sp_session_callbacks Struct Reference
[Session handling]

#include <api.h>

Data Fields
void(*	logged_in )(sp_session *session, sp_error error)
void(*	logged_out )(sp_session *session)
void(*	metadata_updated )(sp_session *session)
void(*	connection_error )(sp_session *session, sp_error error)
void(*	message_to_user )(sp_session *session, const char *message)
void(*	notify_main_thread )(sp_session *session)
int(*	music_delivery )(sp_session *session, const sp_audioformat *format, const void *frames, int num_frames)
void(*	play_token_lost )(sp_session *session)
void(*	log_message )(sp_session *session, const char *data)
void(*	end_of_track )(sp_session *session)
void(*	streaming_error )(sp_session *session, sp_error error)
void(*	userinfo_updated )(sp_session *session)
void(*	start_playback )(sp_session *session)
void(*	stop_playback )(sp_session *session)
void(*	get_audio_buffer_stats )(sp_session *session, sp_audio_buffer_stats *stats)

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Detailed Description

Session callbacks

Registered when you create a session. If some callbacks should not be of interest, set them to NULL.

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Field Documentation

void( * sp_session_callbacks::logged_in)(sp_session *session, sp_error error)

Called when login has been processed and was successful

Parameters:

[in]	session	Session
[in]	error	Error code sp_error

void( * sp_session_callbacks::logged_out)(sp_session *session)

Called when logout has been processed. Either called explicitly if you initialize a logout operation, or implicitly if there is a permanent connection error

Parameters:

[in]

session

Session

void( * sp_session_callbacks::metadata_updated)(sp_session *session)

Called whenever metadata has been updated

If you have metadata cached outside of libspotify, you should purge your caches and fetch new versions.

Parameters:

[in]

session

Session

void( * sp_session_callbacks::connection_error)(sp_session *session, sp_error error)

Called when there is a connection error, and the library has problems reconnecting to the Spotify service. Could be called multiple times (as long as the problem is present)

Parameters:

[in]	session	Session
[in]	error	Status code sp_error

void( * sp_session_callbacks::message_to_user)(sp_session *session, const char *message)

Called when the access point wants to display a message to the user

In the desktop client, these are shown in a blueish toolbar just below the search box.

Parameters:

[in]	session	Session
[in]	message	String in UTF-8 format.

void( * sp_session_callbacks::notify_main_thread)(sp_session *session)

Called when processing needs to take place on the main thread.

You need to call sp_session_process_events() in the main thread to get libspotify to do more work. Failure to do so may cause request timeouts, or a lost connection.

Parameters:

[in]

session

Session

Note:

This function is called from an internal session thread - you need to have proper synchronization!

int( * sp_session_callbacks::music_delivery)(sp_session *session, const sp_audioformat *format, const void *frames, int num_frames)

Called when there is decompressed audio data available.

Parameters:

[in]	session	Session
[in]	format	Audio format descriptor sp_audioformat
[in]	frames	Points to raw PCM data as described by format
[in]	num_frames	Number of available samples in frames. If this is 0, a discontinuity has occured (such as after a seek). The application should flush its audio fifos, etc.

Returns:

Number of frames consumed. This value can be used to rate limit the output from the library if your output buffers are saturated. The library will retry delivery in about 100ms.

Note:

This function is called from an internal session thread - you need to have proper synchronization!

This function must never block. If your output buffers are full you must return 0 to signal that the library should retry delivery in a short while.

void( * sp_session_callbacks::play_token_lost)(sp_session *session)

Music has been paused because only one account may play music at the same time.

Parameters:

[in]

session

Session

void( * sp_session_callbacks::log_message)(sp_session *session, const char *data)

Logging callback.

Parameters:

[in]	session	Session
[in]	data	Log data

void( * sp_session_callbacks::end_of_track)(sp_session *session)

End of track. Called when the currently played track has reached its end.

Note:

This function is invoked from the same internal thread as the music delivery callback

Parameters:

[in]

session

Session

void( * sp_session_callbacks::streaming_error)(sp_session *session, sp_error error)

Streaming error. Called when streaming cannot start or continue

Note:

This function is invoked from the main thread

Parameters:

[in]	session	Session
[in]	errro	Error code describing the error

void( * sp_session_callbacks::userinfo_updated)(sp_session *session)

Called after user info (anything related to sp_user objects) have been updated.

Parameters:

[in]

session

Session

void( * sp_session_callbacks::start_playback)(sp_session *session)

Called when audio playback should start

Note:

For this to work correctly the application must also implement get_audio_buffer_stats()

This function is called from an internal session thread - you need to have proper synchronization!

This function must never block.

Parameters:

[in]

session

Session

void( * sp_session_callbacks::stop_playback)(sp_session *session)

Called when audio playback should stop

Note:

For this to work correctly the application must also implement get_audio_buffer_stats()

This function is called from an internal session thread - you need to have proper synchronization!

This function must never block.

Parameters:

[in]

session

Session

void( * sp_session_callbacks::get_audio_buffer_stats)(sp_session *session, sp_audio_buffer_stats *stats)

Called to query application about its audio buffer

Note:

This function is called from an internal session thread - you need to have proper synchronization!

This function must never block.

Parameters:

[in]	session	Session
[out]	stats	Stats struct to be filled by application

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The documentation for this struct was generated from the following file:

• api.h