/**
 * This example was written by Bruno Lowagie in answer to a question by a customer.
 */
package sandbox.stamper;

import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Element;
import com.itextpdf.text.Font;
import com.itextpdf.text.Font.FontFamily;
import com.itextpdf.text.Phrase;
import com.itextpdf.text.pdf.ColumnText;
import com.itextpdf.text.pdf.PdfContentByte;
import com.itextpdf.text.pdf.PdfGState;
import com.itextpdf.text.pdf.PdfReader;
import com.itextpdf.text.pdf.PdfStamper;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import sandbox.WrapToTest;

@WrapToTest
public class TransparentWatermark {

    public static final String SRC = "resources/pdfs/hero.pdf";
    public static final String DEST = "results/stamper/hero_watermarked.pdf";

    public static void main(String[] args) throws IOException, DocumentException {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new TransparentWatermark().manipulatePdf(SRC, DEST);
    }

    public void manipulatePdf(String src, String dest) throws IOException, DocumentException {
        PdfReader reader = new PdfReader(src);
        PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
        PdfContentByte under = stamper.getUnderContent(1);
        Font f = new Font(FontFamily.HELVETICA, 15);
        Phrase p = new Phrase("This watermark is added UNDER the existing content", f);
        ColumnText.showTextAligned(under, Element.ALIGN_CENTER, p, 297, 550, 0);
        PdfContentByte over = stamper.getOverContent(1);
        p = new Phrase("This watermark is added ON TOP OF the existing content", f);
        ColumnText.showTextAligned(over, Element.ALIGN_CENTER, p, 297, 500, 0);
        p = new Phrase("This TRANSPARENT watermark is added ON TOP OF the existing content", f);
        over.saveState();
        PdfGState gs1 = new PdfGState();
        gs1.setFillOpacity(0.5f);
        over.setGState(gs1);
        ColumnText.showTextAligned(over, Element.ALIGN_CENTER, p, 297, 450, 0);
        over.restoreState();
        stamper.close();
        reader.close();
    }
}