLITE_DONE || result == ProgressResult::Cancelled || result == ProgressResult::Failed)
-      {
-         // If this fails (probably due to memory or disk space), the transaction will
-         // (presumably) stil be active, so further updates to the project file will
-         // fail as well. Not really much we can do about it except tell the user.
-         auto result = sqlite3_exec(db, "ROLLBACK;", nullptr, nullptr, nullptr);
-
-         // Only capture the error if there wasn't a previous error
-         if (result != SQLITE_OK && rc == SQLITE_DONE)
-         {
-            SetDBError(
-               XO("Failed to rollback transaction during import")
-            );
-         }
-
-         return false;
-      }
-
-      // Go ahead and commit now. If this fails (probably due to memory or disk space),
-      // the transaction will (presumably) stil be active, so further updates to the
-      // project file will fail as well. Not really much we can do about it except tell
-      // the user.
-      rc = sqlite3_exec(db, "COMMIT;", nullptr, nullptr, nullptr);
-      if (rc != SQLITE_OK)
-      {
-         SetDBError(
-            XO("Unable to commit transaction during import")
-         );
-
-         return false;
-      }
-
-      // Copy over tags...likely to produce duplicates...needs work once used
-      rc = sqlite3_exec(db,
-                        "INSERT INTO main.tags SELECT * FROM inbound.tags;",
-                        nullptr,
-                        nullptr,
-                        nullptr);
-      if (rc != SQLITE_OK)
-      {
-         SetDBError(
-            XO("Failed to import tags")
-         );
-
-         return false;
-      }
-   }
-
-   // Recreate the project doc with the revisions we've made above. If this fails
-   // it's probably due to memory.
-   wxStringOutputStream output;
-   if (!doc.Save(output))
-   {
-      SetError(
-         XO("Unable to recreate project information.")
-      );
-
-      return false;
-   }
-
-   // Now load the document as normal
-   XMLFileReader xmlFile;
-   if (!xmlFile.ParseString(this, output.GetString()))
-   {
-      SetError(
-         XO("Unable to parse project information."), xmlFile.GetErrorStr()
-      );
-
-      return false;
-   }
-
-   return true;
-}
-
 bool ProjectFileIO::LoadProject(const FilePath &fileName, bool ignoreAutosave)
 {
    bool success = false;

src/ProjectFileIO.h

@@ -92,7 +92,6 @@ public:
    bool CloseProject();
    bool ReopenProject();
 
-   bool ImportProject(const FilePath &fileName);
    bool LoadProject(const FilePath &fileName, bool ignoreAutosave);
    bool UpdateSaved(const TrackList *tracks = nullptr);
    bool SaveProject(const FilePath &fileName, const TrackList *lastSaved);

src/ProjectFileManager.cpp

@@ -1137,6 +1137,29 @@ ProjectFileManager::AddImportedTracks(const FilePath &fileName,
    //   HandleResize();
 }
 
+namespace {
+bool ImportProject(AudacityProject &dest, const FilePath &fileName)
+{
+   InvisibleTemporaryProject temp;
+   auto &project = temp.Project();
+
+   auto &projectFileIO = ProjectFileIO::Get(project);
+   if (!projectFileIO.LoadProject(fileName, false))
+      return false;
+   auto &srcTracks = TrackList::Get(project);
+   auto &destTracks = TrackList::Get(dest);
+   for (const Track *pTrack : srcTracks.Any()) {
+      auto destTrack = pTrack->PasteInto(dest);
+      Track::FinishCopy(pTrack, destTrack.get());
+      if (destTrack.use_count() == 1)
+         destTracks.Add(destTrack);
+   }
+   Tags::Get(dest).Merge(Tags::Get(project));
+
+   return true;
+}
+}
+
 // If pNewTrackList is passed in non-NULL, it gets filled with the pointers to NEW tracks.
 bool ProjectFileManager::Import(
    const FilePath &fileName,
@@ -1151,7 +1174,7 @@ bool ProjectFileManager::Import(
 
    // Handle AUP3 ("project") files directly
    if (fileName.AfterLast('.').IsSameAs(wxT("aup3"), false)) {
-      if (projectFileIO.ImportProject(fileName)) {
+      if (ImportProject(project, fileName)) {
          auto &history = ProjectHistory::Get(project);
 
          // If the project was clean and temporary (not permanently saved), then set

src/SelectUtilities.cpp

@@ -85,7 +85,7 @@ void SelectAllIfNone( AudacityProject &project )
 {
    auto &viewInfo = ViewInfo::Get( project );
    auto flags = MenuManager::Get( project ).GetUpdateFlags();
-   if((flags & TracksSelectedFlag()).none() ||
+   if((flags & EditableTracksSelectedFlag()).none() ||
       viewInfo.selectedRegion.isPoint())
       DoSelectAllAudio( project );
 }
@@ -98,7 +98,7 @@ bool SelectAllIfNoneAndAllowed( AudacityProject &project )
    auto &viewInfo = ViewInfo::Get( project );
    auto flags = MenuManager::Get( project ).GetUpdateFlags();
 
-   if((flags & TracksSelectedFlag()).none() ||
+   if((flags & EditableTracksSelectedFlag()).none() ||
       viewInfo.selectedRegion.isPoint()) {
       if (!allowed) {
          return false;

src/Tags.cpp

@@ -268,6 +268,13 @@ std::shared_ptr<Tags> Tags::Duplicate() const
    return std::make_shared<Tags>(*this);
 }
 
+void Tags::Merge( const Tags &other )
+{
+   for ( auto &pair : other.mMap ) {
+      SetTag( pair.first, pair.second );
+   }
+}
+
 Tags & Tags::operator=(const Tags & src)
 {
    mEditTitle = src.mEditTitle;

src/Tags.h

@@ -88,6 +88,8 @@ class AUDACITY_DLL_API Tags final
 
    std::shared_ptr<Tags> Duplicate() const;
 
+   void Merge( const Tags &other );
+
    Tags & operator= (const Tags & src );
 
    bool ShowEditDialog(

src/TimeTrack.cpp

@@ -52,6 +52,11 @@ static ProjectFileIORegistry::Entry registerFactory{
 TimeTrack::TimeTrack(const ZoomInfo *zoomInfo):
    Track()
    , mZoomInfo(zoomInfo)
+{
+   CleanState();
+}
+
+void TimeTrack::CleanState()
 {
    mEnvelope = std::make_unique<BoundedEnvelope>(true, TIMETRACK_MIN, TIMETRACK_MAX, 1.0);
 
@@ -131,6 +136,31 @@ void TimeTrack::SetRangeUpper(double upper)
    mEnvelope->SetRangeUpper( upper );
 }
 
+bool TimeTrack::SupportsBasicEditing() const
+{
+   return false;
+}
+
+Track::Holder TimeTrack::PasteInto( AudacityProject &project ) const
+{
+   // Maintain uniqueness of the time track!
+   std::shared_ptr<TimeTrack> pNewTrack;
+   if( auto pTrack = *TrackList::Get( project ).Any<TimeTrack>().begin() )
+      pNewTrack = pTrack->SharedPointer<TimeTrack>();
+   else
+      pNewTrack = std::make_shared<TimeTrack>( &ViewInfo::Get( project ) );
+
+   // Should come here only for .aup3 import, not for paste (because the
+   // track is skipped in cut/copy commands)
+   // And for import we agree to replace the track contents completely
+   pNewTrack->CleanState();
+   pNewTrack->Init(*this);
+   pNewTrack->Paste(0.0, this);
+   pNewTrack->SetRangeLower(this->GetRangeLower());
+   pNewTrack->SetRangeUpper(this->GetRangeUpper());
+   return pNewTrack;
+}
+
 Track::Holder TimeTrack::Cut( double t0, double t1 )
 {
    auto result = Copy( t0, t1, false );

src/TimeTrack.h

@@ -40,6 +40,10 @@ class TimeTrack final : public Track {
    virtual ~TimeTrack();
 
 
+   bool SupportsBasicEditing() const override;
+
+   Holder PasteInto( AudacityProject & ) const override;
+
    Holder Cut( double t0, double t1 ) override;
    Holder Copy( double t0, double t1, bool forClipboard ) const override;
    void Clear(double t0, double t1) override;
@@ -91,6 +95,8 @@ class TimeTrack final : public Track {
    Ruler &GetRuler() const { return *mRuler; }
 
  private:
+   void CleanState();
+
    // Identifying the type of track
    TrackKind GetKind() const override { return TrackKind::Time; }
 

src/Track.cpp

@@ -1224,6 +1224,11 @@ std::shared_ptr<const Track> Track::SubstituteOriginalTrack() const
    return SharedPointer();
 }
 
+bool Track::SupportsBasicEditing() const
+{
+   return true;
+}
+
 auto Track::GetIntervals() const -> ConstIntervals
 {
    return {};

src/Track.h

@@ -318,6 +318,15 @@ class AUDACITY_DLL_API Track /* not final */
    using ConstInterval = ConstTrackInterval;
    using ConstIntervals = std::vector< ConstInterval >;
 
+   //! Whether this track type implements cut-copy-paste; by default, true
+   virtual bool SupportsBasicEditing() const;
+
+   using Holder = std::shared_ptr<Track>;
+
+   //! Find or create the destination track for a paste, maybe in a different project
+   /*! @return A smart pointer to the track; its `use_count()` can tell whether it is new */
+   virtual Holder PasteInto( AudacityProject & ) const = 0;
+
    //! Report times on the track where important intervals begin and end, for UI to snap to
    /*!
    Some intervals may be empty, and no ordering of the intervals is assumed.
@@ -390,7 +399,6 @@ private:
 
    void Init(const Track &orig);
 
-   using Holder = std::shared_ptr<Track>;
    // public nonvirtual duplication function that invokes Clone():
    virtual Holder Duplicate() const;
 

src/WaveTrack.cpp

@@ -334,6 +334,15 @@ static Container MakeIntervals(const std::vector<WaveClipHolder> &clips)
    return result;
 }
 
+Track::Holder WaveTrack::PasteInto( AudacityProject &project ) const
+{
+   auto &trackFactory = WaveTrackFactory::Get( project );
+   auto &pSampleBlockFactory = trackFactory.GetSampleBlockFactory();
+   auto pNewTrack = EmptyCopy( pSampleBlockFactory );
+   pNewTrack->Paste(0.0, this);
+   return pNewTrack;
+}
+
 auto WaveTrack::GetIntervals() const -> ConstIntervals
 {
    return MakeIntervals<ConstIntervals>( mClips );

src/WaveTrack.h

@@ -537,6 +537,8 @@ private:
       std::shared_ptr<WaveClip> pClip;
    };
 
+   Track::Holder PasteInto( AudacityProject & ) const override;
+
    ConstIntervals GetIntervals() const override;
    Intervals GetIntervals() override;
 

src/menus/EditMenus.cpp

@@ -11,7 +11,6 @@
 #include "../ProjectSettings.h"
 #include "../ProjectWindow.h"
 #include "../SelectUtilities.h"
-#include "../TimeTrack.h"
 #include "../TrackPanel.h"
 #include "../TrackPanelAx.h"
 #include "../UndoManager.h"
@@ -76,8 +75,6 @@ bool DoPasteText(AudacityProject &project)
 bool DoPasteNothingSelected(AudacityProject &project)
 {
    auto &tracks = TrackList::Get( project );
-   auto &trackFactory = WaveTrackFactory::Get( project );
-   auto &pSampleBlockFactory = trackFactory.GetSampleBlockFactory();
    auto &selectedRegion = ViewInfo::Get( project ).selectedRegion;
    auto &viewInfo = ViewInfo::Get( project );
    auto &window = ProjectWindow::Get( project );
@@ -94,44 +91,18 @@ bool DoPasteNothingSelected(AudacityProject &project)
 
       Track* pFirstNewTrack = NULL;
       for (auto pClip : clipTrackRange) {
-         Track::Holder uNewTrack;
+         auto pNewTrack = pClip->PasteInto( project );
-         Track *pNewTrack;
+         bool newTrack = (pNewTrack.use_count() == 1);
-         pClip->TypeSwitch(
-            [&](const WaveTrack *wc) {
-               uNewTrack = wc->EmptyCopy( pSampleBlockFactory );
-               pNewTrack = uNewTrack.get();
-            },
-#ifdef USE_MIDI
-            [&](const NoteTrack *) {
-               uNewTrack = std::make_shared<NoteTrack>(),
-               pNewTrack = uNewTrack.get();
-            },
-#endif
-            [&](const LabelTrack *) {
-               uNewTrack = std::make_shared<LabelTrack>(),
-               pNewTrack = uNewTrack.get();
-            },
-            [&](const TimeTrack *) {
-               // Maintain uniqueness of the time track!
-               pNewTrack = *tracks.Any<TimeTrack>().begin();
-               if (!pNewTrack)
-                  uNewTrack = std::make_shared<TimeTrack>( &viewInfo ),
-                  pNewTrack = uNewTrack.get();
-            }
-         );
-
          wxASSERT(pClip);
 
-         pNewTrack->Paste(0.0, pClip);
-
          if (!pFirstNewTrack)
-            pFirstNewTrack = pNewTrack;
+            pFirstNewTrack = pNewTrack.get();
 
          pNewTrack->SetSelected(true);
-         if (uNewTrack)
+         if (newTrack)
-            FinishCopy(pClip, uNewTrack, tracks);
+            FinishCopy(pClip, pNewTrack, tracks);
          else
-            Track::FinishCopy(pClip, pNewTrack);
+            Track::FinishCopy(pClip, pNewTrack.get());
       }
 
       // Select some pasted samples, which is probably impossible to get right
@@ -263,10 +234,12 @@ void OnCut(const CommandContext &context)
       },
 #endif
       [&](Track *n) {
+         if (n->SupportsBasicEditing()) {
             auto dest = n->Copy(selectedRegion.t0(),
                     selectedRegion.t1());
             FinishCopy(n, dest, newClipboard);
          }
+      }
    );
 
    // Survived possibility of exceptions.  Commit changes to the clipboard now.
@@ -298,8 +271,8 @@ void OnCut(const CommandContext &context)
             fallthrough();
       },
       [&](Track *n) {
-         n->Clear(selectedRegion.t0(),
+         if (n->SupportsBasicEditing())
-                  selectedRegion.t1());
+            n->Clear(selectedRegion.t0(), selectedRegion.t1());
       }
    );
 
@@ -321,6 +294,8 @@ void OnDelete(const CommandContext &context)
    auto &window = ProjectWindow::Get( project );
 
    for (auto n : tracks.Any()) {
+      if (!n->SupportsBasicEditing())
+         continue;
       if (n->GetSelected() || n->IsSyncLockSelected()) {
          n->Clear(selectedRegion.t0(), selectedRegion.t1());
       }
@@ -359,10 +334,12 @@ void OnCopy(const CommandContext &context)
    auto &newClipboard = *pNewClipboard;
 
    for (auto n : tracks.Selected()) {
+      if (n->SupportsBasicEditing()) {
          auto dest = n->Copy(selectedRegion.t0(),
                  selectedRegion.t1());
          FinishCopy(n, dest, newClipboard);
       }
+   }
 
    // Survived possibility of exceptions.  Commit changes to the clipboard now.
    clipboard.Assign( std::move( newClipboard ),
@@ -643,6 +620,9 @@ void OnDuplicate(const CommandContext &context)
    auto range = tracks.Selected();
    auto last = *range.rbegin();
    for (auto n : range) {
+      if (!n->SupportsBasicEditing())
+         continue;
+
       // Make copies not for clipboard but for direct addition to the project
       auto dest = n->Copy(selectedRegion.t0(),
               selectedRegion.t1(), false);
@@ -683,6 +663,7 @@ void OnSplitCut(const CommandContext &context)
             FinishCopy(n, dest, newClipboard);
       },
       [&](Track *n) {
+         if (n->SupportsBasicEditing()) {
             dest = n->Copy(selectedRegion.t0(),
                     selectedRegion.t1());
             n->Silence(selectedRegion.t0(),
@@ -690,6 +671,7 @@ void OnSplitCut(const CommandContext &context)
             if (dest)
                FinishCopy(n, dest, newClipboard);
          }
+      }
    );
 
    // Survived possibility of exceptions.  Commit changes to the clipboard now.
@@ -713,6 +695,7 @@ void OnSplitDelete(const CommandContext &context)
                          selectedRegion.t1());
       },
       [&](Track *n) {
+         if (n->SupportsBasicEditing())
             n->Silence(selectedRegion.t0(),
                        selectedRegion.t1());
       }
@@ -1004,7 +987,7 @@ static const ReservedCommandFlag
       if (
          TimeSelectedPred( project )
       &&
-         TracksSelectedPred( project )
+         EditableTracksSelectedPred( project )
       )
          return true;
 
@@ -1020,7 +1003,7 @@ BaseItemSharedPtr EditMenu()
    using Options = CommandManager::Options;
 
    static const auto NotBusyTimeAndTracksFlags =
-      AudioIONotBusyFlag() | TimeSelectedFlag() | TracksSelectedFlag();
+      AudioIONotBusyFlag() | TimeSelectedFlag() | EditableTracksSelectedFlag();
 
    // The default shortcut key for Redo is different on different platforms.
    static constexpr auto redoKey =
@@ -1065,7 +1048,7 @@ BaseItemSharedPtr EditMenu()
             AudioIONotBusyFlag() | CutCopyAvailableFlag() | NoAutoSelect(),
             wxT("Ctrl+X") ),
          Command( wxT("Delete"), XXO("&Delete"), FN(OnDelete),
-            AudioIONotBusyFlag() | TracksSelectedFlag() | TimeSelectedFlag() | NoAutoSelect(),
+            AudioIONotBusyFlag() | EditableTracksSelectedFlag() | TimeSelectedFlag() | NoAutoSelect(),
             wxT("Ctrl+K") ),
          /* i18n-hint: (verb)*/
          Command( wxT("Copy"), XXO("&Copy"), FN(OnCopy),
@@ -1160,7 +1143,7 @@ BaseItemSharedPtr ExtraEditMenu()
 {
    using Options = CommandManager::Options;
    static const auto flags =
-      AudioIONotBusyFlag() | TracksSelectedFlag() | TimeSelectedFlag();
+      AudioIONotBusyFlag() | EditableTracksSelectedFlag() | TimeSelectedFlag();
    static BaseItemSharedPtr menu{
    ( FinderScope{ findCommandHandler },
    Menu( wxT("Edit"), XXO("&Edit"),
@@ -1184,7 +1167,7 @@ auto selectAll = []( AudacityProject &project, CommandFlag flagsRqd ){
 
 RegisteredMenuItemEnabler selectTracks{{
    []{ return TracksExistFlag(); },
-   []{ return TracksSelectedFlag(); },
+   []{ return EditableTracksSelectedFlag(); },
    canSelectAll,
    selectAll
 }};

src/menus/SelectMenus.cpp

@@ -483,7 +483,7 @@ void OnSelectSyncLockSel(const CommandContext &context)
    auto &tracks = TrackList::Get( project );
 
    bool selected = false;
-   for (auto t : tracks.Any()
+   for (auto t : tracks.Any() + &Track::SupportsBasicEditing
          + &Track::IsSyncLockSelected - &Track::IsSelected) {
       t->SetSelected(true);
       selected = true;
@@ -866,7 +866,7 @@ void OnCursorTrackStart(const CommandContext &context)
 
    double kWayOverToRight = std::numeric_limits<double>::max();
 
-   auto trackRange = tracks.Selected();
+   auto trackRange = tracks.Selected() + &Track::SupportsBasicEditing;
    if (trackRange.empty())
       // This should have been prevented by command manager
       return;
@@ -892,7 +892,7 @@ void OnCursorTrackEnd(const CommandContext &context)
 
    double kWayOverToLeft = std::numeric_limits<double>::lowest();
 
-   auto trackRange = tracks.Selected();
+   auto trackRange = tracks.Selected() + &Track::SupportsBasicEditing;
    if (trackRange.empty())
       // This should have been prevented by command manager
       return;
@@ -1059,7 +1059,7 @@ BaseItemSharedPtr SelectMenu()
             ,
             Command( wxT("SelSyncLockTracks"), XXO("In All &Sync-Locked Tracks"),
                FN(OnSelectSyncLockSel),
-               TracksSelectedFlag() | IsSyncLockedFlag(),
+               EditableTracksSelectedFlag() | IsSyncLockedFlag(),
                Options{ wxT("Ctrl+Shift+Y"), XO("Select Sync-Locked") } )
    #endif
          ),
@@ -1131,7 +1131,7 @@ BaseItemSharedPtr SelectMenu()
 
       Section( "",
          Command( wxT("ZeroCross"), XXO("At &Zero Crossings"),
-            FN(OnZeroCrossing), TracksSelectedFlag(),
+            FN(OnZeroCrossing), EditableTracksSelectedFlag(),
             Options{ wxT("Z"), XO("Select Zero Crossing") } )
       )
    ) ) };
@@ -1216,11 +1216,11 @@ BaseItemSharedPtr CursorMenu()
 
       Command( wxT("CursTrackStart"), XXO("Track &Start"),
          FN(OnCursorTrackStart),
-         TracksSelectedFlag(),
+         EditableTracksSelectedFlag(),
          Options{ wxT("J"), XO("Cursor to Track Start") } ),
       Command( wxT("CursTrackEnd"), XXO("Track &End"),
          FN(OnCursorTrackEnd),
-         TracksSelectedFlag(),
+         EditableTracksSelectedFlag(),
          Options{ wxT("K"), XO("Cursor to Track End") } ),
 
       Command( wxT("CursProjectStart"), XXO("&Project Start"),

src/menus/TrackMenus.cpp

@@ -1356,9 +1356,9 @@ BaseItemSharedPtr TracksMenu()
             Command( wxT("UnmuteAllTracks"), XXO("&Unmute All Tracks"),
                FN(OnUnmuteAllTracks), TracksExistFlag(), wxT("Ctrl+Shift+U") ),
             Command( wxT("MuteTracks"), XXO("Mut&e Tracks"),
-               FN(OnMuteSelectedTracks), TracksSelectedFlag(), wxT("Ctrl+Alt+U") ),
+               FN(OnMuteSelectedTracks), EditableTracksSelectedFlag(), wxT("Ctrl+Alt+U") ),
             Command( wxT("UnmuteTracks"), XXO("U&nmute Tracks"),
-               FN(OnUnmuteSelectedTracks), TracksSelectedFlag(), wxT("Ctrl+Alt+Shift+U") )
+               FN(OnUnmuteSelectedTracks), EditableTracksSelectedFlag(), wxT("Ctrl+Alt+Shift+U") )
          ),
 
          Menu( wxT("Pan"), XXO("&Pan"),
@@ -1367,13 +1367,13 @@ BaseItemSharedPtr TracksMenu()
             // in the project could very easily be lost unless we
             // require the tracks to be selected.
             Command( wxT("PanLeft"), XXO("&Left"), FN(OnPanLeft),
-               TracksSelectedFlag(),
+               EditableTracksSelectedFlag(),
                Options{}.LongName( XO("Pan Left") ) ),
             Command( wxT("PanRight"), XXO("&Right"), FN(OnPanRight),
-               TracksSelectedFlag(),
+               EditableTracksSelectedFlag(),
                Options{}.LongName( XO("Pan Right") ) ),
             Command( wxT("PanCenter"), XXO("&Center"), FN(OnPanCenter),
-               TracksSelectedFlag(),
+               EditableTracksSelectedFlag(),
                Options{}.LongName( XO("Pan Center") ) )
          )
       ),
@@ -1387,14 +1387,14 @@ BaseItemSharedPtr TracksMenu()
                      { wxT("EndToEnd"),     XXO("&Align End to End") },
                      { wxT("Together"),     XXO("Align &Together") },
                   },
-                  FN(OnAlignNoSync), AudioIONotBusyFlag() | TracksSelectedFlag())
+                  FN(OnAlignNoSync), AudioIONotBusyFlag() | EditableTracksSelectedFlag())
             ),
 
             Section( "",
                // Alignment commands using selection or zero
                CommandGroup(wxT("Align"),
                   alignLabels(),
-                  FN(OnAlign), AudioIONotBusyFlag() | TracksSelectedFlag())
+                  FN(OnAlign), AudioIONotBusyFlag() | EditableTracksSelectedFlag())
             ),
 
             Section( "",
@@ -1411,7 +1411,7 @@ BaseItemSharedPtr TracksMenu()
          // Do we need this sub-menu at all?
          Menu( wxT("MoveSelectionAndTracks"), XO("Move Sele&ction and Tracks"), {
             CommandGroup(wxT("AlignMove"), alignLabels(),
-               FN(OnAlignMoveSel), AudioIONotBusyFlag() | TracksSelectedFlag()),
+               FN(OnAlignMoveSel), AudioIONotBusyFlag() | EditableTracksSelectedFlag()),
          } ),
    #endif