More constructors for SnapManager...

one taking candidate list directly, the others delegating to it.

Some members removed, some in-class initializers.

The special constructor for TimeShift only has extra arguments.  It will go
away.

src/Snap.cpp

@@ -39,6 +39,108 @@ TrackClip::~TrackClip()
 
 }
 
+SnapManager::SnapManager(const AudacityProject &project,
+                         SnapPointArray candidates,
+                         const ZoomInfo &zoomInfo,
+                         bool noTimeSnap,
+                         int pixelTolerance)
+: mProject{ &project }
+, mZoomInfo{ &zoomInfo }
+, mPixelTolerance{ pixelTolerance }
+, mNoTimeSnap{ noTimeSnap }
+, mCandidates{ std::move( candidates ) }
+, mSnapPoints{}
+, mConverter{ NumericConverter::TIME }
+{
+   Reinit();
+}
+
+namespace {
+SnapPointArray FindCandidates( const TrackList &tracks )
+{
+   SnapPointArray candidates;
+   for ( const auto track : tracks.Any() ) {
+      auto intervals = track->GetIntervals();
+      for (const auto &interval : intervals) {
+         candidates.emplace_back( interval.Start(), track );
+         if ( interval.Start() != interval.End() )
+            candidates.emplace_back( interval.End(), track );
+      }
+   }
+   return candidates;
+}
+
+SnapPointArray FindCandidates(
+   const TrackList &tracks,
+   const TrackClipArray *clipExclusions, const TrackArray *trackExclusions )
+{
+   // Special case restricted candidates for time shift
+   SnapPointArray candidates;
+   auto trackRange =
+      tracks.Any()
+         - [&](const Track *pTrack){
+            return trackExclusions &&
+               make_iterator_range( *trackExclusions ).contains( pTrack );
+         };
+   trackRange.Visit(
+      [&](const LabelTrack *labelTrack) {
+         for (int i = 0, cnt = labelTrack->GetNumLabels(); i < cnt; ++i)
+         {
+            const LabelStruct *label = labelTrack->GetLabel(i);
+            const double t0 = label->getT0();
+            const double t1 = label->getT1();
+            candidates.emplace_back(t0, labelTrack);
+            if (t1 != t0)
+               candidates.emplace_back(t1, labelTrack);
+         }
+      },
+      [&](const WaveTrack *waveTrack) {
+         for (const auto &clip: waveTrack->GetClips())
+         {
+            if (clipExclusions)
+            {
+               bool skip = false;
+               for (size_t j = 0, cnt = clipExclusions->size(); j < cnt; ++j)
+               {
+                  if ((*clipExclusions)[j].track == waveTrack &&
+                      (*clipExclusions)[j].clip == clip.get())
+                  {
+                     skip = true;
+                     break;
+                  }
+               }
+
+               if (skip)
+                  continue;
+            }
+
+            candidates.emplace_back(clip->GetStartTime(), waveTrack);
+            candidates.emplace_back(clip->GetEndTime(), waveTrack);
+         }
+      }
+#ifdef USE_MIDI
+      ,
+      [&](const NoteTrack *track) {
+         candidates.emplace_back(track->GetStartTime(), track);
+         candidates.emplace_back(track->GetEndTime(), track);
+      }
+#endif
+   );
+   return candidates;
+}
+}
+
+SnapManager::SnapManager(const AudacityProject &project,
+            const TrackList &tracks,
+            const ZoomInfo &zoomInfo,
+            bool noTimeSnap,
+            int pixelTolerance)
+   : SnapManager{ project,
+      FindCandidates( tracks ),
+      zoomInfo, noTimeSnap, pixelTolerance }
+{
+}
+
 SnapManager::SnapManager(const AudacityProject &project,
                          const TrackList &tracks,
                          const ZoomInfo &zoomInfo,
@@ -46,26 +148,10 @@ SnapManager::SnapManager(const AudacityProject &project,
                          int pixelTolerance,
                          const TrackClipArray *clipExclusions,
                          const TrackArray *trackExclusions)
-:  mConverter(NumericConverter::TIME)
+   : SnapManager{ project,
+      FindCandidates( tracks, clipExclusions, trackExclusions ),
+      zoomInfo, noTimeSnap, pixelTolerance }
 {
-   mTracks = &tracks;
-   mZoomInfo = &zoomInfo;
-   mClipExclusions = clipExclusions;
-   mTrackExclusions = trackExclusions;
-   mPixelTolerance = pixelTolerance;
-   mNoTimeSnap = noTimeSnap;
-
-   mProject = &project;
-   wxASSERT(mProject);
-
-   mSnapTo = 0;
-   mRate = 0.0;
-   mFormat = {};
-
-   // Two time points closer than this are considered the same
-   mEpsilon = 1 / 44100.0;
-
-   Reinit();
 }
 
 SnapManager::~SnapManager()
@@ -106,58 +192,9 @@ void SnapManager::Reinit()
    // Add a SnapPoint at t=0
    mSnapPoints.push_back(SnapPoint{});
 
-   auto trackRange =
-      mTracks->Any()
-         - [&](const Track *pTrack){
-            return mTrackExclusions &&
-               make_iterator_range( *mTrackExclusions ).contains( pTrack );
-         };
-   trackRange.Visit(
-      [&](const LabelTrack *labelTrack) {
-         for (int i = 0, cnt = labelTrack->GetNumLabels(); i < cnt; ++i)
-         {
-            const LabelStruct *label = labelTrack->GetLabel(i);
-            const double t0 = label->getT0();
-            const double t1 = label->getT1();
-            CondListAdd(t0, labelTrack);
-            if (t1 != t0)
-            {
-               CondListAdd(t1, labelTrack);
-            }
-         }
-      },
-      [&](const WaveTrack *waveTrack) {
-         for (const auto &clip: waveTrack->GetClips())
-         {
-            if (mClipExclusions)
-            {
-               bool skip = false;
-               for (size_t j = 0, cnt = mClipExclusions->size(); j < cnt; ++j)
-               {
-                  if ((*mClipExclusions)[j].track == waveTrack &&
-                      (*mClipExclusions)[j].clip == clip.get())
-                  {
-                     skip = true;
-                     break;
-                  }
-               }
-
-               if (skip)
-                  continue;
-            }
-
-            CondListAdd(clip->GetStartTime(), waveTrack);
-            CondListAdd(clip->GetEndTime(), waveTrack);
-         }
-      }
-#ifdef USE_MIDI
-      ,
-      [&](const NoteTrack *track) {
-         CondListAdd(track->GetStartTime(), track);
-         CondListAdd(track->GetEndTime(), track);
-      }
-#endif
-   );
+   // Adjust and filter the candidate points
+   for (const auto &candidate : mCandidates)
+      CondListAdd( candidate.t, candidate.track );
 
    // Sort all by time
    std::sort(mSnapPoints.begin(), mSnapPoints.end());

src/Snap.h

@@ -77,11 +77,23 @@ struct SnapResults {
 class SnapManager
 {
 public:
+   SnapManager(const AudacityProject &project,
+               SnapPointArray candidates,
+               const ZoomInfo &zoomInfo,
+               bool noTimeSnap = false,
+               int pixelTolerance = kPixelTolerance);
+
    SnapManager(const AudacityProject &project,
                const TrackList &tracks,
                const ZoomInfo &zoomInfo,
                bool noTimeSnap = false,
-               int pixelTolerance = kPixelTolerance,
+               int pixelTolerance = kPixelTolerance);
+
+   SnapManager(const AudacityProject &project,
+               const TrackList &tracks,
+               const ZoomInfo &zoomInfo,
+               bool noTimeSnap,
+               int pixelTolerance,
                const TrackClipArray *clipExclusions = NULL,
                const TrackArray *trackExclusions = NULL);
    ~SnapManager();
@@ -112,23 +124,22 @@ private:
 private:
 
    const AudacityProject *mProject;
-   const TrackList *mTracks;
-   const TrackClipArray *mClipExclusions;
-   const TrackArray *mTrackExclusions;
    const ZoomInfo *mZoomInfo;
    int mPixelTolerance;
    bool mNoTimeSnap;
    
-   double mEpsilon;
+   //! Two time points closer than this are considered the same
+   double mEpsilon{ 1 / 44100.0 };
+   SnapPointArray mCandidates;
    SnapPointArray mSnapPoints;
 
    // Info for snap-to-time
    NumericConverter mConverter;
-   bool mSnapToTime;
+   bool mSnapToTime{ false };
 
-   int mSnapTo;
-   double mRate;
-   NumericFormatSymbol mFormat;
+   int mSnapTo{ 0 };
+   double mRate{ 0.0 };
+   NumericFormatSymbol mFormat{};
 };
 
 #endif