/**
     * create the prefix with the current time, it is create only if the last message was received
     * more than PAUSE_DETECTION_TIME_MS ms ago
     *
     * @param append if true force to create the prefix string
     * @return prefix string with the current time
     */
    private String appendDateTime(Boolean append) {
      String str = "";
      Date now = new Date();
      if (append || (now.getTime() - mLastMessageReceived.getTime() > PAUSE_DETECTION_TIME_MS)) {
        str += "\n[" + DATE_FORMAT.format(now) + mTargetConsole.getPrefix() + "]";
      }
      mLastMessageReceived = now;

      return str;
    } // appendDateTime
    /**
     * append the message to the console
     *
     * @param message message to add
     * @param std console to use for add the string
     */
    private void appendMessage(String message, ConsoleType std) {
      boolean forceAppendPrefix = (mTargetConsole != std);
      mTargetConsole = std;

      final SpannableStringBuilder displayText = new SpannableStringBuilder();

      displayText.append(appendDateTime(forceAppendPrefix));
      displayText.append(message);

      displayText.setSpan(
          new ForegroundColorSpan(getResources().getColor(mTargetConsole.getColorID())),
          0,
          displayText.length(),
          Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

      DebugConsoleActivity.this.runOnUiThread(
          new Runnable() {
            @Override
            public void run() {
              mConsole.append(displayText);
              mConsoleView.fullScroll(View.FOCUS_DOWN);
            } // run
          });
    } // appendMessage