content: /*
   * Copyright (C) 2013 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package com.example.android.common.logger;
  
  /**
   * Helper class for a list (or tree) of LoggerNodes.
   *
   * <p>When this is set as the head of the list,
   * an instance of it can function as a drop-in replacement for {@link android.util.Log}.
   * Most of the methods in this class server only to map a method call in Log to its equivalent
   * in LogNode.</p>
   */
  public class Log {
      // Grabbing the native values from Android's native logging facilities,
      // to make for easy migration and interop.
      public static final int NONE = -1;
      public static final int VERBOSE = android.util.Log.VERBOSE;
      public static final int DEBUG = android.util.Log.DEBUG;
      public static final int INFO = android.util.Log.INFO;
      public static final int WARN = android.util.Log.WARN;
      public static final int ERROR = android.util.Log.ERROR;
      public static final int ASSERT = android.util.Log.ASSERT;
  
      // Stores the beginning of the LogNode topology.
      private static LogNode mLogNode;
  
      /**
       * Returns the next LogNode in the linked list.
       */
      public static LogNode getLogNode() {
          return mLogNode;
      }
  
      /**
       * Sets the LogNode data will be sent to.
       */
      public static void setLogNode(LogNode node) {
          mLogNode = node;
      }
  
      /**
       * Instructs the LogNode to print the log data provided. Other LogNodes can
       * be chained to the end of the LogNode as desired.
       *
       * @param priority Log level of the data being logged. Verbose, Error, etc.
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void println(int priority, String tag, String msg, Throwable tr) {
          if (mLogNode != null) {
              mLogNode.println(priority, tag, msg, tr);
          }
      }
  
      /**
       * Instructs the LogNode to print the log data provided. Other LogNodes can
       * be chained to the end of the LogNode as desired.
       *
       * @param priority Log level of the data being logged. Verbose, Error, etc.
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged. The actual message to be logged.
       */
      public static void println(int priority, String tag, String msg) {
          println(priority, tag, msg, null);
      }
  
     /**
       * Prints a message at VERBOSE priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void v(String tag, String msg, Throwable tr) {
          println(VERBOSE, tag, msg, tr);
      }
  
      /**
       * Prints a message at VERBOSE priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       */
      public static void v(String tag, String msg) {
          v(tag, msg, null);
      }
  
  
      /**
       * Prints a message at DEBUG priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void d(String tag, String msg, Throwable tr) {
          println(DEBUG, tag, msg, tr);
      }
  
      /**
       * Prints a message at DEBUG priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       */
      public static void d(String tag, String msg) {
          d(tag, msg, null);
      }
  
      /**
       * Prints a message at INFO priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void i(String tag, String msg, Throwable tr) {
          println(INFO, tag, msg, tr);
      }
  
      /**
       * Prints a message at INFO priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       */
      public static void i(String tag, String msg) {
          i(tag, msg, null);
      }
  
      /**
       * Prints a message at WARN priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void w(String tag, String msg, Throwable tr) {
          println(WARN, tag, msg, tr);
      }
  
      /**
       * Prints a message at WARN priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       */
      public static void w(String tag, String msg) {
          w(tag, msg, null);
      }
  
      /**
       * Prints a message at WARN priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void w(String tag, Throwable tr) {
          w(tag, null, tr);
      }
  
      /**
       * Prints a message at ERROR priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void e(String tag, String msg, Throwable tr) {
          println(ERROR, tag, msg, tr);
      }
  
      /**
       * Prints a message at ERROR priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       */
      public static void e(String tag, String msg) {
          e(tag, msg, null);
      }
  
      /**
       * Prints a message at ASSERT priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void wtf(String tag, String msg, Throwable tr) {
          println(ASSERT, tag, msg, tr);
      }
  
      /**
       * Prints a message at ASSERT priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param msg The actual message to be logged.
       */
      public static void wtf(String tag, String msg) {
          wtf(tag, msg, null);
      }
  
      /**
       * Prints a message at ASSERT priority.
       *
       * @param tag Tag for for the log data. Can be used to organize log statements.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      public static void wtf(String tag, Throwable tr) {
          wtf(tag, null, tr);
      }
  }
  