How to Dynamically Change the Page Layout When Changing the Screen Orientation

class DynamicPageLayoutActivity : PdfActivity() {

    override fun onCreate(savedInstanceState: Bundle) {
        val isLandscape = resources.configuration.orientation == ORIENTATION_LANDSCAPE
        val pageLayoutMode = if (isLandscape) PageLayoutMode.DOUBLE else PageLayoutMode.SINGLE
        val newConfiguration = PdfActivityConfiguration.Builder(configuration)
            .layoutMode(pageLayoutMode)
            .build()

        configuration = newConfiguration

        // Make sure to call super on the parent `PdfActivity`.
        super.onCreate(savedInstanceState)
    }
}

public class DynamicPageLayoutActivity extends PdfActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        boolean isLandscape = getResources().getConfiguration().orientation == ORIENTATION_LANDSCAPE;
        PageLayoutMode pageLayoutMode = isLandscape ? PageLayoutMode.DOUBLE : PageLayoutMode.SINGLE;
        PdfActivityConfigurations newConfiguration = new PdfActivityConfiguration.Builder(configuration)
            .layoutMode(pageLayoutMode)
            .build()

        // Set the new configuration.
        setConfiguration(newConfiguration);

        // Make sure to call super on the parent `PdfActivity`.
        super.onCreate(savedInstanceState);
    }
}