javaexample.RadialTextPdf.java Source code

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Here is the source code for javaexample.RadialTextPdf.java

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/*
 * Copyright (C) 2016 Andrea Binello ("andbin")
 *
 * This file is part of the "Java Examples" project and is licensed under the
 * MIT License. See one of the license files included in the root of the project
 * for the full text of the license.
 */

package javaexample;

import static javaexample.util.MeasureUtils.degrees2Radians;
import java.awt.Color;
import java.awt.geom.AffineTransform;
import java.io.IOException;
import org.apache.pdfbox.exceptions.COSVisitorException;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDDocumentInformation;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.edit.PDPageContentStream;
import org.apache.pdfbox.pdmodel.font.PDFont;
import org.apache.pdfbox.pdmodel.font.PDType1Font;

public class RadialTextPdf {
    private String filename;
    private PDRectangle pageRect;

    public RadialTextPdf(String filename, PDRectangle pageRect) {
        this.filename = filename;
        this.pageRect = pageRect;
    }

    public String getFilename() {
        return filename;
    }

    public void generateDocument() throws IOException, COSVisitorException {
        PDDocument document = new PDDocument();

        try {
            // Sets some document metadata.
            PDDocumentInformation information = new PDDocumentInformation();
            information.setTitle("Radial Text PDF example with Apache PDFBox");
            information.setAuthor("Andrea Binello (\"andbin\")");
            document.setDocumentInformation(information);

            // Generates and saves the document.
            generatePage(document);
            document.save(filename);
        } finally {
            try {
                document.close();
            } catch (IOException e) {
            }
        }
    }

    private void generatePage(PDDocument document) throws IOException {
        // Creates a new page.
        PDPage page = new PDPage(pageRect);
        document.addPage(page);

        // Gets boundings of the page.
        PDRectangle rect = page.getMediaBox();

        // Calculates the side of the square that fits into the page.
        float squareSide = Math.min(rect.getWidth(), rect.getHeight());

        // Calculates the center point of the page.
        float centerX = (rect.getLowerLeftX() + rect.getUpperRightX()) / 2;
        float centerY = (rect.getLowerLeftY() + rect.getUpperRightY()) / 2;

        PDPageContentStream cos = new PDPageContentStream(document, page);

        // Creates the font for the radial text.
        PDFont font = PDType1Font.HELVETICA_BOLD; // Standard font
        float fontSize = squareSide / 30;
        float fontAscent = font.getFontDescriptor().getAscent() / 1000 * fontSize;

        // Calculates key values for the drawings.
        float textX = squareSide / 3.4F; // x of the text.
        float textY = -fontAscent / 2; // y of the text (for vertical centering of text).
        float lineToX = textX * 0.97F; // x destination for the line.
        float lineWidth = squareSide / 900; // width of lines.

        // Moves the origin (0,0) of the axes to the center of the page.
        cos.concatenate2CTM(AffineTransform.getTranslateInstance(centerX, centerY));

        for (float degrees = 0; degrees < 360; degrees += 7.5) {
            double radians = degrees2Radians(degrees);

            // Creates a pure color with the hue based on the angle.
            Color textColor = Color.getHSBColor(degrees / 360.0F, 1, 1);

            // Saves the graphics state because the angle changes on each iteration.
            cos.saveGraphicsState();

            // Rotates the axes by the angle expressed in radians.
            cos.concatenate2CTM(AffineTransform.getRotateInstance(radians));

            // Draws a line from the center of the page.
            cos.setLineWidth(lineWidth);
            cos.moveTo(0, 0);
            cos.lineTo(lineToX, 0);
            cos.stroke();

            // Draws the radial text.
            cos.beginText();
            cos.setNonStrokingColor(textColor);
            cos.setFont(font, fontSize);
            cos.moveTextPositionByAmount(textX, textY);
            cos.drawString("PDF");
            cos.endText();

            // Restores the graphics state to remove rotation transformation.
            cos.restoreGraphicsState();
        }

        cos.close();
    }
}