/*
LV2 UI Extension
Copyright 2009-2012 David Robillard <d@drobilla.net>
Copyright 2006-2011 Lars Luthman <lars.luthman@gmail.com>
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/**
@file ui.h
C header for the LV2 UI extension <http://lv2plug.in/ns/extensions/ui>.
*/
#ifndef LV2_UI_H
#define LV2_UI_H
#include <stdint.h>
#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
#define LV2_UI_URI "http://lv2plug.in/ns/extensions/ui"
#define LV2_UI_PREFIX LV2_UI_URI "#"
#define LV2_UI__GtkUI LV2_UI_PREFIX "GtkUI"
#define LV2_UI__PortNotification LV2_UI_PREFIX "PortNotification"
#define LV2_UI__Qt4UI LV2_UI_PREFIX "Qt4UI"
#define LV2_UI__UI LV2_UI_PREFIX "UI"
#define LV2_UI__X11UI LV2_UI_PREFIX "X11UI"
#define LV2_UI__fixedSize LV2_UI_PREFIX "fixedSize"
#define LV2_UI__noUserResize LV2_UI_PREFIX "noUserResize"
#define LV2_UI__notifyType LV2_UI_PREFIX "notifyType"
#define LV2_UI__parent LV2_UI_PREFIX "parent"
#define LV2_UI__plugin LV2_UI_PREFIX "plugin"
#define LV2_UI__portIndex LV2_UI_PREFIX "portIndex"
#define LV2_UI__portMap LV2_UI_PREFIX "portMap"
#define LV2_UI__portNotification LV2_UI_PREFIX "portNotification"
#define LV2_UI__resize LV2_UI_PREFIX "resize"
#define LV2_UI__touch LV2_UI_PREFIX "touch"
/**
The index returned by LV2_UI_Port_Port::port_index() for unknown ports.
*/
#define LV2UI_INVALID_PORT_INDEX ((uint32_t)-1)
#ifdef __cplusplus
extern "C" {
#else
# include <stdbool.h>
#endif
/**
A pointer to some widget or other type of UI handle.
The actual type is defined by the type of the UI.
*/
typedef void* LV2UI_Widget;
/**
A pointer to an 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 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;
/**
A pointer to opaque data for a feature.
*/
typedef void* LV2UI_Feature_Handle;
/**
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 format of this data and how the host should use it is defined by
the @c port_protocol. This buffer is owned by the UI and is only valid for
the duration of this call.
The @c port_protocol parameter should either be 0 or the URID for a
ui:PortProtocol. If it is 0, the protocol is implicitly ui:floatProtocol,
the port must be an lv2:ControlPort input, @c buffer must point to a single
float value, and @c buffer_size must be sizeof(float).
The UI SHOULD NOT use a PortProtocol not supported by the host (i.e. one not
passed by the host as a feature), but the host MUST gracefully ignore any
port_protocol it does not understand.
*/
typedef void (*LV2UI_Write_Function)(LV2UI_Controller controller,
uint32_t port_index,
uint32_t buffer_size,
uint32_t port_protocol,
const void* buffer);
/**
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);
/**
Return 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;
/**
UI Resize Feature (LV2_UI__resize)
This structure may be used in two ways: as a feature passed by the host via
LV2UI_Descriptor::instantiate(), or as extension data provided by a UI via
LV2UI_Descriptor::extension_data()).
*/
typedef struct _LV2UI_Resize {
/**
Pointer to opaque data which must be passed to ui_resize().
*/
LV2UI_Feature_Handle handle;
/**
Request or advertise a size change.
When this struct is provided by the host, the UI may call this
function to inform the host about the size of the UI.
When this struct is provided by the UI, the host may call this
function to notify the UI that it should change its size accordingly.
@return 0 on success.
*/
int (*ui_resize)(LV2UI_Feature_Handle handle, int width, int height);
} LV2UI_Resize;
/**
Port Map Feature (LV2_UI__portMap).
This feature can be used by the UI to get the index for a port with the
given symbol. This makes it possible to implement and distribute a UI
separately from the plugin (since symbol is a guaranteed stable port
identifier while index is not).
*/
typedef struct _LV2UI_Port_Map {
/**
Pointer to opaque data which must be passed to ui_resize().
*/
LV2UI_Feature_Handle handle;
/**
Get the index for the port with the given @p symbol.
@return The index of the port, or LV2_UI_INVALID_PORT_INDEX if no such
port is found.
*/
uint32_t (*port_index)(LV2UI_Feature_Handle handle, const char* symbol);
} LV2UI_Port_Map;
/**
Port subscription feature (LV2_UI__portSubscribe);
*/
typedef struct _LV2UI_Port_Subscribe {
/**
Pointer to opaque data which must be passed to ui_resize().
*/
LV2UI_Feature_Handle handle;
/**
Subscribe to updates for a port.
This means that the host will call the UI's port_event() function when
the port value changes (as defined by protocol).
Calling this function with the same @c port_index and @c port_protocol
as an already active subscription has no effect.
@param handle The handle field of this struct.
@param port_index The index of the port.
@param port_protocol The URID of the ui:PortProtocol.
@param data Extra data as defined by the port protocol, or NULL.
*/
void (*subscribe)(LV2UI_Feature_Handle handle,
uint32_t port_index,
uint32_t port_protocol,
const void* options);
/**
Unsubscribe from updates for a port.
This means that the host will cease calling calling port_event() when
the port value changes.
Calling this function with a @c port_index and @c port_protocol that
does not refer to an active port subscription has no effect.
@param handle The handle field of this struct.
@param port_index The index of the port.
@param port_protocol The URID of the ui:PortProtocol.
@param data Extra data as defined by the port protocol, or NULL.
*/
void (*unsubscribe)(LV2UI_Feature_Handle handle,
uint32_t port_index,
uint32_t port_protocol,
const void* options);
} LV2UI_Port_Subscribe;
/**
A feature to notify the host the user has grabbed a UI control.
*/
typedef struct _LV2UI_Touch {
/**
Pointer to opaque data which must be passed to ui_resize().
*/
LV2UI_Feature_Handle handle;
/**
Notify the host that a control has been grabbed or released.
@param handle The handle field of this struct.
@param port_index The index of the port associated with the control.
@param grabbed If true, the control has been grabbed, otherwise the
control has been released.
*/
void (*touch)(LV2UI_Feature_Handle handle,
uint32_t port_index,
bool grabbed);
} LV2UI_Touch;
/**
Peak data for a slice of time, the update format for ui:peakProtocol.
*/
typedef struct _LV2UI_Peak_Data {
/**
The start of the measurement period. This is just a running counter
that is only meaningful in comparison to previous values and must not be
interpreted as an absolute time.
*/
uint32_t period_start;
/**
The size of the measurement period, in the same units as period_start.
*/
uint32_t period_size;
/**
The peak value for the measurement period. This should be the maximal
value for abs(sample) over all the samples in the period.
*/
float peak;
} LV2UI_Peak_Data;
/**
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 is
loaded from the library by the UI host and called to get a
LV2UI_Descriptor 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);
/**
The type of the lv2ui_descriptor() function.
*/
typedef const LV2UI_Descriptor* (*LV2UI_DescriptorFunction)(uint32_t index);
#ifdef __cplusplus
}
#endif
#endif /* LV2_UI_H */