Preview & Scaling in Printer Dialog

[ademmler]

Hi to all,

can somebody pls tell me if such a Printer Dialog with "Preview" and "Scaling Option" is available by default from QPrintDialog?

[SGaist]

Hi,

AFAIR, on macOS, it's the system dialog that is shown so you should have your OS standard feature in there.

[ademmler]

@SGaist That is what I thought also, but it does not appear.
I get hat you can see below. It is missing the Preview, Auto-Rotate and "Fit to Size" Options.

[SGaist]

@ademmler what about QPrintPreviewDialog ?

[ademmler]

@SGaist hi, it does not look like Mac Native Dialog.

[Ronel_qtmaster]

@ademmler it seems that you will have to implement you own

[ademmler]

@Ronel_qtmaster Yes maybe - but still laundering, because the first image I have send is MacNative Dialog.
I check further into this.

[SGaist]

@ademmler Can you provide a minimal compilable example so that we can check things on the same level ?

[ademmler]

@SGaist Sure - I have put both Dialogs into one example - you can choose which one to use at the top of main.cpp.

#include <QApplication>
#include <QPrinter>
#include <QPrintDialog>
#include <QPrintPreviewDialog>
#include <QPainter>

#define usePreview 0

class MyPrintPreviewDialog : public QPrintPreviewDialog
{
public:
    MyPrintPreviewDialog(QPrinter *printer, QWidget *parent = nullptr)
        : QPrintPreviewDialog(printer, parent)
    {
        // Connect the signal for generating the preview
        connect(this, &QPrintPreviewDialog::paintRequested, this, &MyPrintPreviewDialog::printPreview);
    }

private:
    void printPreview(QPrinter *printer)
    {
        // Create a QPainter to draw on the printer
        QPainter painter(printer);
        
        // Draw some text on the printer
        painter.drawText(QRect(20, 20, 200, 200), "Hello, World!");
    }
};


int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

#if usePreview
    // Create a printer object
    QPrinter printer;

    // Create a print preview dialog
    MyPrintPreviewDialog dialog(&printer);
    // Show the print preview dialog
    dialog.exec();
#else
    // Create a printer object
    QPrinter printer;

    printer.setPageSize(QPrinter::A4);
    printer.setOrientation(QPrinter::Portrait);
    printer.setResolution(300);

    // Create a print dialog and get print settings from the user
    QPrintDialog printDialog(&printer);
    if (printDialog.exec() != QDialog::Accepted) {
        return 0; // User canceled the print dialog
    }

    // Create a QPainter object and set it to draw on the printer
    QPainter painter(&printer);

    // Use the QPainter to draw on the printer
    painter.drawText(QRect(100, 100, 200, 200), "Hello, World!");
    painter.drawLine(QPointF(0, 0), QPointF(100, 100));
    // ...

    // End the painting and release the printer
    painter.end();
#endif

    return app.exec();
}

QtCreator project file:

######################################################################
# Automatically generated by qmake (3.1) Tue Feb 13 09:33:07 2024
######################################################################

QT       += core gui network printsupport

TEMPLATE = app
TARGET = trial
INCLUDEPATH += .

# Input
SOURCES += main.cpp

[SGaist]

The preview dialog is indeed non-native but the setup part is.

As for having the preview in the print dialog, you would have to modify the backend part to set it up.

[ademmler]

@SGaist Thx for checking this out. Do I understand you right - did you ment to take the default QPrinter class and add more "setup functionality" aka native code to get the OS related preview activated?

[SGaist]

@ademmler no, lower level, down to the platform plugin.