PDF Viewer Events

PSPDFKit provides the DocumentListener interface, which allows you to hook into interesting document events like document loading, page changes, page clicks, and more. Have a look at FragmentExample or CustomLayoutExample of the Catalog app, both of which, among other examples, showcase DocumentListener usage.

Registering a Document Listener

Add a document listener to a PdfFragment by registering it using the addDocumentListener() method. You can register as many document listeners as you like:


ℹ️ Note: To prevent memory leaks, PdfFragment removes all previously registered listeners inside its #onDetach method.

Unregistering a Document Listener

If you want to stop receiving document events on a listener, provide the listener instance to removeDocumentListener(). Performance wise, you’re encouraged to unregister the listener as soon as you don’t need it anymore, e.g. inside your activity’s onStop() method:


Document Events

The DocumentListener interface provides callback methods for important and interesting document events:

ℹ️ Note: All page numbers in PSPDFKit have a zero-based index, meaning 0 denotes the first page of a document and pageCount - 1 denotes the last document page.

Activity Callbacks

PdfActivity implements DocumentListener interfaces by default, allowing you to listen for events by overriding the associated methods in your subclassed activities:

class MyActivity : PdfActivity() {

    override fun onDocumentLoaded(document : PdfDocument) {
        Toast.makeText(this, "Document has been loaded with ${document.pageCount} pages",

    override fun onDocumentLoadFailed(exception : Throwable?) {
        Toast.makeText(this, "Document loading failed!", Toast.LENGTH_SHORT).show()
public class MyActivity extends PdfActivity {

    public void onDocumentLoaded(@NonNull PdfDocument document) {
        Toast.makeText(this, String.format("Document has been loaded with %d pages",
            document.getPageCount(), Toast.LENGTH_SHORT).show();

    public void onDocumentLoadFailed(Throwable exception) {
        Toast.makeText(this, "Document loading failed!", Toast.LENGTH_SHORT).show();