Mouseover highlight 1) MIDI buttons 2) other buttons 3) sliders...

... in Track Contol Panel.

Each of these three can be separately referted if we don't like it.

The first is independent of theme and does not use image files.

The second uses HiliteButtonExpand.png, which looks wrong in Classic theme, as
if that file was intended for Dark instead.

The third uses files SliderThumbHilited.png and SilderThumbRotatedHilited.png
as are also used to highlight other sliders in the toolbars.  The appearance
is distinguished only in Classic theme now.

Some cleanup of button drawing code is also done, removing a global variable,
and some change of arguments of other drawing functions is also done, to
make it easier to implement highlighting of other things in TrackPanel in a
way analogous to these.

mac/Audacity.xcodeproj/project.pbxproj

@@ -3061,6 +3061,7 @@
 		5E3FFE701EC9032B0020F7C9 /* NoteTrackSliderHandles.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = NoteTrackSliderHandles.cpp; sourceTree = "<group>"; };
 		5E3FFE711EC9032B0020F7C9 /* NoteTrackSliderHandles.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = NoteTrackSliderHandles.h; sourceTree = "<group>"; };
 		5E4685F81CCA9D84008741F2 /* CommandFunctors.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CommandFunctors.h; sourceTree = "<group>"; };
+		5E52335F1EFDD57D001E4BB8 /* TrackPanelDrawingContext.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = TrackPanelDrawingContext.h; sourceTree = "<group>"; };
 		5E61EE0C1CBAA6BB0009FCF1 /* MemoryX.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MemoryX.h; sourceTree = "<group>"; };
 		5E667A5E1F0BEE5F00C942A5 /* WaveTrackVZoomHandle.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = WaveTrackVZoomHandle.cpp; sourceTree = "<group>"; };
 		5E667A5F1F0BEE5F00C942A5 /* WaveTrackVZoomHandle.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = WaveTrackVZoomHandle.h; sourceTree = "<group>"; };
@@ -4157,6 +4158,7 @@
 				1790B0EF09883BFD008A330A /* TrackPanelAx.h */,
 				5E74D2D91CC4427B00D88B0B /* TrackPanelCell.h */,
 				5E74D2DA1CC4427B00D88B0B /* TrackPanelCellIterator.h */,
+				5E52335F1EFDD57D001E4BB8 /* TrackPanelDrawingContext.h */,
 				2803C8B619F35AA000278526 /* TrackPanelListener.h */,
 				5E15123A1DB000C000702E29 /* TrackPanelMouseEvent.h */,
 				5E7396611DAFDB1E00BA0A4D /* TrackPanelResizeHandle.h */,

src/AColor.cpp

@@ -230,10 +230,13 @@ void AColor::Bevel(wxDC & dc, bool up, const wxRect & r)
    AColor::Line(dc, r.x, r.y + r.height, r.x + r.width, r.y + r.height);
 }
 
-void AColor::Bevel2(wxDC & dc, bool up, const wxRect & r, bool bSel)
+void AColor::Bevel2
+(wxDC & dc, bool up, const wxRect & r, bool bSel, bool bHighlight)
 {
    int index = 0;
-   if( bSel )
+   if ( bHighlight )
+      index = bmpHiliteButtonExpand;
+   else if( bSel )
       index = up ? bmpUpButtonExpandSel : bmpDownButtonExpandSel;
    else
       index = up ? bmpUpButtonExpand : bmpDownButtonExpand;

src/AColor.h

@@ -66,7 +66,8 @@ class AColor {
    static void Line(wxDC & dc, wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2);
    static void DrawFocus(wxDC & dc, wxRect & r);
    static void Bevel(wxDC & dc, bool up, const wxRect & r);
-   static void Bevel2(wxDC & dc, bool up, const wxRect & r, bool bSel=false);
+   static void Bevel2
+      (wxDC & dc, bool up, const wxRect & r, bool bSel=false, bool bHighlight = false);
    static void BevelTrackInfo(wxDC & dc, bool up, const wxRect & r);
    static wxColour Blend(const wxColour & c1, const wxColour & c2);
 

src/Envelope.cpp

@@ -311,11 +311,15 @@ static void DrawPoint(wxDC & dc, const wxRect & r, int x, int y, bool top)
    }
 }
 
+#include "TrackPanelDrawingContext.h"
+
 /// TODO: This should probably move to track artist.
-void Envelope::DrawPoints(wxDC & dc, const wxRect & r, const ZoomInfo &zoomInfo,
+void Envelope::DrawPoints
-                    bool dB, double dBRange,
+(TrackPanelDrawingContext &context, const wxRect & r, const ZoomInfo &zoomInfo,
-                    float zoomMin, float zoomMax, bool mirrored) const
+ bool dB, double dBRange,
+ float zoomMin, float zoomMax, bool mirrored) const
 {
+   auto &dc = context.dc;
    dc.SetPen(AColor::envelopePen);
    dc.SetBrush(*wxWHITE_BRUSH);
 

src/Envelope.h

@@ -73,6 +73,7 @@ private:
 };
 
 typedef std::vector<EnvPoint> EnvArray;
+struct TrackPanelDrawingContext;
 
 class Envelope final : public XMLTagHandler {
 public:
@@ -117,7 +118,9 @@ public:
    XMLTagHandler *HandleXMLChild(const wxChar *tag) override;
    void WriteXML(XMLWriter &xmlFile) const /* not override */;
 
-   void DrawPoints(wxDC & dc, const wxRect & r, const ZoomInfo &zoomInfo,
+   void DrawPoints(
+      TrackPanelDrawingContext &context,
+      const wxRect & r, const ZoomInfo &zoomInfo,
       bool dB, double dBRange,
       float zoomMin, float zoomMax, bool mirrored) const;
 

src/LabelTrack.cpp

@@ -773,13 +773,17 @@ namespace {
    }
 }
 
+#include "TrackPanelDrawingContext.h"
+
 /// Draw calls other functions to draw the LabelTrack.
 ///   @param  dc the device context
 ///   @param  r  the LabelTrack rectangle.
-void LabelTrack::Draw(wxDC & dc, const wxRect & r,
+void LabelTrack::Draw
-   const SelectedRegion &selectedRegion,
+(TrackPanelDrawingContext &context, const wxRect & r,
-   const ZoomInfo &zoomInfo) const
+ const SelectedRegion &selectedRegion,
+ const ZoomInfo &zoomInfo) const
 {
+   auto &dc = context.dc;
    auto pHit = findHit();
 
    if(msFont.Ok())

src/LabelTrack.h

@@ -40,6 +40,7 @@ class ZoomInfo;
 
 
 struct LabelTrackHit;
+struct TrackPanelDrawingContext;
 
 class LabelStruct
 {
@@ -147,7 +148,7 @@ class AUDACITY_DLL_API LabelTrack final : public Track
    static wxFont GetFont(const wxString &faceName, int size = DefaultFontSize);
    static void ResetFont();
 
-   void Draw(wxDC & dc, const wxRect & r,
+   void Draw(TrackPanelDrawingContext &context, const wxRect & r,
              const SelectedRegion &selectedRegion,
              const ZoomInfo &zoomInfo) const;
 

src/Makefile.am

@@ -247,6 +247,7 @@ audacity_SOURCES = \
 	TrackPanelAx.h \
 	TrackPanelCell.h \
 	TrackPanelCellIterator.h \
+	TrackPanelDrawingContext.h \
 	TrackPanelListener.h \
 	TrackPanelMouseEvent.h \
 	TrackPanelResizeHandle.cpp \

src/Makefile.in

@@ -328,7 +328,8 @@ am__audacity_SOURCES_DIST = BlockFile.cpp BlockFile.h DirManager.cpp \
 	TimerRecordDialog.cpp TimerRecordDialog.h TimeTrack.cpp \
 	TimeTrack.h Track.cpp Track.h TrackArtist.cpp TrackArtist.h \
 	TrackPanel.cpp TrackPanel.h TrackPanelAx.cpp TrackPanelAx.h \
-	TrackPanelCell.h TrackPanelCellIterator.h TrackPanelListener.h \
+	TrackPanelCell.h TrackPanelCellIterator.h \
+	TrackPanelDrawingContext.h TrackPanelListener.h \
 	TrackPanelMouseEvent.h TrackPanelResizeHandle.cpp \
 	TrackPanelResizeHandle.h TrackPanelResizerCell.cpp \
 	TrackPanelResizerCell.h TranslatableStringArray.h UIHandle.h \
@@ -1342,7 +1343,8 @@ audacity_SOURCES = $(libaudacity_la_SOURCES) AboutDialog.cpp \
 	TimerRecordDialog.cpp TimerRecordDialog.h TimeTrack.cpp \
 	TimeTrack.h Track.cpp Track.h TrackArtist.cpp TrackArtist.h \
 	TrackPanel.cpp TrackPanel.h TrackPanelAx.cpp TrackPanelAx.h \
-	TrackPanelCell.h TrackPanelCellIterator.h TrackPanelListener.h \
+	TrackPanelCell.h TrackPanelCellIterator.h \
+	TrackPanelDrawingContext.h TrackPanelListener.h \
 	TrackPanelMouseEvent.h TrackPanelResizeHandle.cpp \
 	TrackPanelResizeHandle.h TrackPanelResizerCell.cpp \
 	TrackPanelResizerCell.h TranslatableStringArray.h UIHandle.h \

src/NoteTrack.cpp

@@ -251,7 +251,7 @@ void NoteTrack::WarpAndTransposeNotes(double t0, double t1,
 // Draws the midi channel toggle buttons within the given rect.
 // The rect should be evenly divisible by 4 on both axis.
 void NoteTrack::DrawLabelControls
-( const NoteTrack *pTrack, wxDC & dc, const wxRect &rect )
+( const NoteTrack *pTrack, wxDC & dc, const wxRect &rect, int highlightedChannel )
 {
    wxASSERT_MSG(rect.width % 4 == 0, "Midi channel control rect width must be divisible by 4");
    wxASSERT_MSG(rect.height % 4 == 0, "Midi channel control rect height must be divisible by 4");
@@ -273,7 +273,11 @@ void NoteTrack::DrawLabelControls
 
          bool visible = pTrack ? pTrack->IsVisibleChan(chanName - 1) : true;
          if (visible) {
-            AColor::MIDIChannel(&dc, chanName);
+            // highlightedChannel counts 0 based
+            if ( chanName == highlightedChannel + 1 )
+               AColor::LightMIDIChannel(&dc, chanName);
+            else
+               AColor::MIDIChannel(&dc, chanName);
             dc.DrawRectangle(box);
 // two choices: channel is enabled (to see and play) when button is in
 // "up" position (original Audacity style) or in "down" position
@@ -299,7 +303,10 @@ void NoteTrack::DrawLabelControls
                          box.x, box.y + box.height - 1,
                          box.x + box.width - 1, box.y + box.height - 1);
          } else {
-            AColor::MIDIChannel(&dc, 0);
+            if ( chanName == highlightedChannel + 1 )
+               AColor::LightMIDIChannel(&dc, chanName);
+            else
+               AColor::MIDIChannel(&dc, 0);
             dc.DrawRectangle(box);
 #if CHANNEL_ON_IS_DOWN
             AColor::LightMIDIChannel(&dc, 0);

src/NoteTrack.h

@@ -90,7 +90,8 @@ class AUDACITY_DLL_API NoteTrack final
                               const TimeWarper &warper, double semitones);
 
    static void DrawLabelControls
-      ( const NoteTrack *pTrack, wxDC & dc, const wxRect &rect );
+      ( const NoteTrack *pTrack, wxDC & dc, const wxRect &rect,
+        int highlightedChannel = -1 );
    int FindChannel(const wxRect &rect, int mx, int my);
    bool LabelClick(const wxRect &rect, int x, int y, bool right);
 

src/Printing.cpp

@@ -32,6 +32,8 @@
 
 #include "Experimental.h"
 
+#include "TrackPanelDrawingContext.h"
+
 // Globals, so that we remember settings from session to session
 wxPrintData &gPrintData()
 {
@@ -97,7 +99,9 @@ bool AudacityPrintout::OnPrintPage(int WXUNUSED(page))
       r.width = width;
       r.height = (int)(n->GetHeight() * scale);
 
-      artist.DrawTrack(n, *dc, r, SelectedRegion(), zoomInfo, false, false, false, false);
+      TrackPanelDrawingContext context{ *dc, {}, {} };
+      artist.DrawTrack(
+         context, n, r, SelectedRegion(), zoomInfo, false, false, false, false);
 
       dc->SetPen(*wxBLACK_PEN);
       AColor::Line(*dc, 0, r.y, width, r.y);

src/TimeTrack.cpp

@@ -257,8 +257,13 @@ void TimeTrack::WriteXML(XMLWriter &xmlFile) const
    xmlFile.EndTag(wxT("timetrack"));
 }
 
-void TimeTrack::Draw(wxDC & dc, const wxRect & r, const ZoomInfo &zoomInfo) const
+#include "TrackPanelDrawingContext.h"
+
+void TimeTrack::Draw
+(TrackPanelDrawingContext &context, const wxRect & r, const ZoomInfo &zoomInfo) const
 {
+   auto &dc = context.dc;
+
    double min = zoomInfo.PositionToTime(0);
    double max = zoomInfo.PositionToTime(r.width);
    if (min > max)

src/TimeTrack.h

@@ -22,6 +22,7 @@ class wxDC;
 class Envelope;
 class Ruler;
 class ZoomInfo;
+struct TrackPanelDrawingContext;
 
 class EnvelopeHandle;
 
@@ -67,7 +68,9 @@ class TimeTrack final : public Track {
    double GetStartTime() const override { return 0.0; }
    double GetEndTime() const override { return 0.0; }
 
-   void Draw(wxDC & dc, const wxRect & r, const ZoomInfo &zoomInfo) const;
+   void Draw
+      (TrackPanelDrawingContext &context,
+       const wxRect & r, const ZoomInfo &zoomInfo) const;
 
    // XMLTagHandler callback methods for loading and saving
 

src/TrackArtist.cpp

@@ -183,6 +183,8 @@ audio tracks.
 #include "Theme.h"
 #include "AllThemeResources.h"
 #include "Experimental.h"
+#include "TrackPanelDrawingContext.h"
+
 
 #undef PROFILE_WAVEFORM
 #ifdef PROFILE_WAVEFORM
@@ -315,9 +317,9 @@ void TrackArtist::SetMargins(int left, int top, int right, int bottom)
    mMarginBottom = bottom;
 }
 
-void TrackArtist::DrawTracks(TrackList * tracks,
+void TrackArtist::DrawTracks(TrackPanelDrawingContext &context,
+                             TrackList * tracks,
                              Track * start,
-                             wxDC & dc,
                              const wxRegion & reg,
                              const wxRect & rect,
                              const wxRect & clip,
@@ -409,7 +411,7 @@ void TrackArtist::DrawTracks(TrackList * tracks,
          rr.y += mMarginTop;
          rr.width -= (mMarginLeft + mMarginRight);
          rr.height -= (mMarginTop + mMarginBottom);
-         DrawTrack(t, dc, rr,
+         DrawTrack(context, t, rr,
                    selectedRegion, zoomInfo,
                    drawEnvelope, bigPoints, drawSliders, hasSolo);
       }
@@ -438,8 +440,8 @@ void TrackArtist::DrawTracks(TrackList * tracks,
    }
 }
 
-void TrackArtist::DrawTrack(const Track * t,
+void TrackArtist::DrawTrack(TrackPanelDrawingContext &context,
-                            wxDC & dc,
+                            const Track * t,
                             const wxRect & rect,
                             const SelectedRegion &selectedRegion,
                             const ZoomInfo &zoomInfo,
@@ -448,6 +450,7 @@ void TrackArtist::DrawTrack(const Track * t,
                             bool drawSliders,
                             bool hasSolo)
 {
+   auto &dc = context.dc;
    switch (t->GetKind()) {
    case Track::Wave:
    {
@@ -466,7 +469,7 @@ void TrackArtist::DrawTrack(const Track * t,
 
       switch (wt->GetDisplay()) {
       case WaveTrack::Waveform:
-         DrawWaveform(wt, dc, rect, selectedRegion, zoomInfo,
+         DrawWaveform(context, wt, rect, selectedRegion, zoomInfo,
                       drawEnvelope,  bigPoints, drawSliders, muted);
          break;
       case WaveTrack::Spectrum:
@@ -503,16 +506,18 @@ void TrackArtist::DrawTrack(const Track * t,
    }
    #endif // USE_MIDI
    case Track::Label:
-      DrawLabelTrack((LabelTrack *)t, dc, rect, selectedRegion, zoomInfo);
+      DrawLabelTrack(context, (LabelTrack *)t, rect, selectedRegion, zoomInfo);
       break;
    case Track::Time:
-      DrawTimeTrack((TimeTrack *)t, dc, rect, zoomInfo);
+      DrawTimeTrack(context, (TimeTrack *)t, rect, zoomInfo);
       break;
    }
 }
 
-void TrackArtist::DrawVRuler(const Track *t, wxDC * dc, wxRect & rect)
+void TrackArtist::DrawVRuler
+(TrackPanelDrawingContext &context, const Track *t, wxRect & rect)
 {
+   auto dc = &context.dc;
    int kind = t->GetKind();
 
    // Label and Time tracks do not have a vruler
@@ -1468,8 +1473,8 @@ void TrackArtist::DrawEnvLine(wxDC &dc, const wxRect &rect, int x0, int y0, int
    }
 }
 
-void TrackArtist::DrawWaveform(const WaveTrack *track,
+void TrackArtist::DrawWaveform(TrackPanelDrawingContext &context,
-                               wxDC & dc,
+                               const WaveTrack *track,
                                const wxRect & rect,
                                const SelectedRegion &selectedRegion,
                                const ZoomInfo &zoomInfo,
@@ -1478,13 +1483,14 @@ void TrackArtist::DrawWaveform(const WaveTrack *track,
                                bool drawSliders,
                                bool muted)
 {
+   auto &dc = context.dc;
    const bool dB = !track->GetWaveformSettings().isLinear();
 
    DrawBackgroundWithSelection(&dc, rect, track, blankSelectedBrush, blankBrush,
          selectedRegion, zoomInfo);
 
    for (const auto &clip: track->GetClips())
-      DrawClipWaveform(track, clip.get(), dc, rect, selectedRegion, zoomInfo,
+      DrawClipWaveform(context, track, clip.get(), rect, selectedRegion, zoomInfo,
                        drawEnvelope, bigPoints,
                        dB, muted);
 
@@ -1737,9 +1743,9 @@ void FindWavePortions
 }
 }
 
-void TrackArtist::DrawClipWaveform(const WaveTrack *track,
+void TrackArtist::DrawClipWaveform(TrackPanelDrawingContext &context,
+                                   const WaveTrack *track,
                                    const WaveClip *clip,
-                                   wxDC & dc,
                                    const wxRect & rect,
                                    const SelectedRegion &selectedRegion,
                                    const ZoomInfo &zoomInfo,
@@ -1748,6 +1754,7 @@ void TrackArtist::DrawClipWaveform(const WaveTrack *track,
                                    bool dB,
                                    bool muted)
 {
+   auto &dc = context.dc;
 #ifdef PROFILE_WAVEFORM
    Profiler profiler;
 #endif
@@ -1954,7 +1961,8 @@ void TrackArtist::DrawClipWaveform(const WaveTrack *track,
 
    if (drawEnvelope) {
       DrawEnvelope(dc, mid, env, zoomMin, zoomMax, dB, dBRange);
-      clip->GetEnvelope()->DrawPoints(dc, rect, zoomInfo, dB, dBRange, zoomMin, zoomMax, true);
+      clip->GetEnvelope()->DrawPoints
+         (context, rect, zoomInfo, dB, dBRange, zoomMin, zoomMax, true);
    }
 
    // Draw arrows on the left side if the track extends to the left of the
@@ -3188,8 +3196,8 @@ void TrackArtist::DrawNoteTrack(const NoteTrack *track,
 #endif // USE_MIDI
 
 
-void TrackArtist::DrawLabelTrack(const LabelTrack *track,
+void TrackArtist::DrawLabelTrack(TrackPanelDrawingContext &context,
-                                 wxDC & dc,
+                                 const LabelTrack *track,
                                  const wxRect & rect,
                                  const SelectedRegion &selectedRegion,
                                  const ZoomInfo &zoomInfo)
@@ -3200,15 +3208,15 @@ void TrackArtist::DrawLabelTrack(const LabelTrack *track,
    if (!track->GetSelected() && !track->IsSyncLockSelected())
       sel0 = sel1 = 0.0;
 
-   track->Draw(dc, rect, SelectedRegion(sel0, sel1), zoomInfo);
+   track->Draw(context, rect, SelectedRegion(sel0, sel1), zoomInfo);
 }
 
-void TrackArtist::DrawTimeTrack(const TimeTrack *track,
+void TrackArtist::DrawTimeTrack(TrackPanelDrawingContext &context,
-                                wxDC & dc,
+                                const TimeTrack *track,
                                 const wxRect & rect,
                                 const ZoomInfo &zoomInfo)
 {
-   track->Draw(dc, rect, zoomInfo);
+   track->Draw(context, rect, zoomInfo);
    wxRect envRect = rect;
    envRect.height -= 2;
    double lower = track->GetRangeLower(), upper = track->GetRangeUpper();
@@ -3217,8 +3225,9 @@ void TrackArtist::DrawTimeTrack(const TimeTrack *track,
       lower = LINEAR_TO_DB(std::max(1.0e-7, lower)) / mdBrange + 1.0;
       upper = LINEAR_TO_DB(std::max(1.0e-7, upper)) / mdBrange + 1.0;
    }
-   track->GetEnvelope()->DrawPoints(dc, envRect, zoomInfo,
+   track->GetEnvelope()->DrawPoints
-               track->GetDisplayLog(), mdBrange, lower, upper, false);
+      (context, envRect, zoomInfo,
+       track->GetDisplayLog(), mdBrange, lower, upper, false);
 }
 
 void TrackArtist::UpdatePrefs()

src/TrackArtist.h

@@ -41,6 +41,8 @@ class Ruler;
 class SelectedRegion;
 class ZoomInfo;
 
+struct TrackPanelDrawingContext;
+
 #ifndef uchar
 typedef unsigned char uchar;
 #endif
@@ -52,19 +54,22 @@ class AUDACITY_DLL_API TrackArtist {
    ~TrackArtist();
 
    void SetColours();
-   void DrawTracks(TrackList *tracks, Track *start,
+   void DrawTracks(TrackPanelDrawingContext &context,
-                   wxDC & dc, const wxRegion & reg,
+                   TrackList *tracks, Track *start,
+                   const wxRegion & reg,
                    const wxRect & rect, const wxRect & clip,
                    const SelectedRegion &selectedRegion, const ZoomInfo &zoomInfo,
                    bool drawEnvelope, bool bigPoints, bool drawSliders);
 
-   void DrawTrack(const Track *t,
+   void DrawTrack(TrackPanelDrawingContext &context,
-                  wxDC & dc, const wxRect & rect,
+                  const Track *t,
+                  const wxRect & rect,
                   const SelectedRegion &selectedRegion, const ZoomInfo &zoomInfo,
                   bool drawEnvelope, bool bigPoints, bool drawSliders,
                   bool hasSolo);
 
-   void DrawVRuler(const Track *t, wxDC *dc, wxRect & rect);
+   void DrawVRuler(TrackPanelDrawingContext &context,
+                   const Track *t, wxRect & rect);
 
    void UpdateVRuler(const Track *t, wxRect & rect);
 
@@ -94,8 +99,9 @@ class AUDACITY_DLL_API TrackArtist {
    // Lower-level drawing functions
    //
 
-   void DrawWaveform(const WaveTrack *track,
+   void DrawWaveform(TrackPanelDrawingContext &context,
-                     wxDC & dc, const wxRect & rect,
+                     const WaveTrack *track,
+                     const wxRect & rect,
                      const SelectedRegion &selectedRegion, const ZoomInfo &zoomInfo,
                      bool drawEnvelope, bool bigPoints, bool drawSliders,
                      bool muted);
@@ -117,18 +123,21 @@ class AUDACITY_DLL_API TrackArtist {
                       bool muted);
 #endif // USE_MIDI
 
-   void DrawLabelTrack(const LabelTrack *track,
+   void DrawLabelTrack(TrackPanelDrawingContext &context,
-                       wxDC & dc, const wxRect & rect,
+                       const LabelTrack *track,
+                       const wxRect & rect,
                        const SelectedRegion &selectedRegion, const ZoomInfo &zoomInfo);
 
-   void DrawTimeTrack(const TimeTrack *track,
+   void DrawTimeTrack(TrackPanelDrawingContext &context,
-                      wxDC & dc, const wxRect & rect, const ZoomInfo &zoomInfo);
+                      const TimeTrack *track,
+                      const wxRect & rect, const ZoomInfo &zoomInfo);
 
    void DrawTimeSlider(wxDC & dc, const wxRect & rect,
                        bool rightwards);
 
-   void DrawClipWaveform(const WaveTrack *track, const WaveClip *clip,
+   void DrawClipWaveform(TrackPanelDrawingContext &context,
-                         wxDC & dc, const wxRect & rect,
+                         const WaveTrack *track, const WaveClip *clip,
+                         const wxRect & rect,
                          const SelectedRegion &selectedRegion, const ZoomInfo &zoomInfo,
                          bool drawEnvelope, bool bigPoints,
                          bool dB, bool muted);

src/TrackPanel.cpp

@@ -1066,11 +1066,9 @@ void TrackPanel::OnContextMenu(wxContextMenuEvent & WXUNUSED(event))
 
 struct TrackInfo::TCPLine {
    using DrawFunction = void (*)(
-      wxDC *dc,
+      TrackPanelDrawingContext &context,
       const wxRect &rect,
-      const Track *maybeNULL,
+      const Track *maybeNULL
-      int pressed, // a value from MouseCaptureEnum; TODO: make it bool
-      bool captured
    );
 
    unsigned items; // a bitwise OR of values of the enum above
@@ -1696,6 +1694,8 @@ void TrackPanel::Refresh(bool eraseBackground /* = TRUE */,
    DisplaySelection();
 }
 
+#include "TrackPanelDrawingContext.h"
+
 /// Draw the actual track areas.  We only draw the borders
 /// and the little buttons and menues and whatnot here, the
 /// actual contents of each track are drawn by the TrackArtist.
@@ -1718,26 +1718,28 @@ void TrackPanel::DrawTracks(wxDC * dc)
    bool bigPointsFlag  = pTtb->IsDown(drawTool) || bMultiToolDown;
    bool sliderFlag     = bMultiToolDown;
 
+   TrackPanelDrawingContext context{ *dc, Target(), mLastMouseState };
+
    // The track artist actually draws the stuff inside each track
    auto first = GetProject()->GetFirstVisible();
-   mTrackArtist->DrawTracks(GetTracks(), first.get(),
+   mTrackArtist->DrawTracks(context, GetTracks(), first.get(),
-                            *dc, region, tracksRect, clip,
+                            region, tracksRect, clip,
                             mViewInfo->selectedRegion, *mViewInfo,
                             envelopeFlag, bigPointsFlag, sliderFlag);
 
-   DrawEverythingElse(dc, region, clip);
+   DrawEverythingElse(context, region, clip);
 }
 
 /// Draws 'Everything else'.  In particular it draws:
 ///  - Drop shadow for tracks and vertical rulers.
 ///  - Zooming Indicators.
 ///  - Fills in space below the tracks.
-void TrackPanel::DrawEverythingElse(wxDC * dc,
+void TrackPanel::DrawEverythingElse(TrackPanelDrawingContext &context,
                                     const wxRegion &region,
                                     const wxRect & clip)
 {
    // We draw everything else
-
+   auto dc = &context.dc;
    wxRect focusRect(-1, -1, 0, 0);
    wxRect trackRect = clip;
    trackRect.height = 0;   // for drawing background in no tracks case.
@@ -1787,7 +1789,7 @@ void TrackPanel::DrawEverythingElse(wxDC * dc,
          if (mAx->IsFocused(t)) {
             focusRect = borderRect;
          }
-         DrawOutside(borderTrack, dc, borderRect);
+         DrawOutside(context, borderTrack, borderRect);
       }
 
       // Believe it or not, we can speed up redrawing if we don't
@@ -1806,7 +1808,7 @@ void TrackPanel::DrawEverythingElse(wxDC * dc,
          rect.y += kTopMargin;
          rect.width = GetVRulerWidth();
          rect.height -= (kTopMargin + kBottomMargin);
-         mTrackArtist->DrawVRuler(t, dc, rect);
+         mTrackArtist->DrawVRuler(context, t, rect);
       }
 
 #ifdef EXPERIMENTAL_OUTPUT_DISPLAY
@@ -1819,7 +1821,7 @@ void TrackPanel::DrawEverythingElse(wxDC * dc,
             rect.y += kTopMargin;
             rect.width = GetVRulerWidth();
             rect.height -= (kTopMargin + kBottomMargin);
-            mTrackArtist->DrawVRuler(t, dc, rect);
+            mTrackArtist->DrawVRuler(context, t, rect);
          }
       }
 #endif
@@ -1856,20 +1858,21 @@ void TrackPanel::DrawEverythingElse(wxDC * dc,
 #include "tracks/ui/TrackControls.h"
 
 void TrackInfo::DrawItems
-( wxDC *dc, const wxRect &rect, const Track &track,
+( TrackPanelDrawingContext &context,
-  int mouseCapture, bool captured )
+  const wxRect &rect, const Track &track  )
 {
    const auto topLines = getTCPLines( track );
    const auto bottomLines = commonTrackTCPBottomLines;
    DrawItems
-      ( dc, rect, &track, topLines, bottomLines, mouseCapture, captured );
+      ( context, rect, &track, topLines, bottomLines );
 }
 
 void TrackInfo::DrawItems
-( wxDC *dc, const wxRect &rect, const Track *pTrack,
+( TrackPanelDrawingContext &context,
-  const std::vector<TCPLine> &topLines, const std::vector<TCPLine> &bottomLines,
+  const wxRect &rect, const Track *pTrack,
-  int mouseCapture, bool captured )
+  const std::vector<TCPLine> &topLines, const std::vector<TCPLine> &bottomLines )
 {
+   auto dc = &context.dc;
    TrackInfo::SetTrackInfoFont(dc);
    dc->SetTextForeground(theTheme.Colour(clrTrackPanelText));
 
@@ -1882,7 +1885,7 @@ void TrackInfo::DrawItems
          };
          if ( !TrackInfo::HideTopItem( rect, itemRect ) &&
               line.drawFunction )
-            line.drawFunction( dc, itemRect, pTrack, mouseCapture, captured );
+            line.drawFunction( context, itemRect, pTrack );
          yy += line.height + line.extraSpace;
       }
    }
@@ -1895,21 +1898,27 @@ void TrackInfo::DrawItems
                rect.x, rect.y + yy,
                rect.width, line.height
             };
-            line.drawFunction( dc, itemRect, pTrack, mouseCapture, captured );
+            line.drawFunction( context, itemRect, pTrack );
          }
       }
    }
 }
 
+#include "tracks/ui/TrackButtonHandles.h"
 void TrackInfo::CloseTitleDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
    bool selected = pTrack ? pTrack->GetSelected() : true;
    {
-      bool down = captured && (pressed == TrackPanel::IsClosing);
       wxRect bev = rect;
       GetCloseBoxHorizontalBounds( rect, bev );
-      AColor::Bevel2(*dc, !down, bev, selected );
+      auto target = dynamic_cast<CloseButtonHandle*>( context.target.get() );
+      bool hit = target && target->GetTrack().get() == pTrack;
+      bool captured = hit && target->IsClicked();
+      bool down = captured && bev.Contains( context.lastState.GetPosition());
+      AColor::Bevel2(*dc, !down, bev, selected, hit );
 
 #ifdef EXPERIMENTAL_THEMING
       wxPen pen( theTheme.Colour( clrTrackPanelText ));
@@ -1935,14 +1944,17 @@ void TrackInfo::CloseTitleDrawFunction
    }
 
    {
+      wxRect bev = rect;
+      GetTitleBarHorizontalBounds( rect, bev );
+      auto target = dynamic_cast<MenuButtonHandle*>( context.target.get() );
+      bool hit = target && target->GetTrack().get() == pTrack;
+      bool captured = hit && target->IsClicked();
+      bool down = captured && bev.Contains( context.lastState.GetPosition());
       wxString titleStr =
          pTrack ? pTrack->GetName() : _("Name");
 
-      bool down = captured && (pressed == TrackPanel::IsPopping);
-      wxRect bev = rect;
-      GetTitleBarHorizontalBounds( rect, bev );
       //bev.Inflate(-1, -1);
-      AColor::Bevel2(*dc, !down, bev, selected);
+      AColor::Bevel2(*dc, !down, bev, selected, hit);
 
       // Draw title text
       SetTrackInfoFont(dc);
@@ -1993,21 +2005,26 @@ void TrackInfo::CloseTitleDrawFunction
 }
 
 void TrackInfo::MinimizeSyncLockDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
    bool selected = pTrack ? pTrack->GetSelected() : true;
    bool syncLockSelected = pTrack ? pTrack->IsSyncLockSelected() : true;
    bool minimized = pTrack ? pTrack->GetMinimized() : false;
    {
-      bool down = captured && (pressed == TrackPanel::IsMinimizing);
       wxRect bev = rect;
       GetMinimizeHorizontalBounds(rect, bev);
+      auto target = dynamic_cast<MinimizeButtonHandle*>( context.target.get() );
+      bool hit = target && target->GetTrack().get() == pTrack;
+      bool captured = hit && target->IsClicked();
+      bool down = captured && bev.Contains( context.lastState.GetPosition());
 
       // Clear background to get rid of previous arrow
       //AColor::MediumTrackInfo(dc, t->GetSelected());
       //dc->DrawRectangle(bev);
 
-      AColor::Bevel2(*dc, !down, bev, selected);
+      AColor::Bevel2(*dc, !down, bev, selected, hit);
 
 #ifdef EXPERIMENTAL_THEMING
       wxColour c = theTheme.Colour(clrTrackPanelText);
@@ -2039,14 +2056,19 @@ void TrackInfo::MinimizeSyncLockDrawFunction
    }
 }
 
+#include "tracks/playabletrack/notetrack/ui/NoteTrackButtonHandle.h"
 void TrackInfo::MidiControlsDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int, bool )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
 #ifdef EXPERIMENTAL_MIDI_OUT
+   auto target = dynamic_cast<NoteTrackButtonHandle*>( context.target.get() );
+   auto channel = target ? target->GetChannel() : -1;
+   auto &dc = context.dc;
    wxRect midiRect = rect;
    GetMidiControlsHorizontalBounds(rect, midiRect);
    NoteTrack::DrawLabelControls
-      ( static_cast<const NoteTrack *>(pTrack), *dc, midiRect );
+      ( static_cast<const NoteTrack *>(pTrack), dc, midiRect, channel );
 #endif // EXPERIMENTAL_MIDI_OUT
 }
 
@@ -2054,43 +2076,59 @@ template<typename TrackClass>
 void TrackInfo::SliderDrawFunction
 ( LWSlider *(*Selector)
     (const wxRect &sliderRect, const TrackClass *t, bool captured, wxWindow*),
-  wxDC *dc, const wxRect &rect, const Track *pTrack, bool captured )
+  wxDC *dc, const wxRect &rect, const Track *pTrack,
+  bool captured, bool highlight )
 {
    wxRect sliderRect = rect;
    TrackInfo::GetSliderHorizontalBounds( rect.GetTopLeft(), sliderRect );
    auto wt = static_cast<const TrackClass*>( pTrack );
-   Selector( sliderRect, wt, captured, nullptr )->OnPaint(*dc, false);
+   Selector( sliderRect, wt, captured, nullptr )->OnPaint(*dc, highlight);
 }
 
+#include "tracks/playabletrack/wavetrack/ui/WaveTrackSliderHandles.h"
 void TrackInfo::PanSliderDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto target = dynamic_cast<PanSliderHandle*>( context.target.get() );
+   auto dc = &context.dc;
+   bool hit = target && target->GetTrack().get() == pTrack;
+   bool captured = hit && target->IsClicked();
    SliderDrawFunction<WaveTrack>
-      ( &TrackInfo::PanSlider, dc, rect, pTrack, captured);
+      ( &TrackInfo::PanSlider, dc, rect, pTrack, captured, hit);
 }
 
 void TrackInfo::GainSliderDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto target = dynamic_cast<GainSliderHandle*>( context.target.get() );
+   auto dc = &context.dc;
+   bool hit = target && target->GetTrack().get() == pTrack;
+   bool captured = hit && target->IsClicked();
    SliderDrawFunction<WaveTrack>
-      ( &TrackInfo::GainSlider, dc, rect, pTrack, captured);
+      ( &TrackInfo::GainSlider, dc, rect, pTrack, captured, hit);
 }
 
 #ifdef EXPERIMENTAL_MIDI_OUT
+#include "tracks/playabletrack/notetrack/ui/NoteTrackSliderHandles.h"
 void TrackInfo::VelocitySliderDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
+   auto target = dynamic_cast<VelocitySliderHandle*>( context.target.get() );
+   bool hit = target && target->GetTrack().get() == pTrack;
+   bool captured = hit && target->IsClicked();
    SliderDrawFunction<NoteTrack>
-      ( &TrackInfo::VelocitySlider, dc, rect, pTrack, captured);
+      ( &TrackInfo::VelocitySlider, dc, rect, pTrack, captured, hit);
 }
 #endif
 
 void TrackInfo::MuteOrSoloDrawFunction
-( wxDC *dc, const wxRect &bev, const Track *pTrack, int pressed, bool captured,
+( wxDC *dc, const wxRect &bev, const Track *pTrack, bool down, bool captured,
-  bool solo )
+  bool solo, bool hit )
 {
-   bool down = captured &&
-      (pressed == ( solo ? TrackPanel::IsSoloing : TrackPanel::IsMuting ));
    //bev.Inflate(-1, -1);
    bool selected = pTrack ? pTrack->GetSelected() : true;
    auto pt = dynamic_cast<const PlayableTrack *>(pTrack);
@@ -2129,7 +2167,7 @@ void TrackInfo::MuteOrSoloDrawFunction
       *dc,
       value == down,
       bev,
-      selected
+      selected, hit
    );
 
    SetTrackInfoFont(dc);
@@ -2137,25 +2175,40 @@ void TrackInfo::MuteOrSoloDrawFunction
    dc->DrawText(str, bev.x + (bev.width - textWidth) / 2, bev.y + (bev.height - textHeight) / 2);
 }
 
+#include "tracks/playabletrack/ui/PlayableTrackButtonHandles.h"
 void TrackInfo::WideMuteDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
    wxRect bev = rect;
    GetWideMuteSoloHorizontalBounds( rect, bev );
-   MuteOrSoloDrawFunction( dc, bev, pTrack, pressed, captured, false );
+   auto target = dynamic_cast<MuteButtonHandle*>( context.target.get() );
+   bool hit = target && target->GetTrack().get() == pTrack;
+   bool captured = hit && target->IsClicked();
+   bool down = captured && bev.Contains( context.lastState.GetPosition());
+   MuteOrSoloDrawFunction( dc, bev, pTrack, down, captured, false, hit );
 }
 
 void TrackInfo::WideSoloDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
    wxRect bev = rect;
    GetWideMuteSoloHorizontalBounds( rect, bev );
-   MuteOrSoloDrawFunction( dc, bev, pTrack, pressed, captured, true );
+   auto target = dynamic_cast<SoloButtonHandle*>( context.target.get() );
+   bool hit = target && target->GetTrack().get() == pTrack;
+   bool captured = hit && target->IsClicked();
+   bool down = captured && bev.Contains( context.lastState.GetPosition());
+   MuteOrSoloDrawFunction( dc, bev, pTrack, down, captured, true, hit );
 }
 
 void TrackInfo::MuteAndSoloDrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed, bool captured )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
    bool bHasSoloButton = TrackPanel::HasSoloButton();
 
    wxRect bev = rect;
@@ -2163,13 +2216,25 @@ void TrackInfo::MuteAndSoloDrawFunction
       GetNarrowMuteHorizontalBounds( rect, bev );
    else
       GetWideMuteSoloHorizontalBounds( rect, bev );
-   MuteOrSoloDrawFunction( dc, bev, pTrack, pressed, captured, false );
+   {
+      auto target = dynamic_cast<MuteButtonHandle*>( context.target.get() );
+      bool hit = target && target->GetTrack().get() == pTrack;
+      bool captured = hit && target->IsClicked();
+      bool down = captured && bev.Contains( context.lastState.GetPosition());
+      MuteOrSoloDrawFunction( dc, bev, pTrack, down, captured, false, hit );
+   }
 
    if( !bHasSoloButton )
       return;
 
    GetNarrowSoloHorizontalBounds( rect, bev );
-   MuteOrSoloDrawFunction( dc, bev, pTrack, pressed, captured, true );
+   {
+      auto target = dynamic_cast<SoloButtonHandle*>( context.target.get() );
+      bool hit = target && target->GetTrack().get() == pTrack;
+      bool captured = hit && target->IsClicked();
+      bool down = captured && bev.Contains( context.lastState.GetPosition());
+      MuteOrSoloDrawFunction( dc, bev, pTrack, down, captured, true, hit );
+   }
 }
 
 void TrackInfo::StatusDrawFunction
@@ -2180,8 +2245,10 @@ void TrackInfo::StatusDrawFunction
 }
 
 void TrackInfo::Status1DrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int, bool )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
    auto wt = static_cast<const WaveTrack*>(pTrack);
 
    /// Returns the string to be displayed in the track label
@@ -2208,23 +2275,28 @@ void TrackInfo::Status1DrawFunction
 }
 
 void TrackInfo::Status2DrawFunction
-( wxDC *dc, const wxRect &rect, const Track *pTrack, int, bool )
+( TrackPanelDrawingContext &context,
+  const wxRect &rect, const Track *pTrack )
 {
+   auto dc = &context.dc;
    auto wt = static_cast<const WaveTrack*>(pTrack);
    auto format = wt ? wt->GetSampleFormat() : floatSample;
    auto s = GetSampleFormatStr(format);
    StatusDrawFunction( s, dc, rect );
 }
 
-void TrackPanel::DrawOutside(Track * t, wxDC * dc, const wxRect & rec)
+void TrackPanel::DrawOutside
+(TrackPanelDrawingContext &context,
+ Track * t, const wxRect & rec)
 {
+   auto dc = &context.dc;
    bool bIsWave = (t->GetKind() == Track::Wave);
 
    // Draw things that extend right of track control panel
    {
       // Start with whole track rect
       wxRect rect = rec;
-      DrawOutsideOfTrack(t, dc, rect);
+      DrawOutsideOfTrack(context, t, rect);
 
       // Now exclude left, right, and top insets
       rect.x += kLeftInset;
@@ -2256,16 +2328,7 @@ void TrackPanel::DrawOutside(Track * t, wxDC * dc, const wxRect & rec)
    rect.y += kTopMargin;
    rect.height -= (kBottomMargin + kTopMargin);
 
-   // Need to know which button, if any, to draw as pressed.
+   TrackInfo::DrawItems( context, rect, *t );
-   const MouseCaptureEnum mouseCapture =
-      // This public global variable is a hack for now, which should go away
-      // when TrackPanelCell gets a virtual function into which we move this
-      // drawing code.
-      MouseCaptureEnum(TrackControls::gCaptureState);
-   auto pClickedTrack = GetTracks()->Lock(mpClickedTrack);
-   const bool captured = (t == pClickedTrack.get());
-
-   TrackInfo::DrawItems( dc, rect, *t, mouseCapture, captured );
 
    //mTrackInfo.DrawBordersWithin( dc, rect, *t );
 }
@@ -2274,8 +2337,11 @@ void TrackPanel::DrawOutside(Track * t, wxDC * dc, const wxRect & rec)
 // Paint the inset areas left, top, and right in a background color
 // If linked to a following channel, also paint the separator area, which
 // overlaps the next track rectangle's top
-void TrackPanel::DrawOutsideOfTrack(Track * t, wxDC * dc, const wxRect & rect)
+void TrackPanel::DrawOutsideOfTrack
+(TrackPanelDrawingContext &context, Track * t, const wxRect & rect)
 {
+   auto dc = &context.dc;
+
    // Fill in area outside of the track
    AColor::TrackPanelBackground(dc, false);
    wxRect side;

src/TrackPanel.h

@@ -61,6 +61,8 @@ using UIHandlePtr = std::shared_ptr<UIHandle>;
 // Declared elsewhere, to reduce compilation dependencies
 class TrackPanelListener;
 
+struct TrackPanelDrawingContext;
+
 enum class UndoPush : unsigned char;
 
 // JKC Nov 2011: Disabled warning C4251 which is to do with DLL linkage
@@ -93,74 +95,75 @@ public:
    struct TCPLine;
 
    static void DrawItems
-      ( wxDC *dc, const wxRect &rect, const Track &track, int mouseCapture,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track &track );
 
    static void DrawItems
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack,
+      ( TrackPanelDrawingContext &context,
+        const wxRect &rect, const Track *pTrack,
         const std::vector<TCPLine> &topLines,
-        const std::vector<TCPLine> &bottomLines,
+        const std::vector<TCPLine> &bottomLines );
-        int mouseCapture, bool captured );
 
    static void CloseTitleDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    static void MinimizeSyncLockDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    static void MidiControlsDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    template<typename TrackClass>
    static void SliderDrawFunction
       ( LWSlider *(*Selector)
            (const wxRect &sliderRect, const TrackClass *t, bool captured,
             wxWindow*),
-        wxDC *dc, const wxRect &rect, const Track *pTrack, bool captured );
+        wxDC *dc, const wxRect &rect, const Track *pTrack,
+        bool captured, bool highlight );
 
    static void PanSliderDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    static void GainSliderDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
 #ifdef EXPERIMENTAL_MIDI_OUT
    static void VelocitySliderDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 #endif
 
    static void MuteOrSoloDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( wxDC *dc, const wxRect &rect, const Track *pTrack, bool down,
-        bool captured, bool solo );
+        bool captured, bool solo, bool hit );
 
    static void WideMuteDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    static void WideSoloDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    static void MuteAndSoloDrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    static void StatusDrawFunction
       ( const wxString &string, wxDC *dc, const wxRect &rect );
 
    static void Status1DrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
    static void Status2DrawFunction
-      ( wxDC *dc, const wxRect &rect, const Track *pTrack, int pressed,
+      ( TrackPanelDrawingContext &context,
-        bool captured );
+        const wxRect &rect, const Track *pTrack );
 
 public:
    int GetTrackInfoWidth() const;
@@ -169,7 +172,6 @@ public:
 
    void DrawBackground(wxDC * dc, const wxRect & rect, bool bSelected, bool bHasMuteSolo, const int labelw, const int vrul) const;
    void DrawBordersWithin(wxDC * dc, const wxRect & rect, const Track &track ) const;
-   void DrawVRuler(wxDC * dc, const wxRect & rect, Track * t) const;
 
    static void GetCloseBoxHorizontalBounds( const wxRect & rect, wxRect &dest );
    static void GetCloseBoxRect(const wxRect & rect, wxRect &dest);
@@ -410,14 +412,19 @@ public:
 protected:
    void DrawTracks(wxDC * dc);
 
-   void DrawEverythingElse(wxDC *dc, const wxRegion & region,
+   void DrawEverythingElse(TrackPanelDrawingContext &context,
+                           const wxRegion & region,
                            const wxRect & clip);
-   void DrawOutside(Track *t, wxDC *dc, const wxRect & rec);
+   void DrawOutside
+      (TrackPanelDrawingContext &context,
+       Track *t, const wxRect & rec);
 
    void HighlightFocusedTrack (wxDC* dc, const wxRect &rect);
    void DrawShadow            (Track *t, wxDC* dc, const wxRect & rect);
    void DrawBordersAroundTrack(Track *t, wxDC* dc, const wxRect & rect, const int labelw, const int vrul);
-   void DrawOutsideOfTrack    (Track *t, wxDC* dc, const wxRect & rect);
+   void DrawOutsideOfTrack
+      (TrackPanelDrawingContext &context,
+       Track *t, const wxRect & rect);
 
 public:
    // Set the object that performs catch-all event handling when the pointer
@@ -492,20 +499,6 @@ protected:
    int mMouseMostRecentX;
    int mMouseMostRecentY;
 
-public:
-   // Old enumeration of click-and-drag states, which will shrink and disappear
-   // as UIHandle subclasses take over the repsonsibilities.
-   enum   MouseCaptureEnum
-   {
-      IsUncaptured = 0,
-      IsClosing,
-      IsMuting,
-      IsSoloing,
-      IsMinimizing,
-      IsPopping,
-   };
-
-protected:
    friend class TrackPanelAx;
 
 #if wxUSE_ACCESSIBILITY

src/TrackPanelDrawingContext.h

@@ -0,0 +1,28 @@
+/**********************************************************************
+
+ Audacity: A Digital Audio Editor
+
+ TrackPanelDrawingContext.h
+
+ Paul Licameli
+
+ **********************************************************************/
+
+#ifndef __AUDACITY_TRACK_PANEL_DRAWING_CONTEXT__
+#define __AUDACITY_TRACK_PANEL_DRAWING_CONTEXT__
+
+#include "MemoryX.h"
+
+class UIHandle;
+using UIHandlePtr = std::shared_ptr<UIHandle>;
+class wxDC;
+
+#include <wx/mousestate.h>
+
+struct TrackPanelDrawingContext {
+   wxDC &dc;
+   UIHandlePtr target;
+   wxMouseState lastState;
+};
+
+#endif

src/effects/Equalization.cpp

@@ -2871,6 +2871,7 @@ void EqualizationPanel::OnSize(wxSizeEvent &  WXUNUSED(event))
    Refresh( false );
 }
 
+#include "TrackPanelDrawingContext.h"
 void EqualizationPanel::OnPaint(wxPaintEvent &  WXUNUSED(event))
 {
    wxPaintDC dc(this);
@@ -3038,8 +3039,10 @@ void EqualizationPanel::OnPaint(wxPaintEvent &  WXUNUSED(event))
    memDC.SetPen(*wxBLACK_PEN);
    if( mEffect->mDraw->GetValue() )
    {
-      mEffect->mEnvelope->DrawPoints(memDC, mEnvRect, ZoomInfo(0.0, mEnvRect.width-1), false, 0.0,
+      TrackPanelDrawingContext context{ memDC, {}, {} };
-                                     mEffect->mdBMin, mEffect->mdBMax, false);
+      mEffect->mEnvelope->DrawPoints(
+         context, mEnvRect, ZoomInfo(0.0, mEnvRect.width-1), false, 0.0,
+      mEffect->mdBMin, mEffect->mdBMax, false);
    }
 
    dc.Blit(0, 0, mWidth, mHeight, &memDC, 0, 0, wxCOPY, FALSE);

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

@@ -24,12 +24,23 @@ NoteTrackButtonHandle::NoteTrackButtonHandle
    : mpTrack{ pTrack }
    , mChannel{ channel }
    , mRect{ rect }
-{}
+{
+   mChangeHighlight = RefreshCode::RefreshCell;
+}
 
 NoteTrackButtonHandle::~NoteTrackButtonHandle()
 {
 }
 
+UIHandle::Result NoteTrackButtonHandle::NeedChangeHighlight
+(const NoteTrackButtonHandle &oldState, const NoteTrackButtonHandle &newState)
+{
+   if (oldState.GetChannel() != newState.GetChannel())
+      // Repaint whenever the highlighted button is different
+      return RefreshCode::RefreshCell;
+   return 0;
+}
+
 UIHandlePtr NoteTrackButtonHandle::HitTest
    (std::weak_ptr<NoteTrackButtonHandle> &holder,
     const wxMouseState &state, const wxRect &rect,

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

@@ -42,6 +42,10 @@ public:
 
    int GetChannel() const { return mChannel; }
 
+   static UIHandle::Result NeedChangeHighlight
+      (const NoteTrackButtonHandle &oldState,
+       const NoteTrackButtonHandle &newState);
+
 protected:
    Result Click
       (const TrackPanelMouseEvent &event, AudacityProject *pProject) override;

src/tracks/playabletrack/ui/PlayableTrackButtonHandles.cpp

@@ -20,7 +20,7 @@ Paul Licameli split from TrackPanel.cpp
 
 MuteButtonHandle::MuteButtonHandle
 ( const std::shared_ptr<Track> &pTrack, const wxRect &rect )
-   : ButtonHandle{ pTrack, rect, TrackPanel::IsMuting }
+   : ButtonHandle{ pTrack, rect }
 {}
 
 MuteButtonHandle::~MuteButtonHandle()
@@ -62,7 +62,7 @@ UIHandlePtr MuteButtonHandle::HitTest
 
 SoloButtonHandle::SoloButtonHandle
 ( const std::shared_ptr<Track> &pTrack, const wxRect &rect )
-   : ButtonHandle{ pTrack, rect, TrackPanel::IsSoloing }
+   : ButtonHandle{ pTrack, rect }
 {}
 
 SoloButtonHandle::~SoloButtonHandle()

src/tracks/playabletrack/ui/PlayableTrackButtonHandles.h

@@ -12,8 +12,6 @@ Paul Licameli split from TrackPanel.cpp
 #define __AUDACITY_PLAYABLE_TRACK_BUTTON_HANDLES__
 
 #include "../../ui/ButtonHandle.h"
-#include "../../../TrackPanel.h"
-
 class wxMouseState;
 
 class MuteButtonHandle final : public ButtonHandle
@@ -50,7 +48,7 @@ class SoloButtonHandle final : public ButtonHandle
 
 public:
    explicit SoloButtonHandle
-   ( const std::shared_ptr<Track> &pTrack, const wxRect &rect );
+      ( const std::shared_ptr<Track> &pTrack, const wxRect &rect );
 
    SoloButtonHandle &operator=(const SoloButtonHandle&) = default;
 

src/tracks/ui/ButtonHandle.cpp

@@ -21,11 +21,12 @@ Paul Licameli
 #include "../ui/TrackControls.h"
 
 ButtonHandle::ButtonHandle
-( const std::shared_ptr<Track> &pTrack, const wxRect &rect, int dragCode )
+( const std::shared_ptr<Track> &pTrack, const wxRect &rect )
    : mpTrack{ pTrack }
    , mRect{ rect }
-   , mDragCode{ dragCode }
+{
-{}
+   mChangeHighlight = RefreshCode::RefreshCell;
+}
 
 ButtonHandle::~ButtonHandle()
 {
@@ -45,7 +46,8 @@ UIHandle::Result ButtonHandle::Click
 
    // Come here for left click or double click
    if (mRect.Contains(event.m_x, event.m_y)) {
-      TrackControls::gCaptureState = mDragCode;
+      mWasIn = true;
+      mIsClicked = true;
       // Toggle visible button state
       return RefreshCell;
    }
@@ -62,14 +64,10 @@ UIHandle::Result ButtonHandle::Drag
    if (!pTrack)
       return Cancelled;
 
-   const int newState =
+   auto isIn = mRect.Contains(event.m_x, event.m_y);
-      mRect.Contains(event.m_x, event.m_y) ? mDragCode : 0;
+   auto result = (isIn == mWasIn) ? RefreshNone : RefreshCell;
-   if (TrackControls::gCaptureState == newState)
+   mWasIn = isIn;
-      return RefreshNone;
+   return result;
-   else {
-      TrackControls::gCaptureState = newState;
-      return RefreshCell;
-   }
 }
 
 HitTestPreview ButtonHandle::Preview
@@ -90,22 +88,13 @@ UIHandle::Result ButtonHandle::Release
 
    Result result = RefreshNone;
    const wxMouseEvent &event = evt.event;
-   if (TrackControls::gCaptureState) {
-      TrackControls::gCaptureState = 0;
-      result = RefreshCell;
-   }
    if (pTrack && mRect.Contains(event.m_x, event.m_y))
-      result |= CommitChanges(event, pProject, pParent);
+      result |= RefreshCell | CommitChanges(event, pProject, pParent);
    return result;
 }
 
 UIHandle::Result ButtonHandle::Cancel(AudacityProject *pProject)
 {
    using namespace RefreshCode;
-   if (TrackControls::gCaptureState) {
+   return RefreshCell; // perhaps unnecessarily if pointer is out of the box
-      TrackControls::gCaptureState = 0;
-      return RefreshCell;
-   }
-   else
-      return RefreshNone;
 }

src/tracks/ui/ButtonHandle.h

@@ -23,9 +23,13 @@ class ButtonHandle /* not final */ : public UIHandle
 {
    ButtonHandle(const ButtonHandle&) = delete;
 
+public:
+   std::shared_ptr<Track> GetTrack() const { return mpTrack.lock(); }
+   bool IsClicked() const { return mIsClicked; }
+
 protected:
    explicit ButtonHandle
-      ( const std::shared_ptr<Track> &pTrack, const wxRect &rect, int dragCode );
+      ( const std::shared_ptr<Track> &pTrack, const wxRect &rect );
 
    ButtonHandle &operator=(const ButtonHandle&) = default;
 
@@ -56,7 +60,8 @@ protected:
 
    std::weak_ptr<Track> mpTrack;
    wxRect mRect;
-   int mDragCode;
+   bool mWasIn{ true };
+   bool mIsClicked{};
 };
 
 #endif

src/tracks/ui/SliderHandle.cpp

@@ -21,7 +21,9 @@ SliderHandle::SliderHandle
    : mSliderFn{ sliderFn }
    , mRect{ rect }
    , mpTrack{ pTrack }
-{}
+{
+   mChangeHighlight = RefreshCode::RefreshCell;
+}
 
 SliderHandle::~SliderHandle()
 {
@@ -44,8 +46,10 @@ UIHandle::Result SliderHandle::Click
       // Just did a modal dialog in OnMouseEvent
       // Do not start a drag
       return RefreshCell | Cancelled;
-   else
+   else {
+      mIsClicked = true;
       return RefreshCell;
+   }
 }
 
 UIHandle::Result SliderHandle::Drag

src/tracks/ui/SliderHandle.h

@@ -32,6 +32,9 @@ public:
 
    SliderHandle &operator=(const SliderHandle&) = default;
 
+   std::shared_ptr<Track> GetTrack() const { return mpTrack.lock(); }
+   bool IsClicked() const { return mIsClicked; }
+
 protected:
    virtual ~SliderHandle();
 
@@ -67,6 +70,8 @@ protected:
    LWSlider *GetSlider( AudacityProject *pProject );
 
    float mStartingValue {};
+
+   bool mIsClicked{};
 };
 
 #endif

src/tracks/ui/TrackButtonHandles.cpp

@@ -19,7 +19,7 @@ Paul Licameli split from TrackPanel.cpp
 
 MinimizeButtonHandle::MinimizeButtonHandle
 ( const std::shared_ptr<Track> &pTrack, const wxRect &rect )
-   : ButtonHandle{ pTrack, rect, TrackPanel::IsMinimizing }
+   : ButtonHandle{ pTrack, rect }
 {}
 
 MinimizeButtonHandle::~MinimizeButtonHandle()
@@ -69,7 +69,7 @@ UIHandlePtr MinimizeButtonHandle::HitTest
 
 CloseButtonHandle::CloseButtonHandle
 ( const std::shared_ptr<Track> &pTrack, const wxRect &rect )
-   : ButtonHandle{ pTrack, rect, TrackPanel::IsClosing }
+   : ButtonHandle{ pTrack, rect }
 {}
 
 CloseButtonHandle::~CloseButtonHandle()
@@ -121,7 +121,7 @@ UIHandlePtr CloseButtonHandle::HitTest
 MenuButtonHandle::MenuButtonHandle
 ( const std::shared_ptr<TrackPanelCell> &pCell,
   const std::shared_ptr<Track> &pTrack, const wxRect &rect )
-   : ButtonHandle{ pTrack, rect, TrackPanel::IsPopping }
+   : ButtonHandle{ pTrack, rect }
    , mpCell{ pCell }
 {}
 

src/tracks/ui/TrackButtonHandles.h

@@ -12,7 +12,6 @@ Paul Licameli split from TrackPanel.cpp
 #define __AUDACITY_TRACK_BUTTON_HANDLES__
 
 #include "../ui/ButtonHandle.h"
-#include "../../TrackPanel.h"
 
 class wxMouseState;
 

src/tracks/ui/TrackControls.cpp

@@ -21,8 +21,6 @@ Paul Licameli split from TrackPanel.cpp
 #include "../../Track.h"
 #include <wx/textdlg.h>
 
-int TrackControls::gCaptureState;
-
 TrackControls::TrackControls( std::shared_ptr<Track> pTrack )
    : mwTrack{ pTrack }
 {

src/tracks/ui/TrackControls.h

@@ -42,9 +42,6 @@ public:
       unsigned result;
    };
 
-   // Make this hack go away!  See TrackPanel::DrawOutside
-   static int gCaptureState;
-
 protected:
    // An override is supplied for derived classes to call through but it is
    // still marked pure virtual

win/Projects/Audacity/Audacity.vcxproj

@@ -508,6 +508,7 @@
     <ClInclude Include="..\..\..\src\toolbars\SpectralSelectionBarListener.h" />
     <ClInclude Include="..\..\..\src\TrackPanelCell.h" />
     <ClInclude Include="..\..\..\src\TrackPanelCellIterator.h" />
+    <ClInclude Include="..\..\..\src\TrackPanelDrawingContext.h" />
     <ClInclude Include="..\..\..\src\TrackPanelListener.h" />
     <ClInclude Include="..\..\..\src\TrackPanelMouseEvent.h" />
     <ClInclude Include="..\..\..\src\tracks\playabletrack\notetrack\ui\NoteTrackButtonHandle.h" />

win/Projects/Audacity/Audacity.vcxproj.filters

@@ -1933,6 +1933,9 @@
     <ClInclude Include="..\..\..\src\RealFFTf48x.h">
       <Filter>src</Filter>
     </ClInclude>
+    <ClInclude Include="..\..\..\src\TrackPanelDrawingContext.h">
+      <Filter>src</Filter>
+    </ClInclude>
     <ClInclude Include="..\..\..\src\TrackPanelCell.h">
       <Filter>src</Filter>
     </ClInclude>