public void setIndicatorFormatter(String formatter) {
        if (mIndicator != null) {
            mIndicatorFormatter = formatter;
            updateProgressMessage(mValue);
        }
    }
Sets the current Indicator formatter string

@param formatter Value formatter
@see String#format(String, Object...)
@see #setNumericTransformer(NumericTransformer)
caprice/ui/src/main/java/net/qiujuer/genius/ui/widget/AbsSeekBar.java