Lower EVT_TRACK_PANEL_TIMER into Project...

... so there are fewer dependencies on TrackPanel.

This frees ASlider, Ruler, and ViewInfo from cycles

src/LyricsWindow.cpp

@@ -15,7 +15,6 @@
 #include "Prefs.h" // for RTL_WORKAROUND
 #include "Project.h"
 #include "ProjectAudioIO.h"
-#include "TrackPanel.h" // for EVT_TRACK_PANEL_TIMER
 #include "ViewInfo.h"
 
 #include <wx/radiobut.h>

src/Project.cpp

@@ -19,6 +19,7 @@
 #include <wx/frame.h>
 
 wxDEFINE_EVENT(EVT_PROJECT_STATUS_UPDATE, wxCommandEvent);
+wxDEFINE_EVENT(EVT_TRACK_PANEL_TIMER, wxCommandEvent);
 
 size_t AllProjects::size() const
 {

src/Project.h

@@ -100,6 +100,9 @@ using AttachedWindows = ClientData::Site<
 wxDECLARE_EXPORTED_EVENT(AUDACITY_DLL_API,
                          EVT_PROJECT_STATUS_UPDATE, wxCommandEvent);
 
+wxDECLARE_EXPORTED_EVENT(AUDACITY_DLL_API,
+                         EVT_TRACK_PANEL_TIMER, wxCommandEvent);
+
 ///\brief The top-level handle to an Audacity project.  It serves as a source
 /// of events that other objects can bind to, and a container of associated
 /// sub-objects that it treats opaquely.  It stores a filename and a status

src/TrackPanel.cpp

@@ -110,8 +110,6 @@ is time to refresh some aspect of the screen.
 
 #include <wx/dcclient.h>
 
-wxDEFINE_EVENT(EVT_TRACK_PANEL_TIMER, wxCommandEvent);
-
 /**
 
 \class TrackPanel

src/TrackPanel.h

@@ -56,9 +56,6 @@ struct TrackPanelDrawingContext;
 
 enum class UndoPush : unsigned char;
 
-wxDECLARE_EXPORTED_EVENT(AUDACITY_DLL_API,
-                         EVT_TRACK_PANEL_TIMER, wxCommandEvent);
-
 enum {
    kTimerInterval = 50, // milliseconds
 };

src/ViewInfo.cpp

@@ -18,7 +18,6 @@ Paul Licameli
 #include "prefs/GUISettings.h"
 #include "Prefs.h"
 #include "Project.h"
-#include "TrackPanel.h" // for EVT_TRACK_PANEL_TIMER
 #include "xml/XMLWriter.h"
 #include "prefs/TracksBehaviorsPrefs.h"
 #include "xml/XMLWriter.h"