//
// Swiss QR Bill Generator
// Copyright (c) 2017 Manuel Bleichenbacher
// Licensed under MIT License
// https://opensource.org/licenses/MIT
//
package net.codecrete.qrbill.canvas;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.util.Matrix;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
/**
* Canvas for generating PDF files.
* <p>
* The PDF generator currently only supports the Helvetica font.
* </p>
*/
public class PDFCanvas extends AbstractCanvas implements ByteArrayResult {
/**
* Add the QR bill on the last page of the PDF document.
*/
public static final int LAST_PAGE = -1;
/**
* Add the QR bill on a new page at the end of the PDF document.
*/
public static final int NEW_PAGE_AT_END = -2;
private PDDocument document;
private PDPageContentStream contentStream;
private int lastStrokingColor = 0;
private int lastNonStrokingColor = 0;
private double lastLineWidth = 1;
private LineStyle lastLineStyle = LineStyle.Solid;
private boolean hasSavedGraphicsState = false;
/**
* Creates a new instance using the specified page size.
* @param width page width, in mm
* @param height page height, in mm
* @throws IOException thrown if the creation fails
*/
public PDFCanvas(double width, double height) throws IOException {
setupFontMetrics("Helvetica");
document = new PDDocument();
document.getDocumentInformation().setTitle("Swiss QR Bill");
PDPage page = new PDPage(new PDRectangle((float) (width * MM_TO_PT), (float) (height * MM_TO_PT)));
document.addPage(page);
contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.OVERWRITE, true);
}
/**
* Creates a new instance for adding the QR bill to an exiting PDF document.
* <p>
* The QR bill can either be added to an existing page by specifying the page number
* of an existing page (or {@link #LAST_PAGE}), or it can be added to a new page
* at the end of the document (see {@link #NEW_PAGE_AT_END}).
* </p>
* <p>
* The created instance assumes that the page for the QR bill has A4 format and
* will add the QR bill at the bottom of the page.
* </p>
* @param path path to exiting document
* @param pageNo the zero-based number of the page the QR bill should be added to
* @throws IOException thrown if the creation fails
*/
public PDFCanvas(Path path, int pageNo) throws IOException {
setupFontMetrics("Helvetica");
document = PDDocument.load(path.toFile());
if (pageNo == NEW_PAGE_AT_END) {
PDPage page = new PDPage(new PDRectangle((float) (210 * MM_TO_PT), (float) (297 * MM_TO_PT)));
document.addPage(page);
contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.OVERWRITE, true, true);
} else {
if (pageNo == LAST_PAGE)
pageNo = document.getNumberOfPages() - 1;
PDPage page = document.getPage(pageNo);
PDRectangle rect = page.getBBox();
contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.APPEND, true, true);
}
}
@Override
public void setTransformation(double translateX, double translateY, double rotate, double scaleX, double scaleY) throws IOException {
translateX *= MM_TO_PT;
translateY *= MM_TO_PT;
if (hasSavedGraphicsState) {
contentStream.restoreGraphicsState();
lastStrokingColor = 0;
lastNonStrokingColor = 0;
lastLineWidth = 1;
}
contentStream.saveGraphicsState();
hasSavedGraphicsState = true;
Matrix matrix = new Matrix();
matrix.translate((float) translateX, (float) translateY);
if (rotate != 0)
matrix.rotate(rotate);
if (scaleX != 1 || scaleY != 1)
matrix.scale((float) scaleX, (float) scaleY);
contentStream.transform(matrix);
}
@Override
public void putText(String text, double x, double y, int fontSize, boolean isBold) throws IOException {
x *= MM_TO_PT;
y *= MM_TO_PT;
contentStream.setFont(isBold ? PDType1Font.HELVETICA_BOLD : PDType1Font.HELVETICA, fontSize);
contentStream.beginText();
contentStream.newLineAtOffset((float) x, (float) y);
contentStream.showText(text);
contentStream.endText();
}
@Override
public void putTextLines(String[] lines, double x, double y, int fontSize, double leading) throws IOException {
x *= MM_TO_PT;
y *= MM_TO_PT;
float lineHeight = (float) ((fontMetrics.getLineHeight(fontSize) + leading) * MM_TO_PT);
contentStream.setFont(PDType1Font.HELVETICA, fontSize);
contentStream.beginText();
contentStream.newLineAtOffset((float) x, (float) y);
boolean isFirstLine = true;
for (String line : lines) {
if (isFirstLine) {
isFirstLine = false;
} else {
contentStream.newLineAtOffset(0, -lineHeight);
}
contentStream.showText(line);
}
contentStream.endText();
}
@Override
public void startPath() {
// path is start implicitly
}
@Override
public void moveTo(double x, double y) throws IOException {
x *= MM_TO_PT;
y *= MM_TO_PT;
contentStream.moveTo((float) x, (float) y);
}
@Override
public void lineTo(double x, double y) throws IOException {
x *= MM_TO_PT;
y *= MM_TO_PT;
contentStream.lineTo((float) x, (float) y);
}
@Override
public void cubicCurveTo(double x1, double y1, double x2, double y2, double x, double y) throws IOException {
x1 *= MM_TO_PT;
y1 *= MM_TO_PT;
x2 *= MM_TO_PT;
y2 *= MM_TO_PT;
x *= MM_TO_PT;
y *= MM_TO_PT;
contentStream.curveTo((float) x1, (float) y1, (float) x2, (float) y2, (float) x, (float) y);
}
@Override
public void addRectangle(double x, double y, double width, double height) throws IOException {
x *= MM_TO_PT;
y *= MM_TO_PT;
width *= MM_TO_PT;
height *= MM_TO_PT;
contentStream.addRect((float) x, (float) y, (float) width, (float) height);
}
@Override
public void closeSubpath() throws IOException {
contentStream.closePath();
}
@Override
public void fillPath(int color) throws IOException {
if (color != lastNonStrokingColor) {
lastNonStrokingColor = color;
int r = (color >> 16) & 0xff;
int g = (color >> 8) & 0xff;
int b = (color >> 8) & 0xff;
contentStream.setNonStrokingColor(r / 255f, g / 255f, b / 255f);
}
contentStream.fill();
}
@Override
public void strokePath(double strokeWidth, int color) throws IOException {
strokePath(strokeWidth, color, LineStyle.Solid);
}
@Override
public void strokePath(double strokeWidth, int color, LineStyle lineStyle) throws IOException {
if (color != lastStrokingColor) {
lastStrokingColor = color;
int r = (color >> 16) & 0xff;
int g = (color >> 8) & 0xff;
int b = (color >> 8) & 0xff;
contentStream.setStrokingColor(r / 255f, g / 255f, b / 255f);
}
if (lineStyle != lastLineStyle || (lineStyle != LineStyle.Solid && strokeWidth != lastLineWidth)) {
lastLineStyle = lineStyle;
float[] pattern;
switch (lineStyle) {
case Dashed:
pattern = new float[] { 4 * (float)strokeWidth };
break;
case Dotted:
pattern = new float[] { 0, 3 * (float)strokeWidth };
break;
default:
pattern = new float[] { };
}
contentStream.setLineCapStyle(lineStyle == LineStyle.Dotted ? 1 : 0);
contentStream.setLineDashPattern(pattern, 0);
}
if (strokeWidth != lastLineWidth) {
lastLineWidth = strokeWidth;
contentStream.setLineWidth((float) (strokeWidth));
}
contentStream.stroke();
}
@Override
public byte[] toByteArray() throws IOException {
if (contentStream != null) {
contentStream.close();
contentStream = null;
}
try (ByteArrayOutputStream os = new ByteArrayOutputStream()) {
document.save(os);
return os.toByteArray();
}
}
/**
* Writes the resulting PDF document to the specified output stream.
* @param os the output stream
* @throws IOException thrown if the image cannot be written
*/
public void writeTo(OutputStream os) throws IOException {
if (contentStream != null) {
contentStream.close();
contentStream = null;
}
document.save(os);
}
/**
* Saves the resulting PDF document to the specified path.
* @param path the path to write to
* @throws IOException thrown if the image cannot be written
*/
public void saveAs(Path path) throws IOException {
if (contentStream != null) {
contentStream.close();
contentStream = null;
}
try (OutputStream os = Files.newOutputStream(path)) {
document.save(os);
}
}
@Override
public void close() throws IOException {
if (contentStream != null) {
contentStream.close();
contentStream = null;
}
if (document != null) {
document.close();
document = null;
}
}
}
