RBShellPlayer

## RBShellPlayer RBShellPlayer — playback state management |

## Synopsis

    enum                RBShellPlayerError;
    GQuark              rb_shell_player_error_quark         (void);
    struct              RBShellPlayer;
    struct              RBShellPlayerClass;
    RBShellPlayer *     rb_shell_player_new                 (RhythmDB *db);
    void                rb_shell_player_set_selected_source (RBShellPlayer *player,
                                                             RBSource *source);
    void                rb_shell_player_set_playing_source  (RBShellPlayer *player,
                                                             RBSource *source);
    RBSource *          rb_shell_player_get_playing_source  (RBShellPlayer *player);
    RBSource *          rb_shell_player_get_active_source   (RBShellPlayer *player);
    void                rb_shell_player_jump_to_current     (RBShellPlayer *player);
    void                rb_shell_player_play_entry          (RBShellPlayer *player,
                                                             RhythmDBEntry *entry,
                                                             RBSource *source);
    gboolean            rb_shell_player_play                (RBShellPlayer *player,
                                                             GError **error);
    gboolean            rb_shell_player_pause               (RBShellPlayer *player,
                                                             GError **error);
    gboolean            rb_shell_player_playpause           (RBShellPlayer *player,
                                                             gboolean unused,
                                                             GError **error);
    void                rb_shell_player_stop                (RBShellPlayer *player);
    gboolean            rb_shell_player_do_previous         (RBShellPlayer *player,
                                                             GError **error);
    gboolean            rb_shell_player_do_next             (RBShellPlayer *player,
                                                             GError **error);
    char *              rb_shell_player_get_playing_time_string
                                                            (RBShellPlayer *player);
    gboolean            rb_shell_player_get_playing_time    (RBShellPlayer *player,
                                                             guint *time,
                                                             GError **error);
    gboolean            rb_shell_player_set_playing_time    (RBShellPlayer *player,
                                                             guint time,
                                                             GError **error);
    gboolean            rb_shell_player_seek                (RBShellPlayer *player,
                                                             gint32 offset,
                                                             GError **error);
    long                rb_shell_player_get_playing_song_duration
                                                            (RBShellPlayer *player);
    gboolean            rb_shell_player_get_playing         (RBShellPlayer *player,
                                                             gboolean *playing,
                                                             GError **error);
    gboolean            rb_shell_player_get_playing_path    (RBShellPlayer *player,
                                                             const gchar **path,
                                                             GError **error);
    void                rb_shell_player_set_playback_state  (RBShellPlayer *player,
                                                             gboolean shuffle,
                                                             gboolean repeat);
    gboolean            rb_shell_player_get_playback_state  (RBShellPlayer *player,
                                                             gboolean *shuffle,
                                                             gboolean *repeat);
    RhythmDBEntry *     rb_shell_player_get_playing_entry   (RBShellPlayer *player);
    gboolean            rb_shell_player_set_volume          (RBShellPlayer *player,
                                                             gdouble volume,
                                                             GError **error);
    gboolean            rb_shell_player_get_volume          (RBShellPlayer *player,
                                                             gdouble *volume,
                                                             GError **error);
    gboolean            rb_shell_player_set_volume_relative (RBShellPlayer *player,
                                                             gdouble delta,
                                                             GError **error);
    gboolean            rb_shell_player_set_mute            (RBShellPlayer *player,
                                                             gboolean mute,
                                                             GError **error);
    gboolean            rb_shell_player_get_mute            (RBShellPlayer *player,
                                                             gboolean *mute,
                                                             GError **error);
    void                rb_shell_player_add_play_order      (RBShellPlayer *player,
                                                             const char *name,
                                                             const char *description,
                                                             GType order_type,
                                                             gboolean hidden);
    void                rb_shell_player_remove_play_order   (RBShellPlayer *player,
                                                             const char *name);

## Object Hierarchy

      GEnum
       +----RBShellPlayerError

      GObject
       +----RBShellPlayer

## Properties

      "db"                       RhythmDB*             : Read / Write / Construct Only
      "has-next"                 gboolean              : Read
      "has-prev"                 gboolean              : Read
      "header"                   RBHeader*             : Read / Write
      "mute"                     gboolean              : Read / Write
      "play-order"               gchar*                : Read
      "player"                   GObject*              : Read
      "playing"                  gboolean              : Read
      "playing-from-queue"       gboolean              : Read
      "queue-only"               gboolean              : Read / Write
      "queue-source"             RBPlaylistSource*     : Read / Write
      "source"                   RBSource*             : Read / Write
      "volume"                   gfloat                : Read / Write

## Signals

      "elapsed-changed"                                : Run Last
      "elapsed-nano-changed"                           : Run Last
      "playing-changed"                                : Run Last
      "playing-song-changed"                           : Run Last
      "playing-song-property-changed"                  : Run Last
      "playing-source-changed"                         : Run Last
      "playing-uri-changed"                            : Run Last
      "window-title-changed"                           : Run Last

## Description

The shell player (or player shell, depending on who you're talking to) manages the RBPlayer instance, tracks the current playing RhythmDBEntry, and manages the various RBPlayOrder instances. It provides simple operations such as next, previous, play/pause, and seek.

When playing internet radio streams, it first attempts to read the stream URL as a playlist. If this succeeds, the URLs from the playlist are stored in a list and tried in turn in case of errors. If the playlist parsing fails, the stream URL is played directly.

The mapping from the separate shuffle and repeat settings to an RBPlayOrder instance occurs in here. The play order logic can also support a number of additional play orders not accessible via the shuffle and repeat buttons.

If the player backend supports multiple streams, the shell player crossfades between streams by watching the elapsed time of the current stream and simulating an end-of-stream event when it gets within the crossfade duration of the actual end.

## Details

### enum RBShellPlayerError

    typedef enum {
    	RB_SHELL_PLAYER_ERROR_PLAYLIST_PARSE_ERROR,
    	RB_SHELL_PLAYER_ERROR_END_OF_PLAYLIST,
    	RB_SHELL_PLAYER_ERROR_NOT_PLAYING,
    	RB_SHELL_PLAYER_ERROR_NOT_SEEKABLE,
    	RB_SHELL_PLAYER_ERROR_POSITION_NOT_AVAILABLE,
    } RBShellPlayerError;

`RB_SHELL_PLAYER_ERROR_PLAYLIST_PARSE_ERROR` |
`RB_SHELL_PLAYER_ERROR_END_OF_PLAYLIST` |
`RB_SHELL_PLAYER_ERROR_NOT_PLAYING` |
`RB_SHELL_PLAYER_ERROR_NOT_SEEKABLE` |
`RB_SHELL_PLAYER_ERROR_POSITION_NOT_AVAILABLE` |

### rb_shell_player_error_quark ()

    GQuark              rb_shell_player_error_quark         (void);

### struct RBShellPlayer

    struct RBShellPlayer;

### struct RBShellPlayerClass

    struct RBShellPlayerClass {
    	GObjectClass parent_class;

    	void (*window_title_changed) (RBShellPlayer *player, const char *window_title);
    	void (*elapsed_changed) (RBShellPlayer *player, guint elapsed);
    	void (*elapsed_nano_changed) (RBShellPlayer *player, gint64 elapsed);
    	void (*playing_changed) (RBShellPlayer *player, gboolean playing);
    	void (*playing_source_changed) (RBShellPlayer *player, RBSource *source);
    	void (*playing_uri_changed) (RBShellPlayer *player, const char *uri);
    	void (*playing_song_changed) (RBShellPlayer *player, RhythmDBEntry *entry);
    	void (*playing_song_property_changed) (RBShellPlayer *player,
    					       const char *uri,
    					       const char *property,
    					       GValue *old,
    					       GValue *newValue);
    };

### rb_shell_player_new ()

    RBShellPlayer *     rb_shell_player_new                 (RhythmDB *db);

Creates the RBShellPlayer

`db` : | the RhythmDB
Returns : | the RBShellPlayer instance

### rb_shell_player_set_selected_source ()

    void                rb_shell_player_set_selected_source (RBShellPlayer *player,
                                                             RBSource *source);

Updates the player to reflect a new source being selected.

`player` : | the RBShellPlayer
`source` : | the RBSource to select

### rb_shell_player_set_playing_source ()

    void                rb_shell_player_set_playing_source  (RBShellPlayer *player,
                                                             RBSource *source);

Replaces the current playing source.

`player` : | the RBShellPlayer
`source` : | the new playing RBSource

### rb_shell_player_get_playing_source ()

    RBSource *          rb_shell_player_get_playing_source  (RBShellPlayer *player);

Retrieves the current playing source. That is, the source from which the current song was drawn. This differs from rb_shell_player_get_active_source when the current song came from the play queue.

`player` : | the RBShellPlayer
Returns : | the current playing RBSource. [transfer none]

### rb_shell_player_get_active_source ()

    RBSource *          rb_shell_player_get_active_source   (RBShellPlayer *player);

Retrieves the active source. This is the source that the user selected for playback.

`player` : | the RBShellPlayer
Returns : | the active RBSource. [transfer none]

### rb_shell_player_jump_to_current ()

    void                rb_shell_player_jump_to_current     (RBShellPlayer *player);

### rb_shell_player_play_entry ()

    void                rb_shell_player_play_entry          (RBShellPlayer *player,
                                                             RhythmDBEntry *entry,
                                                             RBSource *source);

Plays a specified entry.

`player` : | the RBShellPlayer
`entry` : | the RhythmDBEntry to play
`source` : | the new RBSource to set as playing (or NULL to use the selected source)

### rb_shell_player_play ()

    gboolean            rb_shell_player_play                (RBShellPlayer *player,
                                                             GError **error);

Starts playback, if it is not already playing.

`player` : | a RBShellPlayer
`error` : | error return
Returns : | whether playback is now occurring (TRUE when successfully started or already playing).

### rb_shell_player_pause ()

    gboolean            rb_shell_player_pause               (RBShellPlayer *player,
                                                             GError **error);

Pauses playback if possible, completely stopping if not.

`player` : | a RBShellPlayer
`error` : | error return
Returns : | whether playback is not occurring (TRUE when successfully paused/stopped or playback was not occurring).

### rb_shell_player_playpause ()

    gboolean            rb_shell_player_playpause           (RBShellPlayer *player,
                                                             gboolean unused,
                                                             GError **error);

Toggles between playing and paused state. If there is no playing entry, chooses an entry from (in order of preference) the play queue, the selection in the current source, or the play order.

`player` : | the RBShellPlayer
`unused` : | nothing
`error` : | returns error information
Returns : | `TRUE` if successful

### rb_shell_player_stop ()

    void                rb_shell_player_stop                (RBShellPlayer *player);

Completely stops playback, freeing resources and unloading the file.

In general `rb_shell_player_pause()` should be used instead, as it stops the audio, but does not completely free resources.

`player` : | a RBShellPlayer.

### rb_shell_player_do_previous ()

    gboolean            rb_shell_player_do_previous         (RBShellPlayer *player,
                                                             GError **error);

If the current song has been playing for more than 3 seconds, restarts it, otherwise, goes back to the previous song. Fails if there is no current song, or if inside the first 3 seconds of the first song in the play order.

`player` : | the RBShellPlayer
`error` : | returns any error information
Returns : | `TRUE` if successful

### rb_shell_player_do_next ()

    gboolean            rb_shell_player_do_next             (RBShellPlayer *player,
                                                             GError **error);

Skips to the next song. Consults the play queue and handles transitions between the play queue and the active source. Fails if there is no entry to play after the current one.

`player` : | the RBShellPlayer
`error` : | returns error information
Returns : | `TRUE` if successful

### rb_shell_player_get_playing_time_string ()

    char *              rb_shell_player_get_playing_time_string
                                                            (RBShellPlayer *player);

Constructs a string showing the current playback position, taking the time display settings into account.

`player` : | the RBShellPlayer
Returns : | allocated playing time string

### rb_shell_player_get_playing_time ()

    gboolean            rb_shell_player_get_playing_time    (RBShellPlayer *player,
                                                             guint *time,
                                                             GError **error);

Retrieves the current playback position. Fails if the player currently cannot provide the playback position.

`player` : | the RBShellPlayer
`time` : | returns the current playback position. [out]
`error` : | returns error information
Returns : | `TRUE` if successful

### rb_shell_player_set_playing_time ()

    gboolean            rb_shell_player_set_playing_time    (RBShellPlayer *player,
                                                             guint time,
                                                             GError **error);

Attempts to set the playback position. Fails if the current song is not seekable.

`player` : | the RBShellPlayer
`time` : | the target playback position (in seconds)
`error` : | returns error information
Returns : | `TRUE` if successful

### rb_shell_player_seek ()

    gboolean            rb_shell_player_seek                (RBShellPlayer *player,
                                                             gint32 offset,
                                                             GError **error);

Seeks forwards or backwards in the current playing song. Fails if the current song is not seekable.

`player` : | the RBShellPlayer
`offset` : | relative seek target (in seconds)
`error` : | returns error information
Returns : | `TRUE` if successful

### rb_shell_player_get_playing_song_duration ()

    long                rb_shell_player_get_playing_song_duration
                                                            (RBShellPlayer *player);

Retrieves the duration of the current playing song.

`player` : | the RBShellPlayer
Returns : | duration, or -1 if not playing

### rb_shell_player_get_playing ()

    gboolean            rb_shell_player_get_playing         (RBShellPlayer *player,
                                                             gboolean *playing,
                                                             GError **error);

Reports whether playback is occuring by setting playing.

`player` : | a RBShellPlayer
`playing` : | playback state return. [out]
`error` : | error return
Returns : | `TRUE` if successful

### rb_shell_player_get_playing_path ()

    gboolean            rb_shell_player_get_playing_path    (RBShellPlayer *player,
                                                             const gchar **path,
                                                             GError **error);

Retrieves the URI of the current playing entry. The caller must not free the returned string.

`player` : | the RBShellPlayer
`path` : | returns the URI of the current playing entry. [out callee-allocates][transfer full]
`error` : | returns error information
Returns : | `TRUE` if successful

### rb_shell_player_set_playback_state ()

    void                rb_shell_player_set_playback_state  (RBShellPlayer *player,
                                                             gboolean shuffle,
                                                             gboolean repeat);

Sets the state of the shuffle and repeat settings.

`player` : | the RBShellPlayer
`shuffle` : | whether to enable the shuffle setting
`repeat` : | whether to enable the repeat setting

### rb_shell_player_get_playback_state ()

    gboolean            rb_shell_player_get_playback_state  (RBShellPlayer *player,
                                                             gboolean *shuffle,
                                                             gboolean *repeat);

Retrieves the current state of the shuffle and repeat settings.

`player` : | the RBShellPlayer
`shuffle` : | returns the current shuffle setting. [out]
`repeat` : | returns the current repeat setting. [out]
Returns : | `TRUE` if successful.

### rb_shell_player_get_playing_entry ()

    RhythmDBEntry *     rb_shell_player_get_playing_entry   (RBShellPlayer *player);

Retrieves the currently playing RhythmDBEntry, or NULL if nothing is playing. The caller must unref the entry (using rhythmdb_entry_unref) when it is no longer needed.

`player` : | the RBShellPlayer
Returns : | the currently playing RhythmDBEntry, or NULL. [transfer full][allow-none]

### rb_shell_player_set_volume ()

    gboolean            rb_shell_player_set_volume          (RBShellPlayer *player,
                                                             gdouble volume,
                                                             GError **error);

Sets the playback volume level.

`player` : | the RBShellPlayer
`volume` : | the volume level (between 0 and 1)
`error` : | returns the error information
Returns : | `TRUE` on success

### rb_shell_player_get_volume ()

    gboolean            rb_shell_player_get_volume          (RBShellPlayer *player,
                                                             gdouble *volume,
                                                             GError **error);

Returns the current volume level

`player` : | the RBShellPlayer
`volume` : | returns the volume level. [out]
`error` : | returns error information
Returns : | the current volume level.

### rb_shell_player_set_volume_relative ()

    gboolean            rb_shell_player_set_volume_relative (RBShellPlayer *player,
                                                             gdouble delta,
                                                             GError **error);

Adds the specified value to the current volume level.

`player` : | the RBShellPlayer
`delta` : | difference to apply to the volume level (between -1 and 1)
`error` : | returns error information
Returns : | `TRUE` on success

### rb_shell_player_set_mute ()

    gboolean            rb_shell_player_set_mute            (RBShellPlayer *player,
                                                             gboolean mute,
                                                             GError **error);

Updates the mute setting on the player.

`player` : | the RBShellPlayer
`mute` : | `TRUE` to mute playback
`error` : | returns error information
Returns : | `TRUE` if successful

### rb_shell_player_get_mute ()

    gboolean            rb_shell_player_get_mute            (RBShellPlayer *player,
                                                             gboolean *mute,
                                                             GError **error);

Returns `TRUE` if currently muted

`player` : | the RBShellPlayer
`mute` : | returns the current mute setting. [out]
`error` : | returns error information
Returns : | `TRUE` if currently muted

### rb_shell_player_add_play_order ()

    void                rb_shell_player_add_play_order      (RBShellPlayer *player,
                                                             const char *name,
                                                             const char *description,
                                                             GType order_type,
                                                             gboolean hidden);

Adds a new play order to the set of available play orders.

`player` : | the RBShellPlayer
`name` : | name of the new play order
`description` : | description of the new play order
`order_type` : | the GType of the play order class
`hidden` : | if `TRUE`, don't display the play order in the UI

### rb_shell_player_remove_play_order ()

    void                rb_shell_player_remove_play_order   (RBShellPlayer *player,
                                                             const char *name);

Removes a play order previously added with rb_shell_player_add_play_order from the set of available play orders.

`player` : | the RBShellPlayer
`name` : | name of the play order to remove

## Property Details

### The `"db"` property

      "db"                       RhythmDB*             : Read / Write / Construct Only

The RhythmDB

### The `"has-next"` property

      "has-next"                 gboolean              : Read

Whether there is a track to play after the current track.

Default value: FALSE

### The `"has-prev"` property

      "has-prev"                 gboolean              : Read

Whether there was a previous track before the current track.

Default value: FALSE

### The `"header"` property

      "header"                   RBHeader*             : Read / Write

The RBHeader object

### The `"mute"` property

      "mute"                     gboolean              : Read / Write

Whether playback is currently muted.

Default value: FALSE

### The `"play-order"` property

      "play-order"               gchar*                : Read

The current play order object.

Default value: "linear"

### The `"player"` property

      "player"                   GObject*              : Read

The player backend object (an object implementing the RBPlayer interface).

### The `"playing"` property

      "playing"                  gboolean              : Read

Whether Rhythmbox is currently playing something

Default value: FALSE

### The `"playing-from-queue"` property

      "playing-from-queue"       gboolean              : Read

If `TRUE`, the current playing entry came from the play queue.

Default value: FALSE

### The `"queue-only"` property

      "queue-only"               gboolean              : Read / Write

If `TRUE`, activating an entry should only add it to the play queue.

Default value: FALSE

### The `"queue-source"` property

      "queue-source"             RBPlaylistSource*     : Read / Write

The play queue source

### The `"source"` property

      "source"                   RBSource*             : Read / Write

The current source that is selected for playback.

### The `"volume"` property

      "volume"                   gfloat                : Read / Write

The current playback volume (between 0.0 and 1.0)

Allowed values: [0,1]

Default value: 1

## Signal Details

### The `"elapsed-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            guint          elapsed,
                                                            gpointer       user_data)      : Run Last

Emitted when the playback position changes.

`player` : | the RBShellPlayer
`elapsed` : | the new playback position in seconds
`user_data` : | user data set when the signal handler was connected.

### The `"elapsed-nano-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            gint64         elapsed,
                                                            gpointer       user_data)      : Run Last

Emitted when the playback position changes. Only use this (as opposed to elapsed-changed) when you require subsecond precision. This signal will be emitted multiple times per second.

`player` : | the RBShellPlayer
`elapsed` : | the new playback position in nanoseconds
`user_data` : | user data set when the signal handler was connected.

### The `"playing-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            gboolean       playing,
                                                            gpointer       user_data)      : Run Last

Emitted when playback either stops or starts.

`player` : | the RBShellPlayer
`playing` : | flag indicating playback state
`user_data` : | user data set when the signal handler was connected.

### The `"playing-song-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            RhythmDBEntry *entry,
                                                            gpointer       user_data)      : Run Last

Emitted when the playing database entry changes

`player` : | the RBShellPlayer
`entry` : | the new playing RhythmDBEntry
`user_data` : | user data set when the signal handler was connected.

### The `"playing-song-property-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            gchar         *uri,
                                                            gchar         *property,
                                                            GValue        *old,
                                                            GValue        *newvalue,
                                                            gpointer       user_data)      : Run Last

Emitted when a property of the playing database entry changes.

`player` : | the RBShellPlayer
`uri` : | the URI of the playing entry
`property` : | the name of the property that changed
`old` : | the previous value for the property
`newvalue` : | the new value of the property
`user_data` : | user data set when the signal handler was connected.

### The `"playing-source-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            RBSource      *source,
                                                            gpointer       user_data)      : Run Last

Emitted when a new RBSource instance starts playing

`player` : | the RBShellPlayer
`source` : | the RBSource that is now playing
`user_data` : | user data set when the signal handler was connected.

### The `"playing-uri-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            gchar         *uri,
                                                            gpointer       user_data)      : Run Last

Emitted when the playing database entry changes, providing the URI of the entry.

`player` : | the RBShellPlayer
`uri` : | the URI of the new playing entry
`user_data` : | user data set when the signal handler was connected.

### The `"window-title-changed"` signal

    void                user_function                      (RBShellPlayer *player,
                                                            gchar         *title,
                                                            gpointer       user_data)      : Run Last

Emitted when the main window title text should be changed

`player` : | the RBShellPlayer
`title` : | the new window title
`user_data` : | user data set when the signal handler was connected.