TrackVRulerControl is directly owned by TrackView not Track...

... in anticipation of making views to tracks many-to-one, but then the rulers
should be one-to-one with the views.  So go through the view to get the ruler.
The ruler is really a left-hand extension for each view.

src/LabelTrack.h

@@ -321,7 +321,6 @@ private:
 protected:
    std::shared_ptr<TrackView> DoGetView() override;
    std::shared_ptr<TrackControls> DoGetControls() override;
-   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 
    friend class GetInfoCommand; // to get labels.
    friend class SetLabelCommand; // to set labels.

src/NoteTrack.h

@@ -228,7 +228,6 @@ class AUDACITY_DLL_API NoteTrack final
 protected:
    std::shared_ptr<TrackView> DoGetView() override;
    std::shared_ptr<TrackControls> DoGetControls() override;
-   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 };
 
 /// Data used to display a note track

src/TimeTrack.h

@@ -125,7 +125,6 @@ class TimeTrack final : public Track {
 protected:
    std::shared_ptr<TrackView> DoGetView() override;
    std::shared_ptr<TrackControls> DoGetControls() override;
-   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 };
 
 

src/Track.h

@@ -38,7 +38,6 @@ class LabelTrack;
 class TimeTrack;
 class TrackControls;
 class TrackView;
-class TrackVRulerControls;
 class TrackPanelResizerCell;
 class WaveTrack;
 class NoteTrack;
@@ -297,11 +296,7 @@ class AUDACITY_DLL_API Track /* not final */
    std::shared_ptr<const TrackPanelCell> GetTrackControls() const;
 
    // Return another, associated TrackPanelCell object that implements the
-   // mouse actions for the vertical ruler
-   std::shared_ptr<TrackVRulerControls> GetVRulerControls();
-   std::shared_ptr<const TrackVRulerControls> GetVRulerControls() const;
 
-   // Return another, associated TrackPanelCell object that implements the
    // click and drag to resize
    std::shared_ptr<TrackPanelCell> GetResizer();
 
@@ -760,12 +755,10 @@ protected:
    // These are called to create controls on demand:
    virtual std::shared_ptr<TrackView> DoGetView() = 0;
    virtual std::shared_ptr<TrackControls> DoGetControls() = 0;
-   virtual std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() = 0;
 
    // These hold the controls:
    std::shared_ptr<TrackView> mpView;
    std::shared_ptr<TrackControls> mpControls;
-   std::shared_ptr<TrackVRulerControls> mpVRulerContols;
    std::shared_ptr<TrackPanelResizerCell> mpResizer;
 
    std::weak_ptr<SelectHandle> mSelectHandle;

src/TrackPanel.cpp

@@ -101,7 +101,7 @@ is time to refresh some aspect of the screen.
 #include "toolbars/ControlToolBar.h"
 
 #include "tracks/ui/TrackControls.h"
-#include "tracks/ui/TrackVRulerControls.h" // for inheritance relation
+#include "tracks/ui/TrackVRulerControls.h"
 
 //This loads the appropriate set of cursors, depending on platform.
 #include "../images/Cursors.h"

src/WaveTrack.h

@@ -701,7 +701,6 @@ private:
 protected:
    std::shared_ptr<TrackView> DoGetView() override;
    std::shared_ptr<TrackControls> DoGetControls() override;
-   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 };
 
 // This is meant to be a short-lived object, during whose lifetime,

src/tracks/labeltrack/ui/LabelTrackVRulerControls.h

@@ -23,8 +23,8 @@ class LabelTrackVRulerControls final : public TrackVRulerControls
 
 public:
    explicit
-   LabelTrackVRulerControls( std::shared_ptr<Track> pTrack )
+   LabelTrackVRulerControls( const std::shared_ptr<TrackView> &pTrackView )
-      : TrackVRulerControls( pTrack ) {}
+      : TrackVRulerControls( pTrackView ) {}
    ~LabelTrackVRulerControls();
 };
 

src/tracks/labeltrack/ui/LabelTrackView.cpp

@@ -15,6 +15,7 @@ Paul Licameli split from TrackPanel.cpp
 #include "LabelTrackVRulerControls.h"
 #include "LabelGlyphHandle.h"
 #include "LabelTextHandle.h"
+#include "LabelTrackVRulerControls.h"
 
 #include "../../../HitTestResult.h"
 #include "../../../TrackPanelMouseEvent.h"
@@ -54,7 +55,8 @@ std::shared_ptr<TrackControls> LabelTrack::DoGetControls()
    return std::make_shared<LabelTrackControls>( SharedPointer() );
 }
 
-std::shared_ptr<TrackVRulerControls> LabelTrack::DoGetVRulerControls()
+std::shared_ptr<TrackVRulerControls> LabelTrackView::DoGetVRulerControls()
 {
-   return std::make_shared<LabelTrackVRulerControls>( SharedPointer() );
+   return
+      std::make_shared<LabelTrackVRulerControls>( shared_from_this() );
 }

src/tracks/labeltrack/ui/LabelTrackView.h

@@ -23,6 +23,9 @@ public:
    LabelTrackView( const std::shared_ptr<Track> &pTrack )
       : CommonTrackView{ pTrack } {}
    ~LabelTrackView() override;
+
+private:
+   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 };
 
 #endif

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

@@ -22,8 +22,8 @@ class NoteTrackVRulerControls final : public TrackVRulerControls
 
 public:
    explicit
-   NoteTrackVRulerControls( std::shared_ptr<Track> pTrack )
+   NoteTrackVRulerControls( const std::shared_ptr<TrackView> &pTrackView )
-      : TrackVRulerControls( pTrack ) {}
+      : TrackVRulerControls( pTrackView ) {}
    ~NoteTrackVRulerControls();
 
    std::vector<UIHandlePtr> HitTest

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

@@ -57,8 +57,10 @@ std::shared_ptr<TrackControls> NoteTrack::DoGetControls()
    return std::make_shared<NoteTrackControls>( SharedPointer() );
 }
 
-std::shared_ptr<TrackVRulerControls> NoteTrack::DoGetVRulerControls()
+std::shared_ptr<TrackVRulerControls> NoteTrackView::DoGetVRulerControls()
 {
-   return std::make_shared<NoteTrackVRulerControls>( SharedPointer() );
+   return
+      std::make_shared<NoteTrackVRulerControls>( shared_from_this() );
 }
+
 #endif

src/tracks/playabletrack/notetrack/ui/NoteTrackView.h

@@ -23,6 +23,8 @@ public:
    NoteTrackView( const std::shared_ptr<Track> &pTrack )
       : CommonTrackView{ pTrack } {}
    ~NoteTrackView() override;
+
+   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 };
 
 #endif

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

@@ -22,8 +22,8 @@ class WaveTrackVRulerControls final : public TrackVRulerControls
 
 public:
    explicit
-   WaveTrackVRulerControls( std::shared_ptr<Track> pTrack )
+   WaveTrackVRulerControls( const std::shared_ptr<TrackView> &pTrackView )
-      : TrackVRulerControls( pTrack ) {}
+      : TrackVRulerControls( pTrackView ) {}
    ~WaveTrackVRulerControls();
 
    std::vector<UIHandlePtr> HitTest

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

@@ -14,6 +14,7 @@ Paul Licameli split from TrackPanel.cpp
 #include "WaveTrackControls.h"
 #include "WaveTrackVRulerControls.h"
 
+#include "WaveTrackVRulerControls.h"
 #include "../../../../HitTestResult.h"
 #include "../../../../TrackPanelMouseEvent.h"
 
@@ -116,7 +117,8 @@ std::shared_ptr<TrackControls> WaveTrack::DoGetControls()
    return std::make_shared<WaveTrackControls>( SharedPointer() );
 }
 
-std::shared_ptr<TrackVRulerControls> WaveTrack::DoGetVRulerControls()
+std::shared_ptr<TrackVRulerControls> WaveTrackView::DoGetVRulerControls()
 {
-   return std::make_shared<WaveTrackVRulerControls>( SharedPointer() );
+   return
+      std::make_shared<WaveTrackVRulerControls>( shared_from_this() );
 }

src/tracks/playabletrack/wavetrack/ui/WaveTrackView.h

@@ -23,6 +23,8 @@ public:
    WaveTrackView( const std::shared_ptr<Track> &pTrack )
       : CommonTrackView{ pTrack } {}
    ~WaveTrackView() override;
+
+   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
 };
 
 #endif

src/tracks/timetrack/ui/TimeTrackVRulerControls.h

@@ -22,8 +22,8 @@ class TimeTrackVRulerControls final : public TrackVRulerControls
 
 public:
    explicit
-   TimeTrackVRulerControls( std::shared_ptr<Track> pTrack )
+   TimeTrackVRulerControls( const std::shared_ptr<TrackView> &pTrackView )
-      : TrackVRulerControls( pTrack ) {}
+      : TrackVRulerControls( pTrackView ) {}
    ~TimeTrackVRulerControls();
 };
 

src/tracks/timetrack/ui/TimeTrackView.cpp

@@ -14,6 +14,7 @@ Paul Licameli split from TrackPanel.cpp
 #include "TimeTrackControls.h"
 #include "TimeTrackVRulerControls.h"
 
+#include "TimeTrackVRulerControls.h"
 #include "../../../HitTestResult.h"
 #include "../../../TrackPanelMouseEvent.h"
 
@@ -45,7 +46,8 @@ std::shared_ptr<TrackControls> TimeTrack::DoGetControls()
    return std::make_shared<TimeTrackControls>( SharedPointer() );
 }
 
-std::shared_ptr<TrackVRulerControls> TimeTrack::DoGetVRulerControls()
+std::shared_ptr<TrackVRulerControls> TimeTrackView::DoGetVRulerControls()
 {
-   return std::make_shared<TimeTrackVRulerControls>( SharedPointer() );
+   return
+      std::make_shared<TimeTrackVRulerControls>( shared_from_this() );
 }

src/tracks/timetrack/ui/TimeTrackView.h

@@ -23,6 +23,9 @@ public:
    TimeTrackView( const std::shared_ptr<Track> &pTrack )
       : CommonTrackView{ pTrack } {}
    ~TimeTrackView() override;
+
+   std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() override;
+
 };
 
 #endif

src/tracks/ui/TrackVRulerControls.cpp

@@ -11,6 +11,8 @@ Paul Licameli split from TrackPanel.cpp
 #include "../../Audacity.h"
 #include "TrackVRulerControls.h"
 
+#include "TrackView.h"
+
 #include "../../Track.h"
 #include "../../ViewInfo.h"
 
@@ -18,8 +20,9 @@ Paul Licameli split from TrackPanel.cpp
 #include <wx/dc.h>
 #include <wx/translation.h>
 
-TrackVRulerControls::TrackVRulerControls( std::shared_ptr<Track> pTrack )
+TrackVRulerControls::TrackVRulerControls(
-  : mwTrack{ pTrack }
+   const std::shared_ptr<TrackView> &pTrackView )
+  : mwTrackView{ pTrackView }
 {
 }
 
@@ -29,17 +32,30 @@ TrackVRulerControls::~TrackVRulerControls()
 
 TrackVRulerControls &TrackVRulerControls::Get( Track &track )
 {
-   return *track.GetVRulerControls();
+   return *TrackView::Get( track ).GetVRulerControls();
 }
 
 const TrackVRulerControls &TrackVRulerControls::Get( const Track &track )
 {
-   return *track.GetVRulerControls();
+   return *TrackView::Get( track ).GetVRulerControls();
+}
+
+TrackVRulerControls &TrackVRulerControls::Get( TrackView &trackView )
+{
+   return *trackView.GetVRulerControls();
+}
+
+const TrackVRulerControls &TrackVRulerControls::Get( const TrackView &trackView )
+{
+   return *trackView.GetVRulerControls();
 }
 
 std::shared_ptr<Track> TrackVRulerControls::DoFindTrack()
 {
-   return mwTrack.lock();
+   const auto pView = mwTrackView.lock();
+   if ( pView )
+      return pView->FindTrack();
+   return {};
 }
 
 std::vector<UIHandlePtr> TrackVRulerControls::HitTest

src/tracks/ui/TrackVRulerControls.h

@@ -14,6 +14,7 @@ Paul Licameli split from TrackPanel.cpp
 #include "CommonTrackPanelCell.h"
 
 class Track;
+class TrackView;
 class wxDC;
 
 const int kGuard = 5; // 5 pixels to reduce risk of VZooming accidentally
@@ -23,13 +24,16 @@ class TrackVRulerControls /* not final */ : public CommonTrackPanelCell
 {
 public:
    explicit
-   TrackVRulerControls( std::shared_ptr<Track> pTrack );
+   TrackVRulerControls( const std::shared_ptr<TrackView> &pTrackView );
 
    virtual ~TrackVRulerControls() = 0;
 
    static TrackVRulerControls &Get( Track& );
    static const TrackVRulerControls &Get( const Track& );
 
+   static TrackVRulerControls &Get( TrackView& );
+   static const TrackVRulerControls &Get( const TrackView& );
+
    // Define a default hit test method, just for message and cursor
    std::vector<UIHandlePtr> HitTest
       (const TrackPanelMouseState &state,
@@ -44,7 +48,7 @@ protected:
 
    Track *GetTrack() const;
 
-   std::weak_ptr<Track> mwTrack;
+   std::weak_ptr<TrackView> mwTrackView;
 };
 
 #endif

src/tracks/ui/TrackView.cpp

@@ -119,17 +119,17 @@ std::shared_ptr<const TrackPanelCell> Track::GetTrackControls() const
    return const_cast< Track* >( this )->GetTrackControls();
 }
 
-std::shared_ptr<TrackVRulerControls> Track::GetVRulerControls()
+std::shared_ptr<TrackVRulerControls> TrackView::GetVRulerControls()
 {
-   if (!mpVRulerContols)
+   if (!mpVRulerControls)
       // create on demand
-      mpVRulerContols = DoGetVRulerControls();
+      mpVRulerControls = DoGetVRulerControls();
-   return mpVRulerContols;
+   return mpVRulerControls;
 }
 
-std::shared_ptr<const TrackVRulerControls> Track::GetVRulerControls() const
+std::shared_ptr<const TrackVRulerControls> TrackView::GetVRulerControls() const
 {
-   return const_cast< Track* >( this )->GetVRulerControls();
+   return const_cast< TrackView* >( this )->GetVRulerControls();
 }
 
 #include "../../TrackPanelResizeHandle.h"

src/tracks/ui/TrackView.h

@@ -15,8 +15,10 @@ Paul Licameli split from class Track
 #include "CommonTrackPanelCell.h" // to inherit
 
 class Track;
+class TrackVRulerControls;
 
 class TrackView /* not final */ : public CommonTrackCell
+   , public std::enable_shared_from_this<TrackView>
 {
    TrackView( const TrackView& ) = delete;
    TrackView &operator=( const TrackView& ) = delete;
@@ -29,6 +31,18 @@ public:
 
    static TrackView &Get( Track & );
    static const TrackView &Get( const Track & );
+
+   // Return another, associated TrackPanelCell object that implements the
+   // mouse actions for the vertical ruler
+   std::shared_ptr<TrackVRulerControls> GetVRulerControls();
+   std::shared_ptr<const TrackVRulerControls> GetVRulerControls() const;
+
+protected:
+   // Private factory to make appropriate object; class TrackView handles
+   // memory management thereafter
+   virtual std::shared_ptr<TrackVRulerControls> DoGetVRulerControls() = 0;
+
+   std::shared_ptr<TrackVRulerControls> mpVRulerControls;
 };
 
 #endif