content: /*
   * Copyright (C) 2012 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;
  
  import android.util.Log;
  
  /**
   * Helper class which wraps Android's native Log utility in the Logger interface.  This way
   * normal DDMS output can be one of the many targets receiving and outputting logs simultaneously.
   */
  public class LogWrapper implements LogNode {
  
      // For piping:  The next node to receive Log data after this one has done its work.
      private LogNode mNext;
  
      /**
       * Returns the next LogNode in the linked list.
       */
      public LogNode getNext() {
          return mNext;
      }
  
      /**
       * Sets the LogNode data will be sent to..
       */
      public void setNext(LogNode node) {
          mNext = node;
      }
  
      /**
       * Prints data out to the console using Android's native log mechanism.
       * @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.
       * @param tr If an exception was thrown, this can be sent along for the logging facilities
       *           to extract and print useful information.
       */
      @Override
      public void println(int priority, String tag, String msg, Throwable tr) {
          // There actually are log methods that don't take a msg parameter.  For now,
          // if that's the case, just convert null to the empty string and move on.
          String useMsg = msg;
          if (useMsg == null) {
              useMsg = "";
          }
  
          // If an exeption was provided, convert that exception to a usable string and attach
          // it to the end of the msg method.
          if (tr != null) {
              msg += "\n" + Log.getStackTraceString(tr);
          }
  
          // This is functionally identical to Log.x(tag, useMsg);
          // For instance, if priority were Log.VERBOSE, this would be the same as Log.v(tag, useMsg)
          Log.println(priority, tag, useMsg);
  
          // If this isn't the last node in the chain, move things along.
          if (mNext != null) {
              mNext.println(priority, tag, msg, tr);
          }
      }
  }
  