libcamera/base: Move class helpers to the base library

Move the class support infrastructure to the base library.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

2 files changed, 106 insertions, 0 deletions

diff --git a/include/libcamera/base/class.h b/include/libcamera/base/class.h
new file mode 100644
index 00000000..a07dac05
--- /dev/null
+++ b/include/libcamera/base/class.h
@@ -0,0 +1,105 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * class.h - Utilities and helpers for classes
+ */
+#ifndef __LIBCAMERA_BASE_CLASS_H__
+#define __LIBCAMERA_BASE_CLASS_H__
+
+#include <memory>
+
+namespace libcamera {
+
+#ifndef __DOXYGEN__
+#define LIBCAMERA_DISABLE_COPY(klass)  \
+	klass(const klass &) = delete; \
+	klass &operator=(const klass &) = delete;
+
+#define LIBCAMERA_DISABLE_MOVE(klass) \
+	klass(klass &&) = delete;     \
+	klass &operator=(klass &&) = delete;
+
+#define LIBCAMERA_DISABLE_COPY_AND_MOVE(klass) \
+	LIBCAMERA_DISABLE_COPY(klass)          \
+	LIBCAMERA_DISABLE_MOVE(klass)
+#else
+#define LIBCAMERA_DISABLE_COPY(klass)
+#define LIBCAMERA_DISABLE_MOVE(klass)
+#define LIBCAMERA_DISABLE_COPY_AND_MOVE(klass)
+#endif
+
+#ifndef __DOXYGEN__
+#define LIBCAMERA_DECLARE_PRIVATE()					\
+public:									\
+	class Private;							\
+	friend class Private;
+
+#define LIBCAMERA_DECLARE_PUBLIC(klass)					\
+	friend class klass;						\
+	using Public = klass;
+
+#define LIBCAMERA_D_PTR()						\
+	_d<Private>();
+
+#define LIBCAMERA_O_PTR()						\
+	_o<Public>();
+
+#else
+#define LIBCAMERA_DECLARE_PRIVATE()
+#define LIBCAMERA_DECLARE_PUBLIC(klass)
+#define LIBCAMERA_D_PTR()
+#define LIBCAMERA_O_PTR()
+#endif
+
+class Extensible
+{
+public:
+	class Private
+	{
+	public:
+		Private(Extensible *o);
+		virtual ~Private();
+
+#ifndef __DOXYGEN__
+		template<typename T>
+		const T *_o() const
+		{
+			return static_cast<const T *>(o_);
+		}
+
+		template<typename T>
+		T *_o()
+		{
+			return static_cast<T *>(o_);
+		}
+#endif
+
+	private:
+		Extensible *const o_;
+	};
+
+	Extensible(Private *d);
+
+protected:
+#ifndef __DOXYGEN__
+	template<typename T>
+	const T *_d() const
+	{
+		return static_cast<const T *>(d_.get());
+	}
+
+	template<typename T>
+	T *_d()
+	{
+		return static_cast<T *>(d_.get());
+	}
+#endif
+
+private:
+	const std::unique_ptr<Private> d_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_BASE_CLASS_H__ */
diff --git a/include/libcamera/base/meson.build b/include/libcamera/base/meson.build
index 9f0ba6b0..2db756c5 100644
--- a/include/libcamera/base/meson.build
+++ b/include/libcamera/base/meson.build
@@ -3,6 +3,7 @@
 libcamera_base_include_dir = libcamera_include_dir / 'base'
 
 libcamera_base_headers = files([
+    'class.h',
     'utils.h',
 ])