public void setMaxWidth(float maxWidth) {
        mMaxWidth = convertDpToPx(maxWidth);
        mLastWidth = (mMinWidth + mMaxWidth) / 2f;
    }
Set the maximum width of the stroke in pixel.

@param maxWidth the width in dp.
signature-pad/src/main/java/com/github/gcacace/signaturepad/views/SignaturePad.java