barcodeprinter.cpp

#include "barcodeprinter.h"
#include <QPrinter>
#include <QFont>

BarcodePrinter::BarcodePrinter(QObject *parent) :
    QObject(parent),
    printerConfigured(FALSE)
{

}

QStringList BarcodePrinter::getAvailablePrinters()
{
    QStringList availablePrinters;

    QPrinterInfo pInfo;
    foreach (QPrinterInfo info, pInfo.availablePrinters()) {
        availablePrinters << info.printerName();
    }

    return availablePrinters;
}

bool BarcodePrinter::configurePrinter(QString printerName)
{
    bool printerAvailable = getAvailablePrinters().contains(printerName);
    if(printerAvailable)
    {
        mPrinter.setPrinterName(printerName);
        configurePage();

        qDebug() << "Printer initialized. State:" + mPrinter.printerState();
    }
    else //If the printer is unavailable, generate pdf instead
    {
        mPrinter.setOutputFileName("barcode.pdf");
        mPrinter.setOutputFormat(QPrinter::PdfFormat);
        configurePage();

        qDebug() << "Printer initialized to generate pdf";
    }

    printerConfigured = TRUE;

    return printerAvailable;

}

void BarcodePrinter::printBarcode(QString barcodeText)
{
    if(!printerConfigured)
    {
        qDebug() << "Printer not configured, abort.";
        return;
    }

    qDebug() << "Printing : \"" + barcodeText + "\" ...";

    double MmToDot = 8; //Printer DPI = 203 => 8 dots per mm
    QPainter painter(&mPrinter);

    QRect barcodeRect = QRect(5*MmToDot,10*MmToDot,67.5*MmToDot,10*MmToDot);
    QRect barcodeTextRect = QRect(5*MmToDot,20.5*MmToDot,67.5*MmToDot,5*MmToDot);

    QFont barcodefont = QFont("Code 128", 46, QFont::Normal);
    barcodefont.setLetterSpacing(QFont::AbsoluteSpacing,0.0);
    painter.setFont(barcodefont);

    QString arr = encodeBarcode(barcodeText);
    painter.drawText(barcodeRect, Qt::AlignCenter, arr);

    painter.setFont(QFont("PT Sans", 10));
    painter.drawText(barcodeTextRect, Qt::AlignCenter, barcodeText);

    painter.end();

    qDebug() << "Printing finished";
}

void BarcodePrinter::configurePage()
{
    //
    mPrinter.setColorMode(QPrinter::GrayScale);
    mPrinter.setPageSizeMM(QSizeF(80,40));
    mPrinter.setPaperSize(QSizeF(80,40), QPrinter::Millimeter);
    mPrinter.setResolution(203);
    mPrinter.setPageMargins(0,0,0,0, QPrinter::Millimeter);
    mPrinter.setOrientation(QPrinter::Portrait);
}

QString BarcodePrinter::encodeBarcode(QString code)
{
    QString encoded;

    encoded.prepend(QChar(codeToChar(CODE128_B_START))); //Start set with B Code 104
    encoded.append(code);
    encoded.append(QChar(calculateCheckCharacter(code)));
    encoded.append(QChar(codeToChar(CODE128_STOP))); //End set with Stop Code 106

    return encoded;
}

int BarcodePrinter::calculateCheckCharacter(QString code)
{
    QByteArray encapBarcode(code.toUtf8()); //Convert code to utf8

    //Calculate check character
    long long sum = CODE128_B_START; //The sum starts with the B Code start character value
    int weight = 1; //Initial weight is 1

    foreach(char ch, encapBarcode) {
        int code_char = charToCode((int)ch); //Calculate character code
        sum += code_char*weight; //add weighted code to sum
        weight++; //increment weight
    }

    int remain = sum%103; //The check character is the modulo 103 of the sum

    //Calculate the font integer from the code integer
    if(remain >= 95)
        remain += 105;
    else
        remain += 32;

    return remain;
}

int BarcodePrinter::codeToChar(int code)
{
    return code + 105;
}

int BarcodePrinter::charToCode(int ch)
{
    return ch - 32;
}