sintonia/library/ecasound-2.7.2/libecasound/midiio.h

185 lines
4.1 KiB
C++

#ifndef INCLUDED_MIDIIO_H
#define INCLUDED_MIDIIO_H
#include <string>
#include "dynamic-object.h"
/**
* Virtual base for all MIDI I/O classes.
*
* - type definitions
*
* - attributes
*
* - configuration (setting and getting configuration parameters)
*
* - functionality (control and runtime information)
*
* - runtime information
*
* - constructors and destructors
*
* @author Kai Vehmanen
*/
class MIDI_IO : public DYNAMIC_OBJECT<std::string> {
public:
/** @name Public type definitions and constants */
/*@{*/
/**
* Input/Output mode
*
* @see io_mode()
*
* io_read
*
* Object is opened for input. If opening a file,
* it must exist.
*
* io_write
*
* Object is opened for output. If opening a file and
* and output exists, it is first truncated.
*
* io_readwrite
*
* Object is opened for both reading and writing. If
* opening a file, a new file is created if needed.
* When switching from read to write or vica versa,
* position should be reset before using the device.
**/
enum Io_mode { io_read = 1, io_write = 2, io_readwrite = 4 };
/*@}*/
public:
/** @name Constructors and destructors */
/*@{*/
virtual MIDI_IO* clone(void) const = 0;
virtual MIDI_IO* new_expr(void) const = 0;
virtual ~MIDI_IO(void);
MIDI_IO(const std::string& name = "unknown",
int mode = io_read);
/*@}*/
/** @name Attribute functions */
/*@{*/
virtual int supported_io_modes(void) const;
virtual bool supports_nonblocking_mode(void) const;
/*@}*/
/** @name Configuration
*
* For setting and getting configuration parameters.
*/
/*@{*/
int io_mode(void) const;
const std::string& label(void) const;
void io_mode(int mode);
void label(const std::string& id_label);
void toggle_nonblocking_mode(bool value);
virtual std::string parameter_names(void) const { return("label"); }
virtual void set_parameter(int param, std::string value);
virtual std::string get_parameter(int param) const;
/*@}*/
/** @name Main functionality */
/*@{*/
public:
/**
* Low-level routine for reading MIDI bytes. Number of read bytes
* is returned. This must be implemented by all subclasses.
*/
virtual long int read_bytes(void* target_buffer, long int bytes) = 0;
/**
* Low-level routine for writing MIDI bytes. Number of bytes written
* is returned. This must be implemented by all subclasses.
*/
virtual long int write_bytes(void* target_buffer, long int bytes) = 0;
/**
* Opens the MIDI object (possibly in exclusive mode).
* This routine is meant for opening files and devices,
* loading libraries, etc.
*
* ensure:
* readable() == true || writable() == true
*/
virtual void open(void) = 0;
/**
* Closes the MIDI object. After calling this routine,
* all resources (ie. soundcard) must be freed
* (they can be used by other processes).
*
* ensure:
* readable() != true
* writable() != true
*/
virtual void close(void) = 0;
/*@}*/
/** @name Runtime information */
/*@{*/
/**
* Returns a file descriptor id suitable for poll() and
* select() system calls. If polling is not supported,
* returns value of '-1'.
*/
virtual int poll_descriptor(void) const { return(-1); }
/**
* Has device been opened (with open())?
*/
bool is_open(void) const { return(open_rep); }
/**
* Whether all data has been processed? If opened in mode 'io_read',
* this means that end of stream has been reached. If opened in
* 'io_write' or 'io_readwrite' modes, finished status usually
* means that an error has occured (no space left, etc). After
* finished() has returned 'true', further calls to read()
* and/or write() won't process any data.
*/
virtual bool finished(void) const = 0;
virtual bool nonblocking_mode(void) const;
virtual bool readable(void) const;
virtual bool writable(void) const;
/*@}*/
protected:
void toggle_open_state(bool value);
private:
int io_mode_rep;
std::string id_label_rep;
bool nonblocking_rep;
bool readable_rep;
bool writable_rep;
bool open_rep;
};
#endif