Designing receipt for thermal printer in java

Question

I had a project in Android in which i made something like a shopping list app that would print to a receipt thermal printer. The way i designed the receipt was simple : i created an .xml layout in which i added 1 linear layout for the header,3 vertical linearlayouts for the columns and another for the footer.After that i would just programmatically add text to the layouts and then send the .xml to printing. It was great,i could set the font easily,move stuff easily,add images,logos,anything.

Now,i know i can use graphics2d and print GUI components,i tested that with a textarea and it works great.It even scrolls when you have like 100 lines,unlike with jframes where it only prints what it sees.

My issue is that i need 3-4 columns of text.Something like this :

1. Bananas         4     11.20$
2. Toilet paper    12    3.99$
3. Donuts          1     0.49$

I could just add this to the text area and print it but the problem is that the length of the text will vary and the text will be all messy and uneven.

So,how can i do something like in android : add 3-4 columns to which i can add text and even if they have 100 lines the printer will successfully print all of them an not the ones you can see without scrolling down ?

Thanks in advance and have a nice day !

Answer 1

After almost 6 years I finally got around to opening that project again and thought of posting the solution I ended up using, so here it is:

@Log4j2
@Service
public class PrintService implements Printable {

@Autowired
private PreviewManager previewManager;

public boolean printCopies() {

    final JPanel printPanel = new JPanel();
    DefaultListModel listModel = new DefaultListModel();

    printPanel.setLayout(new BoxLayout(printPanel, BoxLayout.PAGE_AXIS));
    printPanel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
    JLabel label = new JLabel("Select the number of copies");
    listModel.addElement("0");
    listModel.addElement("1");
    listModel.addElement("2");
    listModel.addElement("3");
    listModel.addElement("4");
    listModel.addElement("5");

    final JList list = new JList(listModel);
    list.setVisibleRowCount(1);
    list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    list.setLayoutOrientation(JList.HORIZONTAL_WRAP);

    final int[] nrOfCopies = {1};
    list.addListSelectionListener(lse -> nrOfCopies[0] = Integer.parseInt((String) list.getSelectedValue()));
    printPanel.add(label);

    printPanel.add(list);
    label.setAlignmentX(JComponent.CENTER_ALIGNMENT);
    list.setAlignmentX(JComponent.CENTER_ALIGNMENT);
    list.setSelectedIndex(1);
    JOptionPane jop = new JOptionPane(printPanel,
            JOptionPane.PLAIN_MESSAGE,
            JOptionPane.OK_CANCEL_OPTION);
    JDialog dialog = jop.createDialog(EMPTY_STRING);
    dialog.setAlwaysOnTop(true);
    dialog.addComponentListener(new ComponentAdapter() {
        @Override
        public void componentShown(ComponentEvent e) {
            SwingUtilities.invokeLater(list::requestFocusInWindow);
        }
    });
    dialog.setVisible(true);
    int result = (Integer) jop.getValue();
    dialog.dispose();

    if (result == JOptionPane.OK_OPTION) {
        log.info("Printing {} copies of the list", nrOfCopies[0]);
        for (int c = 0; c < nrOfCopies[0]; c++) {
            print();
        }
        return true;
    }
    // todo: bring back
    return false;
}

public void print() {
    PrinterJob pjob = PrinterJob.getPrinterJob();
    javax.print.PrintService[] printServices = PrintServiceLookup.lookupPrintServices(null, null);
    for (javax.print.PrintService printer : printServices) {
        // in my case I use a Star TSP143 thermal printer
        if (printer.getName().contains("tsp143")) {
            try {
                pjob.setPrintService(printer);
            } catch (PrinterException e) {
                log.error(e);
            }
        }
    }
    PageFormat preformat = pjob.defaultPage();
    preformat.setOrientation(PageFormat.PORTRAIT);
    PageFormat postformat = pjob.defaultPage(preformat);
    Paper p = preformat.getPaper();
    p.setImageableArea(0, 0, postformat.getWidth(), postformat.getHeight());
    postformat.setPaper(p);

    //If user does not hit cancel then print.
    if (preformat != postformat) {
        //Set print component
        pjob.setPrintable(PrintService.this, postformat);
        try {
            pjob.print();
        } catch (PrinterException ex) {
            log.error(ex);
        }
    }
}


@Override
public int print(Graphics g, PageFormat format, int page_index) {
    // depends on your use case, printableJpanel is going to be the panel you are going to print
    JPanel printableJpanel = previewManager.getPrintablePanel();
    if (page_index > 0) {
        return Printable.NO_SUCH_PAGE;
    }

    // get the bounds of the component
    Dimension dim = printableJpanel.getSize();
    double cHeight = dim.getHeight();
    double cWidth = dim.getWidth();

    // get the bounds of the printable area
    double pHeight = format.getImageableHeight();
    double pWidth = format.getImageableWidth();

    double pXStart = format.getImageableX();
    double pYStart = format.getImageableY();

    double xRatio = pWidth / cWidth;
    double yRatio = pHeight / cHeight;

    Graphics2D g2 = (Graphics2D) g;
    g2.translate(pXStart, pYStart);
    g2.scale(xRatio, 0.80);
    printableJpanel.paint(g2);

    return Printable.PAGE_EXISTS;

    }
}

Good luck!