Track duplication methods return unique_ptr, although some callers...

... simply release() them for now.

src/LabelTrack.cpp

@@ -1136,9 +1136,9 @@ double LabelTrack::GetEndTime() const
    return end;
 }
 
-Track *LabelTrack::Duplicate() const
+Track::Holder LabelTrack::Duplicate() const
 {
-   return new LabelTrack(*this);
+   return std::make_unique<LabelTrack>( *this );
 }
 
 void LabelTrack::SetSelected(bool s)

src/LabelTrack.h

@@ -139,7 +139,8 @@ class AUDACITY_DLL_API LabelTrack final : public Track
    double GetStartTime() const override;
    double GetEndTime() const override;
 
-   Track *Duplicate() const override;
+   using Holder = std::unique_ptr<LabelTrack>;
+   Track::Holder Duplicate() const override;
 
    void SetSelected(bool s) override;
 

src/NoteTrack.cpp

@@ -135,9 +135,9 @@ NoteTrack::~NoteTrack()
    }
 }
 
-Track *NoteTrack::Duplicate() const
+Track::Holder NoteTrack::Duplicate() const
 {
-   NoteTrack *duplicate = new NoteTrack(mDirManager);
+   auto duplicate = std::make_unique<NoteTrack>(mDirManager);
    duplicate->Init(*this);
    // Duplicate on NoteTrack moves data from mSeq to mSerializationBuffer
    // and from mSerializationBuffer to mSeq on alternate calls. Duplicate
@@ -169,7 +169,7 @@ Track *NoteTrack::Duplicate() const
 #ifdef EXPERIMENTAL_MIDI_OUT
    duplicate->SetGain(GetGain());
 #endif
-   return duplicate;
+   return std::move(duplicate);
 }
 
 
@@ -196,10 +196,10 @@ void NoteTrack::WarpAndTransposeNotes(double t0, double t1,
    // Since this is a duplicate and duplicates convert mSeq to
    // a text string for saving as XML, we probably have to
    // duplicate again to get back an mSeq
-   NoteTrack *nt = this;
-   double offset = nt->GetOffset(); // track is shifted this amount
+   double offset = this->GetOffset(); // track is shifted this amount
    if (!mSeq) { // replace saveme with an (unserialized) duplicate
-      nt = (NoteTrack *) this->Duplicate();
+      Track::Holder unt{ Duplicate() };
+      const auto nt = static_cast<NoteTrack*>(unt.get());
       wxASSERT(!mSeq && nt->mSeq && !nt->mSerializationBuffer);
       // swap mSeq and Buffer between this and nt
       nt->mSerializationBuffer = mSerializationBuffer;
@@ -208,7 +208,6 @@ void NoteTrack::WarpAndTransposeNotes(double t0, double t1,
       mSerializationLength = 0;
       mSeq = nt->mSeq;
       nt->mSeq = NULL;
-      delete nt; // delete the duplicate
    }
    mSeq->convert_to_seconds(); // make sure time units are right
    t1 -= offset; // adjust time range to compensate for track offset
@@ -821,9 +820,11 @@ void NoteTrack::WriteXML(XMLWriter &xmlFile)
    // NoteTrack.) In this case, mSeq will be NULL. To avoid a crash
    // and perform WriteXML, we may need to restore NoteTracks from binary
    // blobs to regular data structures (with an Alg_seq member).
+   Track::Holder holder;
    NoteTrack *saveme = this;
    if (!mSeq) { // replace saveme with an (unserialized) duplicate
-      saveme = (NoteTrack *) this->Duplicate();
+      holder = Duplicate();
+      saveme = static_cast<NoteTrack*>(holder.get());
       assert(saveme->mSeq);
    }
    saveme->mSeq->write(data, true);
@@ -841,9 +842,6 @@ void NoteTrack::WriteXML(XMLWriter &xmlFile)
    xmlFile.WriteAttr(wxT("bottomnote"), saveme->mBottomNote);
    xmlFile.WriteAttr(wxT("data"), wxString(data.str().c_str(), wxConvUTF8));
    xmlFile.EndTag(wxT("notetrack"));
-   if (this != saveme) {
-      delete saveme; // DELETE the duplicate
-   }
 }
 
 void NoteTrack::StartVScroll()

src/NoteTrack.h

@@ -57,7 +57,8 @@ class AUDACITY_DLL_API NoteTrack final : public Track {
    NoteTrack(DirManager * projDirManager);
    virtual ~NoteTrack();
 
-   Track *Duplicate() const override;
+   using Holder = std::unique_ptr<NoteTrack>;
+   Track::Holder Duplicate() const override;
 
    int GetKind() const override { return Note; }
 

src/Project.cpp

@@ -2751,7 +2751,7 @@ void AudacityProject::OpenFile(const wxString &fileNameArg, bool addtohistory)
             }
          }
 
-         mLastSavedTracks->Add(t->Duplicate());
+         mLastSavedTracks->Add(t->Duplicate().release());
          t = iter.Next();
       }
 
@@ -3549,7 +3549,7 @@ bool AudacityProject::Save(bool overwrite /* = true */ ,
       Track *t = iter.First();
       Track *dupT;
       while (t) {
-         dupT = t->Duplicate();
+         dupT = t->Duplicate().release();
          mLastSavedTracks->Add(dupT);
 
          //only after the xml has been saved we can mark it saved.
@@ -4066,8 +4066,7 @@ void AudacityProject::PopState(const UndoState &state)
 
    while (t)
    {
-      copyTrack=t->Duplicate();
-      mTracks->Add(copyTrack);
+      mTracks->Add(copyTrack = t->Duplicate().release());
 
       //add the track to OD if the manager exists.  later we might do a more rigorous check...
       if (copyTrack->GetKind() == Track::Wave)

src/TimeTrack.cpp

@@ -109,9 +109,9 @@ TimeTrack::~TimeTrack()
    delete mRuler;
 }
 
-Track *TimeTrack::Duplicate() const
+Track::Holder TimeTrack::Duplicate() const
 {
-   return new TimeTrack(*this);
+   return std::make_unique<TimeTrack>(*this);
 }
 
 bool TimeTrack::GetInterpolateLog() const

src/TimeTrack.h

@@ -132,7 +132,9 @@ class TimeTrack final : public Track {
     * @param orig the TimeTrack to copy from
     */
    void Init(const TimeTrack &orig);
-   Track *Duplicate() const override;
+
+   using Holder = std::unique_ptr<TimeTrack>;
+   Track::Holder Duplicate() const override;
 
    friend class TrackFactory;
 

src/Track.cpp

@@ -746,7 +746,7 @@ void TrackList::DoAssign(const TrackList &that)
    mDestructorDeletesTracks = true;
    TrackListConstIterator it(&that);
    for (const Track *track = it.First(); track; track = it.Next())
-      Add(track->Duplicate());
+      Add(track->Duplicate().release());
 }
 
 void TrackList::Swap(TrackList &that)

src/Track.h

@@ -165,7 +165,9 @@ class AUDACITY_DLL_API Track /* not final */ : public XMLTagHandler
    virtual ~ Track();
 
    void Init(const Track &orig);
-   virtual Track *Duplicate() const = 0;
+
+   using Holder = std::unique_ptr<Track>;
+   virtual Holder Duplicate() const = 0;
 
    // Called when this track is merged to stereo with another, and should
    // take on some paramaters of its partner.

src/UndoManager.cpp

@@ -214,7 +214,7 @@ void UndoManager::ModifyState(const TrackList * l,
    TrackListConstIterator iter(l);
    const Track *t = iter.First();
    while (t) {
-      tracksCopy->Add(t->Duplicate());
+      tracksCopy->Add(t->Duplicate().release());
       t = iter.Next();
    }
 
@@ -259,7 +259,7 @@ void UndoManager::PushState(const TrackList * l,
    TrackListConstIterator iter(l);
    const Track *t = iter.First();
    while (t) {
-      tracksCopy->Add(t->Duplicate());
+      tracksCopy->Add(t->Duplicate().release());
       t = iter.Next();
    }
 

src/WaveTrack.cpp

@@ -65,7 +65,7 @@ bool WaveTrack::mMonoAsVirtualStereo;
 
 WaveTrack* TrackFactory::DuplicateWaveTrack(WaveTrack &orig)
 {
-   return (WaveTrack*)(orig.Duplicate());
+   return (WaveTrack*)(orig.Duplicate().release());
 }
 
 
@@ -355,9 +355,9 @@ void WaveTrack::SetSpectrumBounds(float min, float max) const
    mSpectrumMax = max;
 }
 
-Track *WaveTrack::Duplicate() const
+Track::Holder WaveTrack::Duplicate() const
 {
-   return new WaveTrack(*this);
+   return Track::Holder{ safenew WaveTrack{ *this } };
 }
 
 double WaveTrack::GetRate() const

src/WaveTrack.h

@@ -75,7 +75,9 @@ class AUDACITY_DLL_API WaveTrack final : public Track {
    WaveTrack(const WaveTrack &orig);
 
    void Init(const WaveTrack &orig);
-   virtual Track *Duplicate() const override;
+
+   Track::Holder Duplicate() const override;
+
 #ifdef EXPERIMENTAL_OUTPUT_DISPLAY
    void VirtualStereoInit();
 #endif
@@ -87,6 +89,7 @@ class AUDACITY_DLL_API WaveTrack final : public Track {
 #endif
 
    typedef WaveTrackLocation Location;
+   using Holder = std::unique_ptr<WaveTrack>;
 
    virtual ~WaveTrack();
    double GetOffset() const override;

src/effects/Effect.cpp

@@ -2117,7 +2117,7 @@ void Effect::CopyInputTracks(int trackType)
       if (aTrack->GetSelected() ||
             (trackType == Track::All && aTrack->IsSyncLockSelected()))
       {
-         Track *o = aTrack->Duplicate();
+         Track *o = aTrack->Duplicate().release();
          mOutputTracks->Add(o);
          mIMap.Add(aTrack);
          mOMap.Add(o);

src/toolbars/ControlToolBar.cpp

@@ -1098,11 +1098,11 @@ void ControlToolBar::SetupCutPreviewTracks(double WXUNUSED(playStart), double cu
       if (track1)
       {
          // Duplicate and change tracks
-         track1 = track1->Duplicate();
+         track1 = track1->Duplicate().release();
          track1->Clear(cutStart, cutEnd);
          if (track2)
          {
-            track2 = track2->Duplicate();
+            track2 = track2->Duplicate().release();
             track2->Clear(cutStart, cutEnd);
          }