New attached structure ProjectManager handles project lifetime...

... that is, a factory function, open, close, import, undo/redo/rollback.

Also the callbacks from AudioIO, which need to invoke undo history push when
recording stops.

It is meant as a high-level class using several of the other things attached
to the project, while AudacityProject will be a low level class acting mostly
as just the container of the attached structures.

src/AudacityApp.cpp

@@ -810,9 +810,8 @@ void AudacityApp::MacNewFile()
    // This method should only be used on the Mac platform
    // when no project windows are open.
 
-   if (AllProjects{}.empty()) {
+   if (AllProjects{}.empty())
-      CreateNewAudacityProject();
+      (void) ProjectManager::New();
-   }
 }
 
 #endif //__WXMAC__
@@ -880,7 +879,7 @@ bool AudacityApp::MRUOpen(const FilePath &fullPathStr) {
          // Test here even though AudacityProject::OpenFile() also now checks, because
          // that method does not return the bad result.
          // That itself may be a FIXME.
-         if (AudacityProject::IsAlreadyOpen(fullPathStr))
+         if (ProjectManager::IsAlreadyOpen(fullPathStr))
             return false;
 
          // DMM: If the project is dirty, that means it's been touched at
@@ -893,12 +892,15 @@ bool AudacityApp::MRUOpen(const FilePath &fullPathStr) {
          // there are no tracks, but there's an Undo history, etc, then
          // bad things can happen, including data files moving to the NEW
          // project directory, etc.
-         if (proj && (proj->GetDirty() || !TrackList::Get( *proj ).empty()))
+         if (proj && (
+            ProjectManager::Get( *proj ).GetDirty() ||
+            !TrackList::Get( *proj ).empty()
+         ) )
             proj = nullptr;
          // This project is clean; it's never been touched.  Therefore
          // all relevant member variables are in their initial state,
          // and it's okay to open a NEW project inside this window.
-         AudacityProject::OpenProject( proj, fullPathStr );
+         ( void ) ProjectManager::OpenProject( proj, fullPathStr );
       }
       else {
          // File doesn't exist - remove file from history
@@ -936,7 +938,7 @@ void AudacityApp::OnMRUFile(wxCommandEvent& event) {
    // PRL: Don't call SafeMRUOpen
    // -- if open fails for some exceptional reason of resource exhaustion that
    // the user can correct, leave the file in history.
-   if (!AudacityProject::IsAlreadyOpen(fullPathStr) && !MRUOpen(fullPathStr))
+   if (!ProjectManager::IsAlreadyOpen(fullPathStr) && !MRUOpen(fullPathStr))
       history.RemoveFileFromHistory(n);
 }
 
@@ -1073,7 +1075,7 @@ bool AudacityApp::OnExceptionInMainLoop()
          // Restore the state of the project to what it was before the
          // failed operation
          if (pProject) {
-            pProject->RollbackState();
+            ProjectManager::Get( *pProject ).RollbackState();
 
             // Forget pending changes in the TrackList
             TrackList::Get( *pProject ).ClearPendingTracks();
@@ -1511,7 +1513,7 @@ bool AudacityApp::OnInit()
    // Root cause is problem with wxSplashScreen and other dialogs co-existing, that
    // seemed to arrive with wx3.
    {
-      project = CreateNewAudacityProject();
+      project = ProjectManager::New();
       mCmdHandler->SetProject(project);
       wxWindow * pWnd = MakeHijackPanel();
       if (pWnd)
@@ -2081,7 +2083,7 @@ void AudacityApp::OnMenuNew(wxCommandEvent & event)
    // all platforms.
 
    if(AllProjects{}.empty())
-      CreateNewAudacityProject();
+      (void) ProjectManager::New();
    else
       event.Skip();
 }
@@ -2097,7 +2099,7 @@ void AudacityApp::OnMenuOpen(wxCommandEvent & event)
 
 
    if(AllProjects{}.empty())
-      AudacityProject::OpenFiles(NULL);
+      ProjectManager::OpenFiles(NULL);
    else
       event.Skip();
 

src/AutoRecovery.cpp

@@ -227,7 +227,7 @@ static bool RecoverAllProjects(AudacityProject** pproj)
       // Open project. When an auto-save file has been opened successfully,
       // the opened auto-save file is automatically deleted and a NEW one
       // is created.
-      AudacityProject::OpenProject( proj, files[i], false );
+      (void) ProjectManager::OpenProject( proj, files[i], false );
    }
 
    return true;

src/BatchCommands.cpp

@@ -842,7 +842,7 @@ bool MacroCommands::ApplyMacro(
       if (!res) {
          if(proj) {
             // Macro failed or was cancelled; revert to the previous state
-            proj->RollbackState();
+            ProjectManager::Get( *proj ).RollbackState();
          }
       }
    } );
@@ -888,7 +888,7 @@ bool MacroCommands::ApplyMacro(
    if (!proj)
       return false;
    if( MacroReentryCount <= 1 )
-      proj->PushState(longDesc, shortDesc);
+      ProjectManager::Get( *proj ).PushState(longDesc, shortDesc);
    return true;
 }
 

src/BatchProcessDialog.cpp

@@ -461,7 +461,7 @@ void ApplyMacroDialog::OnApplyToFiles(wxCommandEvent & WXUNUSED(event))
       fileList->EnsureVisible(i);
 
       auto success = GuardedCall< bool >( [&] {
-         project->Import(files[i]);
+         ProjectManager::Get( *project ).Import(files[i]);
          ProjectWindow::Get( *project ).ZoomAfterImport(nullptr);
          SelectActions::DoSelectAll(*project);
          if (!mMacroCommands.ApplyMacro(mCatalog))
@@ -476,7 +476,7 @@ void ApplyMacroDialog::OnApplyToFiles(wxCommandEvent & WXUNUSED(event))
       if (!success)
          break;
       
-      project->ResetProjectToEmpty();
+      ProjectManager::Get( *project ).ResetProjectToEmpty();
    }
 
    Show();

src/HistoryWindow.cpp

@@ -254,7 +254,7 @@ void HistoryWindow::OnDiscard(wxCommandEvent & WXUNUSED(event))
 
    mSelected -= i;
    mManager->RemoveStates(i);
-   mProject->SetStateTo(mSelected + 1);
+   ProjectManager::Get( *mProject ).SetStateTo(mSelected + 1);
 
    while(--i >= 0)
       mList->DeleteItem(i);
@@ -292,7 +292,7 @@ void HistoryWindow::OnItemSelected(wxListEvent &event)
    // entry.  Doing so can cause unnecessary delays upon initial load or while
    // clicking the same entry over and over.
    if (selected != mSelected) {
-      mProject->SetStateTo(selected + 1);
+      ProjectManager::Get( *mProject ).SetStateTo(selected + 1);
    }
    mSelected = selected;
 

src/LabelTrack.cpp

@@ -1813,7 +1813,7 @@ unsigned LabelTrack::KeyDown(wxKeyEvent & event, ViewInfo &viewInfo, wxWindow *W
    // Pass keystroke to labeltrack's handler and add to history if any
    // updates were done
    if (OnKeyDown(viewInfo.selectedRegion, event)) {
-      pProj->PushState(_("Modified Label"),
+      ProjectManager::Get( *pProj ).PushState(_("Modified Label"),
          _("Label Edit"),
          UndoPush::CONSOLIDATE);
    }
@@ -1845,7 +1845,7 @@ unsigned LabelTrack::Char(wxKeyEvent & event, ViewInfo &viewInfo, wxWindow *)
    AudacityProject *const pProj = GetActiveProject();
 
    if (OnChar(viewInfo.selectedRegion, event))
-      pProj->PushState(_("Modified Label"),
+      ProjectManager::Get( *pProj ).PushState(_("Modified Label"),
       _("Label Edit"),
       UndoPush::CONSOLIDATE);
 
@@ -2130,13 +2130,13 @@ bool LabelTrack::OnChar(SelectedRegion &WXUNUSED(newSel), wxKeyEvent & event)
          }
          SetSelected(true);
          AddLabel(selectedRegion, title, -2);
-         p->PushState(_("Added label"), _("Label"));
+         ProjectManager::Get( *p ).PushState(_("Added label"), _("Label"));
          return false;
       }
       else {
          SetSelected(true);
          AddLabel(selectedRegion);
-         p->PushState(_("Added label"), _("Label"));
+         ProjectManager::Get( *p ).PushState(_("Added label"), _("Label"));
       }
    }
 
@@ -2230,7 +2230,7 @@ void LabelTrack::OnContextMenu(wxCommandEvent & evt)
    case OnCutSelectedTextID:
       if (CutSelectedText())
       {
-         p->PushState(_("Modified Label"),
+         ProjectManager::Get( *p ).PushState(_("Modified Label"),
                       _("Label Edit"),
                       UndoPush::CONSOLIDATE);
       }
@@ -2245,7 +2245,7 @@ void LabelTrack::OnContextMenu(wxCommandEvent & evt)
    case OnPasteSelectedTextID:
       if (PasteSelectedText(selectedRegion.t0(), selectedRegion.t1()))
       {
-         p->PushState(_("Modified Label"),
+         ProjectManager::Get( *p ).PushState(_("Modified Label"),
                       _("Label Edit"),
                       UndoPush::CONSOLIDATE);
       }
@@ -2257,7 +2257,7 @@ void LabelTrack::OnContextMenu(wxCommandEvent & evt)
       if (ndx != -1)
       {
          DeleteLabel(ndx);
-         p->PushState(_("Deleted Label"),
+         ProjectManager::Get( *p ).PushState(_("Deleted Label"),
                       _("Label Edit"),
                       UndoPush::CONSOLIDATE);
       }
@@ -3104,7 +3104,8 @@ void LabelTrack::DoEditLabels
 #endif
 
    if (dlg.ShowModal() == wxID_OK) {
-      project.PushState(_("Edited labels"), _("Label"));
+      ProjectManager::Get( project )
+         .PushState(_("Edited labels"), _("Label"));
       window.RedrawProject();
    }
 }

src/Menus.cpp

@@ -327,7 +327,8 @@ void MenuManager::ModifyUndoMenuItems(AudacityProject &project)
       commandManager.Modify(wxT("Undo"),
                              wxString::Format(_("&Undo %s"),
                                               desc));
-      commandManager.Enable(wxT("Undo"), project.UndoAvailable());
+      commandManager.Enable(wxT("Undo"),
+         ProjectManager::Get( project ).UndoAvailable());
    }
    else {
       commandManager.Modify(wxT("Undo"),
@@ -339,7 +340,8 @@ void MenuManager::ModifyUndoMenuItems(AudacityProject &project)
       commandManager.Modify(wxT("Redo"),
                              wxString::Format(_("&Redo %s"),
                                               desc));
-      commandManager.Enable(wxT("Redo"), project.RedoAvailable());
+      commandManager.Enable(wxT("Redo"),
+         ProjectManager::Get( project ).RedoAvailable());
    }
    else {
       commandManager.Modify(wxT("Redo"),
@@ -519,10 +521,11 @@ CommandFlag MenuManager::GetUpdateFlags
    if (!mLastEffect.empty())
       flags |= HasLastEffectFlag;
 
-   if (project.UndoAvailable())
+   auto &projectManager = ProjectManager::Get( project );
+   if (projectManager.UndoAvailable())
       flags |= UndoAvailableFlag;
 
-   if (project.RedoAvailable())
+   if (projectManager.RedoAvailable())
       flags |= RedoAvailableFlag;
 
    if (ViewInfo::Get( project ).ZoomInAvailable() && (flags & TracksExistFlag))

src/MixerBoard.cpp

@@ -412,7 +412,8 @@ void MixerTrackCluster::HandleSliderGain(const bool bWantPushState /*= false*/)
    // Update the TrackPanel correspondingly.
    TrackPanel::Get( *mProject ).RefreshTrack(mTrack.get());
    if (bWantPushState)
-      mProject->PushState(_("Moved gain slider"), _("Gain"), UndoPush::CONSOLIDATE );
+      ProjectManager::Get( *mProject )
+         .PushState(_("Moved gain slider"), _("Gain"), UndoPush::CONSOLIDATE );
 }
 
 #ifdef EXPERIMENTAL_MIDI_OUT
@@ -425,7 +426,9 @@ void MixerTrackCluster::HandleSliderVelocity(const bool bWantPushState /*= false
    // Update the TrackPanel correspondingly.
    TrackPanel::Get( *mProject ).RefreshTrack(mTrack.get());
    if (bWantPushState)
-      mProject->PushState(_("Moved velocity slider"), _("Velocity"), UndoPush::CONSOLIDATE);
+      ProjectManager::Get( *mProject )
+         .PushState(_("Moved velocity slider"), _("Velocity"),
+            UndoPush::CONSOLIDATE);
 }
 #endif
 
@@ -441,7 +444,9 @@ void MixerTrackCluster::HandleSliderPan(const bool bWantPushState /*= false*/)
    TrackPanel::Get( *mProject ).RefreshTrack(mTrack.get());
 
    if (bWantPushState)
-      mProject->PushState(_("Moved pan slider"), _("Pan"), UndoPush::CONSOLIDATE );
+      ProjectManager::Get( *mProject )
+         .PushState(_("Moved pan slider"), _("Pan"),
+            UndoPush::CONSOLIDATE );
 }
 
 void MixerTrackCluster::ResetMeter(const bool bResetClipping)

src/Project.h

@@ -35,8 +35,6 @@
 
 #include "xml/XMLTagHandler.h" // to inherit
 
-const int AudacityProjectTimerID = 5200;
-
 wxDECLARE_EXPORTED_EVENT(AUDACITY_DLL_API,
                          EVT_PROJECT_STATUS_UPDATE, wxCommandEvent);
 
@@ -61,7 +59,6 @@ struct UndoState;
 enum class UndoPush : unsigned char;
 
 
-AudacityProject *CreateNewAudacityProject();
 AUDACITY_DLL_API AudacityProject *GetActiveProject();
 
 void GetDefaultWindowRect(wxRect *defRect);
@@ -165,10 +162,7 @@ using AttachedWindows = ClientData::Site<
 using ProjectWindow = AudacityProject;
 class AUDACITY_DLL_API AudacityProject final : public wxFrame,
                                      public TrackPanelListener,
-                                     public SelectionBarListener,
-                                     public SpectralSelectionBarListener,
                                      public XMLTagHandler,
-                                     public AudioIOListener,
                                      private PrefsListener
    , public AttachedObjects
    , public AttachedWindows
@@ -200,47 +194,6 @@ class AUDACITY_DLL_API AudacityProject final : public wxFrame,
 
    bool IsActive() override;
 
-   // File I/O
-
-   /** @brief Show an open dialogue for opening audio files, and possibly other
-    * sorts of files.
-    *
-    * The file type filter will automatically contain:
-    * - "All files" with any extension or none,
-    * - "All supported files" based on the file formats supported in this
-    *   build of Audacity,
-    * - All of the individual formats specified by the importer plug-ins which
-    *   are built into this build of Audacity, each with the relevant file
-    *   extensions for that format.
-    * The dialogue will start in the DefaultOpenPath directory read from the
-    * preferences, failing that the working directory. The file format filter
-    * will be set to the DefaultOpenType from the preferences, failing that
-    * the first format specified in the dialogue. These two parameters will
-    * be saved to the preferences once the user has chosen a file to open.
-    * @param extraformat Specify the name of an additional format to allow
-    * opening in this dialogue. This string is free-form, but should be short
-    * enough to fit in the file dialogue filter drop-down. It should be
-    * translated.
-    * @param extrafilter Specify the file extension(s) for the additional format
-    * specified by extraformat. The patterns must include the wildcard (e.g.
-    * "*.aup" not "aup" or ".aup"), separate multiple patters with a semicolon,
-    * e.g. "*.aup;*.AUP" because patterns are case-sensitive. Do not add a
-    * trailing semicolon to the string. This string should not be translated
-    * @return Array of file paths which the user selected to open (multiple
-    * selections allowed).
-    */
-   static wxArrayString ShowOpenDialog(const wxString &extraformat = {},
-         const wxString &extrafilter = {});
-   static bool IsAlreadyOpen(const FilePath &projPathName);
-   static void OpenFiles(AudacityProject *proj);
-
-   // Return the given project if that is not NULL, else create a project.
-   // Then open the given project path.
-   // But if an exception escapes this function, create no NEW project.
-   static AudacityProject *OpenProject(
-      AudacityProject *pProject,
-      const FilePath &fileNameArg, bool addtohistory = true);
-
    struct ReadProjectResults
    {
       bool decodeError;
@@ -250,26 +203,14 @@ class AUDACITY_DLL_API AudacityProject final : public wxFrame,
    };
    ReadProjectResults ReadProjectFile( const FilePath &fileName );
 
-   void OpenFile(const FilePath &fileName, bool addtohistory = true);
-
-private:
    void EnqueueODTasks();
 
-public:
    using wxFrame::DetachMenuBar;
 
    bool WarnOfLegacyFile( );
 
-   // If pNewTrackList is passed in non-NULL, it gets filled with the pointers to NEW tracks.
-   bool Import(const FilePath &fileName, WaveTrackArray *pTrackArray = NULL);
-
    void ZoomAfterImport(Track *pTrack);
 
-   // Takes array of unique pointers; returns array of shared
-   std::vector< std::shared_ptr<Track> >
-   AddImportedTracks(const FilePath &fileName,
-                     TrackHolders &&newTracks);
-
    void CloseLock();
 
    bool Save();
@@ -283,7 +224,9 @@ private:
 public:
 
    const FilePath &GetFileName() { return mFileName; }
-   bool GetDirty() { return mDirty; }
+   void SetFileName( const FilePath &value ) { mFileName = value; }
+
+   const FilePath &GetAutoSaveFileName() { return mAutoSaveFileName; }
    void SetProjectTitle( int number =-1);
 
    wxWindow *GetMainPage() { return mMainPage; }
@@ -292,13 +235,8 @@ public:
    // Timer Record Auto Save/Export Routines
    bool SaveFromTimerRecording(wxFileName fnFile);
    bool IsProjectSaved();
-   void ResetProjectToEmpty();
-   void ResetProjectFileIO();
 
-   // Routine to estimate how many minutes of recording time are left on disk
+   void ResetProjectFileIO();
-   int GetEstimatedRecordingMinsLeftOnDisk(long lCaptureChannels = 0);
-   // Converts number of minutes to human readable format
-   wxString GetHoursMinsString(int iMinutes);
 
 
    // Message Handlers
@@ -316,10 +254,7 @@ public:
    void OnMove(wxMoveEvent & event);
    void DoScroll();
    void OnScroll(wxScrollEvent & event);
-   void OnCloseWindow(wxCloseEvent & event);
-   void OnTimer(wxTimerEvent & event);
    void OnToolBarUpdate(wxCommandEvent & event);
-   void OnOpenAudioFile(wxCommandEvent & event);
 
    void HandleResize();
    void UpdateLayout();
@@ -369,35 +304,7 @@ public:
    const wxString &GetStatus() const { return mLastMainStatusMessage; }
    void SetStatus(const wxString &msg);
 
-   void OnStatusChange( wxCommandEvent& );
-
-private:
-   bool SnapSelection();
-
 public:
-   // SelectionBarListener callback methods
-
-   double AS_GetRate() override;
-   void AS_SetRate(double rate) override;
-   int AS_GetSnapTo() override;
-   void AS_SetSnapTo(int snap) override;
-   const NumericFormatSymbol & AS_GetSelectionFormat() override;
-   void AS_SetSelectionFormat(const NumericFormatSymbol & format) override;
-   void AS_ModifySelection(double &start, double &end, bool done) override;
-
-   // SpectralSelectionBarListener callback methods
-
-   double SSBL_GetRate() const override;
-
-   const NumericFormatSymbol & SSBL_GetFrequencySelectionFormatName() override;
-   void SSBL_SetFrequencySelectionFormatName(const NumericFormatSymbol & formatName) override;
-
-   const NumericFormatSymbol & SSBL_GetBandwidthSelectionFormatName() override;
-   void SSBL_SetBandwidthSelectionFormatName(const NumericFormatSymbol & formatName) override;
-
-   void SSBL_ModifySpectralSelection(double &bottom, double &top, bool done) override;
-
-   void SetStateTo(unsigned int n);
 
    // XMLTagHandler callback methods
 
@@ -408,32 +315,13 @@ public:
 
    void WriteXMLHeader(XMLWriter &xmlFile) const;
 
-   // Audio IO callback methods
-   void OnAudioIORate(int rate) override;
-   void OnAudioIOStartRecording() override;
-   void OnAudioIOStopRecording() override;
-   void OnAudioIONewBlockFiles(const AutoSaveFile & blockFileLog) override;
-
-   bool UndoAvailable();
-   bool RedoAvailable();
-
-   void PushState(const wxString &desc, const wxString &shortDesc); // use UndoPush::AUTOSAVE
-   void PushState(const wxString &desc, const wxString &shortDesc, UndoPush flags);
-   void RollbackState();
-
-
  private:
 
    void OnThemeChange(wxCommandEvent & evt);
-   void InitialState();
 
  public:
-   void ModifyState(bool bWantsAutoSave);    // if true, writes auto-save file. Should set only if you really want the state change restored after
-                                             // a crash, as it can take many seconds for large (eg. 10 track-hours) projects
-
-   void PopState(const UndoState &state);
-
    void AutoSave();
+
    void DeleteCurrentAutoSaveFile();
 
  private:
@@ -448,13 +336,10 @@ public:
    std::shared_ptr<TrackList> mLastSavedTracks;
 
 private:
-   bool mDirty{ false };
 
    // Window elements
 
    wxString mLastMainStatusMessage;
-   std::unique_ptr<wxTimer> mTimer;
-   void RestartTimer();
 
    wxPanel *mTopPanel{};
    wxWindow * mMainPage;
@@ -481,24 +366,21 @@ private:
    void SetNormalizedWindowState(wxRect pSizeAndLocation) {  mNormalizedWindowState = pSizeAndLocation;   }
    wxRect GetNormalizedWindowState() const { return mNormalizedWindowState;   }
 
-   bool IsTimerRecordCancelled(){return mTimerRecordCanceled;}
-   void SetTimerRecordCancelled(){mTimerRecordCanceled=true;}
-   void ResetTimerRecordCancelled(){mTimerRecordCanceled=false;}
-
  private:
    bool mIsDeleting{ false };
 
 public:
    bool IsBeingDeleted() const { return mIsDeleting; }
    void SetIsBeingDeleted() { mIsDeleting = true; }
+   bool IsRecovered() const { return mIsRecovered; }
+   void SetImportedDependencies( bool value ) { mImportedDependencies = value; }
+   void SetLoadedFromAup( bool value ) { mbLoadedFromAup = value; }
 private:
 
    bool mLockPlayRegion;
 
-   std::unique_ptr<ImportXMLTagHandler> mImportXMLTagHandler;
-
    // Last auto-save file name and path (empty if none)
-   wxString mAutoSaveFileName;
+   FilePath mAutoSaveFileName;
 
    // Are we currently auto-saving or not?
    bool mAutoSaving{ false };
@@ -509,9 +391,6 @@ private:
    // The auto-save data dir the project has been recovered from
    wxString mRecoveryAutoSaveDataDir;
 
-   // The handler that handles recovery of <recordingrecovery> tags
-   std::unique_ptr<RecordingRecoveryHandler> mRecordingRecoveryHandler;
-
    // Dependencies have been imported and a warning should be shown on save
    bool mImportedDependencies{ false };
 
@@ -519,16 +398,6 @@ private:
 
    wxRect mNormalizedWindowState;
 
-   //flag for cancellation of timer record.
-   bool mTimerRecordCanceled{ false  };
-
-   // Are we currently closing as the result of a menu command?
-   bool mMenuClose{ false };
-
-public:
-   void SetMenuClose(bool value) { mMenuClose = value; }
-
-private:
    bool mbInitializingScrollbar{ false };
 
 public:
@@ -560,14 +429,175 @@ public:
 private:
    std::unique_ptr<PlaybackScroller> mPlaybackScroller;
 
+public:
+   PlaybackScroller &GetPlaybackScroller() { return *mPlaybackScroller; }
+
+   DECLARE_EVENT_TABLE()
+};
+
+class ProjectManager final
+   : public wxEvtHandler
+   , public ClientData::Base
+   , public AudioIOListener
+   , private SelectionBarListener
+   , private SpectralSelectionBarListener
+{
+public:
+   static ProjectManager &Get( AudacityProject &project );
+   static const ProjectManager &Get( const AudacityProject &project );
+
+   explicit ProjectManager( AudacityProject &project );
+   ~ProjectManager() override;
+
+   // This is the factory for projects:
+   static AudacityProject *New();
+
+   // File I/O
+
+   /** @brief Show an open dialogue for opening audio files, and possibly other
+    * sorts of files.
+    *
+    * The file type filter will automatically contain:
+    * - "All files" with any extension or none,
+    * - "All supported files" based on the file formats supported in this
+    *   build of Audacity,
+    * - All of the individual formats specified by the importer plug-ins which
+    *   are built into this build of Audacity, each with the relevant file
+    *   extensions for that format.
+    * The dialogue will start in the DefaultOpenPath directory read from the
+    * preferences, failing that the working directory. The file format filter
+    * will be set to the DefaultOpenType from the preferences, failing that
+    * the first format specified in the dialogue. These two parameters will
+    * be saved to the preferences once the user has chosen a file to open.
+    * @param extraformat Specify the name of an additional format to allow
+    * opening in this dialogue. This string is free-form, but should be short
+    * enough to fit in the file dialogue filter drop-down. It should be
+    * translated.
+    * @param extrafilter Specify the file extension(s) for the additional format
+    * specified by extraformat. The patterns must include the wildcard (e.g.
+    * "*.aup" not "aup" or ".aup"), separate multiple patters with a semicolon,
+    * e.g. "*.aup;*.AUP" because patterns are case-sensitive. Do not add a
+    * trailing semicolon to the string. This string should not be translated
+    * @return Array of file paths which the user selected to open (multiple
+    * selections allowed).
+    */
+   static wxArrayString ShowOpenDialog(const wxString &extraformat = {},
+         const wxString &extrafilter = {});
+
+   static bool IsAlreadyOpen(const FilePath &projPathName);
+
+   // The functions that open and import files can act as factories too, and
+   // they set projects to initial state.
+   static void OpenFiles(AudacityProject *proj);
+   
+   void OpenFile(const FilePath &fileName, bool addtohistory = true);
+
+   // Return the given project if that is not NULL, else create a project.
+   // Then open the given project path.
+   // But if an exception escapes this function, create no NEW project.
+   static AudacityProject *OpenProject(
+      AudacityProject *pProject,
+      const FilePath &fileNameArg, bool addtohistory = true);
+
+   // If pNewTrackList is passed in non-NULL, it gets filled with the pointers to NEW tracks.
+   bool Import(const FilePath &fileName, WaveTrackArray *pTrackArray = NULL);
+
+   // Takes array of unique pointers; returns array of shared
+   std::vector< std::shared_ptr<Track> >
+   AddImportedTracks(const FilePath &fileName,
+                     TrackHolders &&newTracks);
+
+   bool GetDirty() { return mDirty; }
+
+   void ResetProjectToEmpty();
+
+   // Routine to estimate how many minutes of recording time are left on disk
+   int GetEstimatedRecordingMinsLeftOnDisk(long lCaptureChannels = 0);
+   // Converts number of minutes to human readable format
+   wxString GetHoursMinsString(int iMinutes);
+
+   void SetStateTo(unsigned int n);
+   bool UndoAvailable();
+   bool RedoAvailable();
+   void PushState(const wxString &desc, const wxString &shortDesc); // use UndoPush::AUTOSAVE
+   void PushState(const wxString &desc, const wxString &shortDesc, UndoPush flags);
+   void RollbackState();
+   void ModifyState(bool bWantsAutoSave);    // if true, writes auto-save file.
+      // Should set only if you really want the state change restored after
+      // a crash, as it can take many seconds for large (eg. 10 track-hours)
+      // projects
+   void PopState(const UndoState &state);
+
+   bool IsTimerRecordCancelled() { return mTimerRecordCanceled; }
+   void SetTimerRecordCancelled() { mTimerRecordCanceled = true; }
+   void ResetTimerRecordCancelled() { mTimerRecordCanceled = false; }
+
+   void SetMenuClose(bool value) { mMenuClose = value; }
+
+   // SelectionBarListener callback methods
+   double AS_GetRate() override;
+   void AS_SetRate(double rate) override;
+   int AS_GetSnapTo() override;
+   void AS_SetSnapTo(int snap) override;
+   const NumericFormatSymbol & AS_GetSelectionFormat() override;
+   void AS_SetSelectionFormat(const NumericFormatSymbol & format) override;
+   void AS_ModifySelection(double &start, double &end, bool done) override;
+
+   // SpectralSelectionBarListener callback methods
+   double SSBL_GetRate() const override;
+   const NumericFormatSymbol & SSBL_GetFrequencySelectionFormatName() override;
+   void SSBL_SetFrequencySelectionFormatName(
+      const NumericFormatSymbol & formatName) override;
+   const NumericFormatSymbol & SSBL_GetBandwidthSelectionFormatName() override;
+   void SSBL_SetBandwidthSelectionFormatName(
+      const NumericFormatSymbol & formatName) override;
+   void SSBL_ModifySpectralSelection(
+      double &bottom, double &top, bool done) override;
+
+private:
+   void OnCloseWindow(wxCloseEvent & event);
+   void OnTimer(wxTimerEvent & event);
+   void OnOpenAudioFile(wxCommandEvent & event);
+   void OnStatusChange( wxCommandEvent& );
+
+   bool SnapSelection();
+
+   // Audio IO callback methods
+   void OnAudioIORate(int rate) override;
+   void OnAudioIOStartRecording() override;
+   void OnAudioIOStopRecording() override;
+   void OnAudioIONewBlockFiles(const AutoSaveFile & blockFileLog) override;
+
+   void InitialState();
+
+   void RestartTimer();
+
    // Declared in this class so that they can have access to private members
    static XMLTagHandler *RecordingRecoveryFactory( AudacityProject &project );
    static ProjectFileIORegistry::Entry sRecoveryFactory;
    static XMLTagHandler *ImportHandlerFactory( AudacityProject &project );
    static ProjectFileIORegistry::Entry sImportHandlerFactory;
 
-public:
+   // non-static data members
-   PlaybackScroller &GetPlaybackScroller() { return *mPlaybackScroller; }
+   AudacityProject &mProject;
+
+   // The handler that handles recovery of <recordingrecovery> tags
+   std::unique_ptr<RecordingRecoveryHandler> mRecordingRecoveryHandler;
+
+   std::unique_ptr<ImportXMLTagHandler> mImportXMLTagHandler;
+
+   std::unique_ptr<wxTimer> mTimer;
+
+   bool mDirty{ false };
+
+   // See explanation in OnCloseWindow
+   bool mIsBeingDeleted{ false };
+
+   // Are we currently closing as the result of a menu command?
+   bool mMenuClose{ false };
+
+   //flag for cancellation of timer record.
+   bool mTimerRecordCanceled{ false };
 
    DECLARE_EVENT_TABLE()
 };

src/TimerRecordDialog.cpp

@@ -417,9 +417,10 @@ void TimerRecordDialog::OnOK(wxCommandEvent& WXUNUSED(event))
    // as its possible that they plan to free up some
    // space before the recording begins
    AudacityProject* pProject = GetActiveProject();
+   auto &projectManager = ProjectManager::Get( *pProject );
 
    // How many minutes do we have left on the disc?
-   int iMinsLeft = pProject->GetEstimatedRecordingMinsLeftOnDisk();
+   int iMinsLeft = projectManager.GetEstimatedRecordingMinsLeftOnDisk();
 
    // How many minutes will this recording require?
    int iMinsRecording = m_TimeSpan_Duration.GetMinutes();
@@ -429,9 +430,9 @@ void TimerRecordDialog::OnOK(wxCommandEvent& WXUNUSED(event))
 
       // Format the strings
       wxString sRemainingTime;
-      sRemainingTime = pProject->GetHoursMinsString(iMinsLeft);
+      sRemainingTime = projectManager.GetHoursMinsString(iMinsLeft);
       wxString sPlannedTime;
-      sPlannedTime = pProject->GetHoursMinsString(iMinsRecording);
+      sPlannedTime = projectManager.GetHoursMinsString(iMinsRecording);
 
       // Create the message string
       wxString sMessage;

src/TrackPanel.cpp

@@ -610,7 +610,7 @@ void TrackPanel::OnPaint(wxPaintEvent & /* event */)
 
 void TrackPanel::MakeParentModifyState(bool bWantsAutoSave)
 {
-   GetProject()->ModifyState(bWantsAutoSave);
+   ProjectManager::Get( *GetProject() ).ModifyState(bWantsAutoSave);
 }
 
 void TrackPanel::MakeParentRedrawScrollbars()

src/TrackPanelResizeHandle.cpp

@@ -219,7 +219,7 @@ UIHandle::Result TrackPanelResizeHandle::Release
    ///  We also modify the undo state (the action doesn't become
    ///  undo-able, but it gets merged with the previous undo-able
    ///  event).
-   pProject->ModifyState(false);
+   ProjectManager::Get( *pProject ).ModifyState(false);
    return RefreshCode::FixScrollbars;
 }
 

src/commands/ImportExportCommands.cpp

@@ -41,7 +41,7 @@ void ImportCommand::PopulateOrExchange(ShuttleGui & S)
 }
 
 bool ImportCommand::Apply(const CommandContext & context){
-   return context.project.Import(mFileName);
+   return ProjectManager::Get( context.project ).Import(mFileName);
 }
 
 

src/commands/OpenSaveCommands.cpp

@@ -48,11 +48,12 @@ bool OpenProjectCommand::Apply(const CommandContext & context){
    if(mFileName.empty())
    {
       auto project = &context.project;
-      AudacityProject::OpenFiles(project);
+      ProjectManager::OpenFiles(project);
    }
    else
    {
-      context.project.OpenFile(mFileName, mbAddToHistory);
+      ProjectManager::Get( context.project )
+         .OpenFile(mFileName, mbAddToHistory);
    }
    const auto &newFileName = context.project.GetFileName();
 

src/commands/SelectCommand.cpp

@@ -165,7 +165,7 @@ bool SelectFrequenciesCommand::Apply(const CommandContext & context){
    if( !bHasBottom )
       mBottom = 0.0;
 
-   context.project.SSBL_ModifySpectralSelection(
+   ProjectManager::Get( context.project ).SSBL_ModifySpectralSelection(
       mBottom, mTop, false);// false for not done.
    return true;
 }

src/effects/EffectRack.cpp

@@ -297,7 +297,7 @@ void EffectRack::OnApply(wxCommandEvent & WXUNUSED(evt))
    auto state = UndoManager::Get( *project ).GetCurrentState();
    auto cleanup = finally( [&] {
       if(!success)
-         project->SetStateTo(state);
+         ProjectManager::Get( *project ).SetStateTo( state );
    } );
 
    for (size_t i = 0, cnt = mEffects.size(); i < cnt; i++)

src/import/ImportLOF.cpp

@@ -385,7 +385,7 @@ void LOFImportFileHandle::lofOpenFiles(wxString* ln)
           * audio file. TODO: Some sort of message here? */
 
 #endif // USE_MIDI
-         mProject = AudacityProject::OpenProject( mProject, targetfile );
+         mProject = ProjectManager::OpenProject( mProject, targetfile );
 
       // Set tok to right after filename
       temptok2.SetString(targettoken);
@@ -440,7 +440,7 @@ void LOFImportFileHandle::lofOpenFiles(wxString* ln)
                }
 
                // Amend the undo transaction made by import
-               mProject->ModifyState(false);
+               ProjectManager::Get( *mProject ).ModifyState(false);
             } // end of converting "offset" argument
             else
             {
@@ -484,7 +484,7 @@ void LOFImportFileHandle::doDurationAndScrollOffset()
 
    if (doSomething)
       // Amend last undo state
-      mProject->ModifyState(false);
+      ProjectManager::Get( *mProject ).ModifyState(false);
 }
 
 LOFImportFileHandle::~LOFImportFileHandle()

src/menus/ClipMenus.cpp

@@ -389,7 +389,7 @@ void DoSelectClipBoundary(AudacityProject &project, bool next)
       else
          selectedRegion.setT0(results[0].time);
 
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.Refresh(false);
 
       wxString message = ClipBoundaryMessage(results);
@@ -572,7 +572,7 @@ void DoSelectClip(AudacityProject &project, bool next)
       double t0 = results[0].startTime;
       double t1 = results[0].endTime;
       selectedRegion.setTimes(t0, t1);
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.ScrollIntoView(selectedRegion.t0());
       trackPanel.Refresh(false);
 
@@ -618,7 +618,7 @@ void DoCursorClipBoundary
       // value.
       double time = results[0].time;
       selectedRegion.setTimes(time, time);
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.ScrollIntoView(selectedRegion.t0());
       trackPanel.Refresh(false);
 
@@ -720,7 +720,8 @@ void DoClipLeftOrRight
       // keypress (keydown, then keyup), and holding down a key
       // (multiple keydowns followed by a keyup) result in a single
       // entry in Audacity's history dialog.
-      project.PushState(message, _("Time-Shift"), UndoPush::CONSOLIDATE);
+      ProjectManager::Get( project )
+         .PushState(message, _("Time-Shift"), UndoPush::CONSOLIDATE);
    }
 
    if ( amount == 0.0 )

src/menus/EditMenus.cpp

@@ -49,7 +49,8 @@ bool DoPasteText(AudacityProject &project)
          if (pLabelTrack->PasteSelectedText(selectedRegion.t0(),
                                             selectedRegion.t1()))
          {
-            project.PushState(_("Pasted text from the clipboard"), _("Paste"));
+            ProjectManager::Get( project )
+               .PushState(_("Pasted text from the clipboard"), _("Paste"));
 
             // Make sure caret is in view
             int x;
@@ -148,7 +149,8 @@ bool DoPasteNothingSelected(AudacityProject &project)
                 // half a sample earlier
          quantT1 - quantT0);
 
-      project.PushState(_("Pasted from the clipboard"), _("Paste"));
+      ProjectManager::Get( project )
+         .PushState(_("Pasted from the clipboard"), _("Paste"));
 
       window.RedrawProject();
 
@@ -216,7 +218,7 @@ bool DoEditMetadata
       if (tags != *newTags) {
          // Commit the change to project state only now.
          Tags::Set( project, newTags );
-         project.PushState(title, shortUndoDescription);
+         ProjectManager::Get( project ).PushState(title, shortUndoDescription);
       }
       bool bShowInFuture;
       gPrefs->Read(wxT("/AudioFiles/ShowId3Dialog"), &bShowInFuture, true);
@@ -233,7 +235,7 @@ void DoUndo(AudacityProject &project)
    auto &undoManager = UndoManager::Get( project );
    auto &window = ProjectWindow::Get( project );
 
-   if (!project.UndoAvailable()) {
+   if (!ProjectManager::Get( project ).UndoAvailable()) {
       AudacityMessageBox(_("Nothing to undo"));
       return;
    }
@@ -244,7 +246,8 @@ void DoUndo(AudacityProject &project)
    }
 
    undoManager.Undo(
-      [&]( const UndoState &state ){ project.PopState( state ); } );
+      [&]( const UndoState &state ){
+         ProjectManager::Get( project ).PopState( state ); } );
 
    trackPanel.EnsureVisible(trackPanel.GetFirstSelectedTrack());
 
@@ -269,7 +272,7 @@ void OnRedo(const CommandContext &context)
    auto &undoManager = UndoManager::Get( project );
    auto &window = ProjectWindow::Get( project );
 
-   if (!project.RedoAvailable()) {
+   if (!ProjectManager::Get( project ).RedoAvailable()) {
       AudacityMessageBox(_("Nothing to redo"));
       return;
    }
@@ -279,7 +282,8 @@ void OnRedo(const CommandContext &context)
    }
 
    undoManager.Redo(
-      [&]( const UndoState &state ){ project.PopState( state ); } );
+      [&]( const UndoState &state ){
+         ProjectManager::Get( project ).PopState( state ); } );
 
    trackPanel.EnsureVisible(trackPanel.GetFirstSelectedTrack());
 
@@ -366,7 +370,7 @@ void OnCut(const CommandContext &context)
 
    selectedRegion.collapseToT0();
 
-   project.PushState(_("Cut to the clipboard"), _("Cut"));
+   ProjectManager::Get( project ).PushState(_("Cut to the clipboard"), _("Cut"));
 
    // Bug 1663
    //mRuler->ClearPlayRegion();
@@ -392,7 +396,7 @@ void OnDelete(const CommandContext &context)
 
    selectedRegion.collapseToT0();
 
-   project.PushState(wxString::Format(_("Deleted %.2f seconds at t=%.2f"),
+   ProjectManager::Get( project ).PushState(wxString::Format(_("Deleted %.2f seconds at t=%.2f"),
                               seconds,
                               selectedRegion.t0()),
              _("Delete"));
@@ -692,7 +696,8 @@ void OnPaste(const CommandContext &context)
    {
       selectedRegion.setT1( t0 + clipboard.Duration() );
 
-      project.PushState(_("Pasted from the clipboard"), _("Paste"));
+      ProjectManager::Get( project )
+         .PushState(_("Pasted from the clipboard"), _("Paste"));
 
       window.RedrawProject();
 
@@ -724,7 +729,7 @@ void OnDuplicate(const CommandContext &context)
          break;
    }
 
-   project.PushState(_("Duplicated"), _("Duplicate"));
+   ProjectManager::Get( project ).PushState(_("Duplicated"), _("Duplicate"));
 
    window.RedrawProject();
 }
@@ -766,7 +771,7 @@ void OnSplitCut(const CommandContext &context)
    clipboard.Assign( std::move( newClipboard ),
       selectedRegion.t0(), selectedRegion.t1(), &project );
 
-   project.PushState(_("Split-cut to the clipboard"), _("Split Cut"));
+   ProjectManager::Get( project ).PushState(_("Split-cut to the clipboard"), _("Split Cut"));
 
    window.RedrawProject();
 }
@@ -789,7 +794,7 @@ void OnSplitDelete(const CommandContext &context)
       }
    );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       wxString::Format(_("Split-deleted %.2f seconds at t=%.2f"),
          selectedRegion.duration(),
          selectedRegion.t0()),
@@ -808,7 +813,7 @@ void OnSilence(const CommandContext &context)
    for ( auto n : tracks.Selected< AudioTrack >() )
       n->Silence(selectedRegion.t0(), selectedRegion.t1());
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       wxString::Format(_("Silenced selected tracks for %.2f seconds at %.2f"),
          selectedRegion.duration(),
          selectedRegion.t0()),
@@ -841,7 +846,7 @@ void OnTrim(const CommandContext &context)
       }
    );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       wxString::Format(
          _("Trim selected audio tracks from %.2f seconds to %.2f seconds"),
          selectedRegion.t0(), selectedRegion.t1()),
@@ -863,7 +868,7 @@ void OnSplit(const CommandContext &context)
    for (auto wt : tracks.Selected< WaveTrack >())
       wt->Split( sel0, sel1 );
 
-   project.PushState(_("Split"), _("Split"));
+   ProjectManager::Get( project ).PushState(_("Split"), _("Split"));
    trackPanel.Refresh(false);
 #if 0
 //ANSWER-ME: Do we need to keep this commented out OnSplit() code?
@@ -963,7 +968,8 @@ void OnSplitNew(const CommandContext &context)
          break;
    }
 
-   project.PushState(_("Split to new track"), _("Split New"));
+   ProjectManager::Get( project )
+      .PushState(_("Split to new track"), _("Split New"));
 
    window.RedrawProject();
 }
@@ -979,7 +985,7 @@ void OnJoin(const CommandContext &context)
       wt->Join(selectedRegion.t0(),
                selectedRegion.t1());
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       wxString::Format(_("Joined %.2f seconds at t=%.2f"),
          selectedRegion.duration(),
          selectedRegion.t0()),
@@ -999,7 +1005,7 @@ void OnDisjoin(const CommandContext &context)
       wt->Disjoin(selectedRegion.t0(),
                   selectedRegion.t1());
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       wxString::Format(_("Detached %.2f seconds at t=%.2f"),
          selectedRegion.duration(),
          selectedRegion.t0()),

src/menus/FileMenus.cpp

@@ -116,7 +116,7 @@ AudacityProject *DoImportMIDI(
 
    AudacityProject *pNewProject {};
    if ( !pProject )
-      pProject = pNewProject = CreateNewAudacityProject();
+      pProject = pNewProject = ProjectManager::New();
    auto cleanup = finally( [&]
       { if ( pNewProject ) GetProjectFrame( *pNewProject ).Close(true); } );
 
@@ -128,7 +128,8 @@ AudacityProject *DoImportMIDI(
       auto pTrack = tracks.Add( newTrack );
       pTrack->SetSelected(true);
 
-      pProject->PushState(wxString::Format(_("Imported MIDI from '%s'"),
+      ProjectManager::Get( *pProject )
+         .PushState(wxString::Format(_("Imported MIDI from '%s'"),
          fileName), _("Import MIDI"));
 
       ProjectWindow::Get( *pProject ).ZoomAfterImport(pTrack);
@@ -151,13 +152,13 @@ struct Handler : CommandHandlerObject {
 
 void OnNew(const CommandContext & )
 {
-   CreateNewAudacityProject();
+   ( void ) ProjectManager::New();
 }
 
 void OnOpen(const CommandContext &context )
 {
    auto &project = context.project;
-   AudacityProject::OpenFiles(&project);
+   ProjectManager::OpenFiles(&project);
 }
 
 // JKC: This is like OnClose, except it emptys the project in place,
@@ -168,14 +169,14 @@ void OnOpen(const CommandContext &context )
 void OnProjectReset(const CommandContext &context)
 {
    auto &project = context.project;
-   project.ResetProjectToEmpty();
+   ProjectManager::Get( project ).ResetProjectToEmpty();
 }
 
 void OnClose(const CommandContext &context )
 {
    auto &project = context.project;
-   auto &window = GetProjectFrame( project );
+   auto &window = ProjectWindow::Get( project );
-   project.SetMenuClose(true);
+   ProjectManager::Get( project ).SetMenuClose(true);
    window.Close();
 }
 
@@ -405,7 +406,7 @@ void OnImport(const CommandContext &context)
    // this serves to track the file if the users zooms in and such.
    MissingAliasFilesDialog::SetShouldShow(true);
 
-   wxArrayString selectedFiles = project.ShowOpenDialog(wxT(""));
+   wxArrayString selectedFiles = ProjectManager::ShowOpenDialog(wxT(""));
    if (selectedFiles.size() == 0) {
       gPrefs->Write(wxT("/LastOpenType"),wxT(""));
       gPrefs->Flush();
@@ -435,7 +436,7 @@ void OnImport(const CommandContext &context)
 
       FileNames::UpdateDefaultPath(FileNames::Operation::Open, fileName);
 
-      project.Import(fileName);
+      ProjectManager::Get( project ).Import(fileName);
    }
 
    window.ZoomAfterImport(nullptr);
@@ -479,8 +480,8 @@ void OnImportLabels(const CommandContext &context)
       newTrack->SetSelected(true);
       tracks.Add( newTrack );
 
-      project.PushState(wxString::
+      ProjectManager::Get( project ).PushState(
-                Format(_("Imported labels from '%s'"), fileName),
+         wxString::Format(_("Imported labels from '%s'"), fileName),
             _("Import Labels"));
 
       window.ZoomAfterImport(nullptr);
@@ -532,7 +533,7 @@ void OnImportRaw(const CommandContext &context)
    if (newTracks.size() <= 0)
       return;
 
-   project.AddImportedTracks(fileName, std::move(newTracks));
+   ProjectManager::Get( project ).AddImportedTracks(fileName, std::move(newTracks));
    window.HandleResize(); // Adjust scrollers for NEW track sizes.
 }
 

src/menus/HelpMenus.cpp

@@ -251,7 +251,7 @@ void QuickFixDialog::OnFix(wxCommandEvent &event)
       // preference dialogs.
       if( Str == "/SnapTo" )
       {
-         pProject->AS_SetSnapTo( 0 );
+         ProjectManager::Get( *pProject ).AS_SetSnapTo( 0 );
       }
       else
       {

src/menus/LabelMenus.cpp

@@ -71,7 +71,7 @@ int DoAddLabel(
 
    int index = lt->AddLabel(region, title, focusTrackNumber);
 
-   project.PushState(_("Added label"), _("Label"));
+   ProjectManager::Get( project ).PushState(_("Added label"), _("Label"));
 
    window.RedrawProject();
    if (!useDialog) {
@@ -336,7 +336,7 @@ void OnPasteNewLabel(const CommandContext &context)
    }
 
    if (bPastedSomething) {
-      project.PushState(
+      ProjectManager::Get( project ).PushState(
          _("Pasted from the clipboard"), _("Paste Text to New Label"));
 
       // Is this necessary? (carried over from former logic in OnPaste())
@@ -376,7 +376,7 @@ void OnCutLabels(const CommandContext &context)
 
    selectedRegion.collapseToT0();
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
    /* i18n-hint: (verb) past tense.  Audacity has just cut the labeled audio
       regions.*/
       _( "Cut labeled audio regions to clipboard" ),
@@ -400,7 +400,7 @@ void OnDeleteLabels(const CommandContext &context)
 
    selectedRegion.collapseToT0();
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       /* i18n-hint: (verb) Audacity has just deleted the labeled audio regions*/
       _( "Deleted labeled audio regions" ),
       /* i18n-hint: (verb)*/
@@ -422,7 +422,7 @@ void OnSplitCutLabels(const CommandContext &context)
    EditClipboardByLabel( project,
       tracks, selectedRegion, &WaveTrack::SplitCut );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       /* i18n-hint: (verb) Audacity has just split cut the labeled audio
          regions*/
       _( "Split Cut labeled audio regions to clipboard" ),
@@ -444,7 +444,7 @@ void OnSplitDeleteLabels(const CommandContext &context)
 
    EditByLabel( tracks, selectedRegion, &WaveTrack::SplitDelete, false );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       /* i18n-hint: (verb) Audacity has just done a special kind of DELETE on
          the labeled audio regions */
       _( "Split Deleted labeled audio regions" ),
@@ -467,7 +467,7 @@ void OnSilenceLabels(const CommandContext &context)
 
    EditByLabel( tracks, selectedRegion, &WaveTrack::Silence, false );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       /* i18n-hint: (verb)*/
       _( "Silenced labeled audio regions" ),
       /* i18n-hint: (verb)*/
@@ -489,7 +489,7 @@ void OnCopyLabels(const CommandContext &context)
    EditClipboardByLabel( project,
       tracks, selectedRegion, &WaveTrack::CopyNonconst );
 
-   project.PushState( _( "Copied labeled audio regions to clipboard" ),
+   ProjectManager::Get( project ).PushState( _( "Copied labeled audio regions to clipboard" ),
    /* i18n-hint: (verb)*/
       _( "Copy Labeled Audio" ) );
 
@@ -505,7 +505,7 @@ void OnSplitLabels(const CommandContext &context)
 
    EditByLabel( tracks, selectedRegion, &WaveTrack::Split, false );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       /* i18n-hint: (verb) past tense.  Audacity has just split the labeled
          audio (a point or a region)*/
       _( "Split labeled audio (points or regions)" ),
@@ -527,7 +527,7 @@ void OnJoinLabels(const CommandContext &context)
 
    EditByLabel( tracks, selectedRegion, &WaveTrack::Join, false );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       /* i18n-hint: (verb) Audacity has just joined the labeled audio (points or
          regions) */
       _( "Joined labeled audio (points or regions)" ),
@@ -549,7 +549,7 @@ void OnDisjoinLabels(const CommandContext &context)
 
    EditByLabel( tracks, selectedRegion, &WaveTrack::Disjoin, false );
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       /* i18n-hint: (verb) Audacity has just detached the labeled audio regions.
       This message appears in history and tells you about something
       Audacity has done.*/

src/menus/NavigationMenus.cpp

@@ -84,6 +84,7 @@ void NextOrPrevFrame(AudacityProject &project, bool forward)
 void DoPrevTrack(
    AudacityProject &project, bool shift, bool circularTrackNavigation )
 {
+   auto &projectManager = ProjectManager::Get( project );
    auto &trackPanel = TrackPanel::Get( project );
    auto &tracks = TrackList::Get( project );
    auto &selectionState = SelectionState::Get( project );
@@ -94,7 +95,7 @@ void DoPrevTrack(
       t = *tracks.Any().rbegin();
       trackPanel.SetFocusedTrack( t );
       trackPanel.EnsureVisible( t );
-      project.ModifyState(false);
+      projectManager.ModifyState(false);
       return;
    }
 
@@ -126,7 +127,7 @@ void DoPrevTrack(
             ( *t, false, false );
          trackPanel.SetFocusedTrack( p );   // move focus to next track up
          trackPanel.EnsureVisible( p );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
       if( tSelected && !pSelected )
@@ -135,7 +136,7 @@ void DoPrevTrack(
             ( *p, true, false );
          trackPanel.SetFocusedTrack( p );   // move focus to next track up
          trackPanel.EnsureVisible( p );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
       if( !tSelected && pSelected )
@@ -144,7 +145,7 @@ void DoPrevTrack(
             ( *p, false, false );
          trackPanel.SetFocusedTrack( p );   // move focus to next track up
          trackPanel.EnsureVisible( p );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
       if( !tSelected && !pSelected )
@@ -153,7 +154,7 @@ void DoPrevTrack(
             ( *t, true, false );
          trackPanel.SetFocusedTrack( p );   // move focus to next track up
          trackPanel.EnsureVisible( p );
-          project.ModifyState(false);
+          projectManager.ModifyState(false);
          return;
       }
    }
@@ -169,7 +170,7 @@ void DoPrevTrack(
             p = * range.rbegin(); // null if range is empty
             trackPanel.SetFocusedTrack( p );   // Wrap to the last track
             trackPanel.EnsureVisible( p );
-             project.ModifyState(false);
+             projectManager.ModifyState(false);
             return;
          }
          else
@@ -182,7 +183,7 @@ void DoPrevTrack(
       {
          trackPanel.SetFocusedTrack( p );   // move focus to next track up
          trackPanel.EnsureVisible( p );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
    }
@@ -194,6 +195,7 @@ void DoPrevTrack(
 void DoNextTrack(
    AudacityProject &project, bool shift, bool circularTrackNavigation )
 {
+   auto &projectManager = ProjectManager::Get( project );
    auto &trackPanel = TrackPanel::Get( project );
    auto &tracks = TrackList::Get( project );
    auto &selectionState = SelectionState::Get( project );
@@ -204,7 +206,7 @@ void DoNextTrack(
       t = *tracks.Any().begin();
       trackPanel.SetFocusedTrack( t );
       trackPanel.EnsureVisible( t );
-      project.ModifyState(false);
+      projectManager.ModifyState(false);
       return;
    }
 
@@ -230,7 +232,7 @@ void DoNextTrack(
             ( *t, false, false );
          trackPanel.SetFocusedTrack( n );   // move focus to next track down
          trackPanel.EnsureVisible( n );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
       if( tSelected && !nSelected )
@@ -239,7 +241,7 @@ void DoNextTrack(
             ( *n, true, false );
          trackPanel.SetFocusedTrack( n );   // move focus to next track down
          trackPanel.EnsureVisible( n );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
       if( !tSelected && nSelected )
@@ -248,7 +250,7 @@ void DoNextTrack(
             ( *n, false, false );
          trackPanel.SetFocusedTrack( n );   // move focus to next track down
          trackPanel.EnsureVisible( n );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
       if( !tSelected && !nSelected )
@@ -257,7 +259,7 @@ void DoNextTrack(
             ( *t, true, false );
          trackPanel.SetFocusedTrack( n );   // move focus to next track down
          trackPanel.EnsureVisible( n );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
    }
@@ -272,7 +274,7 @@ void DoNextTrack(
             n = *tracks.Any().begin();
             trackPanel.SetFocusedTrack( n );   // Wrap to the first track
             trackPanel.EnsureVisible( n );
-            project.ModifyState(false);
+            projectManager.ModifyState(false);
             return;
          }
          else
@@ -285,7 +287,7 @@ void DoNextTrack(
       {
          trackPanel.SetFocusedTrack( n );   // move focus to next track down
          trackPanel.EnsureVisible( n );
-         project.ModifyState(false);
+         projectManager.ModifyState(false);
          return;
       }
    }
@@ -470,7 +472,7 @@ void OnFirstTrack(const CommandContext &context)
    if (t != f)
    {
       trackPanel.SetFocusedTrack(f);
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
    }
    trackPanel.EnsureVisible(f);
 }
@@ -489,7 +491,7 @@ void OnLastTrack(const CommandContext &context)
    if (t != l)
    {
       trackPanel.SetFocusedTrack(l);
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
    }
    trackPanel.EnsureVisible(l);
 }
@@ -521,7 +523,7 @@ void OnToggle(const CommandContext &context)
    selectionState.SelectTrack
       ( *t, !t->GetSelected(), true );
    trackPanel.EnsureVisible( t );
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 
    trackPanel.GetAx().Updated();
 

src/menus/PluginMenus.cpp

@@ -493,7 +493,7 @@ bool DoEffect(
    {
       wxString shortDesc = em.GetCommandName(ID);
       wxString longDesc = em.GetCommandDescription(ID);
-      project.PushState(longDesc, shortDesc);
+      ProjectManager::Get( project ).PushState(longDesc, shortDesc);
    }
 
    if (!(flags & kDontRepeatLast))

src/menus/SelectMenus.cpp

@@ -38,7 +38,7 @@ void DoSelectTimeAndTracks
       for (auto t : tracks.Any())
          t->SetSelected(true);
 
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.Refresh(false);
    }
 }
@@ -63,7 +63,7 @@ void DoSelectTimeAndAudioTracks
       for (auto t : tracks.Any<WaveTrack>())
          t->SetSelected(true);
 
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.Refresh(false);
    }
 }
@@ -88,7 +88,7 @@ void DoNextPeakFrequency(AudacityProject &project, bool up)
       SpectrumAnalyst analyst;
       SelectHandle::SnapCenterOnce(analyst, viewInfo, pTrack, up);
       trackPanel.Refresh(false);
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
    }
 }
 
@@ -179,7 +179,7 @@ bool OnlyHandleKeyUp( const CommandContext &context )
    if( !bKeyUp )
       return false;
 
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
    return true;
 }
 
@@ -420,7 +420,7 @@ void DoCursorMove(
       MoveWhenAudioInactive(project, seekStep, TIME_UNIT_SECONDS);
    }
 
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 void DoBoundaryMove(AudacityProject &project, int step, SeekInfo &info)
@@ -454,7 +454,7 @@ void DoBoundaryMove(AudacityProject &project, int step, SeekInfo &info)
       else
          viewInfo.selectedRegion.setT1(indicator);
 
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.Refresh(false);
       return;
    }
@@ -483,7 +483,7 @@ void DoBoundaryMove(AudacityProject &project, int step, SeekInfo &info)
    trackPanel.ScrollIntoView(newT);
    trackPanel.Refresh(false);
 
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 }
@@ -533,7 +533,7 @@ void DoListSelection
       trackPanel.SetFocusedTrack(t);
    window.Refresh(false);
    if (modifyState)
-      project.ModifyState(true);
+      ProjectManager::Get( project ).ModifyState(true);
 }
 
 void DoSelectAll(AudacityProject &project)
@@ -583,7 +583,7 @@ void OnSelectNone(const CommandContext &context)
 
    selectedRegion.collapseToT0();
    SelectNone( project );
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 void OnSelectAllTracks(const CommandContext &context)
@@ -606,7 +606,7 @@ void OnSelectSyncLockSel(const CommandContext &context)
    }
 
    if (selected)
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
 
    trackPanel.Refresh(false);
 }
@@ -649,7 +649,7 @@ void OnSetLeftSelection(const CommandContext &context)
 
    if (bSelChanged)
    {
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.Refresh(false);
    }
 }
@@ -689,7 +689,7 @@ void OnSetRightSelection(const CommandContext &context)
 
    if (bSelChanged)
    {
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.Refresh(false);
    }
 }
@@ -715,7 +715,7 @@ void OnSelectStartCursor(const CommandContext &context)
 
    selectedRegion.setT0(minOffset);
 
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 
    trackPanel.Refresh(false);
 }
@@ -741,7 +741,7 @@ void OnSelectCursorEnd(const CommandContext &context)
 
    selectedRegion.setT1(maxEndOffset);
 
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 
    trackPanel.Refresh(false);
 }
@@ -761,7 +761,7 @@ void OnSelectTrackStartToEnd(const CommandContext &context)
       return;
 
    viewInfo.selectedRegion.setTimes( minOffset, maxEndOffset );
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 
    trackPanel.Refresh(false);
 }
@@ -789,7 +789,7 @@ void OnSelectionRestore(const CommandContext &context)
 
    selectedRegion = mRegionSave;
 
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 
    trackPanel.Refresh(false);
 }
@@ -822,7 +822,7 @@ void OnToggleSpectralSelection(const CommandContext &context)
       selectedRegion.setFrequencies(mLastF0, mLastF1);
 
    trackPanel.Refresh(false);
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 void OnNextHigherPeakFrequency(const CommandContext &context)
@@ -857,7 +857,7 @@ void OnSelectCursorStoredCursor(const CommandContext &context)
          std::min(cursorPositionCurrent, mCursorPositionStored),
          std::max(cursorPositionCurrent, mCursorPositionStored));
 
-      project.ModifyState(false);
+      ProjectManager::Get( project ).ModifyState(false);
       trackPanel.Refresh(false);
    }
 }
@@ -890,7 +890,7 @@ void OnZeroCrossing(const CommandContext &context)
          selectedRegion.setTimes(t0, t1);
    }
 
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 
    trackPanel.Refresh(false);
 }
@@ -898,19 +898,19 @@ void OnZeroCrossing(const CommandContext &context)
 void OnSnapToOff(const CommandContext &context)
 {
    auto &project = context.project;
-   project.AS_SetSnapTo(SNAP_OFF);
+   ProjectManager::Get( project ).AS_SetSnapTo(SNAP_OFF);
 }
 
 void OnSnapToNearest(const CommandContext &context)
 {
    auto &project = context.project;
-   project.AS_SetSnapTo(SNAP_NEAREST);
+   ProjectManager::Get( project ).AS_SetSnapTo(SNAP_NEAREST);
 }
 
 void OnSnapToPrior(const CommandContext &context)
 {
    auto &project = context.project;
-   project.AS_SetSnapTo(SNAP_PRIOR);
+   ProjectManager::Get( project ).AS_SetSnapTo(SNAP_PRIOR);
 }
 
 void OnSelToStart(const CommandContext &context)
@@ -918,7 +918,7 @@ void OnSelToStart(const CommandContext &context)
    auto &project = context.project;
    auto &window = ProjectWindow::Get( project );
    window.Rewind(true);
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 void OnSelToEnd(const CommandContext &context)
@@ -926,7 +926,7 @@ void OnSelToEnd(const CommandContext &context)
    auto &project = context.project;
    auto &window = ProjectWindow::Get( project );
    window.SkipEnd(true);
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 // Handler state:
@@ -977,7 +977,7 @@ void OnCursorSelStart(const CommandContext &context)
    auto &selectedRegion = ViewInfo::Get( project ).selectedRegion;
 
    selectedRegion.collapseToT0();
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
    trackPanel.ScrollIntoView(selectedRegion.t0());
    trackPanel.Refresh(false);
 }
@@ -989,7 +989,7 @@ void OnCursorSelEnd(const CommandContext &context)
    auto &selectedRegion = ViewInfo::Get( project ).selectedRegion;
 
    selectedRegion.collapseToT1();
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
    trackPanel.ScrollIntoView(selectedRegion.t1());
    trackPanel.Refresh(false);
 }
@@ -1016,7 +1016,7 @@ void OnCursorTrackStart(const CommandContext &context)
       return;
 
    selectedRegion.setTimes(minOffset, minOffset);
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
    trackPanel.ScrollIntoView(selectedRegion.t0());
    trackPanel.Refresh(false);
 }
@@ -1043,7 +1043,7 @@ void OnCursorTrackEnd(const CommandContext &context)
       return;
 
    selectedRegion.setTimes(maxEndOffset, maxEndOffset);
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
    trackPanel.ScrollIntoView(selectedRegion.t1());
    trackPanel.Refresh(false);
 }
@@ -1055,7 +1055,7 @@ void OnSkipStart(const CommandContext &context)
 
    auto &controlToolBar = ControlToolBar::Get( project );
    controlToolBar.OnRewind(evt);
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 void OnSkipEnd(const CommandContext &context)
@@ -1065,7 +1065,7 @@ void OnSkipEnd(const CommandContext &context)
 
    auto &controlToolBar = ControlToolBar::Get( project );
    controlToolBar.OnFF(evt);
-   project.ModifyState(false);
+   ProjectManager::Get( project ).ModifyState(false);
 }
 
 void OnCursorLeft(const CommandContext &context)

src/menus/TrackMenus.cpp

@@ -91,7 +91,7 @@ void DoMixAndRender
          msg.Printf(_("Rendered all audio in track '%s'"), firstName);
          /* i18n-hint: Convert the audio into a more usable form, so apply
           * panning and amplification and write to some external file.*/
-         project.PushState(msg, _("Render"));
+         ProjectManager::Get( project ).PushState(msg, _("Render"));
       }
       else {
          wxString msg;
@@ -103,7 +103,7 @@ void DoMixAndRender
             msg.Printf(
                _("Mixed and rendered %d tracks into one new mono track"),
                (int)selectedCount);
-         project.PushState(msg, _("Mix and Render"));
+         ProjectManager::Get( project ).PushState(msg, _("Mix and Render"));
       }
 
       trackPanel.SetFocus();
@@ -131,7 +131,8 @@ void DoPanTracks(AudacityProject &project, float PanValue)
 
    auto flags = UndoPush::AUTOSAVE;
    /*i18n-hint: One or more audio tracks have been panned*/
-   project.PushState(_("Panned audio track(s)"), _("Pan Track"), flags);
+   ProjectManager::Get( project )
+      .PushState(_("Panned audio track(s)"), _("Pan Track"), flags);
          flags = flags | UndoPush::CONSOLIDATE;
 }
 
@@ -292,7 +293,7 @@ void DoAlign
    if (moveSel)
       selectedRegion.move(delta);
 
-   project.PushState(action, shortAction);
+   ProjectManager::Get( project ).PushState(action, shortAction);
 
    window.RedrawProject();
 }
@@ -537,7 +538,8 @@ void SetTrackGain(AudacityProject &project, WaveTrack * wt, LWSlider * slider)
    for (auto channel : TrackList::Channels(wt))
       channel->SetGain(newValue);
 
-   project.PushState(_("Adjusted gain"), _("Gain"), UndoPush::CONSOLIDATE);
+   ProjectManager::Get( project )
+      .PushState(_("Adjusted gain"), _("Gain"), UndoPush::CONSOLIDATE);
 
    TrackPanel::Get( project ).RefreshTrack(wt);
 }
@@ -550,7 +552,8 @@ void SetTrackPan(AudacityProject &project, WaveTrack * wt, LWSlider * slider)
    for (auto channel : TrackList::Channels(wt))
       channel->SetPan(newValue);
 
-   project.PushState(_("Adjusted Pan"), _("Pan"), UndoPush::CONSOLIDATE);
+   ProjectManager::Get( project )
+      .PushState(_("Adjusted Pan"), _("Pan"), UndoPush::CONSOLIDATE);
 
    TrackPanel::Get( project ).RefreshTrack(wt);
 }
@@ -595,7 +598,8 @@ void DoRemoveTracks( AudacityProject &project )
    if (f)
       trackPanel.EnsureVisible(f);
 
-   project.PushState(_("Removed audio track(s)"), _("Remove Track"));
+   ProjectManager::Get( project )
+      .PushState(_("Removed audio track(s)"), _("Remove Track"));
 
    trackPanel.UpdateViewIfNoTracks();
    trackPanel.Refresh(false);
@@ -645,7 +649,7 @@ void DoTrackMute(AudacityProject &project, Track *t, bool exclusive)
             track->SetSolo( (nPlaying==1) && (nPlayableTracks > 1 ) && !track->GetMute() );
       }
    }
-   project.ModifyState(true);
+   ProjectManager::Get( project ).ModifyState(true);
 
    trackPanel.UpdateAccessibility();
    trackPanel.Refresh(false);
@@ -698,7 +702,7 @@ void DoTrackSolo(AudacityProject &project, Track *t, bool exclusive)
          }
       }
    }
-   project.ModifyState(true);
+   ProjectManager::Get( project ).ModifyState(true);
 
    trackPanel.UpdateAccessibility();
    trackPanel.Refresh(false);
@@ -734,7 +738,7 @@ void DoRemoveTrack(AudacityProject &project, Track * toRemove)
    if (toRemoveWasFocused)
       trackPanel.SetFocusedTrack(newFocus);
 
-   project.PushState(
+   ProjectManager::Get( project ).PushState(
       wxString::Format(_("Removed track '%s.'"),
       name),
       _("Track Remove"));
@@ -793,7 +797,7 @@ void DoMoveTrack
 
    longDesc = longDesc.Format(target->GetName());
 
-   project.PushState(longDesc, shortDesc);
+   ProjectManager::Get( project ).PushState(longDesc, shortDesc);
    trackPanel.Refresh(false);
 }
 
@@ -818,7 +822,8 @@ void OnNewWaveTrack(const CommandContext &context)
 
    t->SetSelected(true);
 
-   project.PushState(_("Created new audio track"), _("New Track"));
+   ProjectManager::Get( project )
+      .PushState(_("Created new audio track"), _("New Track"));
 
    window.RedrawProject();
    trackPanel.EnsureVisible(t);
@@ -846,7 +851,8 @@ void OnNewStereoTrack(const CommandContext &context)
 
    tracks.GroupChannels(*left, 2);
 
-   project.PushState(_("Created new stereo audio track"), _("New Track"));
+   ProjectManager::Get( project )
+      .PushState(_("Created new stereo audio track"), _("New Track"));
 
    window.RedrawProject();
    trackPanel.EnsureVisible(left);
@@ -866,7 +872,8 @@ void OnNewLabelTrack(const CommandContext &context)
 
    t->SetSelected(true);
 
-   project.PushState(_("Created new label track"), _("New Track"));
+   ProjectManager::Get( project )
+      .PushState(_("Created new label track"), _("New Track"));
 
    window.RedrawProject();
    trackPanel.EnsureVisible(t);
@@ -891,7 +898,8 @@ void OnNewTimeTrack(const CommandContext &context)
 
    t->SetSelected(true);
 
-   project.PushState(_("Created new time track"), _("New Track"));
+   ProjectManager::Get( project )
+      .PushState(_("Created new time track"), _("New Track"));
 
    window.RedrawProject();
    trackPanel.EnsureVisible(t);
@@ -1013,7 +1021,7 @@ void OnResample(const CommandContext &context)
       // commit that to the undo stack.  The second and later times,
       // consolidate.
 
-      project.PushState(
+      ProjectManager::Get( project ).PushState(
          _("Resampled audio track(s)"), _("Resample Track"), flags);
       flags = flags | UndoPush::CONSOLIDATE;
    }
@@ -1047,7 +1055,7 @@ void OnMuteAllTracks(const CommandContext &context)
          pt->SetSolo(false);
    }
 
-   project.ModifyState(true);
+   ProjectManager::Get( project ).ModifyState(true);
    window.RedrawProject();
 }
 
@@ -1068,7 +1076,7 @@ void OnUnmuteAllTracks(const CommandContext &context)
          pt->SetSolo(false);
    }
 
-   project.ModifyState(true);
+   ProjectManager::Get( project ).ModifyState(true);
    window.RedrawProject();
 }
 
@@ -1252,7 +1260,8 @@ void OnSortTime(const CommandContext &context)
    auto &project = context.project;
    DoSortTracks(project, kAudacitySortByTime);
 
-   project.PushState(_("Tracks sorted by time"), _("Sort by Time"));
+   ProjectManager::Get( project )
+      .PushState(_("Tracks sorted by time"), _("Sort by Time"));
 
    auto &trackPanel = TrackPanel::Get( project );
    trackPanel.Refresh(false);
@@ -1263,7 +1272,8 @@ void OnSortName(const CommandContext &context)
    auto &project = context.project;
    DoSortTracks(project, kAudacitySortByName);
 
-   project.PushState(_("Tracks sorted by name"), _("Sort by Name"));
+   ProjectManager::Get( project )
+      .PushState(_("Tracks sorted by name"), _("Sort by Name"));
 
    auto &trackPanel = TrackPanel::Get( project );
    trackPanel.Refresh(false);

src/menus/TransportMenus.cpp

@@ -258,7 +258,7 @@ bool DoPlayStopSelect
          // -- change t0, collapsing to point only if t1 was greater
          selection.setT0(time, false);
 
-      project.ModifyState(false);           // without bWantsAutoSave
+      ProjectManager::Get( project ).ModifyState(false);           // without bWantsAutoSave
       return true;
    }
    return false;
@@ -459,7 +459,7 @@ void OnTimerRecord(const CommandContext &context)
       switch (iTimerRecordingOutcome) {
       case POST_TIMER_RECORD_CANCEL_WAIT:
          // Canceled on the wait dialog
-         project.RollbackState();
+         ProjectManager::Get( project ).RollbackState();
          break;
       case POST_TIMER_RECORD_CANCEL:
          // RunWaitDialog() shows the "wait for start" as well as "recording"
@@ -468,7 +468,7 @@ void OnTimerRecord(const CommandContext &context)
          // However, we can't undo it here because the PushState() is called in TrackPanel::OnTimer(),
          // which is blocked by this function.
          // so instead we mark a flag to undo it there.
-         project.SetTimerRecordCancelled();
+         ProjectManager::Get( project ).SetTimerRecordCancelled();
          break;
       case POST_TIMER_RECORD_NOTHING:
          // No action required
@@ -624,7 +624,7 @@ void OnPunchAndRoll(const CommandContext &context)
       ;
    else
       // Roll back the deletions
-      project.RollbackState();
+      ProjectManager::Get( project ).RollbackState();
 }
 #endif
 

src/menus/ViewMenus.cpp

@@ -280,7 +280,7 @@ void OnZoomFitV(const CommandContext &context)
 
    window.GetVerticalScrollBar().SetThumbPosition(0);
    window.RedrawProject();
-   project.ModifyState(true);
+   ProjectManager::Get( project ).ModifyState(true);
 }
 
 void OnAdvancedVZoom(const CommandContext &context)
@@ -304,7 +304,7 @@ void OnCollapseAllTracks(const CommandContext &context)
    for (auto t : tracks.Any())
       t->SetMinimized(true);
 
-   project.ModifyState(true);
+   ProjectManager::Get( project ).ModifyState(true);
    window.RedrawProject();
 }
 
@@ -317,7 +317,7 @@ void OnExpandAllTracks(const CommandContext &context)
    for (auto t : tracks.Any())
       t->SetMinimized(false);
 
-   project.ModifyState(true);
+   ProjectManager::Get( project ).ModifyState(true);
    window.RedrawProject();
 }
 

src/tracks/labeltrack/ui/LabelGlyphHandle.cpp

@@ -141,7 +141,7 @@ UIHandle::Result LabelGlyphHandle::Release
    auto &viewInfo = ViewInfo::Get( *pProject );
    if (mpLT->HandleGlyphDragRelease
           (mHit, event, mRect, viewInfo, &viewInfo.selectedRegion)) {
-      pProject->PushState(_("Modified Label"),
+      ProjectManager::Get( *pProject ).PushState(_("Modified Label"),
          _("Label Edit"),
          UndoPush::CONSOLIDATE);
    }
@@ -152,7 +152,7 @@ UIHandle::Result LabelGlyphHandle::Release
 
 UIHandle::Result LabelGlyphHandle::Cancel(AudacityProject *pProject)
 {
-   pProject->RollbackState();
+   ProjectManager::Get( *pProject ).RollbackState();
    auto result = LabelDefaultClickHandle::Cancel( pProject );
    return result | RefreshCode::RefreshAll;
 }

src/tracks/labeltrack/ui/LabelTextHandle.cpp

@@ -110,7 +110,7 @@ UIHandle::Result LabelTextHandle::Click
    // PRL: bug1659 -- make selection change undo correctly
    const bool unsafe = ProjectAudioIO::Get( *pProject ).IsAudioActive();
    if (!unsafe)
-      pProject->ModifyState(false);
+      ProjectManager::Get( *pProject ).ModifyState(false);
 
    return result | RefreshCode::RefreshCell | RefreshCode::UpdateSelection;
 }

src/tracks/playabletrack/notetrack/ui/NoteTrackButtonHandle.cpp

@@ -102,7 +102,7 @@ UIHandle::Result NoteTrackButtonHandle::Release
    if (pTrack->LabelClick(mRect, event.m_x, event.m_y,
       event.Button(wxMOUSE_BTN_RIGHT))) {
       // No undo items needed??
-      pProject->ModifyState(false);
+      ProjectManager::Get( *pProject ).ModifyState(false);
       return RefreshAll;
    }
    return RefreshNone;

src/tracks/playabletrack/notetrack/ui/NoteTrackControls.cpp

@@ -116,7 +116,8 @@ void NoteTrackMenuTable::OnChangeOctave(wxCommandEvent &event)
    pTrack->ShiftNoteRange((bDown) ? -12 : 12);
 
    AudacityProject *const project = ::GetActiveProject();
-   project->ModifyState(false);
+   ProjectManager::Get( *project )
+      .ModifyState(false);
    mpData->result = RefreshCode::RefreshAll;
 }
 

src/tracks/playabletrack/notetrack/ui/NoteTrackSliderHandles.cpp

@@ -60,7 +60,9 @@ UIHandle::Result VelocitySliderHandle::SetValue
 UIHandle::Result VelocitySliderHandle::CommitChanges
 (const wxMouseEvent &, AudacityProject *pProject)
 {
-   pProject->PushState(_("Moved velocity slider"), _("Velocity"), UndoPush::CONSOLIDATE);
+   ProjectManager::Get( *pProject )
+      .PushState(_("Moved velocity slider"), _("Velocity"),
+         UndoPush::CONSOLIDATE);
    return RefreshCode::RefreshCell;
 }
 

src/tracks/playabletrack/notetrack/ui/NoteTrackVRulerControls.cpp

@@ -81,7 +81,7 @@ unsigned NoteTrackVRulerControls::HandleWheelRotation
       return RefreshNone;
    }
 
-   pProject->ModifyState(false);
+   ProjectManager::Get( *pProject ).ModifyState(false);
 
    return RefreshCell | UpdateVRuler;
 }

src/tracks/playabletrack/notetrack/ui/NoteTrackVZoomHandle.cpp

@@ -240,7 +240,7 @@ void NoteTrackVRulerMenuTable::OnZoom( int iZoomCode ){
       mpData->pTrack->ShiftNoteRange(-12);
       break;
    }
-   GetActiveProject()->ModifyState(false);
+   ProjectManager::Get( *GetActiveProject() ).ModifyState(false);
    using namespace RefreshCode;
    mpData->result = UpdateVRuler | RefreshAll;
 }
@@ -341,7 +341,7 @@ UIHandle::Result NoteTrackVZoomHandle::Release
    }
 
    mZoomEnd = mZoomStart = 0;
-   pProject->ModifyState(false);
+   ProjectManager::Get( *pProject ).ModifyState(false);
 
    return RefreshAll;
 }

src/tracks/playabletrack/notetrack/ui/StretchHandle.cpp

@@ -252,7 +252,7 @@ UIHandle::Result StretchHandle::Release
 
    /* i18n-hint: (noun) The track that is used for MIDI notes which can be
    dragged to change their duration.*/
-   pProject->PushState(_("Stretch Note Track"),
+   ProjectManager::Get( *pProject ).PushState(_("Stretch Note Track"),
       /* i18n-hint: In the history list, indicates a MIDI note has
       been dragged to change its duration (stretch it). Using either past
       or present tense is fine here.  If unsure, go for whichever is
@@ -264,7 +264,7 @@ UIHandle::Result StretchHandle::Release
 
 UIHandle::Result StretchHandle::Cancel(AudacityProject *pProject)
 {
-   pProject->RollbackState();
+   ProjectManager::Get( *pProject ).RollbackState();
    return RefreshCode::RefreshNone;
 }
 

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

@@ -220,19 +220,21 @@ UIHandle::Result CutlineHandle::Release
    UIHandle::Result result = RefreshCode::RefreshNone;
 
    // Only now commit the result to the undo stack
-   AudacityProject *const project = pProject;
    switch (mOperation) {
    default:
       wxASSERT(false);
    case Merge:
-      project->PushState(_("Merged Clips"), _("Merge"), UndoPush::CONSOLIDATE);
+      ProjectManager::Get( *pProject )
+         .PushState(_("Merged Clips"), _("Merge"), UndoPush::CONSOLIDATE);
       break;
    case Expand:
-      project->PushState(_("Expanded Cut Line"), _("Expand"));
+      ProjectManager::Get( *pProject )
+         .PushState(_("Expanded Cut Line"), _("Expand"));
       result |= RefreshCode::UpdateSelection;
       break;
    case Remove:
-      project->PushState(_("Removed Cut Line"), _("Remove"));
+      ProjectManager::Get( *pProject )
+         .PushState(_("Removed Cut Line"), _("Remove"));
       break;
    }
 
@@ -244,7 +246,7 @@ UIHandle::Result CutlineHandle::Cancel(AudacityProject *pProject)
 {
    using namespace RefreshCode;
    UIHandle::Result result = RefreshCell;
-   pProject->RollbackState();
+   ProjectManager::Get( *pProject ).RollbackState();
    if (mOperation == Expand) {
       AudacityProject &project = *pProject;
       auto &selectedRegion = ViewInfo::Get( project ).selectedRegion;

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

@@ -434,7 +434,7 @@ UIHandle::Result SampleHandle::Release
    //*************************************************
    //On up-click, send the state to the undo stack
    mClickedTrack.reset();       //Set this to NULL so it will catch improper drag events.
-   pProject->PushState(_("Moved Samples"),
+   ProjectManager::Get( *pProject ).PushState(_("Moved Samples"),
       _("Sample Edit"),
       UndoPush::CONSOLIDATE | UndoPush::AUTOSAVE);
 
@@ -444,7 +444,7 @@ UIHandle::Result SampleHandle::Release
 
 UIHandle::Result SampleHandle::Cancel(AudacityProject *pProject)
 {
-   pProject->RollbackState();
+   ProjectManager::Get( *pProject ).RollbackState();
    mClickedTrack.reset();
    return RefreshCode::RefreshCell;
 }

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

@@ -219,7 +219,8 @@ void WaveColorMenuTable::OnWaveColorChange(wxCommandEvent & event)
    for (auto channel : TrackList::Channels(pTrack))
       channel->SetWaveColorIndex(newWaveColor);
 
-   project->PushState(wxString::Format(_("Changed '%s' to %s"),
+   ProjectManager::Get( *project )
+      .PushState(wxString::Format(_("Changed '%s' to %s"),
       pTrack->GetName(),
       GetWaveColorStr(newWaveColor)),
       _("WaveColor Change"));
@@ -337,7 +338,8 @@ void FormatMenuTable::OnFormatChange(wxCommandEvent & event)
       channel->ConvertToSampleFormat(newFormat);
 
    /* i18n-hint: The strings name a track and a format */
-   project->PushState(wxString::Format(_("Changed '%s' to %s"),
+   ProjectManager::Get( *project )
+      .PushState(wxString::Format(_("Changed '%s' to %s"),
       pTrack->GetName(),
       GetSampleFormatStr(newFormat)),
       _("Format Change"));
@@ -438,7 +440,8 @@ void RateMenuTable::SetRate(WaveTrack * pTrack, double rate)
    // Separate conversion of "rate" enables changing the decimals without affecting i18n
    wxString rateString = wxString::Format(wxT("%.3f"), rate);
    /* i18n-hint: The string names a track */
-   project->PushState(wxString::Format(_("Changed '%s' to %s Hz"),
+   ProjectManager::Get( *project )
+      .PushState(wxString::Format(_("Changed '%s' to %s Hz"),
       pTrack->GetName(), rateString),
       _("Rate Change"));
 }
@@ -739,7 +742,7 @@ void WaveTrackMenuTable::OnSetDisplay(wxCommandEvent & event)
       }
 
       AudacityProject *const project = ::GetActiveProject();
-      project->ModifyState(true);
+      ProjectManager::Get( *project ).ModifyState(true);
 
       using namespace RefreshCode;
       mpData->result = RefreshAll | UpdateVRuler;
@@ -794,7 +797,7 @@ void WaveTrackMenuTable::OnSpectrogramSettings(wxCommandEvent &)
    if (0 != dialog.ShowModal()) {
       // Redraw
       AudacityProject *const project = ::GetActiveProject();
-      project->ModifyState(true);
+      ProjectManager::Get( *project ).ModifyState(true);
       //Bug 1725 Toolbar was left greyed out.
       //This solution is overkill, but does fix the problem and is what the
       //prefs dialog normally does.
@@ -880,7 +883,8 @@ void WaveTrackMenuTable::OnMergeStereo(wxCommandEvent &)
       }
 
    /* i18n-hint: The string names a track */
-   project->PushState(wxString::Format(_("Made '%s' a stereo track"),
+   ProjectManager::Get( *project )
+      .PushState(wxString::Format(_("Made '%s' a stereo track"),
       pTrack->GetName()),
       _("Make Stereo"));
 
@@ -948,7 +952,8 @@ void WaveTrackMenuTable::OnSwapChannels(wxCommandEvent &)
       trackPanel.SetFocusedTrack(partner);
 
    /* i18n-hint: The string names a track  */
-   project->PushState(wxString::Format(_("Swapped Channels in '%s'"),
+   ProjectManager::Get( *project )
+      .PushState(wxString::Format(_("Swapped Channels in '%s'"),
       pTrack->GetName()),
       _("Swap Channels"));
 
@@ -962,7 +967,8 @@ void WaveTrackMenuTable::OnSplitStereo(wxCommandEvent &)
    WaveTrack *const pTrack = static_cast<WaveTrack*>(mpData->pTrack);
    AudacityProject *const project = ::GetActiveProject();
    /* i18n-hint: The string names a track  */
-   project->PushState(wxString::Format(_("Split stereo track '%s'"),
+   ProjectManager::Get( *project )
+      .PushState(wxString::Format(_("Split stereo track '%s'"),
       pTrack->GetName()),
       _("Split"));
 
@@ -977,7 +983,8 @@ void WaveTrackMenuTable::OnSplitStereoMono(wxCommandEvent &)
    WaveTrack *const pTrack = static_cast<WaveTrack*>(mpData->pTrack);
    AudacityProject *const project = ::GetActiveProject();
    /* i18n-hint: The string names a track  */
-   project->PushState(wxString::Format(_("Split Stereo to Mono '%s'"),
+   ProjectManager::Get( *project ).
+      PushState(wxString::Format(_("Split Stereo to Mono '%s'"),
       pTrack->GetName()),
       _("Split to Mono"));
 

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

@@ -57,7 +57,8 @@ UIHandle::Result GainSliderHandle::SetValue
 UIHandle::Result GainSliderHandle::CommitChanges
 (const wxMouseEvent &, AudacityProject *pProject)
 {
-   pProject->PushState(_("Moved gain slider"), _("Gain"), UndoPush::CONSOLIDATE);
+   ProjectManager::Get( *pProject )
+      .PushState(_("Moved gain slider"), _("Gain"), UndoPush::CONSOLIDATE);
    return RefreshCode::RefreshCell;
 }
 
@@ -135,7 +136,8 @@ UIHandle::Result PanSliderHandle::SetValue(AudacityProject *pProject, float newV
 UIHandle::Result PanSliderHandle::CommitChanges
 (const wxMouseEvent &, AudacityProject *pProject)
 {
-   pProject->PushState(_("Moved pan slider"), _("Pan"), UndoPush::CONSOLIDATE);
+   ProjectManager::Get( *pProject )
+      .PushState(_("Moved pan slider"), _("Pan"), UndoPush::CONSOLIDATE);
    return RefreshCode::RefreshCell;
 }
 

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

@@ -186,7 +186,7 @@ unsigned WaveTrackVRulerControls::HandleWheelRotation
    else
       return RefreshNone;
 
-   pProject->ModifyState(true);
+   ProjectManager::Get( *pProject ).ModifyState(true);
 
    return RefreshCell | UpdateVRuler;
 }

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

@@ -332,7 +332,7 @@ void WaveTrackVZoomHandle::DoZoom
 
    zoomEnd = zoomStart = 0;
    if( pProject )
-      pProject->ModifyState(true);
+      ProjectManager::Get( *pProject ).ModifyState(true);
 }
 
 enum {
@@ -478,7 +478,7 @@ void WaveformVRulerMenuTable::OnWaveformScaleType(wxCommandEvent &evt)
          channel->GetIndependentWaveformSettings().scaleType = newScaleType;
       }
 
-      ::GetActiveProject()->ModifyState(true);
+      ProjectManager::Get( *::GetActiveProject() ).ModifyState(true);
 
       using namespace RefreshCode;
       mpData->result = UpdateVRuler | RefreshAll;
@@ -550,7 +550,7 @@ void SpectrumVRulerMenuTable::OnSpectrumScaleType(wxCommandEvent &evt)
       for (auto channel : TrackList::Channels(wt))
          channel->GetIndependentSpectrogramSettings().scaleType = newScaleType;
 
-      ::GetActiveProject()->ModifyState(true);
+      ProjectManager::Get( *::GetActiveProject() ).ModifyState(true);
 
       using namespace RefreshCode;
       mpData->result = UpdateVRuler | RefreshAll;

src/tracks/timetrack/ui/TimeTrackControls.cpp

@@ -104,7 +104,8 @@ void TimeTrackMenuTable::OnSetTimeTrackRange(wxCommandEvent & /*event*/)
          AudacityProject *const project = ::GetActiveProject();
          pTrack->SetRangeLower((double)lower / 100.0);
          pTrack->SetRangeUpper((double)upper / 100.0);
-         project->PushState(wxString::Format(_("Set range to '%ld' - '%ld'"),
+         ProjectManager::Get( *project )
+            .PushState(wxString::Format(_("Set range to '%ld' - '%ld'"),
             lower,
             upper),
             /* i18n-hint: (verb)*/
@@ -119,7 +120,8 @@ void TimeTrackMenuTable::OnTimeTrackLin(wxCommandEvent & /*event*/)
    TimeTrack *const pTrack = static_cast<TimeTrack*>(mpData->pTrack);
    pTrack->SetDisplayLog(false);
    AudacityProject *const project = ::GetActiveProject();
-   project->PushState(_("Set time track display to linear"), _("Set Display"));
+   ProjectManager::Get( *project )
+      .PushState(_("Set time track display to linear"), _("Set Display"));
 
    using namespace RefreshCode;
    mpData->result = RefreshAll | UpdateVRuler;
@@ -130,7 +132,8 @@ void TimeTrackMenuTable::OnTimeTrackLog(wxCommandEvent & /*event*/)
    TimeTrack *const pTrack = static_cast<TimeTrack*>(mpData->pTrack);
    pTrack->SetDisplayLog(true);
    AudacityProject *const project = ::GetActiveProject();
-   project->PushState(_("Set time track display to logarithmic"), _("Set Display"));
+   ProjectManager::Get( *project )
+      .PushState(_("Set time track display to logarithmic"), _("Set Display"));
 
    using namespace RefreshCode;
    mpData->result = RefreshAll | UpdateVRuler;
@@ -142,11 +145,13 @@ void TimeTrackMenuTable::OnTimeTrackLogInt(wxCommandEvent & /*event*/)
    AudacityProject *const project = ::GetActiveProject();
    if (pTrack->GetInterpolateLog()) {
       pTrack->SetInterpolateLog(false);
-      project->PushState(_("Set time track interpolation to linear"), _("Set Interpolation"));
+      ProjectManager::Get( *project )
+         .PushState(_("Set time track interpolation to linear"), _("Set Interpolation"));
    }
    else {
       pTrack->SetInterpolateLog(true);
-      project->PushState(_("Set time track interpolation to logarithmic"), _("Set Interpolation"));
+      ProjectManager::Get( *project ).
+         PushState(_("Set time track interpolation to logarithmic"), _("Set Interpolation"));
    }
    mpData->result = RefreshCode::RefreshAll;
 }

src/tracks/ui/EnvelopeHandle.cpp

@@ -287,7 +287,7 @@ UIHandle::Result EnvelopeHandle::Release
 
    const bool needUpdate = ForwardEventToEnvelopes(event, viewInfo);
 
-   pProject->PushState(
+   ProjectManager::Get( *pProject ).PushState(
       /* i18n-hint: (verb) Audacity has just adjusted the envelope .*/
       _("Adjusted envelope."),
       /* i18n-hint: The envelope is a curve that controls the audio loudness.*/
@@ -302,7 +302,7 @@ UIHandle::Result EnvelopeHandle::Release
 
 UIHandle::Result EnvelopeHandle::Cancel(AudacityProject *pProject)
 {
-   pProject->RollbackState();
+   ProjectManager::Get( *pProject ).RollbackState();
    mEnvelopeEditors.clear();
    return RefreshCode::RefreshCell;
 }

src/tracks/ui/SelectHandle.cpp

@@ -579,7 +579,7 @@ UIHandle::Result SelectHandle::Click
          }
       } );
 
-      pProject->ModifyState(false);
+      ProjectManager::Get( *pProject ).ModifyState(false);
 
       // Do not start a drag
       return RefreshAll | UpdateSelection | Cancelled;
@@ -664,7 +664,7 @@ UIHandle::Result SelectHandle::Click
       };
 
       // For persistence of the selection change:
-      pProject->ModifyState(false);
+      ProjectManager::Get( *pProject ).ModifyState(false);
 
       // Get timer events so we can auto-scroll
       Connect(pProject);
@@ -702,7 +702,7 @@ UIHandle::Result SelectHandle::Click
                static_cast<WaveTrack*>(pTrack),
                viewInfo, event.m_y, mRect.y, mRect.height);
             // For persistence of the selection change:
-            pProject->ModifyState(false);
+            ProjectManager::Get( *pProject ).ModifyState(false);
             mSelectionBoundary = SBWidth;
             return UpdateSelection;
          }
@@ -986,7 +986,7 @@ UIHandle::Result SelectHandle::Release
  wxWindow *)
 {
    using namespace RefreshCode;
-   pProject->ModifyState(false);
+   ProjectManager::Get( *pProject ).ModifyState(false);
    mFrequencySnapper.reset();
    mSnapManager.reset();
    if (mSelectionStateChanger) {
@@ -1126,7 +1126,7 @@ void SelectHandle::StartSelection( AudacityProject *pProject )
    // PRL:  commented out the Sonify stuff with the TrackPanel refactor.
    // It was no-op anyway.
    //SonifyBeginModifyState();
-   pProject->ModifyState(false);
+   ProjectManager::Get( *pProject ).ModifyState(false);
    //SonifyEndModifyState();
 }
 

src/tracks/ui/TimeShiftHandle.cpp

@@ -835,7 +835,7 @@ UIHandle::Result TimeShiftHandle::Release
          fabs( mClipMoveState.hSlideAmount ) );
       consolidate = true;
    }
-   pProject->PushState(msg, _("Time-Shift"),
+   ProjectManager::Get( *pProject ).PushState(msg, _("Time-Shift"),
       consolidate ? (UndoPush::CONSOLIDATE) : (UndoPush::AUTOSAVE));
 
    return result | FixScrollbars;
@@ -843,7 +843,7 @@ UIHandle::Result TimeShiftHandle::Release
 
 UIHandle::Result TimeShiftHandle::Cancel(AudacityProject *pProject)
 {
-   pProject->RollbackState();
+   ProjectManager::Get( *pProject ).RollbackState();
    return RefreshCode::RefreshAll;
 }
 

src/tracks/ui/TrackButtonHandles.cpp

@@ -39,7 +39,7 @@ UIHandle::Result MinimizeButtonHandle::CommitChanges
       bool wasMinimized = pTrack->GetMinimized();
       for (auto channel : TrackList::Channels(pTrack.get()))
          channel->SetMinimized(!wasMinimized);
-      pProject->ModifyState(true);
+      ProjectManager::Get( *pProject ).ModifyState(true);
 
       // Redraw all tracks when any one of them expands or contracts
       // (Could we invent a return code that draws only those at or below

src/tracks/ui/TrackControls.cpp

@@ -221,7 +221,8 @@ void TrackMenuTable::OnSetName(wxCommandEvent &)
          for (auto channel : TrackList::Channels(pTrack))
             channel->SetName(newName);
 
-         proj->PushState(wxString::Format(_("Renamed '%s' to '%s'"),
+         ProjectManager::Get( *proj )
+            .PushState(wxString::Format(_("Renamed '%s' to '%s'"),
             oldName,
             newName),
             _("Name Change"));

src/tracks/ui/TrackSelectHandle.cpp

@@ -180,7 +180,7 @@ UIHandle::Result TrackSelectHandle::Release
    wxASSERT( mpTrack );
    if (mRearrangeCount != 0) {
       AudacityProject *const project = ::GetActiveProject();
-      project->PushState(
+      ProjectManager::Get( *project ).PushState(
          wxString::Format(
             /* i18n-hint: will substitute name of track for %s */
             ( mRearrangeCount < 0 ? _("Moved '%s' up") : _("Moved '%s' down") ),
@@ -199,7 +199,7 @@ UIHandle::Result TrackSelectHandle::Release
 
 UIHandle::Result TrackSelectHandle::Cancel(AudacityProject *pProject)
 {
-   pProject->RollbackState();
+   ProjectManager::Get( *pProject ).RollbackState();
    // Bug 1677
    mpTrack.reset();
    return RefreshCode::RefreshAll;