QPrinter and QPrintDialog

[Alexander111122]

Greetings everyone!
I'm having a trouble with printing via Qt.
What I want - is to print the viewable content of MainWindow using QPrint. I have printed test sheets using this code:

void MainWindow::setup_print(void)
{
    dialog = new QPrintDialog(&printer, this);
    if (dialog->exec() == QDialog::Accepted)
    {
        QPainter painter( &printer );
 
        painter.setPen( Qt::black );
 
        for( int page=0; page<5; page++ )
        {
            painter.drawRect( printer.pageRect() );
            painter.drawLine( printer.pageRect().topLeft(), printer.pageRect().bottomRight() );
            painter.drawLine( printer.pageRect().topRight(), printer.pageRect().bottomLeft() );
            painter.drawRect(this->contentsRect() );
            QRectF textArea(
                printer.pageRect().left()  +printer.resolution() * 0.5,
                printer.pageRect().top()   +printer.resolution() * 0.5,
                printer.pageRect().width() -printer.resolution() * 1.0,
                printer.pageRect().height()-printer.resolution() * 1.5 );
 
            painter.drawRect( textArea );
 
            painter.drawText( textArea, Qt::AlignTop | Qt::AlignLeft, QString( "Page %1" ).arg( page+1 ) );
 
            if( page != 4 )
 
              printer.newPage();
        }
    }
}

void MainWindow::setup_print(void)
{
    dialog = new QPrintDialog(&printer, this);
    if (dialog->exec() == QDialog::Accepted)
    {
        QPainter painter( &printer );

        painter.setPen( Qt::black );

        for( int page=0; page<5; page++ )
        {
            painter.drawRect( printer.pageRect() );
            painter.drawLine( printer.pageRect().topLeft(), printer.pageRect().bottomRight() );
            painter.drawLine( printer.pageRect().topRight(), printer.pageRect().bottomLeft() );
            painter.drawRect(this->contentsRect() );
            QRectF textArea(
                printer.pageRect().left()  +printer.resolution() * 0.5,
                printer.pageRect().top()   +printer.resolution() * 0.5,
                printer.pageRect().width() -printer.resolution() * 1.0,
                printer.pageRect().height()-printer.resolution() * 1.5 );

            painter.drawRect( textArea );

            painter.drawText( textArea, Qt::AlignTop | Qt::AlignLeft, QString( "Page %1" ).arg( page+1 ) );

            if( page != 4 )
        
              printer.newPage();
        }
    }
}

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the "printer" object is mainwindow class member.
The problem is that I have no idea how to get the content of mainwindow be represented as a QPainter object.
Can anyone help me with this please?

[anda_skoa]

Well, it is obviously very uncommon to print a widget as screen and printer usually have widely different visual properties, but have you tried QWidget::render()?

Cheers,
_

[Alexander111122]

Thank you very much! That has worked. But now I encountered another problem.
When I'm calling QPrintPreviewDialog, there is two pages, thow I rendered only my central widget. So I have one page with my central widget and another page empty.
Also the Image is printed correctly on the page only if I open the app in fullscreen. If I call my app and it is not stretched to full screen than I see onle part of it on the first page.
I provide the code of my print preview SLOT and connects.

connect(prev_dialog, SIGNAL(paintRequested(QPrinter*)), this, SLOT(print_preview()));
    connect(ui->actionPrint_Preview, SIGNAL(triggered(bool)), this, SLOT(preview_called()));
//////////////////////////////////////////////////////////////////////////////////////////
void MainWindow::print_preview(void)
{
    QPainter painter(&printer);
    painter.setWindow(this->geometry());
 
    this->render(&painter);
    printer.newPage();
    /*if (prev_dialog->exec() == QDialog::Accepted)
    {
 
    }*/
}
 
void MainWindow::preview_called(void)
{
    prev_dialog->exec();
}

connect(prev_dialog, SIGNAL(paintRequested(QPrinter*)), this, SLOT(print_preview()));
    connect(ui->actionPrint_Preview, SIGNAL(triggered(bool)), this, SLOT(preview_called()));
//////////////////////////////////////////////////////////////////////////////////////////
void MainWindow::print_preview(void)
{
    QPainter painter(&printer);
    painter.setWindow(this->geometry());

    this->render(&painter);
    printer.newPage();
    /*if (prev_dialog->exec() == QDialog::Accepted)
    {

    }*/
}

void MainWindow::preview_called(void)
{
    prev_dialog->exec();
}

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Thank you again for helping me to deal with this.