sk.baka.ambient.playlist
Class DynamicPlaylistStrategy

java.lang.Object
  sk.baka.ambient.playlist.DynamicPlaylistStrategy

All Implemented Interfaces:

Serializable, IPlaylistStrategy

public final class DynamicPlaylistStrategy
extends Object
implements IPlaylistStrategy, Serializable

A dynamic playlist - items are added to the front of the playlist and removed from the back of the playlist (if required). Does not support shuffle mode itself - it configures the IDynamicPlaylistTrackProvider to provide tracks in particular order instead.

Queued tracks are lined always in front of a currently playing track.

Author:

Martin Vysny

See Also:

Serialized Form

Constructor Summary

DynamicPlaylistStrategy(IDynamicPlaylistTrackProvider provider, IPlaylistStrategy strategy, int historyLength, int upcomingTrackCount)
Creates new dynamic playlist.

Method Summary

void	add(int index, List<TrackMetadataBean> tracks) Inserts given tracks before track with given index.
void	clearQueue() Clears queue from queued.
void	dequeue(int track) Dequeues given track if it was queued previously.
int	getCurrentHistoryLength() Returns current history size.
int	getCurrentlyPlaying() Returns currently playing track.
List<PlaylistItem>	getPlayItems() Returns list of playlist items.
List<Integer>	getQueue() Returns currently queued tracks.
Random	getRandom() Returns current random mode.
Interval	move(Interval i, int ti) Moves selected tracks before track with given index.
Interval	moveBy(Interval interval, int delta) Moves selected tracks up or down at least delta tracks, depending on the 'delta' value.
int	next() Moves to next track to be played.
int	peekNext() Peeks at the next track without actually changing the current track.
int	play(int track) Plays given track.
int	previous() Returns previous track to be played.
void	queue(Interval interval) Queue this track for playing, after all other queued tracks.
void	reinit() Reinitializes the playlist - recomputes new random track ordering etc.
void	remove(Interval interval) Removes tracks with given index from the playlist.
void	replaceLocations(Map<String,String> locationMap) Modifies the playlist by changing all PlaylistItem locations.
void	setHistoryLength(int historyLength) Sets the history length.
void	setRandom(Random random) Sets the random mode.
void	setUpcomingTrackCount(int upcomingTrackCount) Sets the upcoming track count.
void	shuffle() Randomize the playlist.
int	size() Returns the playlist length.
void	sortByAlbumOrder() Sorts the playlist with album order ordering.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DynamicPlaylistStrategy

public DynamicPlaylistStrategy(IDynamicPlaylistTrackProvider provider,
                               IPlaylistStrategy strategy,
                               int historyLength,
                               int upcomingTrackCount)

Creates new dynamic playlist.

Parameters:

provider - provides tracks for playing.

strategy - if not null then clone this strategy.

historyLength - Number of entries in the history.

upcomingTrackCount - Number of upcoming tracks to show.

Method Detail

setHistoryLength

public void setHistoryLength(int historyLength)

Sets the history length.

Parameters:

historyLength - how many tracks are kept as a history after playback. Cannot be negative.

setUpcomingTrackCount

public void setUpcomingTrackCount(int upcomingTrackCount)

Sets the upcoming track count.

Parameters:

upcomingTrackCount - how many tracks will be shown before the playing track. Cannot be negative.

getPlayItems

public List<PlaylistItem> getPlayItems()

Description copied from interface: IPlaylistStrategy

Returns list of playlist items. The operation must be quick - it should for example provide immutable view on an internal playlist structure, it should not recompute the list anew on each call.

Each PlaylistItem in the list must be an unique instance.

Specified by:

getPlayItems in interface IPlaylistStrategy

Returns:

list of playlist items, will not be modified.

size

public int size()

Description copied from interface: IPlaylistStrategy

Returns the playlist length.

Specified by:

size in interface IPlaylistStrategy

Returns:

the playlist length.

shuffle

public void shuffle()

Description copied from interface: IPlaylistStrategy

Randomize the playlist.

Specified by:

shuffle in interface IPlaylistStrategy

sortByAlbumOrder

public void sortByAlbumOrder()

Description copied from interface: IPlaylistStrategy

Sorts the playlist with album order ordering.

Specified by:

sortByAlbumOrder in interface IPlaylistStrategy

add

public void add(int index,
                List<TrackMetadataBean> tracks)

Description copied from interface: IPlaylistStrategy

Inserts given tracks before track with given index.

Specified by:

add in interface IPlaylistStrategy

Parameters:

index - the index, must not be negative.

tracks - the tracks meta, must not be null.

setRandom

public void setRandom(Random random)

Description copied from interface: IPlaylistStrategy

Sets the random mode. Currently played track must be preserved.

Specified by:

setRandom in interface IPlaylistStrategy

Parameters:

random - the random mode, never null.

getQueue

public List<Integer> getQueue()

Description copied from interface: IPlaylistStrategy

Returns currently queued tracks.

Specified by:

getQueue in interface IPlaylistStrategy

Returns:

queued tracks, never null.

clearQueue

public void clearQueue()

Description copied from interface: IPlaylistStrategy

Clears queue from queued.

Specified by:

clearQueue in interface IPlaylistStrategy

getCurrentlyPlaying

public int getCurrentlyPlaying()

Description copied from interface: IPlaylistStrategy

Returns currently playing track. Note that the playlist is not connected to the player and the player itself may be paused or stopped.

Specified by:

getCurrentlyPlaying in interface IPlaylistStrategy

Returns:

currently playing track or -1 if nothing is being played. Index to the IPlaylistStrategy.getPlayItems() list.

dequeue

public void dequeue(int track)

Description copied from interface: IPlaylistStrategy

Dequeues given track if it was queued previously. Does nothing if the track is not present in the queue anymore.

Specified by:

dequeue in interface IPlaylistStrategy

Parameters:

track - the track to dequeue.

queue

public void queue(Interval interval)

Description copied from interface: IPlaylistStrategy

Queue this track for playing, after all other queued tracks. Does nothing if the track is already queued.

Specified by:

queue in interface IPlaylistStrategy

Parameters:

interval - the tracks to queue, index to the IPlaylistStrategy.getPlayItems() list.

reinit

public void reinit()

Description copied from interface: IPlaylistStrategy

Reinitializes the playlist - recomputes new random track ordering etc. Removes all queued tracks and stops the playback (IPlaylistStrategy.getCurrentlyPlaying() will return -1).

Specified by:

reinit in interface IPlaylistStrategy

peekNext

public int peekNext()

Description copied from interface: IPlaylistStrategy

Peeks at the next track without actually changing the current track.

Specified by:

peekNext in interface IPlaylistStrategy

Returns:

next track index. Returns -1 when there's no track left. Dynamic playlist may return -1 when there are no upcoming tracks and the queue is empty.

next

public int next()

Description copied from interface: IPlaylistStrategy

Moves to next track to be played. Returns -1 if no more tracks are to be played - this also causes the IPlaylistStrategy.getCurrentlyPlaying() method to return -1. Calling this method while not playing anything will start to play first track.

Specified by:

next in interface IPlaylistStrategy

Returns:

play item to play next or -1 if no more items are to be played. Index to the IPlaylistStrategy.getPlayItems() list.

play

public int play(int track)

Description copied from interface: IPlaylistStrategy

Plays given track. The playback continues from this track forward, unless random play is activated.

Specified by:

play in interface IPlaylistStrategy

Parameters:

track - the track to play. Index to the IPlaylistStrategy.getPlayItems() list. If -1 then the current track pointer is moved before first track and the playback is stopped.

Returns:

the track that is being played.

previous

public int previous()

Description copied from interface: IPlaylistStrategy

Returns previous track to be played. Returns -1 if we are at the beginning of the playing track sequence. Calling this method while not playing anything will start to play last track.

Specified by:

previous in interface IPlaylistStrategy

Returns:

which item was played prior current track or -1 if we are at the beginning of the playing track sequence.

remove

public void remove(Interval interval)

Description copied from interface: IPlaylistStrategy

Removes tracks with given index from the playlist. If currently played track is removed then the current song must be set to -1.

Specified by:

remove in interface IPlaylistStrategy

Parameters:

interval - the interval to remove

getRandom

public Random getRandom()

Description copied from interface: IPlaylistStrategy

Returns current random mode.

Specified by:

getRandom in interface IPlaylistStrategy

Returns:

the random mode, never null.

move

public Interval move(Interval i,
                     int ti)

Description copied from interface: IPlaylistStrategy

Moves selected tracks before track with given index. Correctly updates queue indices. Currently played track will not be changed, although the track index may change.

Specified by:

move in interface IPlaylistStrategy

Parameters:

i - the interval to move

ti - move tracks before track with this index. If this index is contained in the interval then nothing is done.

Returns:

a new interval which contains all moved tracks.

getCurrentHistoryLength

public int getCurrentHistoryLength()

Returns current history size.

Returns:

number of items in the history.

moveBy

public Interval moveBy(Interval interval,
                       int delta)

Description copied from interface: IPlaylistStrategy

Moves selected tracks up or down at least delta tracks, depending on the 'delta' value. The playlist may decide to move tracks by more tracks than requested - for example, the dynamic playlist will skip the currently playing/queued tracks. If the move is not possible (for example there are not enough tracks) then move the tracks to the beginning (or end) of the playlist.

Currently played track will not be changed, although the queue indices. Currently played track will not be changed, although the track index may change.

Specified by:

moveBy in interface IPlaylistStrategy

Parameters:

interval - the interval to move

delta - move tracks up 'delta' tracks (if delta is negative), or down 'delta' tracks (if delta is positive). Do nothing if delta is zero.

Returns:

a new interval which contains all moved tracks.

replaceLocations

public void replaceLocations(Map<String,String> locationMap)

Description copied from interface: IPlaylistStrategy

Modifies the playlist by changing all PlaylistItem locations.

Specified by:

replaceLocations in interface IPlaylistStrategy

Parameters:

locationMap - maps old locations to new locations.