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| -rw-r--r-- | lv2_ui.h | 372 |
1 files changed, 0 insertions, 372 deletions
diff --git a/lv2_ui.h b/lv2_ui.h deleted file mode 100644 index 75ccf22..0000000 --- a/lv2_ui.h +++ /dev/null @@ -1,372 +0,0 @@ -/************************************************************************
- *
- * In-process UI extension for LV2
- *
- * Copyright (C) 2006-2008 Lars Luthman <lars.luthman@gmail.com>
- *
- * 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
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * 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
- This extension defines an interface that can be used in LV2 plugins and
- hosts to create UIs for plugins. The UIs are plugins that reside in
- shared object files in an LV2 bundle and are referenced in the RDF data
- using the triples (Turtle shown)
-<pre>
- @@prefix uiext: <http://lv2plug.in/ns/extensions/ui#> .
- <http://my.plugin> uiext:ui <http://my.pluginui> .
- <http://my.plugin> a uiext:GtkUI .
- <http://my.pluginui> uiext:binary <myui.so> .
-</pre>
- where <http://my.plugin> is the URI of the plugin, <http://my.pluginui> is
- the URI of the plugin UI and <myui.so> 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, in this case uiext:GtkUI. The
- class defines what type the UI is, e.g. what graphics toolkit it uses.
- There are no UI classes defined in this extension, those are specified
- separately (and anyone can define their own).
-
- (Note: the prefix above is used throughout this file for the same URI)
-
- It's entirely 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 does not have to be the same. There are many
- valid reasons for having the plugin and the UI in different processes, or
- even on different machines. This means that you can _not_ 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 all you can expect to work.
-
- Since the LV2 specification itself allows for extensions that may add
- new types of data and configuration parameters that plugin authors may
- want 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
-<pre>
- <http://my.pluginui> uiext:requiredFeature <http://my.feature> .
- <http://my.pluginui> uiext:optionalFeature <http://my.feature> .
-</pre>
- These predicates have the same semantics as lv2:requiredFeature and
- lv2:optionalFeature - if a UI is declaring a feature as required, the
- host is NOT allowed to load it unless it supports that feature, and if it
- does support a feature (required or optional) it MUST pass that feature's
- URI and any additional data (specified by the meta-extension that defines
- the feature) in a LV2_Feature struct (as defined in lv2.h) to the UI's
- instantiate() function.
-
- These features may be used to specify how to pass data between the UI
- and the plugin port buffers - see LV2UI_Write_Function for details.
-
- There are four features defined in this extension that hosts may want to
- implement:
-
-<pre>
- uiext:makeResident
-</pre>
- If this feature is required by a UI the host MUST NEVER unload the shared
- library containing the UI implementation during the lifetime of the host
- process (e.g. never calling dlclose() on Linux). This feature may be
- needed by e.g. a Gtk UI that registers its own Glib types using
- g_type_register_static() - if it gets unloaded and then loaded again the
- type registration will break, since there is no way to unregister the
- types when the library is unloaded. The data pointer in the LV2_Feature
- for this feature should always be set to NULL.
-
-<pre>
- uiext:makeSONameResident
-</pre>
- 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 uiext:residentSONames, like this:
-<pre>
- <http://my.pluginui> uiext:residentSONames "libgtkmm-2.4.so.1", "libfoo.so.0"
-</pre>
- 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 uiext: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 uiext: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.
-
-<pre>
- uiext:noUserResize
-</pre>
- If an 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.
-
-<pre>
- uiext:fixedSize
-</pre>
- If an UI requires this feature it indicates the same thing as
- uiext: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.
-
-
- UIs written to this specification do not need to be threadsafe - the
- functions defined below may only be called in the same thread as 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).
-
- 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.
-*/
-
-#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" {
-#endif
-
-
-/** 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;
-
-
-/** This handle indicates 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;
-
-
-/** This handle indicates a particular plugin instance, 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 plugin instance data. */
-typedef void* LV2UI_Controller;
-
-
-/** This is 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 an 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 and the
- buffer should contain a single IEEE-754 float. In this case the @c format
- parameter 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++ 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
-}
-#endif
-
-
-#endif
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