Simonc: Created page with "= Playlist Service = == Overview == The Playlist service provides access to a list of tracks, which can be played in sequence, starting at any point. ‘Shuffle’ and ‘Repeat..."

2015-12-15T13:22:59Z

Created page with "= Playlist Service = == Overview == The Playlist service provides access to a list of tracks, which can be played in sequence, starting at any point. ‘Shuffle’ and ‘Repeat..."

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= Playlist Service =

== Overview ==
The Playlist service provides access to a list of tracks, which can be played in sequence, starting at any point. ‘Shuffle’ and ‘Repeat’ modes also exist, allowing track order to be randomised and playback to loop.

If a device's [[Av:Developer:Eriskay:ProductService | Product]] service reports a source of type <tt>"Playlist"</tt>, then that device is guaranteed to bear the Playlist service. If the Playlist service is available, all its properties and actions must be fully implemented.

== Evented Properties ==
=== Repeat ===
By default a playlist plays each track in sequence then stops after playing the final track. Setting the <tt>Repeat</tt> property changes this behaviour to loop from the last track back to the first, playing it immediately.

By default, <tt>Repeat</tt> is off.

=== Shuffle ===
Tracks are played in random order if the <tt>Shuffle</tt> property is enabled. As with normal playback, each track is played once then the playlist stops. If <tt>Shuffle</tt> is enabled mid-way through a playlist, each track in the list is shuffled, including any that have just been played.

When combined with <tt>Repeat</tt>, each track is played once before any track is played for a second time.

By default, <tt>Shuffle</tt> is off.

=== Id ===
The id of the current track (the track currently playing or that would be played if the <tt>Transport.Play</tt> action was invoked while this source was active). Or <tt>0</tt> if the playlist is empty.

=== IdArray ===
A JSON integer array containing the ids of the tracks currently in the playlist.

For example, <tt>[2, 276, 19]</tt> describes a playlist containing track ids 2, 276, and 19 in that order.

Contains <tt>[0..TracksMax]</tt> elements.

=== TracksMax ===
The maximum number of tracks a playlist can contain. Set on startup and invariant thereafter.

== Actions ==
=== SetRepeat ===
<tt>
Arguments: (in bool repeat)
</tt> 
Enable or disable repeat mode.

=== Repeat ===
<tt>
Arguments: (out bool repeat)
</tt> 
Report whether repeat mode is enabled.

=== SetShuffle ===
<tt>
Arguments: (out bool shuffle)
</tt> 
Enable or disable shuffle mode.

=== Shuffle ===
<tt>
Arguments: (in bool shuffle)
</tt> 
Report whether shuffle mode is enabled.

=== Id ===
<tt>
Arguments: (out uint id)
</tt> 
Return the value of the <tt>Id</tt> state variable.

=== ReadList ===
<tt>
Arguments: (in string ids, out string json)
</tt> 
Given a space separated list of track ids, report their associated uri and metadata in the following JSON form:
<tt>
[
{
"id": integer_id,
"uri": "track_uri",
"metadata": "track_metadata"
},
{
"id": integer_id,
"uri": "track_uri",
"metadata": "track_metadata"
}
]
</tt>
Any ids not in the playlist are ignored.

=== Insert ===
<tt>
Arguments: (in uint afterId, in string uri, in string metadata, out uint newId)
</tt> 
Adds the given uri and metadata as a new track to the playlist.

Set the <tt>AfterId</tt> argument to <tt>0</tt> to insert a track at the start of the playlist.

Reports a <tt>800</tt> fault code if <tt>AfterId</tt> is not <tt>0</tt> and doesn’t appear in the playlist.
 Reports a <tt>801</tt> fault code if the playlist is full (i.e. already contains <tt>TracksMax</tt> tracks).

=== DeleteList ===
<tt>
Arguments: (int string ids)
</tt> 
Given a space separated list of track ids, remove the tracks with these ids from the playlist.

If the id to be deleted is currently playing, the next track becomes current.

Any ids not in the playlist are silently ignored.

=== DeleteAll ===
<tt>
Arguments: None
</tt> 
Delete all tracks from the playlist.

== Move ==
<tt>
Arguments: (in string ids, in uint afterId)
</tt> 
Move a space separated list of ids.

Set <tt>AfterId</tt> to <tt>0</tt> to move the tracks to the start of the playlist.

Any ids not in the playlist are silently ignored.

<tt>AfterId</tt> must not also be in the list to be moved.

=== TracksMax ===
<tt>
Arguments: (out uint max)
</tt> 
Return the value of the <tt>TracksMax</tt> property.

=== IdArray ===
<tt>
Arguments: (out uint token, out string json)
</tt> 
Return the value of the <tt>IdArray</tt> property. Supports polling implementations by returning a token which can be used with the <tt>IdArrayChanged</tt> action.

=== IdArrayChanged ===
<tt>
Arguments: (in uint token, out bool changed)
</tt> 
Check to see if <tt>IdArray</tt> has changed since gathering the specified token. This token must have been previously collected from the <tt>IdArray</tt> action.

This mechanism is provided specifically for any basic control points unable to partake in standard eventing.

== UPnP Service Description ==
For devices supporting the UPnP protocol, the service description is

<tt>name: "Playlist"
 domain: "openhome.org.eriskay"
 version: "1"</tt>

<syntaxhighlight lang="xml">
<?xml version="1.0" encoding="utf-8"?>
<scpd xmlns="urn:schemas-upnp-org:service-1-0">
<specVersion>
<major>1</major>
<minor>0</minor>
</specVersion>
<actionList>
<action>
<name>SetRepeat</name>
<argumentList>
<argument>
<name>Repeat</name>
<direction>in</direction>
<relatedStateVariable>Repeat</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>Repeat</name>
<argumentList>
<argument>
<name>Repeat</name>
<direction>out</direction>
<relatedStateVariable>Repeat</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>SetShuffle</name>
<argumentList>
<argument>
<name>Shuffle</name>
<direction>in</direction>
<relatedStateVariable>Shuffle</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>Shuffle</name>
<argumentList>
<argument>
<name>Shuffle</name>
<direction>out</direction>
<relatedStateVariable>Shuffle</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>Id</name>
<argumentList>
<argument>
<name>Id</name>
<direction>out</direction>
<relatedStateVariable>Id</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>ReadList</name>
<argumentList>
<argument>
<name>IdList</name>
<direction>in</direction>
<relatedStateVariable>IdList</relatedStateVariable>
</argument>
<argument>
<name>TrackList</name>
<direction>out</direction>
<relatedStateVariable>TrackList</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>Insert</name>
<argumentList>
<argument>
<name>AfterId</name>
<direction>in</direction>
<relatedStateVariable>Id</relatedStateVariable>
</argument>
<argument>
<name>Uri</name>
<direction>in</direction>
<relatedStateVariable>Uri</relatedStateVariable>
</argument>
<argument>
<name>Metadata</name>
<direction>in</direction>
<relatedStateVariable>Metadata</relatedStateVariable>
</argument>
<argument>
<name>NewId</name>
<direction>out</direction>
<relatedStateVariable>Id</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>Move</name>
<argumentList>
<argument>
<name>AfterId</name>
<direction>in</direction>
<relatedStateVariable>Id</relatedStateVariable>
</argument>
<argument>
<name>IdList</name>
<direction>in</direction>
<relatedStateVariable>IdList</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>DeleteList</name>
<argumentList>
<argument>
<name>IdList</name>
<direction>in</direction>
<relatedStateVariable>IdList</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>DeleteAll</name>
</action>
<action>
<name>TracksMax</name>
<argumentList>
<argument>
<name>TracksMax</name>
<direction>out</direction>
<relatedStateVariable>TracksMax</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>IdArray</name>
<argumentList>
<argument>
<name>Token</name>
<direction>out</direction>
<relatedStateVariable>IdArrayToken</relatedStateVariable>
</argument>
<argument>
<name>Array</name>
<direction>out</direction>
<relatedStateVariable>IdArray</relatedStateVariable>
</argument>
</argumentList>
</action>
<action>
<name>IdArrayChanged</name>
<argumentList>
<argument>
<name>Token</name>
<direction>in</direction>
<relatedStateVariable>IdArrayToken</relatedStateVariable>
</argument>
<argument>
<name>Value</name>
<direction>out</direction>
<relatedStateVariable>IdArrayChanged</relatedStateVariable>
</argument>
</argumentList>
</action>
</actionList>
<serviceStateTable>
<stateVariable sendEvents="yes">
<name>Repeat</name>
<dataType>boolean</dataType>
</stateVariable>
<stateVariable sendEvents="yes">
<name>Shuffle</name>
<dataType>boolean</dataType>
</stateVariable>
<stateVariable sendEvents="yes">
<name>Id</name>
<dataType>ui4</dataType>
</stateVariable>
<stateVariable sendEvents="yes">
<name>IdArray</name>
<dataType>string</dataType>
</stateVariable>
<stateVariable sendEvents="yes">
<name>TracksMax</name>
<dataType>ui4</dataType>
</stateVariable>
<stateVariable sendEvents="no">
<name>IdList</name>
<dataType>string</dataType>
</stateVariable>
<stateVariable sendEvents="no">
<name>TrackList</name>
<dataType>string</dataType>
</stateVariable>
<stateVariable sendEvents="no">
<name>Uri</name>
<dataType>string</dataType>
</stateVariable>
<stateVariable sendEvents="no">
<name>Metadata</name>
<dataType>string</dataType>
</stateVariable>
<stateVariable sendEvents="no">
<name>IdArrayToken</name>
<dataType>ui4</dataType>
</stateVariable>
<stateVariable sendEvents="no">
<name>IdArrayChanged</name>
<dataType>boolean</dataType>
</stateVariable>
</serviceStateTable>
</scpd>
</syntaxhighlight>

Av:Developer:Eriskay:PlaylistService - Revision history

Simonc: Created page with "= Playlist Service = == Overview == The Playlist service provides access to a list of tracks, which can be played in sequence, starting at any point. ‘Shuffle’ and ‘Repeat..."