function AnnotationLowLevelAPI($doc)
{
$page = $doc->GetPageIterator()->Current();
$annots = $page->GetAnnots();
if (!$annots) {
// If there are no annotations, create a new annotation
// array for the page.
$annots = $doc->CreateIndirectArray();
$page->GetSDFObj()->Put("Annots", $annots);
}
// Create a Text annotation
$annot = $doc->CreateIndirectDict();
$annot->PutName("Subtype", "Text");
$annot->PutBool("Open", true);
$annot->PutString("Contents", "The quick brown fox ate the lazy mouse.");
$annot->PutRect("Rect", 266, 116, 430, 204);
// Insert the annotation in the page annotation array
$annots->PushBack($annot);
// Create a Link annotation
$link1 = $doc->CreateIndirectDict();
$link1->PutName("Subtype", "Link");
$dest = Destination::CreateFit($doc->GetPage(2));
$link1->Put("Dest", $dest->GetSDFObj());
$link1->PutRect("Rect", 85, 705, 503, 661);
$annots->PushBack($link1);
// Create another Link annotation
$link2 = $doc->CreateIndirectDict();
$link2->PutName("Subtype", "Link");
$dest2 = Destination::CreateFit($doc->GetPage(3));
$link2->Put("Dest", $dest2->GetSDFObj());
$link2->PutRect("Rect", 85, 638, 503, 594);
$annots->PushBack($link2);
// Note that PDFNet API can be used to modify existing annotations.
// In the following example we will modify the second link annotation
// (link2) so that it points to the 10th page. We also use a different
// destination page fit type.
// $link2 = $annots->GetAt($annots->Size()-1);
$link2->Put("Dest", Destination::CreateXYZ($doc->GetPage(10), 100, 792 - 70, 10)->GetSDFObj());
// Create a third link annotation with a hyperlink action (all other
// annotation types can be created in a similar way)
$link3 = $doc->CreateIndirectDict();
$link3->PutName("Subtype", "Link");
$link3->PutRect("Rect", 85, 570, 503, 524);
// Create a URI action
$action = $link3->PutDict("A");
$action->PutName("S", "URI");
$action->PutString("URI", "http://www.pdftron.com");
$annots->PushBack($link3);
}