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# LV2 String Port Extension.
# Draft Revision 3
# Copyright (C) 2008 Krzysztof Foltman
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the "Software"),
# to deal in the Software without restriction, including without limitation
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
# and/or sell copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
# THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

@prefix sp:   <http://lv2plug.in/ns/ext/string-port#> .
@prefix lv2:  <http://lv2plug.in/ns/lv2core#> .
@prefix rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix xsd:  <http://www.w3.org/2001/XMLSchema#> .
@prefix doap: <http://usefulinc.com/ns/doap#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .

<http://lv2plug.in/ns/ext/string-port> a lv2:Specification ;
	doap:license <http://usefulinc.com/doap/licenses/mit> ;
	doap:name    "LV2 String Ports" ;
	doap:maintainer [
		a foaf:Person ;
		foaf:name "Krzysztof Foltman" ;
	] ;
	lv2:documentation """
<p>Defines ports which contain string data.</p>

<h4>UI issues</h4>
<p>When using port_event / write_port (and possible other communication
mechanisms), the format parameter should contain the numeric value of URI
LV2_STRING_PORT_URI (mapped with http://lv2plug.in/ns/extensions/ui specified
as map URI).</p>

<p>It's probably possible to use ports belonging to message context
&lt;http://lv2plug.in/ns/ext/contexts#MessageContext&gt; for transfer. However,
contexts mechanism does not offer any way to notify the message recipient about
which ports have been changed. To remedy that, this extension defines a flag
LV2_STRING_DATA_CHANGED_FLAG that carries that information inside a port value
structure.</p>

<h4>Storage</h4>
<p>The value of string port are assumed to be "persistent": if a host saves and
restores a state of a plugin (e.g. control port values), the values of input
string ports should also be assumed to belong to that state. This also applies
to message context: if a session is being restored, the host MUST resend the
last value that was sent to the port before session has been saved. In other
words, string port values "stick" to message ports.</p>
""" .

sp:StringTransfer a lv2:Feature ;
   rdfs:label "String data transfer via LV2_String_Data" .

sp:StringPort a lv2:Port ;
   rdfs:label "String port" ;
   lv2:documentation """
<p>Indicates that the port data points to a LV2_String_Data structure
as defined in accompanying header file.</p>

<h4>Input Port Semantics</h4>
<p>If the port does not have a context specified (it runs in the default,
realtime audio processing context), the values in the structure and the actual
string data MUST remain unchanged for the time a run() function of a plugin
is executed. However, if the port belongs to a different context, the same
data MUST remain unchanged only for the time a run() or message_process()
function of a given context is executed.</p>

<h4>Output Port Semantics</h4>
<p>The plugin may only change the string or length in a run() function (if
the port belongs to default context) or in context-defined counterparts
(if the port belongs to another context). Because of that, using default
context output string ports is contraindicated for longer strings.</p>
""" .

sp:default a rdf:Property ;
   rdfs:label "Default value" ;
   rdfs:domain sp:StringPort ;
   rdfs:range xsd:string ;
   rdfs:comment """
Gives a default value for a string port.
""" .

sp:requiredSpace a rdf:Property ;
   rdfs:label "Required storage space in bytes" ;
   rdfs:domain sp:StringPort ;
   rdfs:range xsd:nonNegativeInteger ;
   rdfs:comment """
Specifies required buffer space for output string ports and those of
input string ports that are meant to be GUI-controlled. The host MUST
allocate a buffer of at least required size to accommodate for all values
that can be produced by the plugin.
""" .