Define annotation behavior with flags on iOS

Every Annotation in a document can specify flags that further define its behavior and capabilities. With Nutrient, you can access these flags directly on your annotation objects using the flags property.

Capabilities of flags

Annotation flags are part of the PDF specification and define an annotation’s behavior, its presentation onscreen and on paper, and the available editing features given to your users. Here are a few examples of things you can do with flags:

• An annotation with an Annotation.Flag.invisible flag will ignore annotation appearance streams.
• An annotation with a flag set to Annotation.Flag.hidden won’t be displayed or printed.
• An annotation with an Annotation.Flag.print flag will be printed. Annotation.Flag.print is the default flag.
• An annotation with a flag set to Annotation.Flag.noView won’t be displayed onscreen, but printing might be allowed.
• Annotations with an Annotation.Flag.readOnly flag don’t allow user interactions. The flag is ignored for widget annotations.
• Annotations with an Annotation.Flag.noZoom flag won’t be zoomed when the page is zoomed, i.e. the size of the annotation on the page will remain the same, irrespective of the zoom level. This flag is currently only supported for stamp annotations.
• If you want to prevent your users from editing an annotation, you can set the Annotation.Flag.locked and Annotation.Flag.lockedContents flags.

Usage example

Here’s an example of how to create a locked annotation, i.e. an annotation that can’t be modified by your users:

// Create a new annotation.
let annotation = StampAnnotation(stampType: .confidential)

// Update the annotation flags.
annotation.flags.update(with: [.locked, .lockedContents])

// Add the newly created annotation to the document.
document.add(annotations: [annotation])

// To add an additional flag, use `update`.
annotation.flags.update(with: .hidden)

// To remove a flag, use `remove`.
annotation.flags.remove(.hidden)

// Create a new annotation.
PSPDFAnnotation *annotation = [[PSPDFStampAnnotation alloc] initWithStampType:PSPDFStampTypeConfidential];

// Update the annotation flags.
annotation.flags |= PSPDFAnnotationFlagLocked | PSPDFAnnotationFlagLockedContents;

// Add the newly created annotation to the document.
[document addAnnotations:@[annotation] options:nil];

// To add an additional flag, use bitwise OR with the flag value.
annotation.flags |= PSPDFAnnotationFlagHidden;

// To remove a flag, use bitwise AND with the reverse flag value.
annotation.flags &= ~PSPDFAnnotationFlagHidden;