How to Print a PDF File Using Cocoa

__UPDATE 2014-03-13:__ [@robwithhair]( created a [command-line tool for printing PDF files]( based on this code which shows some additional options.

Mac OS X is well known for its great [support for PDF files]( You can create a PDF file from anything you can print. I thought that using Apple’s [PDFKit framework]( would make it easy to program a way to print an existing PDF file. That turned out not to be the case.

Sending a file to a printer using the [lp command]( is easy. However, this approach does not work for PDF files formatted for landscape printing. You can specify landscape orientation, but I wanted a way to detect the orientation automatically.

PDFKit has a `PDFView` object that has a `printWithInfo:autoRotate:` method. However, adding a `PDFDocument` to a `PDFView` and telling it to print doesn’t work. I eventually stumbled onto the fact that `PDFDocument`has a [secret method]( that makes printing easy. So here is the code:


– (void)printPDF:(NSURL *)fileURL {

// Create the print settings.
NSPrintInfo *printInfo = [NSPrintInfo sharedPrintInfo];
[printInfo setTopMargin:0.0];
[printInfo setBottomMargin:0.0];
[printInfo setLeftMargin:0.0];
[printInfo setRightMargin:0.0];
[printInfo setHorizontalPagination:NSFitPagination];
[printInfo setVerticalPagination:NSFitPagination];

// Create the document reference.
PDFDocument *pdfDocument = [[[PDFDocument alloc] initWithURL:fileURL] autorelease];

// Invoke private method.
// NOTE: Use NSInvocation because one argument is a BOOL type. Alternately, you could declare the method in a category and just call it.
BOOL autoRotate = YES;
NSMethodSignature *signature = [PDFDocument instanceMethodSignatureForSelector:@selector(getPrintOperationForPrintInfo:autoRotate:)];
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:signature];
[invocation setSelector:@selector(getPrintOperationForPrintInfo:autoRotate:)];
[invocation setArgument:&printInfo atIndex:2];
[invocation setArgument:&autoRotate atIndex:3];
[invocation invokeWithTarget:pdfDocument];

// Grab the returned print operation.
NSPrintOperation *op = nil;
[invocation getReturnValue:&op];

// Run the print operation without showing any dialogs.
[op setShowsPrintPanel:NO];
[op setShowsProgressPanel:NO];
[op runOperation];

I consider this code to be in the public domain. Please feel free to copy and paste. And let me know if you find any problems or have suggestions.