Caret Annotation

Caret annotation is a visual symbol typically used to mark text for some changes or to indicate some missing text. GcPdf provides CaretAnnotation class that allows a user to add Caret annotations to the PDF file.

CaretAnnotation class provides the following properties to set various options for the caret annotation:

Property	Description
UserName	Adds the user name to the text label in the title bar of the annotation’s pop-up window when the annotation is open and active.
Subject	Adds the text representing the subject of the annotation.
Contents	Adds the text to the annotation for display.
RichText	Adds the text to the annotation for display in the pop-up window when opened. You can format this text using HTML tags.
Opacity	Sets the opacity of the annotation.
Color	Sets the annotation color, popup window color, line color, etc.
Rect	Adds the rectangle that defines the location and size of the annotation on a page. The coordinates of the rectangle are relative to the upper left corner of the page's media box, with the Y (vertical) coordinates increasing from top to bottom.

Refer to the following example code to add a caret annotation to a PDF document:

// Initialize GcPdfDocument.
GcPdfDocument doc = new GcPdfDocument();

// Create a file stream.
FileStream fs = new FileStream("Wetlands.pdf", FileMode.Open, FileAccess.Read);

// Load the file stream.
doc.Load(fs);

// Get the first page.
var page = doc.Pages[0];
            
// Get the text map.
var tm = page.GetTextMap();

// Insert the CaretAnnotation after "The Importance" text.
tm.FindText(new FindTextParams("The Importance", false, true), (fp_) =>
{
    // r is bounds of the found text.
    var r = fp_.Bounds[0].ToRect();
    // Create the CaretAnnotation and add it to the page.
    CaretAnnotation ca = new CaretAnnotation();
    ca.Page = page;
    // in this code annotation size is hardcoded, you can make a code
    // which will adjust size of the annotation depending on height of the found text fragment
    ca.Rect = new System.Drawing.RectangleF(r.Right - 4, r.Bottom - 8, 8, 8);
    ca.Opacity = 1f;
    ca.Color = Color.Red;
    ca.Contents = "This is Caret annotation.";
});

doc.Save("CaretAnnotation.pdf");