Question

I am a bit new to iOS development and have a fairly general question regarding iOS and PDFs. I know there is built-in PDF support in iOS4+, but is it possible to open a PDF for viewing then maybe make notes on it and save it again?

I’m sure there are options like opening the PDF as a background and having a “writable” overlay over it, saving it as an image then writing it out as a PDF, but I was wondering if there was a more “inherent” way to do so.

Thanks.

Answer 1

For searching, see this answer: Text searching PDF

For the overlay, you can just draw the pdf youself, and add you own overlay:

    UIGraphicsBeginImageContextWithOptions(pageRect.size, NO, 0.0);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSaveGState(context);
    // Flip the context so that the PDF page is rendered
    // right side up.
    CGContextTranslateCTM(context, 0.0, pageRect.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    // Scale the context so that the PDF page is rendered 
    // at the correct size for the zoom level.
    CGContextScaleCTM(context, pdfScale, pdfScale); 
    CGContextTranslateCTM(context, -pageRect.origin.x, -pageRect.origin.y);
    CGContextDrawPDFPage(context, pdfPage);
    CGContextRestoreGState(context);

    // callback for custom overlay drawing (example_
    if ([document shouldDrawOverlayRectForSize:size]) {
        [document drawOverlayRect:pageRect inContext:context forPage:page zoomScale:1.0 size:size];    
    }

Update: Just a note, pdf can contain rotation information, so the actual drawing should read that metadata and transform the context accordingly.