Initial log api definition

fixed WithLogImpl::setLog; removed global ConsoleLog instance;
updated Freenect2 to manage lifetime of Log instance

renamed Log to Logger

added LIBFREENECT2_API macro to logging classes

added environment variable LIBFREENECT2_LOGGER_LEVEL to change
default logger level, possible values
'debug','info','warning','error'

made logger level immutable

Author: christiankerl

examples/protonect/CMakeLists.txt

@@ -102,6 +102,7 @@ SET(SOURCES
   src/command_transaction.cpp
   src/registration.cpp
   src/timer.cpp
+  src/logging.cpp
   src/libfreenect2.cpp
 
   ${LIBFREENECT2_THREADING_SOURCE}

examples/protonect/Protonect.cpp

@@ -58,6 +58,9 @@ int main(int argc, char *argv[])
   }
 
   libfreenect2::Freenect2 freenect2;
+  // create a console logger with debug level (default is console logger with info level)
+  freenect2.setLogger(libfreenect2::createConsoleLogger(libfreenect2::Logger::Debug));
+
   libfreenect2::Freenect2Device *dev = 0;
   libfreenect2::PacketPipeline *pipeline = 0;
 

examples/protonect/include/libfreenect2/libfreenect2.hpp

@@ -29,6 +29,7 @@
 
 #include <libfreenect2/config.h>
 #include <libfreenect2/frame_listener.hpp>
+#include <libfreenect2/logging.h>
 
 namespace libfreenect2
 {
@@ -95,12 +96,15 @@ class LIBFREENECT2_API Freenect2Device
 
 class Freenect2Impl;
 
-class LIBFREENECT2_API Freenect2
+class LIBFREENECT2_API Freenect2 : public WithLogger
 {
 public:
   Freenect2(void *usb_context = 0);
   virtual ~Freenect2();
 
+  virtual void setLogger(Logger *logger);
+  virtual Logger *logger();
+
   int enumerateDevices();
 
   std::string getDeviceSerialNumber(int idx);

examples/protonect/include/libfreenect2/logging.h

@@ -0,0 +1,104 @@
+/*
+ * This file is part of the OpenKinect Project. http://www.openkinect.org
+ *
+ * Copyright (c) 2014 individual OpenKinect contributors. See the CONTRIB file
+ * for details.
+ *
+ * This code is licensed to you under the terms of the Apache License, version
+ * 2.0, or, at your option, the terms of the GNU General Public License,
+ * version 2.0. See the APACHE20 and GPL2 files for the text of the licenses,
+ * or the following URLs:
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * http://www.gnu.org/licenses/gpl-2.0.txt
+ *
+ * If you redistribute this file in source form, modified or unmodified, you
+ * may:
+ *   1) Leave this header intact and distribute it under the same terms,
+ *      accompanying it with the APACHE20 and GPL20 files, or
+ *   2) Delete the Apache 2.0 clause and accompany it with the GPL2 file, or
+ *   3) Delete the GPL v2 clause and accompany it with the APACHE20 file
+ * In all cases you must keep the copyright notice intact and include a copy
+ * of the CONTRIB file.
+ *
+ * Binary distributions must follow the binary distribution requirements of
+ * either License.
+ */
+
+#ifndef LOGGING_H_
+#define LOGGING_H_
+
+#include <string>
+#include <sstream>
+
+#include <libfreenect2/config.h>
+
+namespace libfreenect2
+{
+
+class LIBFREENECT2_API Logger
+{
+public:
+  enum Level
+  {
+    Debug = 1,
+    Info = 2,
+    Warning = 3,
+    Error = 4,
+  };
+  static Level getDefaultLevel();
+
+  virtual ~Logger();
+
+  virtual Level level() const;
+
+  virtual void log(Level level, const std::string &message) = 0;
+protected:
+  Level level_;
+};
+
+LIBFREENECT2_API Logger *createConsoleLogger(Logger::Level level);
+LIBFREENECT2_API Logger *createConsoleLoggerWithDefaultLevel();
+LIBFREENECT2_API Logger *createNoopLogger();
+
+class LIBFREENECT2_API LogMessage
+{
+private:
+  Logger *logger_;
+  Logger::Level level_;
+  std::ostringstream stream_;
+public:
+  LogMessage(Logger *logger, Logger::Level level);
+  ~LogMessage();
+
+  std::ostream &stream();
+};
+
+class LIBFREENECT2_API WithLogger
+{
+public:
+  virtual ~WithLogger();
+  virtual void setLogger(Logger *logger) = 0;
+  virtual Logger *logger() = 0;
+};
+
+class LIBFREENECT2_API WithLoggerImpl : public WithLogger
+{
+protected:
+  Logger *logger_;
+
+  virtual void onLoggerChanged(Logger *logger);
+public:
+  WithLoggerImpl();
+  virtual ~WithLoggerImpl();
+  virtual void setLogger(Logger *logger);
+  virtual Logger *logger();
+};
+
+} /* namespace libfreenect2 */
+
+#define LOG_DEBUG (::libfreenect2::LogMessage(logger(), ::libfreenect2::Logger::Debug).stream())
+#define LOG_INFO (::libfreenect2::LogMessage(logger(), ::libfreenect2::Logger::Info).stream())
+#define LOG_WARNING (::libfreenect2::LogMessage(logger(), ::libfreenect2::Logger::Warning).stream())
+#define LOG_ERROR (::libfreenect2::LogMessage(logger(), ::libfreenect2::Logger::Error).stream())
+
+#endif /* LOGGING_H_ */