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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
      5  * use this file except in compliance with the License. You may obtain a copy of
      6  * 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, WITHOUT
     12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
     13  * License for the specific language governing permissions and limitations under
     14  * the License.
     15  */
     16 
     17 package com.android.inputmethod.latin.utils;
     18 
     19 import android.util.Log;
     20 
     21 import com.android.inputmethod.latin.define.DebugFlags;
     22 
     23 /**
     24  * A class for logging and debugging utility methods.
     25  */
     26 public final class DebugLogUtils {
     27     private final static String TAG = DebugLogUtils.class.getSimpleName();
     28     private final static boolean sDBG = DebugFlags.DEBUG_ENABLED;
     29 
     30     /**
     31      * Calls .toString() on its non-null argument or returns "null"
     32      * @param o the object to convert to a string
     33      * @return the result of .toString() or null
     34      */
     35     public static String s(final Object o) {
     36         return null == o ? "null" : o.toString();
     37     }
     38 
     39     /**
     40      * Get the string representation of the current stack trace, for debugging purposes.
     41      * @return a readable, carriage-return-separated string for the current stack trace.
     42      */
     43     public static String getStackTrace() {
     44         return getStackTrace(Integer.MAX_VALUE - 1);
     45     }
     46 
     47     /**
     48      * Get the string representation of the current stack trace, for debugging purposes.
     49      * @param limit the maximum number of stack frames to be returned.
     50      * @return a readable, carriage-return-separated string for the current stack trace.
     51      */
     52     public static String getStackTrace(final int limit) {
     53         final StringBuilder sb = new StringBuilder();
     54         try {
     55             throw new RuntimeException();
     56         } catch (final RuntimeException e) {
     57             final StackTraceElement[] frames = e.getStackTrace();
     58             // Start at 1 because the first frame is here and we don't care about it
     59             for (int j = 1; j < frames.length && j < limit + 1; ++j) {
     60                 sb.append(frames[j].toString() + "\n");
     61             }
     62         }
     63         return sb.toString();
     64     }
     65 
     66     /**
     67      * Get the stack trace contained in an exception as a human-readable string.
     68      * @param t the throwable
     69      * @return the human-readable stack trace
     70      */
     71     public static String getStackTrace(final Throwable t) {
     72         final StringBuilder sb = new StringBuilder();
     73         final StackTraceElement[] frames = t.getStackTrace();
     74         for (int j = 0; j < frames.length; ++j) {
     75             sb.append(frames[j].toString() + "\n");
     76         }
     77         return sb.toString();
     78     }
     79 
     80     /**
     81      * Helper log method to ease null-checks and adding spaces.
     82      *
     83      * This sends all arguments to the log, separated by spaces. Any null argument is converted
     84      * to the "null" string. It uses a very visible tag and log level for debugging purposes.
     85      *
     86      * @param args the stuff to send to the log
     87      */
     88     public static void l(final Object... args) {
     89         if (!sDBG) return;
     90         final StringBuilder sb = new StringBuilder();
     91         for (final Object o : args) {
     92             sb.append(s(o).toString());
     93             sb.append(" ");
     94         }
     95         Log.e(TAG, sb.toString());
     96     }
     97 
     98     /**
     99      * Helper log method to put stuff in red.
    100      *
    101      * This does the same as #l but prints in red
    102      *
    103      * @param args the stuff to send to the log
    104      */
    105     public static void r(final Object... args) {
    106         if (!sDBG) return;
    107         final StringBuilder sb = new StringBuilder("\u001B[31m");
    108         for (final Object o : args) {
    109             sb.append(s(o).toString());
    110             sb.append(" ");
    111         }
    112         sb.append("\u001B[0m");
    113         Log.e(TAG, sb.toString());
    114     }
    115 }
    116