1 /* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.example.android.common.logger; 17 18 import android.app.Activity; 19 import android.content.Context; 20 import android.util.*; 21 import android.widget.TextView; 22 23 /** Simple TextView which is used to output log data received through the LogNode interface. 24 */ 25 public class LogView extends TextView implements LogNode { 26 27 public LogView(Context context) { 28 super(context); 29 } 30 31 public LogView(Context context, AttributeSet attrs) { 32 super(context, attrs); 33 } 34 35 public LogView(Context context, AttributeSet attrs, int defStyle) { 36 super(context, attrs, defStyle); 37 } 38 39 /** 40 * Formats the log data and prints it out to the LogView. 41 * @param priority Log level of the data being logged. Verbose, Error, etc. 42 * @param tag Tag for for the log data. Can be used to organize log statements. 43 * @param msg The actual message to be logged. The actual message to be logged. 44 * @param tr If an exception was thrown, this can be sent along for the logging facilities 45 * to extract and print useful information. 46 */ 47 @Override 48 public void println(int priority, String tag, String msg, Throwable tr) { 49 50 51 String priorityStr = null; 52 53 // For the purposes of this View, we want to print the priority as readable text. 54 switch(priority) { 55 case android.util.Log.VERBOSE: 56 priorityStr = "VERBOSE"; 57 break; 58 case android.util.Log.DEBUG: 59 priorityStr = "DEBUG"; 60 break; 61 case android.util.Log.INFO: 62 priorityStr = "INFO"; 63 break; 64 case android.util.Log.WARN: 65 priorityStr = "WARN"; 66 break; 67 case android.util.Log.ERROR: 68 priorityStr = "ERROR"; 69 break; 70 case android.util.Log.ASSERT: 71 priorityStr = "ASSERT"; 72 break; 73 default: 74 break; 75 } 76 77 // Handily, the Log class has a facility for converting a stack trace into a usable string. 78 String exceptionStr = null; 79 if (tr != null) { 80 exceptionStr = android.util.Log.getStackTraceString(tr); 81 } 82 83 // Take the priority, tag, message, and exception, and concatenate as necessary 84 // into one usable line of text. 85 final StringBuilder outputBuilder = new StringBuilder(); 86 87 String delimiter = "\t"; 88 appendIfNotNull(outputBuilder, priorityStr, delimiter); 89 appendIfNotNull(outputBuilder, tag, delimiter); 90 appendIfNotNull(outputBuilder, msg, delimiter); 91 appendIfNotNull(outputBuilder, exceptionStr, delimiter); 92 93 // In case this was originally called from an AsyncTask or some other off-UI thread, 94 // make sure the update occurs within the UI thread. 95 ((Activity) getContext()).runOnUiThread( (new Thread(new Runnable() { 96 @Override 97 public void run() { 98 // Display the text we just generated within the LogView. 99 appendToLog(outputBuilder.toString()); 100 } 101 }))); 102 103 if (mNext != null) { 104 mNext.println(priority, tag, msg, tr); 105 } 106 } 107 108 public LogNode getNext() { 109 return mNext; 110 } 111 112 public void setNext(LogNode node) { 113 mNext = node; 114 } 115 116 /** Takes a string and adds to it, with a separator, if the bit to be added isn't null. Since 117 * the logger takes so many arguments that might be null, this method helps cut out some of the 118 * agonizing tedium of writing the same 3 lines over and over. 119 * @param source StringBuilder containing the text to append to. 120 * @param addStr The String to append 121 * @param delimiter The String to separate the source and appended strings. A tab or comma, 122 * for instance. 123 * @return The fully concatenated String as a StringBuilder 124 */ 125 private StringBuilder appendIfNotNull(StringBuilder source, String addStr, String delimiter) { 126 if (addStr != null) { 127 if (addStr.length() == 0) { 128 delimiter = ""; 129 } 130 131 return source.append(addStr).append(delimiter); 132 } 133 return source; 134 } 135 136 // The next LogNode in the chain. 137 LogNode mNext; 138 139 /** Outputs the string as a new line of log data in the LogView. */ 140 public void appendToLog(String s) { 141 append("\n" + s); 142 } 143 144 145 }