LV2FeaturesList.h

Go to the documentation of this file.

/**********************************************************************
 
  Audacity: A Digital Audio Editor
 
  @file LV2FeaturesList.h
 
  Paul Licameli split from LV2Effect.h
 
  Audacity(R) is copyright (c) 1999-2013 Audacity Team.
  License: GPL v2 or later.  See License.txt.
 
*********************************************************************/
 
#ifndef __AUDACITY_LV2_FEATURES_LIST__
#define __AUDACITY_LV2_FEATURES_LIST__
 
#if USE_LV2
 
#include "lv2/log/log.h"
#include "lv2/uri-map/uri-map.h"
 
#include "LV2Symbols.h"
#include "LV2Preferences.h" // for DEFAULT_BLOCKSIZE
 
// Define a reasonable default sequence size in bytes
#define DEFAULT_SEQSIZE 8192
 
using LilvNodesPtr = Lilv_ptr<LilvNodes, lilv_nodes_free>;
 
class LV2FeaturesListBase {
public:
   explicit LV2FeaturesListBase(const LilvPlugin &plug);
   virtual ~LV2FeaturesListBase();
 
   LV2FeaturesListBase(const LV2FeaturesListBase&) = delete;
   LV2FeaturesListBase& operator=(const LV2FeaturesListBase&) = delete;
 
   using FeaturePointers = std::vector<const LV2_Feature *>;
   virtual FeaturePointers GetFeaturePointers() const = 0;
 
   bool ValidateFeatures(const LilvNode *subject);
 
   bool CheckFeatures(const LilvNode *subject, bool required);
 
   const LilvPlugin &mPlug;
   bool mNoResize{ false };
};
 
// Dummy "keyword" argument prevents overload resolution to the copy ctor
struct WithBase_t{};
constexpr WithBase_t WithBase;
 
class ExtendedLV2FeaturesList : public LV2FeaturesListBase {
public:
   explicit ExtendedLV2FeaturesList(WithBase_t,
      const LV2FeaturesListBase &baseFeatures);
   virtual ~ExtendedLV2FeaturesList();
   FeaturePointers GetFeaturePointers() const override;
   void AddFeature(const char *uri, const void *data);
   const LV2FeaturesListBase &mBaseFeatures;
protected:
   std::vector<LV2_Feature> mFeatures;
};
 
class LV2FeaturesList : public LV2FeaturesListBase {
public:
   static ComponentInterfaceSymbol GetPluginSymbol(const LilvPlugin &plug);
 
   explicit LV2FeaturesList(const LilvPlugin &plug);
   ~LV2FeaturesList() override;
 
   bool InitializeFeatures();
 
   FeaturePointers GetFeaturePointers() const override;
 
   static bool SuppliesWorkerInterface(const LilvPlugin &plug);
 
   bool SuppliesWorkerInterface() const { return mSuppliesWorkerInterface; }
 
   void AddFeature(const char *uri, const void *data);
 
   // lv2 functions require a pointer to non-const in places, but presumably
   // have no need to mutate the members of this structure
   LV2_URID_Map *URIDMapFeature() const
   { return const_cast<LV2_URID_Map*>(&mURIDMapFeature); }
 
   LV2_URID URID_Map(const char *uri) const;
 
protected:
   static uint32_t uri_to_id(LV2_URI_Map_Callback_Data callback_data,
      const char *map, const char *uri);
   static LV2_URID urid_map(LV2_URID_Map_Handle handle, const char *uri);
   static const char *urid_unmap(LV2_URID_Unmap_Handle handle, LV2_URID urid);
   const char *URID_Unmap(LV2_URID urid);
 
   static int log_printf(LV2_Log_Handle handle,
      LV2_URID type, const char *fmt, ...);
   static int log_vprintf(LV2_Log_Handle handle,
      LV2_URID type, const char *fmt, va_list ap);
   int LogVPrintf(LV2_URID type, const char *fmt, va_list ap);
 
   // These objects contain C-style virtual function tables that we fill in
   const LV2_URI_Map_Feature mUriMapFeature{
      this, LV2FeaturesList::uri_to_id }; // Features we support
   const LV2_URID_Map mURIDMapFeature{ this, LV2FeaturesList::urid_map };
   const LV2_URID_Unmap mURIDUnmapFeature{ this, LV2FeaturesList::urid_unmap };
   const LV2_Log_Log mLogFeature{
      this, LV2FeaturesList::log_printf, LV2FeaturesList::log_vprintf };
 
 
   mutable LV2Symbols::URIDMap mURIDMap;
 
   std::vector<LV2_Feature> mFeatures;
 
   const bool mSuppliesWorkerInterface;
 
public:
   const bool mOk;
};
 
#endif
#endif