A framework for searching PDF documents on iOS.
iOS, up to and including the current fifth version, does not provide any public APIs for searching PDF documents, or determining where on a page a given word is drawn. Any developer aiming to provide these features in an app must use low-level Core Graphics APIs, and keep track of the stateful process of laying out the content of the page.
This project is meant to facilitate this by implementing a complete workflow, taking as input a PDF document, a keyword string, and returning a set of selections that can be drawn on top of the PDF document.
First, create a new instance of the scanner.
Scanner *scanner = [[Scanner alloc] init];
Set a keyword (case-insensitive) and scan a page.
scanner.keyword = @"happiness";
CGPDFPageRef page = CGPDFDocumentGetPage(document, 1);
[scanner scanPage:page];
Finally, scan the page and draw the selections.
for (Selection *selection in scanner.selections)
{
// draw selection
}
The PDF specification is huge, allowing for different fonts, text encodings et cetera. This means strict design is a must, and thorough testing is needed. At this point, this project is not fully compatible with all font types, and especially suppert for non-latin characters will require further development.
This software is provided as is, meaning that we are not responsible for the results of its use.
Despite my continuing interest in this project, I have too much on my time table to consider doing this full (or part) time.