Use type aliases PluginPath, PluginPaths...

... for wxString and vector thereof, when holding plugin paths (which may or
may not be interpreted as file paths, depending on the module); to be replaced
later with different types

include/audacity/ComponentInterface.h

@@ -113,7 +113,7 @@ public:
    virtual ~ComponentInterface() {};
 
    // These should return an untranslated value
-   virtual wxString GetPath() = 0;
+   virtual PluginPath GetPath() = 0;
 
    // The internal string persists in configuration files
    // So config compatibility will break if it is changed across Audacity versions

include/audacity/ModuleInterface.h

@@ -98,7 +98,7 @@ public:
    // For modules providing an interface to other dynamically loaded plugins,
    // the module returns a list of path names that will be presented to the
    // user as "New" for enablement.
-   virtual wxArrayString FindPluginPaths(PluginManagerInterface & pluginManager) = 0;
+   virtual PluginPaths FindPluginPaths(PluginManagerInterface & pluginManager) = 0;
 
    // Once the user selects desired paths from FindPluginPaths(),
    // a call to DiscoverPluginsAtPath()
@@ -115,16 +115,16 @@ public:
       std::function<
          const PluginID &(ModuleInterface *, ComponentInterface *) >;
    virtual unsigned DiscoverPluginsAtPath(
-      const wxString & path, wxString &errMsg,
+      const PluginPath & path, wxString &errMsg,
       const RegistrationCallback &callback )
          = 0;
 
    // For modules providing an interface to other dynamically loaded plugins,
    // the module returns true if the plugin is still valid, otherwise false.
-   virtual bool IsPluginValid(const wxString & path, bool bFast) = 0;
+   virtual bool IsPluginValid(const PluginPath & path, bool bFast) = 0;
 
    // When appropriate, CreateInstance() will be called to instantiate the plugin.
-   virtual ComponentInterface *CreateInstance(const wxString & path) = 0;
+   virtual ComponentInterface *CreateInstance(const PluginPath & path) = 0;
 
    // When appropriate, DeleteInstance() will be called to delete the plugin.
    virtual void DeleteInstance(ComponentInterface *instance) = 0;

include/audacity/PluginInterface.h

@@ -61,7 +61,7 @@ public:
    static const PluginID &AudacityCommandRegistrationCallback(
       ModuleInterface *provider, ComponentInterface *ident );
 
-   virtual bool IsPluginRegistered(const wxString & path) = 0;
+   virtual bool IsPluginRegistered(const PluginPath & path) = 0;
 
    virtual const PluginID & RegisterPlugin(ModuleInterface *module) = 0;
    virtual const PluginID & RegisterPlugin(ModuleInterface *provider, EffectDefinitionInterface *effect, int type) = 0;

include/audacity/Types.h

@@ -46,6 +46,7 @@
 #include <wx/string.h>
 #include <wx/arrstr.h>
 #include <type_traits>
+#include <vector>
 
 // ----------------------------------------------------------------------------
 // TODO:  I'd imagine this header may be replaced by other public headers. But,
@@ -53,6 +54,15 @@
 //        until proper public headers are created for the stuff in here.
 // ----------------------------------------------------------------------------
 
+/**************************************************************************//**
+
+\brief type alias for identifying a Plugin supplied by a module, each module
+defining its own interpretation of the strings, which may or may not be as a
+file system path
+********************************************************************************/
+using PluginPath = wxString;
+using PluginPaths = std::vector< PluginPath >;
+
 // ----------------------------------------------------------------------------
 // A native 64-bit integer...used when referring to any number of samples
 // ----------------------------------------------------------------------------