A single UIHandle can define multiple rotation states

src/TrackPanel.cpp

@@ -950,8 +950,8 @@ void TrackPanel::HandleMotion
          // Did not move cell to cell, but did change the target
          refreshCode = updateFlags;
 
-      if (handle)
-         handle->Enter();
+      if (handle != oldHandle)
+         handle->Enter(true);
    }
 
    // UIHANDLE PREVIEW
@@ -977,15 +977,30 @@ void TrackPanel::HandleMotion
       this, GetRuler(), newTrack.get(), newTrack.get(), refreshCode);
 }
 
-bool TrackPanel::HasRotation() const
+bool TrackPanel::HasRotation()
 {
    // Is there a nontrivial TAB key rotation?
-   return !mUIHandle && mTargets.size() > 1;
+   if ( mTargets.size() > 1 )
+      return true;
+   auto target = Target();
+   return target && target->HasRotation();
 }
 
 void TrackPanel::RotateTarget(bool forward)
 {
    auto size = mTargets.size();
+
+   auto target = Target();
+   if (target && target->HasRotation()) {
+      if(target->Rotate(forward))
+         return;
+      else if (size == 1 || IsMouseCaptured()) {
+         // Rotate through the states of this target only.
+         target->Enter(forward);
+         return;
+      }
+   }
+
    if (size > 1) {
       if (forward)
          ++mTarget;
@@ -993,7 +1008,7 @@ void TrackPanel::RotateTarget(bool forward)
          mTarget += size - 1;
       mTarget %= size;
       if (Target())
-         Target()->Enter();
+         Target()->Enter(forward);
    }
 }
 

src/TrackPanel.h

@@ -549,7 +549,7 @@ protected:
       mMouseOverUpdateFlags = 0;
    }
 
-   bool HasRotation() const;
+   bool HasRotation();
 
    void RotateTarget(bool forward);
 

src/UIHandle.cpp

@@ -15,10 +15,20 @@ UIHandle::~UIHandle()
 {
 }
 
-void UIHandle::Enter()
+void UIHandle::Enter(bool)
 {
 }
 
+bool UIHandle::HasRotation() const
+{
+   return false;
+}
+
+bool UIHandle::Rotate(bool)
+{
+   return false;
+}
+
 void UIHandle::DrawExtras
    (DrawingPass, wxDC *, const wxRegion &, const wxRect &)
 {

src/UIHandle.h

@@ -48,8 +48,19 @@ public:
    virtual ~UIHandle() = 0;
 
    // Before clicking, the handle is notified that it has been "hit"
+   // This might put the handle into its first rotated state
+   // (or last, if forward is false) or mark itself as needing a highlight.
    // Default does nothing.
-   virtual void Enter();
+   virtual void Enter(bool forward);
+
+   // Tell whether the handle has more than one TAB key rotation state.
+   // Default is always false.
+   virtual bool HasRotation() const;
+
+   // If not previously in the last rotation state (or first if !forward),
+   // change rotation state and return true; else return false
+   // Default does nothing and returns false
+   virtual bool Rotate(bool forward);
 
    // Assume hit test (implemented in other classes) was positive.
    // May return Cancelled, overriding the hit test decision and stopping drag.

src/tracks/labeltrack/ui/LabelGlyphHandle.cpp

@@ -32,7 +32,7 @@ LabelGlyphHandle::LabelGlyphHandle
 {
 }
 
-void LabelGlyphHandle::Enter()
+void LabelGlyphHandle::Enter(bool)
 {
    mChangeHighlight = RefreshCode::RefreshCell;
 }

src/tracks/labeltrack/ui/LabelGlyphHandle.h

@@ -54,7 +54,7 @@ public:
 
    virtual ~LabelGlyphHandle();
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

src/tracks/labeltrack/ui/LabelTextHandle.cpp

@@ -26,7 +26,7 @@ LabelTextHandle::LabelTextHandle
 {
 }
 
-void LabelTextHandle::Enter()
+void LabelTextHandle::Enter(bool)
 {
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
    mChangeHighlight = RefreshCode::RefreshCell;

src/tracks/labeltrack/ui/LabelTextHandle.h

@@ -38,7 +38,7 @@ public:
    std::shared_ptr<LabelTrack> GetTrack() const { return mpLT.lock(); }
    int GetLabelNum() const { return mLabelNum; }
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

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

@@ -27,7 +27,7 @@ NoteTrackButtonHandle::NoteTrackButtonHandle
 {
 }
 
-void NoteTrackButtonHandle::Enter()
+void NoteTrackButtonHandle::Enter(bool)
 {
    mChangeHighlight = RefreshCode::RefreshCell;
 }

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

@@ -47,7 +47,7 @@ public:
        const NoteTrackButtonHandle &newState);
 
 protected:
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

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

@@ -42,7 +42,7 @@ NoteTrackVZoomHandle::NoteTrackVZoomHandle
 {
 }
 
-void NoteTrackVZoomHandle::Enter()
+void NoteTrackVZoomHandle::Enter(bool)
 {
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
    mChangeHighlight = RefreshCode::RefreshCell;

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

@@ -38,7 +38,7 @@ public:
 
    std::shared_ptr<NoteTrack> GetTrack() const { return mpTrack.lock(); }
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

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

@@ -30,7 +30,7 @@ CutlineHandle::CutlineHandle
 {
 }
 
-void CutlineHandle::Enter()
+void CutlineHandle::Enter(bool)
 {
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
    mChangeHighlight = RefreshCode::RefreshCell;

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

@@ -45,7 +45,7 @@ public:
    const WaveTrackLocation &GetLocation() { return mLocation; }
    std::shared_ptr<WaveTrack> GetTrack() { return mpTrack; }
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

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

@@ -40,7 +40,7 @@ SampleHandle::SampleHandle( const std::shared_ptr<WaveTrack> &pTrack )
 {
 }
 
-void SampleHandle::Enter()
+void SampleHandle::Enter(bool)
 {
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
    mChangeHighlight = RefreshCode::RefreshCell;

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

@@ -46,7 +46,7 @@ public:
 
    std::shared_ptr<WaveTrack> GetTrack() const { return mClickedTrack; }
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

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

@@ -51,7 +51,7 @@ WaveTrackVZoomHandle::WaveTrackVZoomHandle
 {
 }
 
-void WaveTrackVZoomHandle::Enter()
+void WaveTrackVZoomHandle::Enter(bool)
 {
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
    mChangeHighlight = RefreshCode::RefreshCell;

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

@@ -38,7 +38,7 @@ public:
 
    std::shared_ptr<WaveTrack> GetTrack() const { return mpTrack.lock(); }
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

src/tracks/ui/ButtonHandle.cpp

@@ -31,7 +31,7 @@ ButtonHandle::~ButtonHandle()
 {
 }
 
-void ButtonHandle::Enter()
+void ButtonHandle::Enter(bool)
 {
    mChangeHighlight = RefreshCode::RefreshCell;
 }

src/tracks/ui/ButtonHandle.h

@@ -42,7 +42,7 @@ protected:
    virtual Result CommitChanges
       (const wxMouseEvent &event, AudacityProject *pProject, wxWindow *pParent) = 0;
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

src/tracks/ui/EnvelopeHandle.cpp

@@ -32,7 +32,7 @@ EnvelopeHandle::EnvelopeHandle( Envelope *pEnvelope )
 {
 }
 
-void EnvelopeHandle::Enter()
+void EnvelopeHandle::Enter(bool)
 {
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
    mChangeHighlight = RefreshCode::RefreshCell;

src/tracks/ui/EnvelopeHandle.h

@@ -56,7 +56,7 @@ public:
 
    Envelope *GetEnvelope() const { return mEnvelope; }
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

src/tracks/ui/SliderHandle.cpp

@@ -24,7 +24,7 @@ SliderHandle::SliderHandle
 {
 }
 
-void SliderHandle::Enter()
+void SliderHandle::Enter(bool)
 {
    mChangeHighlight = RefreshCode::RefreshCell;
 }

src/tracks/ui/SliderHandle.h

@@ -47,7 +47,7 @@ protected:
    virtual Result CommitChanges
       (const wxMouseEvent &event, AudacityProject *pProject) = 0;
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

src/tracks/ui/TimeShiftHandle.cpp

@@ -30,7 +30,7 @@ TimeShiftHandle::TimeShiftHandle
 {
 }
 
-void TimeShiftHandle::Enter()
+void TimeShiftHandle::Enter(bool)
 {
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING
    mChangeHighlight = RefreshCode::RefreshCell;

src/tracks/ui/TimeShiftHandle.h

@@ -75,7 +75,7 @@ public:
 
    virtual ~TimeShiftHandle();
 
-   void Enter() override;
+   void Enter(bool forward) override;
 
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;