libcamera: Move extensible to class

The Extensible concept is a generic Class helper. To prepare for
further class helper additions, move the specific extensible
implementation and header to a more generic class header and source.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/camera.h

@@ -12,8 +12,8 @@
 #include <stdint.h>
 #include <string>
 
+#include <libcamera/class.h>
 #include <libcamera/controls.h>
-#include <libcamera/extensible.h>
 #include <libcamera/object.h>
 #include <libcamera/request.h>
 #include <libcamera/signal.h>

include/libcamera/camera_manager.h

@@ -12,7 +12,7 @@
 #include <sys/types.h>
 #include <vector>
 
-#include <libcamera/extensible.h>
+#include <libcamera/class.h>
 #include <libcamera/object.h>
 #include <libcamera/signal.h>
 

include/libcamera/class.h

@@ -2,10 +2,10 @@
 /*
  * Copyright (C) 2020, Google Inc.
  *
- * extensible.h - Utilities to create extensible public classes with stable ABIs
+ * class.h - Utilities and helpers for classes
  */
-#ifndef __LIBCAMERA_EXTENSIBLE_H__
-#define __LIBCAMERA_EXTENSIBLE_H__
+#ifndef __LIBCAMERA_CLASS_H__
+#define __LIBCAMERA_CLASS_H__
 
 #include <memory>
 
@@ -84,4 +84,4 @@ private:
 
 } /* namespace libcamera */
 
-#endif /* __LIBCAMERA_EXTENSIBLE_H__ */
+#endif /* __LIBCAMERA_CLASS_H__ */

include/libcamera/meson.build

@@ -5,9 +5,9 @@ libcamera_public_headers = files([
     'buffer.h',
     'camera.h',
     'camera_manager.h',
+    'class.h',
     'compiler.h',
     'controls.h',
-    'extensible.h',
     'file_descriptor.h',
     'framebuffer_allocator.h',
     'geometry.h',

src/libcamera/class.cpp

@@ -2,14 +2,17 @@
 /*
  * Copyright (C) 2020, Google Inc.
  *
- * extensible.cpp - Utilities to create extensible public classes with stable ABIs
+ * class.cpp - Utilities and helpers for classes
  */
 
-#include <libcamera/extensible.h>
+#include <libcamera/class.h>
 
 /**
- * \file extensible.h
- * \brief Utilities to create extensible public classes with stable ABIs
+ * \file class.h
+ * \brief Utilities to help constructing class interfaces
+ *
+ * The extensible class can be inherited to create public classes with stable
+ * ABIs.
  */
 
 namespace libcamera {

src/libcamera/meson.build

@@ -9,6 +9,7 @@ libcamera_sources = files([
     'camera_controls.cpp',
     'camera_manager.cpp',
     'camera_sensor.cpp',
+    'class.cpp',
     'controls.cpp',
     'control_serializer.cpp',
     'control_validator.cpp',
@@ -18,7 +19,6 @@ libcamera_sources = files([
     'event_dispatcher.cpp',
     'event_dispatcher_poll.cpp',
     'event_notifier.cpp',
-    'extensible.cpp',
     'file.cpp',
     'file_descriptor.cpp',
     'formats.cpp',