/*
 * Example written in answer to a question on StackOverflow.
 * http://stackoverflow.com/questions/39437838
 */
package com.itextpdf.sandbox.text;
 
import com.itextpdf.kernel.color.Color;
import com.itextpdf.kernel.geom.PageSize;
import com.itextpdf.kernel.geom.Rectangle;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
import com.itextpdf.kernel.pdf.canvas.draw.ILineDrawer;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.element.Tab;
import com.itextpdf.layout.element.TabStop;
import com.itextpdf.layout.property.TabAlignment;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
 
/**
 * @author bruno
 */
public class CenterText {
    class MyLine implements ILineDrawer {
        private float lineWidth = 1;
        private float offset = 5;
        private Color color = Color.BLACK;
        @Override
        public void draw(PdfCanvas canvas, Rectangle drawArea) {
            canvas.saveState()
                .setStrokeColor(color)
                .setLineWidth(lineWidth)
                .moveTo(drawArea.getX(), drawArea.getY() + lineWidth / 2 + offset)
                .lineTo(drawArea.getX() + drawArea.getWidth(), drawArea.getY() + lineWidth / 2 + offset)
                .stroke()
                .restoreState();
        }
 
        @Override
        public float getLineWidth() {
            return lineWidth;
        }
        @Override
        public void setLineWidth(float lineWidth) {
            this.lineWidth = lineWidth;
        }
        @Override
        public Color getColor() {
            return color;
        }
        @Override
        public void setColor(Color color) {
            this.color = color;
        }
        public float getOffset() {
            return offset;
        }
        public void setOffset(float poffset) {
            this.offset = offset;
        }
        
    }
    
    public static final String DEST = "results/text/center_text.pdf";
    
    public static void main(String[] args) throws IOException {
        File file = new File(DEST);
        file.getParentFile().mkdirs();
        new CenterText().createPdf(DEST);
    }
    public void createPdf(String dest) throws IOException {
        PdfDocument pdf = new PdfDocument(new PdfWriter(dest));
        PageSize pagesize = PageSize.A4;
        Document document = new Document(pdf, pagesize);
        float w = pagesize.getWidth() - document.getLeftMargin() - document.getRightMargin();
        MyLine line = new MyLine();
        List<TabStop> tabstops = new ArrayList();
        tabstops.add(new TabStop(w / 2, TabAlignment.CENTER, line));
        tabstops.add(new TabStop(w, TabAlignment.LEFT, line));
        Paragraph p = new Paragraph();
        p.addTabStops(tabstops);
        p.add(new Tab()).add("Text in the middle").add(new Tab());
        document.add(p);
        document.close();
    }
}