New Track virtual eliminates a track_cast in CommonCommandFlags...

... Also a better name for one of the command flags

This allows removal of special mention of TimeTrack

src/CommonCommandFlags.cpp

@@ -41,16 +41,16 @@ cycles.
 
 */
 
-// Really means, some track is selected, that isn't a time track
+// Strong predicate excludes tracks that do not support basic editing.
-bool TracksSelectedPred( const AudacityProject &project )
+bool EditableTracksSelectedPred( const AudacityProject &project )
 {
    auto range = TrackList::Get( project ).Selected()
      - []( const Track *pTrack ){
-        return track_cast<const TimeTrack*>( pTrack ); };
+        return !pTrack->SupportsBasicEditing(); };
    return !range.empty();
 };
 
-// This predicate includes time tracks too.
+// Weaker predicate.
 bool AnyTracksSelectedPred( const AudacityProject &project )
 {
    auto range = TrackList::Get( project ).Selected();
@@ -177,8 +177,8 @@ const ReservedCommandFlag&
       CommandFlagOptions{}.DisableDefaultMessage()
    }; return flag; }
 const ReservedCommandFlag&
-   TracksSelectedFlag() { static ReservedCommandFlag flag{
+   EditableTracksSelectedFlag() { static ReservedCommandFlag flag{
-      TracksSelectedPred, // exclude TimeTracks
+      EditableTracksSelectedPred,
       { []( const TranslatableString &Name ){ return
          // i18n-hint: %s will be replaced by the name of an action, such as "Remove Tracks".
          XO("\"%s\" requires one or more tracks to be selected.").Format( Name );
@@ -186,7 +186,7 @@ const ReservedCommandFlag&
    }; return flag; }
 const ReservedCommandFlag&
    AnyTracksSelectedFlag() { static ReservedCommandFlag flag{
-      AnyTracksSelectedPred, // Allow TimeTracks
+      AnyTracksSelectedPred,
       { []( const TranslatableString &Name ){ return
          // i18n-hint: %s will be replaced by the name of an action, such as "Remove Tracks".
          XO("\"%s\" requires one or more tracks to be selected.").Format( Name );

src/CommonCommandFlags.h

@@ -15,7 +15,7 @@ Paul Licameli split from Menus.cpp
 
 #include "commands/CommandFlag.h"
 
-bool TracksSelectedPred( const AudacityProject &project );
+bool EditableTracksSelectedPred( const AudacityProject &project );
 bool AudioIOBusyPred( const AudacityProject &project );
 bool TimeSelectedPred( const AudacityProject &project );
 extern const CommandFlagOptions &cutCopyOptions();
@@ -27,7 +27,7 @@ extern AUDACITY_DLL_API const ReservedCommandFlag
    &TimeSelectedFlag(), // This is equivalent to check if there is a valid selection, so it's used for Zoom to Selection too
    &WaveTracksSelectedFlag(),
    &TracksExistFlag(),
-   &TracksSelectedFlag(),
+   &EditableTracksSelectedFlag(),
    &AnyTracksSelectedFlag(),
    &TrackPanelHasFocus();  //lll
 

src/SelectUtilities.cpp

@@ -85,7 +85,7 @@ void SelectAllIfNone( AudacityProject &project )
 {
    auto &viewInfo = ViewInfo::Get( project );
    auto flags = MenuManager::Get( project ).GetUpdateFlags();
-   if((flags & TracksSelectedFlag()).none() ||
+   if((flags & EditableTracksSelectedFlag()).none() ||
       viewInfo.selectedRegion.isPoint())
       DoSelectAllAudio( project );
 }
@@ -98,7 +98,7 @@ bool SelectAllIfNoneAndAllowed( AudacityProject &project )
    auto &viewInfo = ViewInfo::Get( project );
    auto flags = MenuManager::Get( project ).GetUpdateFlags();
 
-   if((flags & TracksSelectedFlag()).none() ||
+   if((flags & EditableTracksSelectedFlag()).none() ||
       viewInfo.selectedRegion.isPoint()) {
       if (!allowed) {
          return false;

src/TimeTrack.cpp

@@ -131,6 +131,11 @@ void TimeTrack::SetRangeUpper(double upper)
    mEnvelope->SetRangeUpper( upper );
 }
 
+bool TimeTrack::SupportsBasicEditing() const
+{
+   return false;
+}
+
 Track::Holder TimeTrack::Cut( double t0, double t1 )
 {
    auto result = Copy( t0, t1, false );

src/TimeTrack.h

@@ -40,6 +40,8 @@ class TimeTrack final : public Track {
    virtual ~TimeTrack();
 
 
+   bool SupportsBasicEditing() const override;
+
    Holder Cut( double t0, double t1 ) override;
    Holder Copy( double t0, double t1, bool forClipboard ) const override;
    void Clear(double t0, double t1) override;

src/Track.cpp

@@ -1224,6 +1224,11 @@ std::shared_ptr<const Track> Track::SubstituteOriginalTrack() const
    return SharedPointer();
 }
 
+bool Track::SupportsBasicEditing() const
+{
+   return true;
+}
+
 auto Track::GetIntervals() const -> ConstIntervals
 {
    return {};

src/Track.h

@@ -318,6 +318,9 @@ class AUDACITY_DLL_API Track /* not final */
    using ConstInterval = ConstTrackInterval;
    using ConstIntervals = std::vector< ConstInterval >;
 
+   //! Whether this track type implements cut-copy-paste; by default, true
+   virtual bool SupportsBasicEditing() const;
+
    //! Report times on the track where important intervals begin and end, for UI to snap to
    /*!
    Some intervals may be empty, and no ordering of the intervals is assumed.

src/menus/EditMenus.cpp

@@ -1004,7 +1004,7 @@ static const ReservedCommandFlag
       if (
          TimeSelectedPred( project )
       &&
-         TracksSelectedPred( project )
+         EditableTracksSelectedPred( project )
       )
          return true;
 
@@ -1020,7 +1020,7 @@ BaseItemSharedPtr EditMenu()
    using Options = CommandManager::Options;
 
    static const auto NotBusyTimeAndTracksFlags =
-      AudioIONotBusyFlag() | TimeSelectedFlag() | TracksSelectedFlag();
+      AudioIONotBusyFlag() | TimeSelectedFlag() | EditableTracksSelectedFlag();
 
    // The default shortcut key for Redo is different on different platforms.
    static constexpr auto redoKey =
@@ -1065,7 +1065,7 @@ BaseItemSharedPtr EditMenu()
             AudioIONotBusyFlag() | CutCopyAvailableFlag() | NoAutoSelect(),
             wxT("Ctrl+X") ),
          Command( wxT("Delete"), XXO("&Delete"), FN(OnDelete),
-            AudioIONotBusyFlag() | TracksSelectedFlag() | TimeSelectedFlag() | NoAutoSelect(),
+            AudioIONotBusyFlag() | EditableTracksSelectedFlag() | TimeSelectedFlag() | NoAutoSelect(),
             wxT("Ctrl+K") ),
          /* i18n-hint: (verb)*/
          Command( wxT("Copy"), XXO("&Copy"), FN(OnCopy),
@@ -1160,7 +1160,7 @@ BaseItemSharedPtr ExtraEditMenu()
 {
    using Options = CommandManager::Options;
    static const auto flags =
-      AudioIONotBusyFlag() | TracksSelectedFlag() | TimeSelectedFlag();
+      AudioIONotBusyFlag() | EditableTracksSelectedFlag() | TimeSelectedFlag();
    static BaseItemSharedPtr menu{
    ( FinderScope{ findCommandHandler },
    Menu( wxT("Edit"), XXO("&Edit"),
@@ -1184,7 +1184,7 @@ auto selectAll = []( AudacityProject &project, CommandFlag flagsRqd ){
 
 RegisteredMenuItemEnabler selectTracks{{
    []{ return TracksExistFlag(); },
-   []{ return TracksSelectedFlag(); },
+   []{ return EditableTracksSelectedFlag(); },
    canSelectAll,
    selectAll
 }};

src/menus/SelectMenus.cpp

@@ -1059,7 +1059,7 @@ BaseItemSharedPtr SelectMenu()
             ,
             Command( wxT("SelSyncLockTracks"), XXO("In All &Sync-Locked Tracks"),
                FN(OnSelectSyncLockSel),
-               TracksSelectedFlag() | IsSyncLockedFlag(),
+               EditableTracksSelectedFlag() | IsSyncLockedFlag(),
                Options{ wxT("Ctrl+Shift+Y"), XO("Select Sync-Locked") } )
    #endif
          ),
@@ -1131,7 +1131,7 @@ BaseItemSharedPtr SelectMenu()
 
       Section( "",
          Command( wxT("ZeroCross"), XXO("At &Zero Crossings"),
-            FN(OnZeroCrossing), TracksSelectedFlag(),
+            FN(OnZeroCrossing), EditableTracksSelectedFlag(),
             Options{ wxT("Z"), XO("Select Zero Crossing") } )
       )
    ) ) };
@@ -1216,11 +1216,11 @@ BaseItemSharedPtr CursorMenu()
 
       Command( wxT("CursTrackStart"), XXO("Track &Start"),
          FN(OnCursorTrackStart),
-         TracksSelectedFlag(),
+         EditableTracksSelectedFlag(),
          Options{ wxT("J"), XO("Cursor to Track Start") } ),
       Command( wxT("CursTrackEnd"), XXO("Track &End"),
          FN(OnCursorTrackEnd),
-         TracksSelectedFlag(),
+         EditableTracksSelectedFlag(),
          Options{ wxT("K"), XO("Cursor to Track End") } ),
 
       Command( wxT("CursProjectStart"), XXO("&Project Start"),

src/menus/TrackMenus.cpp

@@ -1356,9 +1356,9 @@ BaseItemSharedPtr TracksMenu()
             Command( wxT("UnmuteAllTracks"), XXO("&Unmute All Tracks"),
                FN(OnUnmuteAllTracks), TracksExistFlag(), wxT("Ctrl+Shift+U") ),
             Command( wxT("MuteTracks"), XXO("Mut&e Tracks"),
-               FN(OnMuteSelectedTracks), TracksSelectedFlag(), wxT("Ctrl+Alt+U") ),
+               FN(OnMuteSelectedTracks), EditableTracksSelectedFlag(), wxT("Ctrl+Alt+U") ),
             Command( wxT("UnmuteTracks"), XXO("U&nmute Tracks"),
-               FN(OnUnmuteSelectedTracks), TracksSelectedFlag(), wxT("Ctrl+Alt+Shift+U") )
+               FN(OnUnmuteSelectedTracks), EditableTracksSelectedFlag(), wxT("Ctrl+Alt+Shift+U") )
          ),
 
          Menu( wxT("Pan"), XXO("&Pan"),
@@ -1367,13 +1367,13 @@ BaseItemSharedPtr TracksMenu()
             // in the project could very easily be lost unless we
             // require the tracks to be selected.
             Command( wxT("PanLeft"), XXO("&Left"), FN(OnPanLeft),
-               TracksSelectedFlag(),
+               EditableTracksSelectedFlag(),
                Options{}.LongName( XO("Pan Left") ) ),
             Command( wxT("PanRight"), XXO("&Right"), FN(OnPanRight),
-               TracksSelectedFlag(),
+               EditableTracksSelectedFlag(),
                Options{}.LongName( XO("Pan Right") ) ),
             Command( wxT("PanCenter"), XXO("&Center"), FN(OnPanCenter),
-               TracksSelectedFlag(),
+               EditableTracksSelectedFlag(),
                Options{}.LongName( XO("Pan Center") ) )
          )
       ),
@@ -1387,14 +1387,14 @@ BaseItemSharedPtr TracksMenu()
                      { wxT("EndToEnd"),     XXO("&Align End to End") },
                      { wxT("Together"),     XXO("Align &Together") },
                   },
-                  FN(OnAlignNoSync), AudioIONotBusyFlag() | TracksSelectedFlag())
+                  FN(OnAlignNoSync), AudioIONotBusyFlag() | EditableTracksSelectedFlag())
             ),
 
             Section( "",
                // Alignment commands using selection or zero
                CommandGroup(wxT("Align"),
                   alignLabels(),
-                  FN(OnAlign), AudioIONotBusyFlag() | TracksSelectedFlag())
+                  FN(OnAlign), AudioIONotBusyFlag() | EditableTracksSelectedFlag())
             ),
 
             Section( "",
@@ -1411,7 +1411,7 @@ BaseItemSharedPtr TracksMenu()
          // Do we need this sub-menu at all?
          Menu( wxT("MoveSelectionAndTracks"), XO("Move Sele&ction and Tracks"), {
             CommandGroup(wxT("AlignMove"), alignLabels(),
-               FN(OnAlignMoveSel), AudioIONotBusyFlag() | TracksSelectedFlag()),
+               FN(OnAlignMoveSel), AudioIONotBusyFlag() | EditableTracksSelectedFlag()),
          } ),
    #endif