[Traverso-commit] traverso/src/3rdparty/slv2/slv2 lv2-gtk2gui.h

[Remon Sijrier]

CVSROOT:        /sources/traverso
Module name:    traverso
Changes by:     Remon Sijrier <r_sijrier>       07/11/06 18:32:22

Added files:
        src/3rdparty/slv2/slv2: lv2-gtk2gui.h 

Log message:
        added in version 0.2.0

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/traverso/src/3rdparty/slv2/slv2/lv2-gtk2gui.h?cvsroot=traverso&rev=1.1

Patches:
Index: lv2-gtk2gui.h
===================================================================
RCS file: lv2-gtk2gui.h
diff -N lv2-gtk2gui.h
--- /dev/null   1 Jan 1970 00:00:00 -0000
+++ lv2-gtk2gui.h       6 Nov 2007 18:32:21 -0000       1.1
@@ -0,0 +1,212 @@
+/************************************************************************
+ *
+ * GTK2 in-process UI extension for LV2
+ *
+ * Copyright (C) 2006 Lars Luthman <address@hidden>
+ * 
+ * Based on lv2.h, which is 
+ *
+ * Copyright (C) 2000-2002 Richard W.E. Furse, Paul Barton-Davis, Stefan
+ * Westerfeld
+ * Copyright (C) 2006 Steve Harris, Dave 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 GTK2 GUIs for plugins. The GUIs will be plugins that
+    will reside in shared object files in a LV2 bundle and be referenced in 
+    the RDF file using the triples
+<pre>    
+    <http://my.plugin> <http://ll-plugins.nongnu.org/lv2/ext/gtk2gui#gui> 
<http://my.plugingui>
+    <http://my.plugingui> 
<http://ll-plugins.nongnu.org/lv2/ext/gtk2gui#binary> <mygui.so>
+</pre>
+    where <http://my.plugin> is the URI of the plugin, <http://my.plugingui> is
+    the URI of the plugin GUI and <mygui.so> is the relative URI to the shared 
+    object file. While it is possible to have the plugin GUI 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 GUIs don't have to load the GUI 
code.
+    
+    It's entirely possible to have multiple GUIs for the same plugin, or to 
have
+    the GUI for a plugin in a different bundle from the actual plugin - this
+    way people other than the plugin author can write plugin GUIs independently
+    without editing the original plugin bundle. If a GUI is in a separate 
bundle
+    the first triple above should be in that bundle's manifest.ttl file so that
+    hosts can find the GUI when scanning the manifests.
+    
+    Note that the process that loads the shared object file containing the GUI
+    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 GUI 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
+    GUI 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 GUI, this extension allows for meta-extensions that
+    can extend the interface between the GUI and the host. See the
+    instantiate() and extension_data() callback pointers for more details.
+    
+    Note that this extension is NOT a Host Feature. There is no way for a 
plugin
+    to know whether the host that loads it supports GUIs or not, and the plugin
+    must ALWAYS work without the GUI (although it may be rather useless unless
+    it has been configured using the GUI in a previous session).
+    
+    GUIs written to this specification do not need to be threadsafe - the 
+    functions defined below may only be called in the same thread as the GTK
+    main loop is running in.
+*/
+
+#ifndef LV2_GTK2GUI_H
+#define LV2_GTK2GUI_H
+
+#include "lv2.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The original header includes <gtk/gtkwidget.h>, but we don't want
+   libslv2 to depend on GTK+ so we forward declare the _GtkWidget struct
+   instead. */
+struct _GtkWidget;
+
+
+
+/** This handle indicates a particular instance of a GUI.
+    It is valid to compare this to NULL (0 for C++) but otherwise the 
+    host MUST not attempt to interpret it. The GUI 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 
+    GUI plugin MUST not attempt to interpret it. The host may use it to 
+    reference internal instance data. */
+typedef void* LV2UI_Controller;
+
+
+/** This is the type of the host-provided function that changes the value
+    of a control rate float input port in a plugin instance. A function
+    pointer of this type will be provided to the GUI by the host in the
+    instantiate() function. */
+typedef void (*LV2UI_Set_Control_Function)(LV2UI_Controller controller,
+                                           uint32_t         port,
+                                           float            value);
+
+
+typedef struct _LV2UI_Descriptor {
+  
+  /** The URI for this GUI (not for the plugin it controls). */
+  const char* URI;
+  
+  /** Create a new GUI object and return a handle to it. This function works
+      similarly to the instantiate() member in LV2_Descriptor, with the 
+      additions that the URI for the plugin that this GUI is for is passed
+      as a parameter, a function pointer and a controller handle are passed to
+      allow the plugin to change control port values in the plugin 
+      (control_function and controller) and a pointer to a GtkWidget pointer
+      is passed, which the GUI plugin should set to point to a newly created
+      widget which will be the main GUI for the plugin.
+      
+      The features array works like the one in the instantiate() member
+      in LV2_Descriptor, except that the URIs should be denoted with the 
triples
+      <pre>
+      <http://my.plugingui> 
<http://ll-plugins.nongnu.org/lv2/dev/gtk2gui#optionalFeature> 
<http://my.guifeature>
+      </pre>
+      or 
+      <pre>
+      <http://my.plugingui> 
<http://ll-plugins.nongnu.org/lv2/dev/gtk2gui#requiredFeature> 
<http://my.guifeature>
+      </pre>
+      in the RDF file, instead of the lv2:optionalFeature or 
lv2:requiredFeature
+      that is used by host features. These features are associated with the 
GUI,
+      not with the plugin - they are not actually LV2 Host Features, they just
+      use the same data structure.
+      
+      The same rules apply for these features as for normal host features -
+      if a feature is listed as required in the RDF file and the host does not
+      support it, it must not load the GUI.
+  */
+  LV2UI_Handle (*instantiate)(const struct _LV2UI_Descriptor* descriptor,
+                              const char*                     plugin_uri,
+                              const char*                     bundle_path,
+                              LV2UI_Set_Control_Function      control_function,
+                              LV2UI_Controller                controller,
+                              struct _GtkWidget**             widget,
+                              const LV2_Host_Feature**        features);
+
+  
+  /** Destroy the GUI object and the associated widget. 
+   */
+  void (*cleanup)(LV2UI_Handle  gui);
+  
+  /** Tell the GUI that a control port value has changed. This member may be
+      set to NULL if the GUI is not interested in control port changes. 
+  */
+  void (*set_control)(LV2UI_Handle   gui,
+                      uint32_t       port,
+                      float          value);
+  
+  /** 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 GUI is not interested in supporting any extensions. This is 
similar
+      to the extension_data() member in LV2_Descriptor.
+  */
+  void* (*extension_data)(LV2UI_Handle    gui,
+                          const char*     uri);
+
+} LV2UI_Descriptor;
+
+
+
+/** Accessing a plugin GUI.
+    
+    A plugin 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 GUI 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
+    is returned.
+*/
+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