Error Handling in QPrinter

Question

When printing to PDF with QTextDocument and QPrinter is there any way of detecting errors (e.g. not being able to write to the PDF file)? I'm using the following code:

QTextDocument document;
QPrinter printer( QPrinter::HighResolution );
printer.setOutputFormat( QPrinter::PdfFormat );
printer.setOutputFileName( filename );
document.print( &printer );

Answer 1

In the docs you'll find QPrinter::printerState. So you can definitely do:

if (printer.printerState() == QPrinter::Error)
    // do some error handling

I admit that's not a lot work with, as there are only 4 QPrinter::PrinterState's. You might want to do your best to avoid errors in the first place. The detailed description in the doc states:

Note that setting parameters like paper size and resolution on an invalid printer is undefined. You can use QPrinter::isValid() to verify this before changing any parameters.

Additionaly, you could check if the filename you are setting already exists using QFile::exists. Also, when setting it all up you can call and handle QPrinter::supportedResolutions(), QPrinter::supportedPaperSources() and QPrinter::supportsMultipleCopies(). Of course, printing to PDF you might not have to worry about these.