audacity/include/audacity/ImporterInterface.h

/**********************************************************************

   Audacity: A Digital Audio Editor

   ImporterInterface.h

   Leland Lucius

   Copyright (c) 2014, Audacity Team 
   All rights reserved.

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   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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**********************************************************************/

#ifndef __AUDACITY_IMPORTERINTERFACE_H__
#define __AUDACITY_IMPORTERINTERFACE_H__

#include "audacity/Types.h"
#include "audacity/ConfigInterface.h"
#include "audacity/IdentInterface.h"

// ============================================================================
//
// ImporterInterface class
//
// ============================================================================

class ImporterHostInterface;
class ImporterClientInterface;
class ImporterInterface : public IdentInterface
{
public:
   virtual ~ImporterInterface() {};

   // Get unique string ID of this plugin, usually it corresponds
   // to the underlying library, i.e. "libsndfile", "libflac", "libav"
   // These MUST NOT change across Audacity versions (but new IDs can
   // be added).
   virtual wxString GetPluginStringID() = 0;

   // Get a description of the file type this importer can import.
   // Examples: "Ogg Vorbis", "MP3", "Uncompressed PCM"
   virtual wxString GetPluginFormatDescription() = 0;

   // Get a list of extensions this plugin expects to be able to
   // import.  If a filename matches any of these extensions,
   // this importer will get first dibs on importing it.
   virtual wxArrayString GetSupportedExtensions() = 0;
   virtual bool SupportsExtension(const wxString & extension) = 0;

   // Create the client that will be used to import a file.
   virtual ImporterClientInterface *CreateClient() = 0;
};


// ============================================================================
//
// ImporterHostInterface class
//
// ============================================================================

class ImporterHostInterface
{
public:
   virtual ~ImporterHostInterface() {};

   // Called by the client to add a new stream to the import.
   virtual bool AddStream(int stream,
                          sampleFormat sampleformat,
                          float sampleRate,
                          int numChannels,
                          ChannelName *channelMap) = 0;

   // Accepts interleaved samples from the client.
   virtual bool PutSamples(int stream, size_t numSamples, samplePtr inBuffer) = 0;

   // Accepts non-interleaved samples from the client.
   virtual bool PutSamples(int stream, int channel, size_t numSamples, samplePtr inBuffer) = 0;
   
   // The client will call this as the import progresses.
   virtual bool UpdateProgress(float current, float total) = 0;
};

// ============================================================================
//
// ImporterClientInterface class
//
// ============================================================================

class ImporterClientInterface
{
public:
   virtual ~ImporterClientInterface() {};

   // Provides a pointer to the assocated host for this importer.
   virtual void SetHost(ImporterHostInterface *host) = 0;

   // Open the given file, returning true if it is a recognized
   // format, false otherwise.  This puts the importer into the open
   // state.
   virtual bool Open(const wxString & fileName) = 0;

   // Do any processing necessary to close the file and release resources.
   // This will be called only if Open() succeeded.
   virtual void Close() = 0;

   // This is similar to GetImporterDescription, but if possible the
   // importer will return a more specific description of the
   // specific file that is open.
   virtual wxString GetFileDescription() = 0;

   // Return stream descriptions list
   virtual void GetStreamInfo(wxArrayString & streamInfo) = 0;

   // Set stream "import/don't import" flag
   virtual void SetStreamUsage(int streamID, bool use) = 0;

   // do the actual import, creating whatever tracks are necessary with
   // the TrackFactory and calling the progress callback every iteration
   // through the importing loop
   virtual bool Import() = 0;
};

#endif // __AUDACITY_IMPORTERINTERFACE_H__