path: root/extensions/ui.lv2
diff options
authorDavid Robillard <d@drobilla.net>2010-10-04 18:21:08 +0000
committerDavid Robillard <d@drobilla.net>2010-10-04 18:21:08 +0000
commitcef9811dac46a9d54dab0f0d82ce5c3ae032fc7c (patch)
tree632b911da25fc24b6b3d331d7ceffc22606b8e5b /extensions/ui.lv2
parent61842745ab15454ee66be54a6f3bcc148a75406f (diff)
Initial import of lv2plug.in universe.
Diffstat (limited to 'extensions/ui.lv2')
3 files changed, 465 insertions, 0 deletions
diff --git a/extensions/ui.lv2/manifest.ttl b/extensions/ui.lv2/manifest.ttl
new file mode 100644
index 0000000..2c20933
--- /dev/null
+++ b/extensions/ui.lv2/manifest.ttl
@@ -0,0 +1,7 @@
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+ a lv2:Specification ;
+ rdfs:seeAlso <ui.ttl> .
diff --git a/extensions/ui.lv2/ui.h b/extensions/ui.lv2/ui.h
new file mode 100644
index 0000000..cedb895
--- /dev/null
+++ b/extensions/ui.lv2/ui.h
@@ -0,0 +1,241 @@
+/* LV2 UI Extension
+ * Copyright (C) 2006-2008 Lars Luthman <lars.luthman@gmail.com>
+ * Copyright (C) 2009-2010 David Robillard <d@drobilla.net>
+ *
+ * Based on lv2.h, which was
+ * Copyright (C) 2000-2002 Richard W.E. Furse, Paul Barton-Davis,
+ * Stefan Westerfeld
+ * Copyright (C) 2006 Steve Harris, David Robillard.
+ *
+ * This header is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License,
+ * or (at your option) any later version.
+ *
+ * This header is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
+ * USA.
+ *
+ */
+/** @file
+ * C header for the LV2 UI extension <http://lv2plug.in/ns/extensions/ui>.
+ */
+#ifndef LV2_UI_H
+#define LV2_UI_H
+#include "lv2.h"
+#define LV2_UI_URI "http://lv2plug.in/ns/extensions/ui"
+#ifdef __cplusplus
+extern "C" {
+/** A pointer to some widget or other type of UI handle.
+ The actual type is defined by the type URI of the UI.
+ All the functionality provided by this extension is toolkit
+ independent, the host only needs to pass the necessary callbacks and
+ display the widget, if possible. Plugins may have several UIs, in various
+ toolkits. */
+typedef void* LV2UI_Widget;
+/** A pointer to a particular instance of a UI.
+ It is valid to compare this to NULL (0 for C++) but otherwise the
+ host MUST not attempt to interpret it. The UI plugin may use it to
+ reference internal instance data. */
+typedef void* LV2UI_Handle;
+/** A pointer to a particular plugin controller, provided by the host.
+ It is valid to compare this to NULL (0 for C++) but otherwise the
+ UI plugin MUST not attempt to interpret it. The host may use it to
+ reference internal instance data. */
+typedef void* LV2UI_Controller;
+/** The type of the host-provided function that the UI can use to
+ send data to a plugin's input ports. The @c buffer parameter must point
+ to a block of data, @c buffer_size bytes large. The contents of this buffer
+ and what the host should do with it depends on the value of the @c format
+ parameter.
+ The @c format parameter should either be 0 or a numeric ID for a "Transfer
+ mechanism". Transfer mechanisms are Features and may be defined in
+ meta-extensions. They specify how to translate the data buffers passed
+ to this function to input data for the plugin ports. If a UI wishes to
+ write data to an input port, it must list a transfer mechanism Feature
+ for that port's class as an optional or required feature (depending on
+ whether the UI will work without being able to write to that port or not).
+ The only exception is when the UI wants to write single float values to
+ input ports of the class lv2:ControlPort, in which case @c buffer_size
+ should always be 4, the buffer should always contain a single IEEE-754
+ float, and @c format should be 0.
+ The numeric IDs for the transfer mechanisms are provided by a
+ URI-to-integer mapping function provided by the host, using the URI Map
+ feature <http://lv2plug.in/ns/ext/uri-map> with the map URI
+ "http://lv2plug.in/ns/extensions/ui". Thus a UI that requires transfer
+ mechanism features also requires the URI Map feature, but this is
+ implicit - the UI does not have to list the URI map feature as a required
+ or optional feature in it's RDF data.
+ An UI MUST NOT pass a @c format parameter value (except 0) that has not
+ been returned by the host-provided URI mapping function for a
+ host-supported transfer mechanism feature URI.
+ The UI MUST NOT try to write to a port for which there is no specified
+ transfer mechanism, or to an output port. The UI is responsible for
+ allocating the buffer and deallocating it after the call.
+typedef void (*LV2UI_Write_Function)(LV2UI_Controller controller,
+ uint32_t port_index,
+ uint32_t buffer_size,
+ uint32_t format,
+ const void* buffer);
+/** This struct contains the implementation of a UI. A pointer to an
+ object of this type is returned by the lv2ui_descriptor() function.
+typedef struct _LV2UI_Descriptor {
+ /** The URI for this UI (not for the plugin it controls). */
+ const char* URI;
+ /** Create a new UI object and return a handle to it. This function works
+ similarly to the instantiate() member in LV2_Descriptor.
+ @param descriptor The descriptor for the UI that you want to instantiate.
+ @param plugin_uri The URI of the plugin that this UI will control.
+ @param bundle_path The path to the bundle containing the RDF data file
+ that references this shared object file, including the
+ trailing '/'.
+ @param write_function A function provided by the host that the UI can
+ use to send data to the plugin's input ports.
+ @param controller A handle for the plugin instance that should be passed
+ as the first parameter of @c write_function.
+ @param widget A pointer to an LV2UI_Widget. The UI will write a
+ widget pointer to this location (what type of widget
+ depends on the RDF class of the UI) that will be the
+ main UI widget.
+ @param features An array of LV2_Feature pointers. The host must pass
+ all feature URIs that it and the UI supports and any
+ additional data, just like in the LV2 plugin
+ instantiate() function. Note that UI features and plugin
+ features are NOT necessarily the same, they just share
+ the same data structure - this will probably not be the
+ same array as the one the plugin host passes to a
+ plugin.
+ */
+ LV2UI_Handle (*instantiate)(const struct _LV2UI_Descriptor* descriptor,
+ const char* plugin_uri,
+ const char* bundle_path,
+ LV2UI_Write_Function write_function,
+ LV2UI_Controller controller,
+ LV2UI_Widget* widget,
+ const LV2_Feature* const* features);
+ /** Destroy the UI object and the associated widget. The host must not try
+ to access the widget after calling this function.
+ */
+ void (*cleanup)(LV2UI_Handle ui);
+ /** Tell the UI that something interesting has happened at a plugin port.
+ What is interesting and how it is written to the buffer passed to this
+ function is defined by the @c format parameter, which has the same
+ meaning as in LV2UI_Write_Function. The only exception is ports of the
+ class lv2:ControlPort, for which this function should be called
+ when the port value changes (it does not have to be called for every
+ single change if the host's UI thread has problems keeping up with the
+ thread the plugin is running in), @c buffer_size should be 4, the buffer
+ should contain a single IEEE-754 float, and @c format should be 0.
+ By default, the host should only call this function for input ports of
+ the lv2:ControlPort class. However, the default setting can be modified
+ by using the following URIs in the UI's RDF data:
+ <pre>
+ uiext:portNotification
+ uiext:noPortNotification
+ uiext:plugin
+ uiext:portIndex
+ </pre>
+ For example, if you want the UI with uri
+ <code><http://my.pluginui></code> for the plugin with URI
+ <code><http://my.plugin></code> to get notified when the value of the
+ output control port with index 4 changes, you would use the following
+ in the RDF for your UI:
+ <pre>
+ <http://my.pluginui> uiext:portNotification [ uiext:plugin <http://my.plugin> ;
+ uiext:portIndex 4 ] .
+ </pre>
+ and similarly with <code>uiext:noPortNotification</code> if you wanted
+ to prevent notifications for a port for which it would be on by default
+ otherwise. The UI is not allowed to request notifications for ports of
+ types for which no transfer mechanism is specified, if it does it should
+ be considered broken and the host should not load it.
+ The @c buffer is only valid during the time of this function call, so if
+ the UI wants to keep it for later use it has to copy the contents to an
+ internal buffer.
+ This member may be set to NULL if the UI is not interested in any
+ port events.
+ */
+ void (*port_event)(LV2UI_Handle ui,
+ uint32_t port_index,
+ uint32_t buffer_size,
+ uint32_t format,
+ const void* buffer);
+ /** Returns a data structure associated with an extension URI, for example
+ a struct containing additional function pointers. Avoid returning
+ function pointers directly since standard C/C++ has no valid way of
+ casting a void* to a function pointer. This member may be set to NULL
+ if the UI is not interested in supporting any extensions. This is similar
+ to the extension_data() member in LV2_Descriptor.
+ */
+ const void* (*extension_data)(const char* uri);
+} LV2UI_Descriptor;
+/** A plugin UI programmer must include a function called "lv2ui_descriptor"
+ with the following function prototype within the shared object
+ file. This function will have C-style linkage (if you are using
+ C++ this is taken care of by the 'extern "C"' clause at the top of
+ the file). This function will be accessed by the UI host using the
+ @c dlsym() function and called to get a LV2UI_UIDescriptor for the
+ wanted plugin.
+ Just like lv2_descriptor(), this function takes an index parameter. The
+ index should only be used for enumeration and not as any sort of ID number -
+ the host should just iterate from 0 and upwards until the function returns
+ NULL or a descriptor with an URI matching the one the host is looking for.
+const LV2UI_Descriptor* lv2ui_descriptor(uint32_t index);
+/** This is the type of the lv2ui_descriptor() function. */
+typedef const LV2UI_Descriptor* (*LV2UI_DescriptorFunction)(uint32_t index);
+#ifdef __cplusplus
diff --git a/extensions/ui.lv2/ui.ttl b/extensions/ui.lv2/ui.ttl
new file mode 100644
index 0000000..496b625
--- /dev/null
+++ b/extensions/ui.lv2/ui.ttl
@@ -0,0 +1,217 @@
+# LV2 UI Extension
+# Copyright (C) 2006-2008 Lars Luthman <lars.luthman@gmail.com>
+# Copyright (C) 2009-2010 David Robillard <d@drobilla.net>
+# 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.
+@prefix ui: <http://lv2plug.in/ns/extensions/ui#> .
+@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 owl: <http://www.w3.org/2002/07/owl#> .
+@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/extensions/ui> a lv2:Specification ;
+ doap:license <http://usefulinc.com/doap/licenses/mit> ;
+ doap:name "LV2 UI" ;
+ doap:release [
+ doap:revision "2pre" ;
+ doap:created "2010-05-10"
+ ] ;
+ doap:maintainer [
+ a foaf:Person ;
+ foaf:name "Lars Luthman" ;
+ foaf:mbox <mailto:lars.luthman@gmail.com>
+ ] , [
+ a foaf:Person ;
+ foaf:name "David Robillard" ;
+ foaf:homepage <http://drobilla.net/> ;
+ rdfs:seeAlso <http://drobilla.net/drobilla.rdf>
+ ] ;
+ rdfs:comment """
+This extension defines an interface that can be used in LV2 plugins and hosts
+to create UIs for plugins. The UIs are similar to plugins and reside in shared object
+files in an LV2 bundle. UIs are associated with a plugin in RDF using the triples
+@prefix ui: &lt;http://lv2plug.in/ns/extensions/ui#&gt; .
+&lt;http://my.plugin&gt; ui:ui &lt;http://my.pluginui&gt; .
+&lt;http://my.pluginui&gt; a ui:GtkUI ;
+ ui:binary &lt;myui.so&gt; .
+where &lt;http://my.plugin&gt; is the URI of the plugin,
+&lt;http://my.pluginui&gt; is the URI of the plugin UI and &lt;myui.so&gt;
+is the relative URI to the shared object file.
+While it is possible to have the plugin UI and the plugin in the same shared
+object file it is probably a good idea to keep them separate so that hosts
+that don't want UIs don't have to load the UI code. A UI MUST specify its
+class in the RDF data (ui:GtkUI in the above example). The class defines what
+type the UI is, e.g. what graphics toolkit it uses. Any type of UI class can
+be defined separately from this extension.
+(Note: the prefix above is used throughout this file for the same URI)
+It is possible to have multiple UIs for the same plugin, or to have the UI
+for a plugin in a different bundle from the actual plugin - this way people
+other than the plugin author can write plugin UIs independently without
+editing the original plugin bundle.
+Note that the process that loads the shared object file containing the UI
+code and the process that loads the shared object file containing the actual
+plugin implementation are not necessarily the same process (and not even
+necessarily on the same machine). This means that plugin and UI code can
+<b>not</b> use singletons and global variables and expect them to refer to
+the same objects in the UI and the actual plugin. The function callback
+interface defined in this header is the only method of communication between
+UIs and plugin instances (extensions may define more, though this is
+discouraged unless absolutely necessary since the significant benefits of
+network transparency and serialisability are lost).
+Since the LV2 specification itself allows for extensions that may add new
+functionality that could be useful to control with a UI, this extension
+allows for meta-extensions that can extend the interface between the UI and
+the host. These extensions mirror the extensions used for plugins - there are
+required and optional "features" that you declare in the RDF data for the UI as
+&lt;http://my.pluginui&gt; lv2:requiredFeature &lt;http://my.feature&gt; .
+&lt;http://my.pluginui&gt; lv2:optionalFeature &lt;http://my.feature&gt; .
+The rules for a UI with a required or optional feature are identical to those
+of lv2:Plugin instances: if a UI declares a feature as required, the host is
+NOT allowed to load it unless it supports that feature; and if it does support
+a feature, it MUST pass an appropriate LV2_Feature struct to the UI's
+instantiate() method. These features may be used to specify how to pass
+specific types of data between the UI and the plugin port buffers
+(see LV2UI_Write_Function for details).
+UIs written to this specification do not need to be threadsafe - the
+functions defined below may only be called in the same thread the UI
+main loop is running in.
+Note that this UI extension is NOT a lv2:Feature. There is no way for a
+plugin to know whether the host that loads it supports UIs or not, and
+the plugin must always work without the UI (although it may be rather
+useless unless it has been configured using the UI in a previous session).
+From the plugin perspective, control from a UI is the same as control
+from anywhere else (e.g. the host, the user): via ports.
+A UI does not have to be a graphical widget, it could just as well be a
+server listening for OSC input or an interface to some sort of hardware
+device, depending on the RDF class of the UI.
+""" .
+ui:UI a rdfs:Class ;
+ rdfs:subClassOf lv2:Resource ;
+ rdfs:label "LV2 UI" ;
+ rdfs:comment "A UI for an LV2 plugin" .
+ui:GtkUI a rdfs:Class ;
+ rdfs:subClassOf ui:UI ;
+ rdfs:comment """
+A UI where the LV2_Widget is a pointer to a Gtk+ 2.0 compatible GtkWidget,
+and the host guarantees that the Gtk+ library has been initialised and the
+Glib main loop is running before an UI of this type is instantiated.""" .
+ui:makeSONameResident a lv2:Feature ;
+ rdfs:comment """
+This feature is ELF specific - it should only be used by UIs that
+use the ELF file format for the UI shared object files (e.g. on Linux).
+If it is required by an UI the UI should also list a number of SO names
+(shared object names) for libraries that the UI shared object
+depends on and that may not be unloaded during the lifetime of the host
+process, using the predicate @c ui:residentSONames, like this:
+&lt;http://my.pluginui&gt; ui:residentSONames "libgtkmm-2.4.so.1", "libfoo.so.0"
+The host MUST then make sure that the shared libraries with the given ELF
+SO names are not unloaded when the plugin UI is, but stay loaded during
+the entire lifetime of the host process. On Linux this can be accomplished
+by calling dlopen() on the shared library file with that SO name and never
+calling a matching dlclose(). However, if a plugin UI requires the
+@c ui:makeSONameResident feature, it MUST ALWAYS be safe for the host to
+just never unload the shared object containing the UI implementation, i.e.
+act as if the UI required the @c ui:makeResident feature instead. Thus
+the host only needs to find the shared library files corresponding to the
+given SO names if it wants to save RAM by unloading the UI shared object
+file when it is no longer needed. The data pointer for the LV2_Feature for
+this feature should always be set to NULL.
+"""^^lv2:basicXHTML .
+ui:noUserResize a lv2:Feature ;
+ rdfs:comment """
+If a UI requires this feature it indicates that it does not make sense
+to let the user resize the main widget, and the host should prevent that.
+This feature may not make sense for all UI types. The data pointer for the
+LV2_Feature for this feature should always be set to NULL.
+""" .
+ui:fixedSize a lv2:Feature ;
+ rdfs:comment """
+If a UI requires this feature it indicates the same thing as
+ui:noUserResize, and additionally it means that the UI will not resize
+the main widget on its own - it will always remain the same size (e.g. a
+pixmap based GUI). This feature may not make sense for all UI types.
+The data pointer for the LV2_Feature for this feature should always be set
+to NULL.
+""" .
+ui:PortNotification a rdfs:Class ;
+ rdfs:subClassOf [
+ a owl:Restriction ;
+ owl:onProperty ui:plugin ;
+ owl:someValuesFrom lv2:Plugin ;
+ owl:cardinality 1 ;
+ rdfs:comment """
+A PortNotification MUST have exactly one ui:plugin which is a lv2:Plugin.
+""" ] , [
+ a owl:Restriction ;
+ owl:onProperty ui:portIndex ;
+ owl:someValuesFrom xsd:decimal ;
+ owl:cardinality 1 ;
+ rdfs:comment """
+A PortNotification MUST have exactly one ui:portIndex which is an xsd:decimal.
+""" ] ;
+ rdfs:comment "Port Notification" .
+ui:portNotification a rdf:Property ;
+ rdfs:domain ui:UI ;
+ rdfs:range ui:PortNotification ;
+ rdfs:comment """
+Indicates that a UI should receive notification (via port_event on
+LV2UI_Descriptor) when a particular port's value changes.
+""" .
+ui:plugin a rdf:Property ;
+ rdfs:domain ui:PortNotification ;
+ rdfs:range lv2:Plugin ;
+ rdfs:comment """
+The plugin a portNotification applies to.
+""" .
+ui:portIndex a rdf:Property ;
+ rdfs:domain ui:PortNotification ;
+ rdfs:range xsd:decimal ;
+ rdfs:comment """
+The index of the port a portNotification applies to.
+""" .