public void setNumericTransformer(NumericTransformer transformer) {
        mNumericTransformer = transformer != null ? transformer : new DefaultNumericTransformer();
        //We need to refresh the PopupIndicator view
        if (!isInEditMode() && mIndicator != null) {
            if (mNumericTransformer.useStringTransform()) {
                mIndicator.setIndicatorSizes(mNumericTransformer.transformToString(mMax));
            } else {
                mIndicator.setIndicatorSizes(convertValueToMessage(mNumericTransformer.transform(mMax)));
            }
        }
        updateProgressMessage(mValue);
    }
Sets the current {@link NumericTransformer}

@param transformer NumericTransformer transformer
@see #getNumericTransformer()
caprice/ui/src/main/java/net/qiujuer/genius/ui/widget/AbsSeekBar.java