diff options
author | David Robillard <d@drobilla.net> | 2011-04-22 08:08:37 +0000 |
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committer | David Robillard <d@drobilla.net> | 2011-04-22 08:08:37 +0000 |
commit | c37722f7dc3c3872095a70eb35bd43f4662d99f5 (patch) | |
tree | a51d2b31118ed41374ea754480f2bc548fda0214 /gtk2_ardour/lv2_ui.h | |
parent | 12bb5b62071e25168922ef0fe27f23493bed05db (diff) |
Use new Suil and SLV2 APIs for LV2 plugin UIs.
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
Diffstat (limited to 'gtk2_ardour/lv2_ui.h')
-rw-r--r-- | gtk2_ardour/lv2_ui.h | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/gtk2_ardour/lv2_ui.h b/gtk2_ardour/lv2_ui.h new file mode 100644 index 0000000000..fa0a711cf4 --- /dev/null +++ b/gtk2_ardour/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 + * 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 |