Foxit Developer

Text extraction ​

Foxit PDF SDK for iOS provides text extraction, selection, search, and retrieval via Core SDK. Page text is organized in FSTextPage, one per page.

FSTextPage is also used for:

  • Text search — construct FSTextSearch from FSTextPage.
  • Hyperlinks — construct FSPageTextLinks from FSTextPage.
  • Selection highlights — compute text regions from selection start/end.

Example: extract all page text ​

objc
#import <FoxitRDK/FSPDFObjC.h>

FSPDFDoc *doc = [[FSPDFDoc alloc] initWithPath:@"path/to/Sample.pdf"];
[doc load:nil];

FSPDFPage *page = [doc getPage:0];
[page startParse:FSPDFPageParsePageNormal pause:nil is_reparse:YES];

FSTextPage *textPage = [[FSTextPage alloc] initWithPage:page flags:FSTextPageParseTextNormal];
NSString *fullText = [textPage getChars:0 count:-1];
NSLog(@"页面文本: %@", fullText);

Example: text rects from selection ​

Compute text regions from selection endpoints for highlight or range markup:

objc
- (NSArray<NSValue *> *)getTextRectsBySelectionOnPage:(FSPDFPage *)page
                                             startPos:(FSPointF *)startPos
                                               endPos:(FSPointF *)endPos {
    FSTextPage *textPage = [[FSTextPage alloc] initWithPage:page
                                                      flags:FSTextPageParseTextNormal];
    if (!textPage) return nil;

    int startIndex = [textPage getIndexAtPos:[startPos getX] y:[startPos getY] tolerance:5];
    int endIndex = [textPage getIndexAtPos:[endPos getX] y:[endPos getY] tolerance:5];

    if (startIndex > endIndex) {
        int temp = startIndex;
        startIndex = endIndex;
        endIndex = temp;
    }

    int count = [textPage getTextRectCount:startIndex count:endIndex - startIndex];
    if (count <= 0) return nil;

    NSMutableArray *rects = [NSMutableArray array];
    for (int i = 0; i < count; i++) {
        FSRectF *rect = [textPage getTextRect:i];
        if (rect) {
            // PDF coordinates; convert to device coordinates before display
            [rects addObject:[NSValue valueWithCGRect:CGRectMake(
                [rect getLeft], [rect getTop],
                [rect getRight] - [rect getLeft],
                [rect getTop] - [rect getBottom])]];
        }
    }
    return rects;
}

API reference

See the API reference for FSTextPage.