A means to specify legacy values of effect choice controls...

... For Truncate Silence only now, perhaps it will find more future use

include/audacity/EffectAutomationParameters.h

@@ -155,7 +155,14 @@ public:
       return Write(key, f);
    }
 
-   bool ReadEnum(const wxString & key, int *pi, const wxArrayString & choices) const
+   // For reading old config files with enumeration names that have been
+   // changed in later versions.  Pair a string with an index into the other
+   // list of non-obsolete names.
+   using ObsoleteMap = std::pair< wxString, size_t >;
+
+   bool ReadEnum(const wxString & key, int *pi, const wxArrayString & choices,
+                 const ObsoleteMap obsoletes[] = nullptr,
+                 size_t nObsoletes = 0) const
    {
       wxString s;
       if (!wxFileConfig::Read(key, &s))
@@ -163,10 +170,21 @@ public:
          return false;
       }
       *pi = choices.Index(s);
+      if (*pi < 0 && obsoletes) {
+         auto index = std::find_if(obsoletes, obsoletes + nObsoletes,
+                                   [&](const ObsoleteMap &entry){
+                                      return entry.first == s; })
+            - obsoletes;
+         if (index < nObsoletes)
+            *pi = (int)obsoletes[index].second;
+      }
       return true;
    }
 
-   bool ReadEnum(const wxString & key, int *pi, int defVal, const wxArrayString & choices) const
+   bool ReadEnum(const wxString & key, int *pi, int defVal,
+                 const wxArrayString & choices,
+                 const ObsoleteMap obsoletes[] = nullptr,
+                 size_t nObsoletes = 0) const
    {
       if (!ReadEnum(key, pi, choices))
       {
@@ -175,7 +193,10 @@ public:
       return true;
    }
 
-   bool ReadEnum(const wxString & key, int *pi, const wxString & defVal, const wxArrayString & choices) const
+   bool ReadEnum(const wxString & key, int *pi, const wxString & defVal,
+                 const wxArrayString & choices,
+                 const ObsoleteMap obsoletes[] = nullptr,
+                 size_t nObsoletes = 0) const
    {
       if (!ReadEnum(key, pi, choices))
       {
@@ -230,15 +251,21 @@ public:
       return true;
    }
 
-   bool ReadAndVerify(const wxString & key, int *val, int defVal, const wxArrayString & choices) const
+   bool ReadAndVerify(const wxString & key, int *val, int defVal,
+                      const wxArrayString & choices,
+                      const ObsoleteMap obsoletes[] = nullptr,
+                      size_t nObsoletes = 0) const
    {
-      ReadEnum(key, val, defVal, choices);
+      ReadEnum(key, val, defVal, choices, obsoletes, nObsoletes);
       return (*val != wxNOT_FOUND);
    }
 
-   bool ReadAndVerify(const wxString & key, int *val, const wxString & defVal, const wxArrayString & choices) const
+   bool ReadAndVerify(const wxString & key, int *val, const wxString & defVal,
+                      const wxArrayString & choices,
+                      const ObsoleteMap obsoletes[] = nullptr,
+                      size_t nObsoletes = 0) const
    {
-      ReadEnum(key, val, defVal, choices);
+      ReadEnum(key, val, defVal, choices, obsoletes, nObsoletes);
       return (*val != wxNOT_FOUND);
    }
 

src/effects/Effect.h

@@ -792,6 +792,12 @@ inline long TrapLong(long x, long min, long max)
    if (!parms.ReadAndVerify(KEY_ ## name, &name, DEF_ ## name, list)) \
       return false;
 
+#define ReadAndVerifyEnumWithObsoletes(name, list, obsoleteList, nObsolete) \
+   int name; \
+   if (!parms.ReadAndVerify(KEY_ ## name, &name, DEF_ ## name, \
+                            list, obsoleteList, nObsolete)) \
+      return false;
+
 #define ReadAndVerifyInt(name) ReadParam(int, name)
 #define ReadAndVerifyDouble(name) ReadParam(double, name)
 #define ReadAndVerifyFloat(name) ReadParam(float, name)

src/effects/TruncSilence.cpp

@@ -50,6 +50,14 @@ static const wxChar *kActionStrings[nActions] =
    XO("Compress Excess Silence")
 };
 
+static CommandParameters::ObsoleteMap kObsoleteActions[] = {
+   // Compatible with 2.1.0 and before
+   { wxT("0"), 0 }, // Remap to Truncate Detected Silence
+   { wxT("1"), 1 }, // Remap to Compress Excess Silence
+};
+
+static const size_t nObsoleteActions = WXSIZEOF( kObsoleteActions );
+
 // Define defaults, minimums, and maximums for each parameter
 #define DefaultAndLimits(name, def, min, max) \
    static const double DEF_ ## name = (def); \
@@ -136,8 +144,6 @@ EffectType EffectTruncSilence::GetType()
 
 bool EffectTruncSilence::DefineParams( ShuttleParams & S ){
    wxArrayString actions(nActions, kActionStrings);
-   //actions.Insert(wxT("0"), 0); // Compatible with 2.1.0 and before
-   //actions.Insert(wxT("1"), 1); // Compatible with 2.1.0 and before
 
    S.SHUTTLE_ENUM_PARAM( mTruncDbChoiceIndex, DbIndex, mDbChoices );
    S.SHUTTLE_ENUM_PARAM( mActionIndex, ActIndex, actions );
@@ -163,14 +169,13 @@ bool EffectTruncSilence::GetAutomationParameters(CommandParameters & parms)
 bool EffectTruncSilence::SetAutomationParameters(CommandParameters & parms)
 {
    wxArrayString actions(nActions, kActionStrings);
-   actions.Insert(wxT("0"), 0); // Compatible with 2.1.0 and before
-   actions.Insert(wxT("1"), 1); // Compatible with 2.1.0 and before
 
    ReadAndVerifyDouble(Minimum);
    ReadAndVerifyDouble(Truncate);
    ReadAndVerifyDouble(Compress);
    ReadAndVerifyEnum(DbIndex, mDbChoices);
-   ReadAndVerifyEnum(ActIndex, actions);
+   ReadAndVerifyEnumWithObsoletes(ActIndex, actions,
+                                  kObsoleteActions, nObsoleteActions);
    ReadAndVerifyBool(Independent);
 
    mInitialAllowedSilence = Minimum;