Text markup annotations

Text markup annotations visually mark existing PDF text. Foxit PDF SDK for iOS provides highlight, underline, strikethrough, and squiggly via FSTextMarkup and subtypes.

Type	Constant	Description
Highlight	FSAnnotHighlight	Semi-transparent overlay
Underline	FSAnnotUnderline	Underline
Strikethrough	FSAnnotStrikeOut	Strikethrough
Squiggly	FSAnnotSquiggly	Squiggly underline

QuadPoints

Text markup positioning uses QuadPoints (four corners per region). Multiple quads form FSQuadPointsArray for multi-line or multi-region text.

first ──────── second
  │               │
third ──────── fourth

• first — top-left
• second — top-right
• third — bottom-left
• fourth — bottom-right

You can create with an empty rect (0, 0, 0, 0); the annot rect is computed from QuadPoints.

Example: highlight from search results

#import <FoxitRDK/FSPDFObjC.h>

FSPDFDoc *doc = [[FSPDFDoc alloc] initWithPath:@"path/to/Sample.pdf"];
[doc load:nil];
FSPDFPage *page = [doc getPage:0];

FSTextSearch *textSearch = [[FSTextSearch alloc] initWithDocument:doc cancel_callback:nil];
[textSearch setPattern:@"foxit"];

if ([textSearch findNext]) {
    FSRectFArray *rects = [textSearch getMatchRects];

    FSQuadPointsArray *quadPointsArray = [[FSQuadPointsArray alloc] init];
    for (int i = 0; i < [rects getSize]; i++) {
        FSRectF *rect = [rects getAt:i];
        FSQuadPoints *qp = [[FSQuadPoints alloc] init];
        FSPointF *first = [[FSPointF alloc] init];
        [first set:[rect getLeft] y:[rect getTop]];
        FSPointF *second = [[FSPointF alloc] init];
        [second set:[rect getRight] y:[rect getTop]];
        FSPointF *third = [[FSPointF alloc] init];
        [third set:[rect getLeft] y:[rect getBottom]];
        FSPointF *fourth = [[FSPointF alloc] init];
        [fourth set:[rect getRight] y:[rect getBottom]];
        [qp setFirst:first];
        [qp setSecond:second];
        [qp setThird:third];
        [qp setFourth:fourth];
        [quadPointsArray add:qp];
    }

    FSRectF *emptyRect = [[FSRectF alloc] initWithLeft1:0 bottom1:0 right1:0 top1:0];
    FSAnnot *annot = [page addAnnot:FSAnnotHighlight rect:emptyRect];
    FSTextMarkup *highlight = [[FSTextMarkup alloc] initWithAnnot:annot];

    [highlight setQuadPoints:quadPointsArray];
    [highlight setBorderColor:0xFFFF0000];
    [highlight setOpacity:0.3f];
    [highlight resetAppearanceStream];
}

[doc saveAs:@"path/to/output.pdf" saveFlags:FSPDFDocSaveFlagNormal];

Example: underline with known coordinates

FSPDFPage *page = [doc getPage:0];

FSQuadPoints *qp = [[FSQuadPoints alloc] init];
FSPointF *first = [[FSPointF alloc] init];
[first set:72 y:750];
FSPointF *second = [[FSPointF alloc] init];
[second set:300 y:750];
FSPointF *third = [[FSPointF alloc] init];
[third set:72 y:730];
FSPointF *fourth = [[FSPointF alloc] init];
[fourth set:300 y:730];
[qp setFirst:first];
[qp setSecond:second];
[qp setThird:third];
[qp setFourth:fourth];

FSQuadPointsArray *quadPointsArray = [[FSQuadPointsArray alloc] init];
[quadPointsArray add:qp];

FSRectF *emptyRect = [[FSRectF alloc] initWithLeft1:0 bottom1:0 right1:0 top1:0];
FSAnnot *annot = [page addAnnot:FSAnnotUnderline rect:emptyRect];
FSTextMarkup *underline = [[FSTextMarkup alloc] initWithAnnot:annot];
[underline setQuadPoints:quadPointsArray];
[underline setBorderColor:0xFF00AA00];
[underline resetAppearanceStream];

Tip

Use FSAnnotStrikeOut or FSAnnotSquiggly instead of FSAnnotUnderline; the rest of the code is the same.

Common properties

Method	Description
getQuadPoints / setQuadPoints:	Quad array
setBorderColor:	Mark color
setOpacity:	Opacity (0.0–1.0)
setContent:	Comment text in panel
setTitle:	Author / title
resetAppearanceStream	Update appearance