Create a table of contents from a pdf file

6
votes

I'm using quartz to display pdf content, and I need to create a table of contents to navigate through the pdf. From reading Apple's documentation I think I am supposed to use CGPDFDocumentGetCatalog, but I can't find any examples on how to use this anywhere. Any ideas?

Update: Still haven't found a solution for this. I tired Alex' solution but the output I get looks like this:

2011-07-27 09:16:19.359 LDS Scriptures App-iPad[624:707] key: Pages
2011-07-27 09:16:19.361 LDS Scriptures App-iPad[624:707] key: Count
2011-07-27 09:16:19.362 LDS Scriptures App-iPad[624:707] pdf integer value: 238
2011-07-27 09:16:19.363 LDS Scriptures App-iPad[624:707] key: Kids
2011-07-27 09:16:19.366 LDS Scriptures App-iPad[624:707] key: Type
2011-07-27 09:16:19.368 LDS Scriptures App-iPad[624:707] key: Outlines
2011-07-27 09:16:19.370 LDS Scriptures App-iPad[624:707] key: Count
2011-07-27 09:16:19.371 LDS Scriptures App-iPad[624:707] pdf integer value: 7
2011-07-27 09:16:19.372 LDS Scriptures App-iPad[624:707] key: First
2011-07-27 09:16:19.374 LDS Scriptures App-iPad[624:707] key: Parent
2011-07-27 09:16:19.375 LDS Scriptures App-iPad[624:707] key: Count
2011-07-27 09:16:19.376 LDS Scriptures App-iPad[624:707] pdf integer value: 7

No idea yet how to turn that into a usable table of contents. Ideally I would like to get to an array of NSDictionary objects with a title and matching page number.

4
iphoneobjective-ccocoa-touchquartz-2d
Ryan, did you found any way to create TOC from existing PDF? If so please guide me. I m searching for the same since few days. – DivineDesert
Have you found any solution? If yes, please add your answer here. – Hemang

4 Answers

6
votes

Something like this might help you get started:

NSURL *documentURL = ...; // URL to file or http resource etc.
CGPDFDocumentRef pdfDocument = CGPDFDocumentCreateWithURL((CFURLRef)documentURL);
CGPDFDictionaryRef pdfDocDictionary = CGPDFDocumentGetCatalog(pdfDocument);
// loop through dictionary...
CGPDFDictionaryApplyFunction(pdfDocDictionary, ListDictionaryObjects, NULL);
CGPDFDocumentRelease(pdfDocument);

...

void ListDictionaryObjects (const char *key, CGPDFObjectRef object, void *info) {
    NSLog("key: %s", key);
    CGPDFObjectType type = CGPDFObjectGetType(object);
    switch (type) { 
        case kCGPDFObjectTypeDictionary: {
            CGPDFDictionaryRef objectDictionary;
            if (CGPDFObjectGetValue(object, kCGPDFObjectTypeDictionary, &objectDictionary)) {
                CGPDFDictionaryApplyFunction(objectDictionary, ListDictionaryObjects, NULL);
            }
        }
        case kCGPDFObjectTypeInteger: {
            CGPDFInteger objectInteger;
            if (CGPDFObjectGetValue(object, kCGPDFObjectTypeInteger, &objectInteger)) {
                NSLog("pdf integer value: %ld", (long int)objectInteger); 
            }
        }
        // test other object type cases here
        // cf. http://developer.apple.com/mac/library/documentation/GraphicsImaging/Reference/CGPDFObject/Reference/reference.html#//apple_ref/doc/uid/TP30001117-CH3g-SW1
    }    
}
4
votes

Here is my approach.
1. Download this framework vfr reader
2. Use this lines of code to get all PDF chapters

NSString *path = [[NSBundle mainBundle] pathForResource:@"Reader" ofType:@"pdf"];
NSURL *targetURL = [NSURL fileURLWithPath:path];
NSArray *arr = [ReaderDocumentOutline outlineFromFileURL:targetURL password:@""];

Hope it will help you.

0
votes

I did it with a freeware library for iOS FastPdfKit

0
votes

You create a Table of Contents (AKA Outlines, Bookmarks) using PDFKit's PDFOutline object. You can also read existing Outlines within a PDF.

CGPDFDocumentGetCatalog is a method for getting the Catalog of PDF data in the file, which is at a much lower-level than human concepts of 'Contents'.

In the absence of existing Outlines, I'm not sure there's a way to get meaningful data from the PDF stream itself, e.g. trying to grok Chapter headings just from the PDF data.