audacia/src/ProjectFileManager.cpp

/**********************************************************************

Audacity: A Digital Audio Editor

ProjectFileManager.cpp

Paul Licameli split from AudacityProject.cpp

**********************************************************************/

#include "ProjectFileManager.h"

#include "Experimental.h"

#include <wx/crt.h> // for wxPrintf

#if defined(__WXGTK__)
#include <wx/evtloop.h>
#endif

#include <wx/frame.h>
#include "Dependencies.h"
#include "FileFormats.h"
#include "FileNames.h"
#include "Legacy.h"
#include "PlatformCompatibility.h"
#include "Project.h"
#include "ProjectFileIO.h"
#include "ProjectFileIORegistry.h"
#include "ProjectFSCK.h"
#include "ProjectHistory.h"
#include "ProjectSelectionManager.h"
#include "ProjectSettings.h"
#include "ProjectStatus.h"
#include "ProjectWindow.h"
#include "SelectUtilities.h"
#include "SelectionState.h"
#include "Sequence.h"
#include "Tags.h"
#include "TrackPanelAx.h"
#include "TrackPanel.h"
#include "UndoManager.h"
#include "WaveClip.h"
#include "WaveTrack.h"
#include "wxFileNameWrapper.h"
#include "export/Export.h"
#include "import/Import.h"
#include "import/ImportMIDI.h"
#include "commands/CommandContext.h"
#include "toolbars/SelectionBar.h"
#include "widgets/AudacityMessageBox.h"
#include "widgets/ErrorDialog.h"
#include "widgets/FileHistory.h"
#include "widgets/Warning.h"
#include "xml/XMLFileReader.h"

static const AudacityProject::AttachedObjects::RegisteredFactory sFileManagerKey{
   []( AudacityProject &parent ){
      auto result = std::make_shared< ProjectFileManager >( parent );
      return result;
   }
};

ProjectFileManager &ProjectFileManager::Get( AudacityProject &project )
{
   return project.AttachedObjects::Get< ProjectFileManager >( sFileManagerKey );
}

const ProjectFileManager &ProjectFileManager::Get( const AudacityProject &project )
{
   return Get( const_cast< AudacityProject & >( project ) );
}

ProjectFileManager::ProjectFileManager( AudacityProject &project )
: mProject{ project }
{
}

ProjectFileManager::~ProjectFileManager() = default;

namespace {

const char *const defaultHelpUrl =
   "FAQ:Errors_on_opening_or_recovering_an_Audacity_project";

using Pair = std::pair< const char *, const char * >;
const Pair helpURLTable[] = {
   {
      "not well-formed (invalid token)",
      "Error:_not_well-formed_(invalid_token)_at_line_x"
   },
   {
      "reference to invalid character number",
      "Error_Opening_Project:_Reference_to_invalid_character_number_at_line_x"
   },
   {
      "mismatched tag",
      "#mismatched"
   },
// This error with FAQ entry is reported elsewhere, not here....
//#[[#corrupt|Error Opening File or Project: File may be invalid or corrupted]]
};

wxString FindHelpUrl( const TranslatableString &libraryError )
{
   wxString helpUrl;
   if ( !libraryError.empty() ) {
      helpUrl = defaultHelpUrl;

      auto msgid = libraryError.MSGID().GET();
      auto found = std::find_if( begin(helpURLTable), end(helpURLTable),
         [&]( const Pair &pair ) {
            return msgid.Contains( pair.first ); }
      );
      if (found != end(helpURLTable)) {
         auto url = found->second;
         if (url[0] == '#')
            helpUrl += url;
         else
            helpUrl = url;
      }
   }

   return helpUrl;
}

}

auto ProjectFileManager::ReadProjectFile( const FilePath &fileName )
  -> ReadProjectResults
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get( project );
   auto &window = GetProjectFrame( project );

   ///
   /// Parse project file
   ///
   bool bParseSuccess = projectFileIO.LoadProject(fileName);
   
   bool err = false;

   if (bParseSuccess)
   {
      if (projectFileIO.IsRecovered())
      {
         bool resaved = projectFileIO.SaveProject(fileName);
         AudacityMessageBox(
            resaved
               ? XO("This project was not saved properly the last time Audacity ran.\n\n"
                    "It has been recovered to the last snapshot.")
               : XO("This project was not saved properly the last time Audacity ran.\n\n"
                    "It has been recovered to the last snapshot, but you must save it\n"
                    "to preserve its contents."),
            XO("Project Recovered"),
            wxICON_WARNING,
            &window);
      }

      // By making a duplicate set of pointers to the existing blocks
      // on disk, we add one to their reference count, guaranteeing
      // that their reference counts will never reach zero and thus
      // the version saved on disk will be preserved until the
      // user selects Save().
      mLastSavedTracks = TrackList::Create( nullptr );

      auto &tracks = TrackList::Get( project );
      for (auto t : tracks.Any())
      {
         if (t->GetErrorOpening())
         {
            wxLogWarning(
               wxT("Track %s had error reading clip values from project file."),
               t->GetName());
            err = true;
         }

         err = ( !t->LinkConsistencyCheck() ) || err;

         mLastSavedTracks->Add(t->Duplicate());
      }
   }

   return
   {
      bParseSuccess,
      err,
      projectFileIO.GetLastError(),
      FindHelpUrl(projectFileIO.GetLibraryError())
   };
}

bool ProjectFileManager::Save()
{
   auto &projectFileIO = ProjectFileIO::Get(mProject);

   // Prompt for file name?
   if (projectFileIO.IsTemporary())
   {
      return SaveAs();
   }

   return DoSave(projectFileIO.GetFileName(), false);
}

#if 0
// I added this to "fix" bug #334.  At that time, we were on wxWidgets 2.8.12 and
// there was a window between the closing of the "Save" progress dialog and the
// end of the actual save where the user was able to close the project window and
// recursively enter the Save code (where they could inadvertently cause the issue
// described in #334).
//
// When we converted to wx3, this "disabler" caused focus problems when returning
// to the project after the save (bug #1172) because the focus and activate events
// weren't being dispatched and the focus would get lost.
//
// After some testing, it looks like the window described above no longer exists,
// so I've disabled the disabler.  However, I'm leaving it here in case we run
// into the problem in the future.  (even though it can't be used as-is)
class ProjectDisabler
{
public:
   ProjectDisabler(wxWindow *w)
   :  mWindow(w)
   {
      mWindow->GetEventHandler()->SetEvtHandlerEnabled(false);
   }
   ~ProjectDisabler()
   {
      mWindow->GetEventHandler()->SetEvtHandlerEnabled(true);
   }
private:
   wxWindow *mWindow;
};
#endif

// Assumes ProjectFileIO::mFileName has been set to the desired path.
bool ProjectFileManager::DoSave(const FilePath & fileName, const bool fromSaveAs)
{
   // See explanation above
   // ProjectDisabler disabler(this);
   auto &proj = mProject;
   auto &window = GetProjectFrame( proj );
   auto &projectFileIO = ProjectFileIO::Get( proj );
   const auto &settings = ProjectSettings::Get( proj );

   // Some confirmation dialogs
   {
      auto &tracks = TrackList::Get( proj );
      if (!tracks.Any())
      {
         if (UndoManager::Get( proj ).UnsavedChanges() &&
               settings.EmptyCanBeDirty())
         {
            int result = AudacityMessageBox(
               XO(
   "Your project is now empty.\nIf saved, the project will have no tracks.\n\nTo save any previously open tracks:\nClick 'No', Edit > Undo until all tracks\nare open, then File > Save Project.\n\nSave anyway?"),
               XO("Warning - Empty Project"),
               wxYES_NO | wxICON_QUESTION,
               &window);
            if (result == wxNO)
            {
               return false;
            }
         }
      }
   }
   // End of confirmations

   // Always save a backup of the original project file
   wxString safetyFileName;
   if (fromSaveAs && wxFileExists(fileName))
   {
#ifdef __WXGTK__
      safetyFileName = fileName + wxT("~");
#else
      safetyFileName = fileName + wxT(".bak");
#endif

      if (wxFileExists(safetyFileName))
      {
         wxRemoveFile(safetyFileName);
      }

      if ( !wxRenameFile(fileName, safetyFileName) )
      {
         AudacityMessageBox(
            XO(
"Audacity failed to write file %s.\nPerhaps disk is full or not writable.")
               .Format(safetyFileName),
            XO("Error Writing to File"),
            wxICON_STOP,
            &window);
         return false;
      }
   }

   bool success = projectFileIO.SaveProject(fileName);
   if (!success)
   {
      AudacityMessageBox(
         XO(
"Could not save project. Perhaps %s \nis not writable or the disk is full.")
            .Format(fileName),
         XO("Error Saving Project"),
         wxICON_ERROR,
         &window);

      if (fromSaveAs)
      {
         if (wxFileExists(fileName))
         {
            wxRemoveFile(fileName);
         }
         wxRename(safetyFileName, fileName);
      }

      return false;
   }

   proj.SetProjectName(wxFileName(fileName).GetName());
   projectFileIO.SetProjectTitle();

   UndoManager::Get(proj).StateSaved();
   ProjectStatus::Get(proj).Set(XO("Saved %s").Format(fileName));

   if (mLastSavedTracks)
   {
      mLastSavedTracks->Clear();
   }
   mLastSavedTracks = TrackList::Create(nullptr);

   auto &tracks = TrackList::Get(proj);
   for (auto t : tracks.Any())
   {
      mLastSavedTracks->Add(t->Duplicate());
   }

   // If we get here, saving the project was successful, so we can DELETE
   // the .bak file (because it now does not fit our block files anymore
   // anyway).
   if (!safetyFileName.empty())
   {
      wxRemoveFile(safetyFileName);
   }

   return true;
}

// This version of SaveAs is invoked only from scripting and does not
// prompt for a file name
bool ProjectFileManager::SaveAs(const FilePath &newFileName, bool addToHistory /*= true*/)
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get( project );

   auto oldFileName = projectFileIO.GetFileName();

   bool bOwnsNewName = !projectFileIO.IsTemporary() && (oldFileName == newFileName);
   //check to see if the NEW project file already exists.
   //We should only overwrite it if this project already has the same name, where the user
   //simply chose to use the save as command although the save command would have the effect.
   if( !bOwnsNewName && wxFileExists(newFileName)) {
      AudacityMessageDialog m(
         nullptr,
         XO("The project was not saved because the file name provided would overwrite another project.\nPlease try again and select an original name."),
         XO("Error Saving Project"),
         wxOK|wxICON_ERROR );
      m.ShowModal();
      return false;
   }

   auto success = DoSave(newFileName, !bOwnsNewName);
   if (success && addToHistory) {
      FileHistory::Global().Append( projectFileIO.GetFileName() );
   }

   return(success);
}

bool ProjectFileManager::SaveAs()
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get( project );
   auto &window = GetProjectFrame( project );
   TitleRestorer Restorer( window, project ); // RAII
   bool bHasPath = true;
   wxFileName filename;
   
   if (projectFileIO.IsTemporary()) {
      filename = FileNames::DefaultToDocumentsFolder(wxT("/SaveAs/Path"));
   }
   else {
      filename = projectFileIO.GetFileName();
   }

   // Bug 1304: Set a default file path if none was given.  For Save/SaveAs/SaveCopy
   if( !FileNames::IsPathAvailable( filename.GetPath( wxPATH_GET_VOLUME| wxPATH_GET_SEPARATOR) ) ){
      bHasPath = false;
      filename.SetPath(FileNames::DefaultToDocumentsFolder(wxT("/SaveAs/Path")).GetPath());
   }

   TranslatableString title = XO("%sSave Project \"%s\" As...")
      .Format( Restorer.sProjNumber, Restorer.sProjName );
   TranslatableString message = XO("\
'Save Project' is for an Audacity project, not an audio file.\n\
For an audio file that will open in other apps, use 'Export'.\n");

   if (ShowWarningDialog(&window, wxT("FirstProjectSave"), message, true) != wxID_OK)
   {
      return false;
   }

   bool bPrompt = (project.mBatchMode == 0) || (projectFileIO.GetFileName().empty());
   FilePath fName;
   bool bOwnsNewName;

   do {
      if (bPrompt) {
         // JKC: I removed 'wxFD_OVERWRITE_PROMPT' because we are checking
         // for overwrite ourselves later, and we disallow it.
         fName = FileNames::SelectFile(FileNames::Operation::Export,
            title,
            filename.GetPath(),
            filename.GetFullName(),
            wxT("aup3"),
            { FileNames::AudacityProjects },
            wxFD_SAVE | wxRESIZE_BORDER,
            &window);

         if (fName.empty())
            return false;

         filename = fName;
      };

      filename.SetExt(wxT("aup3"));

      if (!bPrompt && filename.FileExists()) {
         // Saving a copy of the project should never overwrite an existing project.
         AudacityMessageDialog m(
            nullptr,
            XO("The project was not saved because the file name provided would overwrite another project.\nPlease try again and select an original name."),
            XO("Error Saving Project"),
            wxOK|wxICON_ERROR );
         m.ShowModal();
         return false;
      }

      fName = filename.GetFullPath();

      bOwnsNewName = !projectFileIO.IsTemporary() && ( projectFileIO.GetFileName() == fName );
      // Check to see if the project file already exists, and if it does
      // check that the project file 'belongs' to this project.
      // otherwise, prompt the user before overwriting.
      if (!bOwnsNewName && filename.FileExists()) {
         // Ensure that project of same name is not open in another window.
         // fName is the destination file.
         // mFileName is this project.
         // It is possible for mFileName == fName even when this project is not
         // saved to disk, and we then need to check the destination file is not
         // open in another window.
         int mayOverwrite = ( projectFileIO.GetFileName() == fName ) ? 2 : 1;
         for ( auto p : AllProjects{} ) {
            const wxFileName openProjectName{ ProjectFileIO::Get(*p).GetFileName() };
            if (openProjectName.SameAs(fName)) {
               mayOverwrite -= 1;
               if (mayOverwrite == 0)
                  break;
            }
         }

         if (mayOverwrite > 0) {
            /* i18n-hint: In each case, %s is the name
             of the file being overwritten.*/
            auto Message = XO("\
   Do you want to overwrite the project:\n\"%s\"?\n\n\
   If you select \"Yes\" the project\n\"%s\"\n\
   will be irreversibly overwritten.").Format( fName, fName );

            // For safety, there should NOT be an option to hide this warning.
            int result = AudacityMessageBox(
               Message,
               /* i18n-hint: Heading: A warning that a project is about to be overwritten.*/
               XO("Overwrite Project Warning"),
               wxYES_NO | wxNO_DEFAULT | wxICON_WARNING,
               &window);
            if (result == wxNO) {
               continue;
            }
            if (result == wxCANCEL) {
               return false;
            }
         }
         else
         {
            // Overwrite disallowed. The destination project is open in another window.
            AudacityMessageDialog m(
               nullptr,
               XO("The project was not saved because the selected project is open in another window.\nPlease try again and select an original name."),
               XO("Error Saving Project"),
               wxOK|wxICON_ERROR );
            m.ShowModal();
            continue;
         }
      }

      break;
   } while (bPrompt);


   auto success = DoSave(fName, !bOwnsNewName);
   if (success) {
      FileHistory::Global().Append( projectFileIO.GetFileName() );
      if( !bHasPath )
      {
         gPrefs->Write( wxT("/SaveAs/Path"), filename.GetPath());
         gPrefs->Flush();
      }
   }

   return(success);
}

bool ProjectFileManager::SaveCopy(const FilePath &fileName /* = wxT("") */)
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get(project);
   auto &window = GetProjectFrame(project);
   TitleRestorer Restorer(window, project); // RAII
   wxFileName filename = fileName;

   if (fileName.empty())
   {
      if (projectFileIO.IsTemporary())
      {
         filename = FileNames::DefaultToDocumentsFolder(wxT("/SaveAs/Path"));
      }
      else
      {
         filename = projectFileIO.GetFileName();
         filename.SetFullName(wxT(""));
      }
   }

   // Bug 1304: Set a default file path if none was given.  For Save/SaveAs/SaveCopy
   if (!FileNames::IsPathAvailable(filename.GetPath(wxPATH_GET_VOLUME | wxPATH_GET_SEPARATOR)))
   {
      filename.SetPath(FileNames::DefaultToDocumentsFolder(wxT("/SaveAs/Path")).GetPath());
   }

   TranslatableString title =
      XO("%sSave Copy of Project \"%s\" As...")
         .Format(Restorer.sProjNumber, Restorer.sProjName);

   bool bPrompt = (project.mBatchMode == 0) || (projectFileIO.GetFileName().empty());
   FilePath fName;

   do
   {
      if (bPrompt)
      {
         // JKC: I removed 'wxFD_OVERWRITE_PROMPT' because we are checking
         // for overwrite ourselves later, and we disallow it.
         // We disallow overwrite because we would have to DELETE the many
         // smaller files too, or prompt to move them.
         fName = FileNames::SelectFile(FileNames::Operation::Export,
                                       title,
                                       filename.GetPath(),
                                       filename.GetFullName(),
                                       wxT("aup3"),
                                       { FileNames::AudacityProjects },
                                       wxFD_SAVE | wxRESIZE_BORDER,
                                       &window);

         if (fName.empty())
         {
            return false;
         }

         filename = fName;
      };

      filename.SetExt(wxT("aup3"));

      if (filename.FileExists())
      {
         // Saving a copy of the project should never overwrite an existing project.
         AudacityMessageDialog m(nullptr,
                                 XO("Saving a copy must not overwrite an existing saved project.\nPlease try again and select an original name."),
                                 XO("Error Saving Copy of Project"),
                                 wxOK | wxICON_ERROR);
         m.ShowModal();

         if (project.mBatchMode)
         {
            return false;
         }

         continue;
      }

      fName = filename.GetFullPath();
      break;
   } while (bPrompt);

   if (!projectFileIO.SaveCopy(filename.GetFullPath()))
   {
      // Overwrite disallowed. The destination project is open in another window.
      AudacityMessageDialog m(
         nullptr,
         XO("The project will not saved because the selected project is open in another window.\nPlease try again and select an original name."),
         XO("Error Saving Project"),
         wxOK | wxICON_ERROR);

      m.ShowModal();

      return false;
   }

   return true;
}

void ProjectFileManager::Reset()
{
   // Lock all blocks in all tracks of the last saved version, so that
   // the blockfiles aren't deleted on disk when we DELETE the blockfiles
   // in memory.  After it's locked, DELETE the data structure so that
   // there's no memory leak.
   if (mLastSavedTracks)
   {
      auto &project = mProject;
      auto &projectFileIO = ProjectFileIO::Get(project);

      for (auto wt : mLastSavedTracks->Any<WaveTrack>())
      {
         wt->CloseLock();
      }

      mLastSavedTracks->Clear();
      mLastSavedTracks.reset();
   }
   
   ProjectFileIO::Get( mProject ).Reset();
}

bool ProjectFileManager::SaveFromTimerRecording(wxFileName fnFile)
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get( project );

   // MY: Will save the project to a NEW location a-la Save As
   // and then tidy up after itself.

   wxString sNewFileName = fnFile.GetFullPath();

   // MY: To allow SaveAs from Timer Recording we need to check what
   // the value of mFileName is before we change it.
   FilePath sOldFilename;
   if (!projectFileIO.IsModified()) {
      sOldFilename = projectFileIO.GetFileName();
   }

   // MY: If the project file already exists then bail out
   // and send populate the message string (pointer) so
   // we can tell the user what went wrong.
   if (wxFileExists(sNewFileName)) {
      return false;
   }

   auto success = DoSave(sNewFileName, true);

   if (success) {
      FileHistory::Global().Append( projectFileIO.GetFileName() );
   }

   return success;
}

void ProjectFileManager::VacuumProject()
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get(project);

   // Lock all blocks in all tracks of the last saved version, so that
   // the blockfiles aren't deleted on disk when we DELETE the blockfiles
   // in memory.  After it's locked, DELETE the data structure so that
   // there's no memory leak.
   if (mLastSavedTracks)
   {
      for (auto wt : mLastSavedTracks->Any<WaveTrack>())
      {
         wt->CloseLock();
      }

      // Attempt to vacuum the project
      projectFileIO.Vacuum(mLastSavedTracks);
   }
}

void ProjectFileManager::CloseProject()
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get(project);

   projectFileIO.CloseProject();

   // Blocks were locked in VacuumProject, so DELETE the data structure so that
   // there's no memory leak.
   if (mLastSavedTracks)
   {
      mLastSavedTracks->Clear();
      mLastSavedTracks.reset();
   }
}

// static method, can be called outside of a project
wxArrayString ProjectFileManager::ShowOpenDialog(
   const FileNames::FileType &extraType )
{
   // Construct the filter
   const auto fileTypes = Importer::Get().GetFileTypes( extraType );

   // Retrieve saved path
   auto path = FileNames::FindDefaultPath(FileNames::Operation::Open);

   // Construct and display the file dialog
   wxArrayString selected;

   FileDialogWrapper dlog(nullptr,
      XO("Select one or more files"),
      path,
      wxT(""),
      fileTypes,
      wxFD_OPEN | wxFD_MULTIPLE | wxRESIZE_BORDER);

   dlog.SetFilterIndex( Importer::SelectDefaultOpenType( fileTypes ) );

   int dialogResult = dlog.ShowModal();

   // Convert the filter index to type and save
   auto index = dlog.GetFilterIndex();
   const auto &saveType = fileTypes[ index ];

   Importer::SetDefaultOpenType( saveType );
   Importer::SetLastOpenType( saveType );

   if (dialogResult == wxID_OK) {
      // Return the selected files
      dlog.GetPaths(selected);
   }
   return selected;
}

// static method, can be called outside of a project
bool ProjectFileManager::IsAlreadyOpen(const FilePath &projPathName)
{
   const wxFileName newProjPathName(projPathName);
   auto start = AllProjects{}.begin(), finish = AllProjects{}.end(),
   iter = std::find_if( start, finish,
      [&]( const AllProjects::value_type &ptr ){
         return newProjPathName.SameAs(wxFileNameWrapper{ ProjectFileIO::Get(*ptr).GetFileName() });
      } );
   if (iter != finish) {
      auto errMsg =
      XO("%s is already open in another window.")
         .Format( newProjPathName.GetName() );
      wxLogError(errMsg.Translation()); //Debug?
      AudacityMessageBox(
         errMsg,
         XO("Error Opening Project"),
         wxOK | wxCENTRE);
      return true;
   }
   return false;
}

// XML handler for <import> tag
class ImportXMLTagHandler final : public XMLTagHandler
{
 public:
   ImportXMLTagHandler(AudacityProject* pProject) { mProject = pProject; }

   bool HandleXMLTag(const wxChar *tag, const wxChar **attrs) override;
   XMLTagHandler *HandleXMLChild(const wxChar * WXUNUSED(tag))  override
      { return NULL; }

   // Don't want a WriteXML method because ImportXMLTagHandler is not a WaveTrack.
   // <import> tags are instead written by AudacityProject::WriteXML.
   //    void WriteXML(XMLWriter &xmlFile) /* not override */ { wxASSERT(false); }

 private:
   AudacityProject* mProject;
};

bool ImportXMLTagHandler::HandleXMLTag(const wxChar *tag, const wxChar **attrs)
{
   if (wxStrcmp(tag, wxT("import")) || attrs==NULL || (*attrs)==NULL || wxStrcmp(*attrs++, wxT("filename")))
       return false;
   wxString strAttr = *attrs;

   WaveTrackArray trackArray;

   // Guard this call so that C++ exceptions don't propagate through
   // the expat library
   GuardedCall(
      [&] {
         ProjectFileManager::Get( *mProject ).Import(strAttr, &trackArray); },
      [&] (AudacityException*) { trackArray.clear(); }
   );

   if (trackArray.empty())
      return false;

   // Handle other attributes, now that we have the tracks.
   attrs++;
   const wxChar** pAttr;
   bool bSuccess = true;

   for (size_t i = 0; i < trackArray.size(); i++)
   {
      // Most of the "import" tag attributes are the same as for "wavetrack" tags,
      // so apply them via WaveTrack::HandleXMLTag().
      bSuccess = trackArray[i]->HandleXMLTag(wxT("wavetrack"), attrs);

      // "offset" tag is ignored in WaveTrack::HandleXMLTag except for legacy projects,
      // so handle it here.
      double dblValue;
      pAttr = attrs;
      while (*pAttr)
      {
         const wxChar *attr = *pAttr++;
         const wxChar *value = *pAttr++;
         const wxString strValue = value;
         if (!wxStrcmp(attr, wxT("offset")) &&
               XMLValueChecker::IsGoodString(strValue) &&
               Internat::CompatibleToDouble(strValue, &dblValue))
            trackArray[i]->SetOffset(dblValue);
      }
   }
   return bSuccess;
};

// FIXME:? TRAP_ERR This should return a result that is checked.
//    See comment in AudacityApp::MRUOpen().
void ProjectFileManager::OpenFile(const FilePath &fileNameArg, bool addtohistory)
{
   auto &project = mProject;
   auto &history = ProjectHistory::Get( project );
   auto &projectFileIO = ProjectFileIO::Get( project );
   auto &tracks = TrackList::Get( project );
   auto &trackPanel = TrackPanel::Get( project );
   auto &window = ProjectWindow::Get( project );

   // On Win32, we may be given a short (DOS-compatible) file name on rare
   // occasions (e.g. stuff like "C:\PROGRA~1\AUDACI~1\PROJEC~1.AUP"). We
   // convert these to long file name first.
   auto fileName = PlatformCompatibility::ConvertSlashInFileName(
      PlatformCompatibility::GetLongFileName(fileNameArg));

   // Make sure it isn't already open.
   // Vaughan, 2011-03-25: This was done previously in AudacityProject::OpenFiles()
   //    and AudacityApp::MRUOpen(), but if you open an aup file by double-clicking it
   //    from, e.g., Win Explorer, it would bypass those, get to here with no check,
   //    then open a NEW project from the same data with no warning.
   //    This was reported in http://bugzilla.audacityteam.org/show_bug.cgi?id=137#c17,
   //    but is not really part of that bug. Anyway, prevent it!
   if (IsAlreadyOpen(fileName))
      return;

   // Data loss may occur if users mistakenly try to open ".aup3.bak" files
   // left over from an unsuccessful save or by previous versions of Audacity.
   // So we always refuse to open such files.
   if (fileName.Lower().EndsWith(wxT(".aup3.bak")))
   {
      AudacityMessageBox(
         XO(
"You are trying to open an automatically created backup file.\nDoing this may result in severe data loss.\n\nPlease open the actual Audacity project file instead."),
         XO("Warning - Backup File Detected"),
         wxOK | wxCENTRE,
         &window);
      return;
   }

   if (!::wxFileExists(fileName)) {
      AudacityMessageBox(
         XO("Could not open file: %s").Format( fileName ),
         XO("Error Opening File"),
         wxOK | wxCENTRE,
         &window);
      return;
   }

   {
      wxFFile ff(fileName, wxT("rb"));

      auto cleanup = finally([&]
      {
         if (ff.IsOpened())
         {
            ff.Close();
         }
      });

      if (!ff.IsOpened()) {
         AudacityMessageBox(
            XO("Could not open file: %s").Format( fileName ),
            XO("Error opening file"),
            wxOK | wxCENTRE,
            &window);
         return;
      }

      char buf[7];
      auto numRead = ff.Read(buf, 6);
      if (numRead != 6) {
         AudacityMessageBox(
            XO("File may be invalid or corrupted: \n%s").Format( fileName ),
            XO("Error Opening File or Project"),
            wxOK | wxCENTRE,
            &window);
         return;
      }

      if (wxStrncmp(buf, "SQLite", 6) != 0)
      {
#ifdef EXPERIMENTAL_DRAG_DROP_PLUG_INS
         // Is it a plug-in?
         if (PluginManager::Get().DropFile(fileName))
         {
            MenuCreator::RebuildAllMenuBars();
         }
         else
#endif
#ifdef USE_MIDI
         if (FileNames::IsMidi(fileName))
         {
            DoImportMIDI(project, fileName);
         }
         else
#endif
         {
            Import(fileName);
         }

         window.ZoomAfterImport(nullptr);

         return;
      }
   }

   auto results = ReadProjectFile( fileName );
 
   const bool bParseSuccess = results.parseSuccess;
   const auto &errorStr = results.errorString;
   const bool err = results.trackError;

   if (bParseSuccess) {
      auto &settings = ProjectSettings::Get( project );
      window.mbInitializingScrollbar = true; // this must precede AS_SetSnapTo
         // to make persistence of the vertical scrollbar position work

      auto &selectionManager = ProjectSelectionManager::Get( project );
      selectionManager.AS_SetSnapTo(settings.GetSnapTo());
      selectionManager.AS_SetSelectionFormat(settings.GetSelectionFormat());
      selectionManager.TT_SetAudioTimeFormat(settings.GetAudioTimeFormat());
      selectionManager.SSBL_SetFrequencySelectionFormatName(
      settings.GetFrequencySelectionFormatName());
      selectionManager.SSBL_SetBandwidthSelectionFormatName(
      settings.GetBandwidthSelectionFormatName());

      SelectionBar::Get( project ).SetRate( settings.GetRate() );

      ProjectHistory::Get( project ).InitialState();
      TrackFocus::Get( project ).Set( *tracks.Any().begin() );
      window.HandleResize();
      trackPanel.Refresh(false);
      trackPanel.Update(); // force any repaint to happen now,
      // else any asynch calls into the blockfile code will not have
      // finished logging errors (if any) before the call to ProjectFSCK()

      if (addtohistory)
         FileHistory::Global().Append(fileName);
   }

   if (bParseSuccess) {
      if (projectFileIO.IsRecovered())
      {
         // PushState calls AutoSave(), so no longer need to do so here.
         history.PushState(XO("Project was recovered"), XO("Recover"));
      }
   }
   else {
      // Vaughan, 2011-10-30:
      // See first topic at http://bugzilla.audacityteam.org/show_bug.cgi?id=451#c16.
      // Calling mTracks->Clear() with deleteTracks true results in data loss.

      // PRL 2014-12-19:
      // I made many changes for wave track memory management, but only now
      // read the above comment.  I may have invalidated the fix above (which
      // may have spared the files at the expense of leaked memory).  But
      // here is a better way to accomplish the intent, doing like what happens
      // when the project closes:
      for ( auto pTrack : tracks.Any< WaveTrack >() )
         pTrack->CloseLock();

      tracks.Clear(); //tracks.Clear(true);

      wxLogError(wxT("Could not parse file \"%s\". \nError: %s"), fileName, errorStr.Debug());

      ShowErrorDialog(
         &window,
         XO("Error Opening Project"),
         errorStr,
         results.helpUrl);
   }
}

std::vector< std::shared_ptr< Track > >
ProjectFileManager::AddImportedTracks(const FilePath &fileName,
                                      TrackHolders &&newTracks)
   {
   auto &project = mProject;
   auto &history = ProjectHistory::Get( project );
   auto &projectFileIO = ProjectFileIO::Get( project );
   auto &tracks = TrackList::Get( project );

   std::vector< std::shared_ptr< Track > > results;

   SelectUtilities::SelectNone( project );

   wxFileName fn(fileName);

   bool initiallyEmpty = tracks.empty();
   double newRate = 0;
   wxString trackNameBase = fn.GetName();
   int i = -1;

   // Must add all tracks first (before using Track::IsLeader)
   for (auto &group : newTracks) {
      if (group.empty()) {
         wxASSERT(false);
         continue;
      }
      auto first = group.begin()->get();
      auto nChannels = group.size();
      for (auto &uNewTrack : group) {
         auto newTrack = tracks.Add( uNewTrack );
         results.push_back(newTrack->SharedPointer());
      }
      tracks.GroupChannels(*first, nChannels);
   }
   newTracks.clear();
      
   // Now name them

   // Add numbers to track names only if there is more than one (mono or stereo)
   // track (not necessarily, more than one channel)
   const bool useSuffix =
      make_iterator_range( results.begin() + 1, results.end() )
         .any_of( []( decltype(*results.begin()) &pTrack )
            { return pTrack->IsLeader(); } );

   for (const auto &newTrack : results) {
      if ( newTrack->IsLeader() )
         // Count groups only
         ++i;

      newTrack->SetSelected(true);

      if ( useSuffix )
         newTrack->SetName(trackNameBase + wxString::Format(wxT(" %d" ), i + 1));
      else
         newTrack->SetName(trackNameBase);

      newTrack->TypeSwitch( [&](WaveTrack *wt) {
         if (newRate == 0)
            newRate = wt->GetRate();
      });
   }

   // Automatically assign rate of imported file to whole project,
   // if this is the first file that is imported
   if (initiallyEmpty && newRate > 0) {
      auto &settings = ProjectSettings::Get( project );
      settings.SetRate( newRate );
      SelectionBar::Get( project ).SetRate( newRate );
   }

   history.PushState(XO("Imported '%s'").Format( fileName ),
       XO("Import"));

#if defined(__WXGTK__)
   // See bug #1224
   // The track panel hasn't we been fully created, so the DoZoomFit() will not give
   // expected results due to a window width of zero.  Should be safe to yield here to
   // allow the creation to complete.  If this becomes a problem, it "might" be possible
   // to queue a dummy event to trigger the DoZoomFit().
   wxEventLoopBase::GetActive()->YieldFor(wxEVT_CATEGORY_UI | wxEVT_CATEGORY_USER_INPUT);
#endif

   // If the project was clean and temporary (not permanently saved), then set
   // the filename to the just imported path.
   if (initiallyEmpty && projectFileIO.IsTemporary()) {
      project.SetProjectName(fn.GetName());
      projectFileIO.SetProjectTitle();
   }

   // Moved this call to higher levels to prevent flicker redrawing everything on each file.
   //   HandleResize();

   return results;
}

// If pNewTrackList is passed in non-NULL, it gets filled with the pointers to NEW tracks.
bool ProjectFileManager::Import(
   const FilePath &fileName, WaveTrackArray* pTrackArray /*= NULL*/)
{
   auto &project = mProject;
   auto &projectFileIO = ProjectFileIO::Get(project);
   auto oldTags = Tags::Get( project ).shared_from_this();
   bool initiallyEmpty = TrackList::Get(project).empty();
   TrackHolders newTracks;
   TranslatableString errorMessage;

   // Handle AUP3 ("project") files directly
   if (fileName.AfterLast('.').IsSameAs(wxT("aup3"), false)) {

      if (projectFileIO.ImportProject(fileName)) {
         auto &history = ProjectHistory::Get(project);

         // If the project was clean and temporary (not permanently saved), then set
         // the filename to the just imported path.
         if (initiallyEmpty && projectFileIO.IsTemporary()) {
            project.SetProjectName(wxFileName(fileName).GetName());
            projectFileIO.SetProjectTitle();
         }

         history.PushState(XO("Imported '%s'").Format(fileName), XO("Import"));

         FileHistory::Global().Append(fileName);
      }

      return false;
   }

   {
      // Backup Tags, before the import.  Be prepared to roll back changes.
      bool committed = false;
      auto cleanup = finally([&]{
         if ( !committed )
            Tags::Set( project, oldTags );
      });
      auto newTags = oldTags->Duplicate();
      Tags::Set( project, newTags );

      bool success = Importer::Get().Import(project, fileName,
                                            &TrackFactory::Get( project ),
                                            newTracks,
                                            newTags.get(),
                                            errorMessage);

      if (!errorMessage.empty()) {
         // Error message derived from Importer::Import
         // Additional help via a Help button links to the manual.
         ShowErrorDialog(&GetProjectFrame( project ), XO("Error Importing"),
                         errorMessage, wxT("Importing_Audio"));
      }
      if (!success)
         return false;

      FileHistory::Global().Append(fileName);

      // no more errors, commit
      committed = true;
   }

   // for LOF ("list of files") files, do not import the file as if it
   // were an audio file itself
   if (fileName.AfterLast('.').IsSameAs(wxT("lof"), false)) {
      // PRL: don't redundantly do the steps below, because we already
      // did it in case of LOF, because of some weird recursion back to this
      // same function.  I think this should be untangled.

      // So Undo history push is not bypassed, despite appearances.
      return false;
   }

   // Handle AUP ("legacy project") files directly
   if (fileName.AfterLast('.').IsSameAs(wxT("aup"), false)) {
      // If the project was clean and temporary (not permanently saved), then set
      // the filename to the just imported path.
      if (initiallyEmpty && projectFileIO.IsTemporary()) {
         project.SetProjectName(wxFileName(fileName).GetName());
         projectFileIO.SetProjectTitle();
      }

      auto &history = ProjectHistory::Get( project );

      history.PushState(XO("Imported '%s'").Format( fileName ), XO("Import"));

      return false;
   }

   // PRL: Undo history is incremented inside this:
   auto newSharedTracks = AddImportedTracks(fileName, std::move(newTracks));

   if (pTrackArray) {
      for (const auto &newTrack : newSharedTracks) {
         newTrack->TypeSwitch( [&](WaveTrack *wt) {
            pTrackArray->push_back( wt->SharedPointer< WaveTrack >() );
         });
      }
   }

   return true;
}