David Robillard
c37722f7dc
Add lv2_ui.h (required by lv2_external_ui.h). git-svn-id: svn://localhost/ardour2/branches/3.0@9406 d708f5d6-7413-0410-9779-e7cbd77b26cf
242 lines
11 KiB
C++
242 lines
11 KiB
C++
/* 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
|
|
* 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
|
|
* 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" {
|
|
#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;
|
|
|
|
|
|
/** 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
|
|
}
|
|
#endif
|
|
|
|
|
|
#endif
|