Question

I am porting my code from iPhone to Mac and I have no idea how I can do this in Mac. Here’s my code that I am trying to convert and I know that there’s no UIGraphic in Mac. Can someone point me to a guide or give me a quick hint? Thanks.

NSString *newFilePath = @"path/to/your/newfile.pdf";
NSString *templatePath = @"path/to/your/template.pdf";

//create empty pdf file;
UIGraphicsBeginPDFContextToFile(newFilePath, CGRectMake(0, 0, 792, 612), nil);

CFURLRef url = CFURLCreateWithFileSystemPath (NULL, (CFStringRef)templatePath, kCFURLPOSIXPathStyle, 0);

//open template file
CGPDFDocumentRef templateDocument = CGPDFDocumentCreateWithURL(url);
CFRelease(url);

//get amount of pages in template
size_t count = CGPDFDocumentGetNumberOfPages(templateDocument);

//for each page in template
for (size_t pageNumber = 1; pageNumber <= count; pageNumber++) {
    //get bounds of template page
    CGPDFPageRef templatePage = CGPDFDocumentGetPage(templateDocument, pageNumber);
    CGRect templatePageBounds = CGPDFPageGetBoxRect(templatePage, kCGPDFCropBox);

    //create empty page with corresponding bounds in new document
    UIGraphicsBeginPDFPageWithInfo(templatePageBounds, nil);
    CGContextRef context = UIGraphicsGetCurrentContext();

    //flip context due to different origins
    CGContextTranslateCTM(context, 0.0, templatePageBounds.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    //copy content of template page on the corresponding page in new file
    CGContextDrawPDFPage(context, templatePage);

    //flip context back
    CGContextTranslateCTM(context, 0.0, templatePageBounds.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    /* Here you can do any drawings */
    [@"Test" drawAtPoint:CGPointMake(200, 300) withFont:[UIFont systemFontOfSize:20]];
}
CGPDFDocumentRelease(templateDocument);
UIGraphicsEndPDFContext();

Answer 1

Use CGPDFContextCreateWithURL instead of UIGraphicsBeginPDFContextToFile (the parameters are very similar). To begin/end pages, use CGPDFContextBeginPage and CGPDFContextEndPage. When you’re done, call CGPDFContextClose instead of UIGraphicsEndPDFContext.

The rest can remain the same – Core Graphics exists on both iOS and Mac OS X – which also means that you could use the functions I’ve mentioned above on iOS as well if you want to use the same code on both platforms.