+ TimeFormatter
.twoDigits(calendar.get(Calendar.SECOND));
date = "[" + date + "]";
log_content.append(date);
StyleRange date_style = new StyleRange();
date_style.start = date_begin;
date_style.length = date.length();
date_style.foreground = date_foreground;
log_content.setStyleRange(date_style);
log_content.append(" ");
int style_begin = log_content.getText().length();
log_content.append(text);
log_content.append(System.getProperty("line.separator"));
StyleRange style = new StyleRange();
style.start = style_begin;
style.length = text.length();
style.foreground = foreground;
log_content.setStyleRange(style);