libcamera/base: Move event_notifier to base

Move the event notifier, and associated header updates.

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

include/libcamera/base/event_notifier.h

@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * event_notifier.h - File descriptor event notifier
+ */
+#ifndef __LIBCAMERA_BASE_EVENT_NOTIFIER_H__
+#define __LIBCAMERA_BASE_EVENT_NOTIFIER_H__
+
+#include <libcamera/base/object.h>
+#include <libcamera/base/signal.h>
+
+namespace libcamera {
+
+class Message;
+
+class EventNotifier : public Object
+{
+public:
+	enum Type {
+		Read,
+		Write,
+		Exception,
+	};
+
+	EventNotifier(int fd, Type type, Object *parent = nullptr);
+	virtual ~EventNotifier();
+
+	Type type() const { return type_; }
+	int fd() const { return fd_; }
+
+	bool enabled() const { return enabled_; }
+	void setEnabled(bool enable);
+
+	Signal<EventNotifier *> activated;
+
+protected:
+	void message(Message *msg) override;
+
+private:
+	int fd_;
+	Type type_;
+	bool enabled_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_BASE_EVENT_NOTIFIER_H__ */

include/libcamera/base/meson.build

@@ -7,6 +7,7 @@ libcamera_base_headers = files([
     'class.h',
     'event_dispatcher.h',
     'event_dispatcher_poll.h',
+    'event_notifier.h',
     'file.h',
     'log.h',
     'message.h',