1 /*
2   LV2 UI Extension
3   Copyright 2009-2016 David Robillard <d@drobilla.net>
4   Copyright 2006-2011 Lars Luthman <lars.luthman@gmail.com>
5   Copyright 2018 Ethan Reker <http://cutthroughrecordings.com>
6 
7   Permission to use, copy, modify, and/or distribute this software for any
8   purpose with or without fee is hereby granted, provided that the above
9   copyright notice and this permission notice appear in all copies.
10 
11   THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12   WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13   MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14   ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19 module dplug.lv2.ui;
20 
21 version(LV2):
22 
23 /**
24    @defgroup ui User Interfaces
25 
26    User interfaces of any type for plugins,
27    <http://lv2plug.in/ns/extensions/ui> for details.
28 
29    @{
30 */
31 
32 import core.stdc.stdint;
33 
34 import dplug.lv2.lv2;
35 
36 enum LV2_UI_URI    = "http://lv2plug.in/ns/extensions/ui";  ///< http://lv2plug.in/ns/extensions/ui
37 enum LV2_UI_PREFIX = LV2_UI_URI ~ "#";                        ///< http://lv2plug.in/ns/extensions/ui#
38 enum LV2_UI__CocoaUI          = LV2_UI_PREFIX ~ "CocoaUI";           ///< http://lv2plug.in/ns/extensions/ui#CocoaUI
39 enum LV2_UI__Gtk3UI           = LV2_UI_PREFIX ~ "Gtk3UI";            ///< http://lv2plug.in/ns/extensions/ui#Gtk3UI
40 enum LV2_UI__GtkUI            = LV2_UI_PREFIX ~ "GtkUI";             ///< http://lv2plug.in/ns/extensions/ui#GtkUI
41 enum LV2_UI__PortNotification = LV2_UI_PREFIX ~ "PortNotification";  ///< http://lv2plug.in/ns/extensions/ui#PortNotification
42 enum LV2_UI__PortProtocol     = LV2_UI_PREFIX ~ "PortProtocol";      ///< http://lv2plug.in/ns/extensions/ui#PortProtocol
43 enum LV2_UI__Qt4UI            = LV2_UI_PREFIX ~ "Qt4UI";             ///< http://lv2plug.in/ns/extensions/ui#Qt4UI
44 enum LV2_UI__Qt5UI            = LV2_UI_PREFIX ~ "Qt5UI";             ///< http://lv2plug.in/ns/extensions/ui#Qt5UI
45 enum LV2_UI__UI               = LV2_UI_PREFIX ~ "UI";                ///< http://lv2plug.in/ns/extensions/ui#UI
46 enum LV2_UI__WindowsUI        = LV2_UI_PREFIX ~ "WindowsUI";         ///< http://lv2plug.in/ns/extensions/ui#WindowsUI
47 enum LV2_UI__X11UI            = LV2_UI_PREFIX ~ "X11UI";             ///< http://lv2plug.in/ns/extensions/ui#X11UI
48 enum LV2_UI__binary           = LV2_UI_PREFIX ~ "binary";            ///< http://lv2plug.in/ns/extensions/ui#binary
49 enum LV2_UI__fixedSize        = LV2_UI_PREFIX ~ "fixedSize";         ///< http://lv2plug.in/ns/extensions/ui#fixedSize
50 enum LV2_UI__idleInterface    = LV2_UI_PREFIX ~ "idleInterface";     ///< http://lv2plug.in/ns/extensions/ui#idleInterface
51 enum LV2_UI__noUserResize     = LV2_UI_PREFIX ~ "noUserResize";      ///< http://lv2plug.in/ns/extensions/ui#noUserResize
52 enum LV2_UI__notifyType       = LV2_UI_PREFIX ~ "notifyType";        ///< http://lv2plug.in/ns/extensions/ui#notifyType
53 enum LV2_UI__parent           = LV2_UI_PREFIX ~ "parent";            ///< http://lv2plug.in/ns/extensions/ui#parent
54 enum LV2_UI__plugin           = LV2_UI_PREFIX ~ "plugin";            ///< http://lv2plug.in/ns/extensions/ui#plugin
55 enum LV2_UI__portIndex        = LV2_UI_PREFIX ~ "portIndex";         ///< http://lv2plug.in/ns/extensions/ui#portIndex
56 enum LV2_UI__portMap          = LV2_UI_PREFIX ~ "portMap";           ///< http://lv2plug.in/ns/extensions/ui#portMap
57 enum LV2_UI__portNotification = LV2_UI_PREFIX ~ "portNotification";  ///< http://lv2plug.in/ns/extensions/ui#portNotification
58 enum LV2_UI__portSubscribe    = LV2_UI_PREFIX ~ "portSubscribe";     ///< http://lv2plug.in/ns/extensions/ui#portSubscribe
59 enum LV2_UI__protocol         = LV2_UI_PREFIX ~ "protocol";          ///< http://lv2plug.in/ns/extensions/ui#protocol
60 enum LV2_UI__floatProtocol    = LV2_UI_PREFIX ~ "floatProtocol";     ///< http://lv2plug.in/ns/extensions/ui#floatProtocol
61 enum LV2_UI__peakProtocol     = LV2_UI_PREFIX ~ "peakProtocol";      ///< http://lv2plug.in/ns/extensions/ui#peakProtocol
62 enum LV2_UI__resize           = LV2_UI_PREFIX ~ "resize";            ///< http://lv2plug.in/ns/extensions/ui#resize
63 enum LV2_UI__showInterface    = LV2_UI_PREFIX ~ "showInterface";     ///< http://lv2plug.in/ns/extensions/ui#showInterface
64 enum LV2_UI__touch            = LV2_UI_PREFIX ~ "touch";             ///< http://lv2plug.in/ns/extensions/ui#touch
65 enum LV2_UI__ui               = LV2_UI_PREFIX ~ "ui";                ///< http://lv2plug.in/ns/extensions/ui#ui
66 enum LV2_UI__updateRate       = LV2_UI_PREFIX ~ "updateRate";        ///< http://lv2plug.in/ns/extensions/ui#updateRate
67 enum LV2_UI__windowTitle      = LV2_UI_PREFIX ~ "windowTitle";       ///< http://lv2plug.in/ns/extensions/ui#windowTitle
68 
69 /**
70    The index returned by LV2UI_Port_Map::port_index() for unknown ports.
71 */
72 enum LV2UI_INVALID_PORT_INDEX = cast(uint32_t)(-1);
73 
74 extern(C):
75 nothrow:
76 @nogc:
77 
78 /**
79 A pointer to some widget or other type of UI handle.
80 
81 The actual type is defined by the type of the UI.
82 */
83 alias LV2UI_Widget = void*;
84 
85 /**
86 A pointer to UI instance internals.
87 
88 The host may compare this to NULL, but otherwise MUST NOT interpret it.
89 */
90 alias LV2UI_Handle = void*;
91 
92 /**
93 A pointer to a controller provided by the host.
94 
95 The UI may compare this to NULL, but otherwise MUST NOT interpret it.
96 */
97 alias LV2UI_Controller = void*;
98 
99 /**
100 A pointer to opaque data for a feature.
101 */
102 alias LV2UI_Feature_Handle = void*;
103 
104 /**
105 A host-provided function that sends data to a plugin's input ports.
106 
107 @param controller The opaque controller pointer passed to
108 LV2UI_Descriptor::instantiate().
109 
110 @param port_index Index of the port to update.
111 
112 @param buffer Buffer containing `buffer_size` bytes of data.
113 
114 @param buffer_size Size of `buffer` in bytes.
115 
116 @param port_protocol Either 0 or the URID for a ui:PortProtocol.  If 0, the
117 protocol is implicitly ui:floatProtocol, the port MUST be an lv2:ControlPort
118 input, `buffer` MUST point to a single float value, and `buffer_size` MUST
119 be sizeof(float).  The UI SHOULD NOT use a protocol not supported by the
120 host, but the host MUST gracefully ignore any protocol it does not
121 understand.
122 */
123 alias LV2UI_Write_Function = void function(LV2UI_Controller controller,
124                                     uint32_t         port_index,
125                                     uint32_t         buffer_size,
126                                     uint32_t         port_protocol,
127                                     const void*      buffer);
128 
129 /**
130 A plugin UI.
131 
132 A pointer to an object of this type is returned by the lv2ui_descriptor()
133 function.
134 */
135 struct LV2UI_Descriptor 
136 {
137 nothrow:
138 @nogc:
139 extern(C):
140     /**
141     The URI for this UI (not for the plugin it controls).
142     */
143     char* URI;
144 
145     /**
146     Create a new UI and return a handle to it.  This function works
147     similarly to LV2_Descriptor::instantiate().
148 
149     @param descriptor The descriptor for the UI to instantiate.
150 
151     @param plugin_uri The URI of the plugin that this UI will control.
152 
153     @param bundle_path The path to the bundle containing this UI, including
154     the trailing directory separator.
155 
156     @param write_function A function that the UI can use to send data to the
157     plugin's input ports.
158 
159     @param controller A handle for the UI instance to be passed as the
160     first parameter of UI methods.
161 
162     @param widget (output) widget pointer.  The UI points this at its main
163     widget, which has the type defined by the UI type in the data file.
164 
165     @param features An array of LV2_Feature pointers.  The host must pass
166     all feature URIs that it and the UI supports and any additional data, as
167     in LV2_Descriptor::instantiate().  Note that UI features and plugin
168     features are not necessarily the same.
169 
170     */
171     LV2UI_Handle function(const LV2UI_Descriptor* descriptor,
172                                 const char*                     plugin_uri,
173                                 const char*                     bundle_path,
174                                 LV2UI_Write_Function            write_function,
175                                 LV2UI_Controller                controller,
176                                 LV2UI_Widget*                   widget,
177                                 const (LV2_Feature*)*       features) instantiate;
178 
179 
180     /**
181     Destroy the UI.  The host must not try to access the widget after
182     calling this function.
183     */
184     void function(LV2UI_Handle ui) cleanup;
185 
186     /**
187     Tell the UI that something interesting has happened at a plugin port.
188 
189     What is "interesting" and how it is written to `buffer` is defined by
190     `format`, which has the same meaning as in LV2UI_Write_Function().
191     Format 0 is a special case for lv2:ControlPort, where this function
192     should be called when the port value changes (but not necessarily for
193     every change), `buffer_size` must be sizeof(float), and `buffer`
194     points to a single IEEE-754 float.
195 
196     By default, the host should only call this function for lv2:ControlPort
197     inputs.  However, the UI can request updates for other ports statically
198     with ui:portNotification or dynamicaly with ui:portSubscribe.
199 
200     The UI MUST NOT retain any reference to `buffer` after this function
201     returns, it is only valid for the duration of the call.
202 
203     This member may be NULL if the UI is not interested in any port events.
204     */
205     void function(LV2UI_Handle ui,
206                     uint32_t     port_index,
207                     uint32_t     buffer_size,
208                     uint32_t     format,
209                     const void*  buffer) port_event;
210 
211     /**
212     Return a data structure associated with an extension URI, typically an
213     interface struct with additional function pointers
214 
215     This member may be set to NULL if the UI is not interested in supporting
216     any extensions. This is similar to LV2_Descriptor::extension_data().
217 
218     */
219     const (void)* function(const char* uri) extension_data;
220 }
221 
222 /**
223 Feature/interface for resizable UIs (LV2_UI__resize).
224 
225 This structure is used in two ways: as a feature passed by the host via
226 LV2UI_Descriptor::instantiate(), or as an interface provided by a UI via
227 LV2UI_Descriptor::extension_data()).
228 */
229 struct LV2UI_Resize 
230 {
231 nothrow:
232 @nogc:
233 extern(C):
234 
235     /**
236     Pointer to opaque data which must be passed to ui_resize().
237     */
238     LV2UI_Feature_Handle handle;
239 
240     /**
241     Request/advertise a size change.
242 
243     When provided by the host, the UI may call this function to inform the
244     host about the size of the UI.
245 
246     When provided by the UI, the host may call this function to notify the
247     UI that it should change its size accordingly.  In this case, the host
248     must pass the LV2UI_Handle to provide access to the UI instance.
249 
250     @return 0 on success.
251     */
252     int function(LV2UI_Feature_Handle handle, int width, int height) ui_resize;
253 }
254 
255 /**
256 Feature to map port symbols to UIs.
257 
258 This can be used by the UI to get the index for a port with the given
259 symbol.  This makes it possible to implement and distribute a UI separately
260 from the plugin (since symbol, unlike index, is a stable port identifier).
261 */
262 struct LV2UI_Port_Map 
263 {
264 nothrow:
265 @nogc:
266 extern(C):
267     /**
268     Pointer to opaque data which must be passed to port_index().
269     */
270     LV2UI_Feature_Handle handle;
271 
272     /**
273     Get the index for the port with the given `symbol`.
274 
275     @return The index of the port, or LV2UI_INVALID_PORT_INDEX if no such
276     port is found.
277     */
278     uint32_t function(LV2UI_Feature_Handle handle, const char* symbol) port_index;
279 }
280 
281 /**
282 Feature to subscribe to port updates (LV2_UI__portSubscribe).
283 */
284 struct LV2UI_Port_Subscribe 
285 {
286 extern(C):
287 nothrow:
288 @nogc:
289     /**
290     Pointer to opaque data which must be passed to subscribe() and
291     unsubscribe().
292     */
293     LV2UI_Feature_Handle handle;
294 
295     /**
296     Subscribe to updates for a port.
297 
298     This means that the host will call the UI's port_event() function when
299     the port value changes (as defined by protocol).
300 
301     Calling this function with the same `port_index` and `port_protocol`
302     as an already active subscription has no effect.
303 
304     @param handle The handle field of this struct.
305     @param port_index The index of the port.
306     @param port_protocol The URID of the ui:PortProtocol.
307     @param features Features for this subscription.
308     @return 0 on success.
309     */
310     uint32_t function(LV2UI_Feature_Handle      handle,
311                         uint32_t                  port_index,
312                         uint32_t                  port_protocol,
313                         const (LV2_Feature*)* features) subscribe;
314 
315     /**
316     Unsubscribe from updates for a port.
317 
318     This means that the host will cease calling calling port_event() when
319     the port value changes.
320 
321     Calling this function with a `port_index` and `port_protocol` that
322     does not refer to an active port subscription has no effect.
323 
324     @param handle The handle field of this struct.
325     @param port_index The index of the port.
326     @param port_protocol The URID of the ui:PortProtocol.
327     @param features Features for this subscription.
328     @return 0 on success.
329     */
330     uint32_t function(LV2UI_Feature_Handle      handle,
331                             uint32_t                  port_index,
332                             uint32_t                  port_protocol,
333                             const (LV2_Feature*)* features) unsubscribe;
334 }
335 
336 /**
337 A feature to notify the host that the user has grabbed a UI control.
338 */
339 struct LV2UI_Touch 
340 {
341 nothrow:
342 @nogc:
343 extern(C):
344 
345     /**
346     Pointer to opaque data which must be passed to ui_resize().
347     */
348     LV2UI_Feature_Handle handle;
349 
350     /**
351     Notify the host that a control has been grabbed or released.
352 
353     The host should cease automating the port or otherwise manipulating the
354     port value until the control has been ungrabbed.
355 
356     @param handle The handle field of this struct.
357     @param port_index The index of the port associated with the control.
358     @param grabbed If true, the control has been grabbed, otherwise the
359     control has been released.
360     */
361     void function(LV2UI_Feature_Handle handle,
362                   uint32_t             port_index,
363                   bool                 grabbed) touch;
364 }
365 
366 /**
367 UI Idle Interface (LV2_UI__idleInterface)
368 
369 UIs can provide this interface to have an idle() callback called by the host
370 rapidly to update the UI.
371 */
372 struct LV2UI_Idle_Interface 
373 {
374 nothrow:
375 @nogc:
376 extern(C):
377     /**
378     Run a single iteration of the UI's idle loop.
379 
380     This will be called rapidly in the UI thread at a rate appropriate
381     for a toolkit main loop.  There are no precise timing guarantees, but
382     the host should attempt to call idle() at a high enough rate for smooth
383     animation, at least 30Hz.
384 
385     @return non-zero if the UI has been closed, in which case the host
386     should stop calling idle(), and can either completely destroy the UI, or
387     re-show it and resume calling idle().
388     */
389     int function(LV2UI_Handle ui) idle;
390 }
391 
392 /**
393 UI Show Interface (LV2_UI__showInterface)
394 
395 UIs can provide this interface to show and hide a window, which allows them
396 to function in hosts unable to embed their widget.  This allows any UI to
397 provide a fallback for embedding that works in any host.
398 
399 If used:
400 - The host MUST use LV2UI_Idle_Interface to drive the UI.
401 - The UI MUST return non-zero from LV2UI_Idle_Interface::idle() when it has been closed.
402 - If idle() returns non-zero, the host MUST call hide() and stop calling
403     idle().  It MAY later call show() then resume calling idle().
404 */
405 struct LV2UI_Show_Interface 
406 {
407 nothrow:
408 @nogc:
409 extern(C):
410     /**
411     Show a window for this UI.
412 
413     The window title MAY have been passed by the host to
414     LV2UI_Descriptor::instantiate() as an LV2_Options_Option with key
415     LV2_UI__windowTitle.
416 
417     @return 0 on success, or anything else to stop being called.
418     */
419     int function(LV2UI_Handle ui) show;
420 
421     /**
422     Hide the window for this UI.
423 
424     @return 0 on success, or anything else to stop being called.
425     */
426     int function(LV2UI_Handle ui) hide;
427 }
428 
429 /**
430 Peak data for a slice of time, the update format for ui:peakProtocol.
431 */
432 struct LV2UI_Peak_Data 
433 {
434     /**
435     The start of the measurement period.  This is just a running counter
436     that is only meaningful in comparison to previous values and must not be
437     interpreted as an absolute time.
438     */
439     uint32_t period_start;
440 
441     /**
442     The size of the measurement period, in the same units as period_start.
443     */
444     uint32_t period_size;
445 
446     /**
447     The peak value for the measurement period. This should be the maximal
448     value for abs(sample) over all the samples in the period.
449     */
450     float peak;
451 }
452 
453 /**
454 The type of the lv2ui_descriptor() function.
455 */
456 // typedef const LV2UI_Descriptor* (*LV2UI_DescriptorFunction)(uint32_t index);
457 alias LV2UI_DescriptorFunction = const LV2UI_Descriptor function(uint32_t index);