--- title: "Configure iOS PDF viewer scroll direction & page transition | Nutrient" canonical_url: "https://www.nutrient.io/guides/ios/customizing-the-interface/document-presentation-options/" md_url: "https://www.nutrient.io/guides/ios/customizing-the-interface/document-presentation-options.md" last_updated: "2026-05-23T00:08:18.131Z" description: "You can configure the page transition, scroll direction, and scroll mode of a PDFViewController in PDFConfiguration (see the PDF configuration guide." --- # Configuring scroll directions and page transitions in our viewer You can configure the page transition, scroll direction, and scroll mode of a `PDFViewController` in [`PDFConfiguration`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration) (see the [PDF configuration](https://www.nutrient.io/guides/ios/getting-started/view-controller-configuration.md) guide for more information). In `SettingsExample` from the [Catalog app](https://www.nutrient.io/../../getting-started/example-projects/#nutrient-catalog), you’ll see a complete example of how these properties interact together in the context of a [`PDFSettingsViewController`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfsettingsviewcontroller). A [`PDFSettingsViewController`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfsettingsviewcontroller) is used to change key UX settings that are configurable via the [`PDFConfiguration.settingsOptions`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/settingsoptions) property. ## Recommended configurations For the best user experience, we recommend using one of the following two combinations of settings. ### Book/magazine-style scrolling ```swift let configuration = PDFConfiguration { builder in builder.scrollDirection =.horizontal builder.pageTransition =.scrollPerSpread builder.pageMode =.automatic builder.spreadFitting =.fit } ``` This will show two pages at a time when there is sufficient space (typically on iPad in landscape), and one page at a time in all other situations. ### Continuous vertical scrolling ```swift let configuration = PDFConfiguration { builder in builder.scrollDirection =.vertical builder.pageTransition =.scrollContinuous builder.pageMode =.single builder.spreadFitting =.adaptive } ``` This will show pages fit to the window size in most cases or filling the width on iPhone in landscape. ## Valid combinations You need to be aware of the following constraints when using the [`PDFConfiguration`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration) properties ([`pageTransition`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/pagetransition), [`scrollDirection`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/scrolldirection), and [`pageMode`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/pagemode)) simultaneously. ### Per-spread scrolling If the page transition is [`PageTransition.scrollPerSpread`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagetransition/scrollperspread), there are no constraints: - The [`scrollDirection`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/scrolldirection) property can be either [`ScrollDirection.horizontal`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/scrolldirection/horizontal) or [`ScrollDirection.vertical`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/scrolldirection/vertical). - The [`pageMode`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/pagemode) property can be [`PageMode.single`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/single), [`PageMode.double`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/double), or [`PageMode.automatic`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/automatic). ### SWIFT ```swift let configuration = PDFConfiguration { builder in // When the page transition is `scrollPerPage`. builder.pageTransition =.scrollPerSpread builder.scrollDirection =.vertical // Can also be `.horizontal`. builder.pageMode =.single // Can also be `.double` or `.automatic`. } ``` ### OBJECTIVE-C ```objc PSPDFConfiguration *configuration = [PSPDFConfiguration configurationWithBuilder:^(PSPDFConfigurationBuilder *builder) { // When the page transition is `PSPDFPageTransitionScrollPerSpread`. builder.pageTransition = PSPDFPageTransitionScrollPerSpread; builder.scrollDirection = PSPDFScrollDirectionVertical; // Can also be `PSPDFScrollDirectionHorizontal`. builder.pageMode = PSPDFPageModeSingle; // Can also be `PSPDFPageModeDouble` or `PSPDFPageModeAutomatic`. }]; ``` ### Continuous scrolling If the page transition is [`PageTransition.scrollContinuous`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagetransition/scrollcontinuous): - The [`scrollDirection`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/scrolldirection) property can be either [`ScrollDirection.horizontal`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/scrolldirection/horizontal) or [`ScrollDirection.vertical`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/scrolldirection/vertical). - If [`ScrollDirection.vertical`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/scrolldirection/vertical) is used, the [`pageMode`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/pagemode) property can be [`PageMode.single`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/single), [`PageMode.double`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/double), or [`PageMode.automatic`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/automatic). It’ll be forced to [`PageMode.single`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/single) if [`ScrollDirection.horizontal`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/scrolldirection/horizontal) is used. ### SWIFT ```swift let configuration = PDFConfiguration { builder in // When the page transition is `scrollContinuous`. builder.pageTransition =.scrollContinuous builder.scrollDirection =.vertical // Can also be `.horizontal`. builder.pageMode =.single // Setting a value to `pageMode` will only be honored if `scrollDirection` is `.vertical`. It will be forced to single otherwise. } ``` ### OBJECTIVE-C ```objc PSPDFConfiguration *configuration = [PSPDFConfiguration configurationWithBuilder:^(PSPDFConfigurationBuilder *builder) { // When the page transition is `PSPDFPageTransitionScrollContinuous`. builder.pageTransition = PSPDFPageTransitionScrollContinuous; builder.scrollDirection = PSPDFScrollDirectionVertical; // Can also be `PSPDFScrollDirectionHorizontal`. builder.pageMode = PSPDFPageModeSingle; // Setting a value to `pageMode` will only be honored if `scrollDirection` is `PSPDFScrollDirectionVertical`. It will be forced to `PSPDFPageModeSingle` otherwise. }]; ``` ### Page curl If the page transition is [`PageTransition.curl`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagetransition/curl): - The value of [`scrollDirection`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/scrolldirection) will be forced to [`ScrollDirection.horizontal`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/scrolldirection/horizontal). - The [`pageMode`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration/pagemode) property can be [`PageMode.single`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/single), [`PageMode.double`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/double), or [`PageMode.automatic`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pagemode/automatic). ### SWIFT ```swift let configuration = PDFConfiguration { builder in // When the page transition is `curl`. builder.pageTransition =.curl builder.scrollDirection =.horizontal // Setting a value to the `scrollDirection` property will be ignored. It will be forced to `.horizontal`. builder.pageMode =.single // Can also be `.double` or `.automatic`. } ``` ### OBJECTIVE-C ```objc PSPDFConfiguration *configuration = [PSPDFConfiguration configurationWithBuilder:^(PSPDFConfigurationBuilder *builder) { // When the page transition is `PSPDFPageTransitionCurl`. builder.pageTransition = PSPDFPageTransitionCurl; builder.scrollDirection = PSPDFScrollDirectionHorizontal; // Setting a value to the `scrollDirection` property will be ignored. It will be forced to `PSPDFScrollDirectionHorizontal`. builder.pageMode = PSPDFPageModeSingle; // Can also be `PSPDFPageModeDouble` or `PSPDFPageModeAutomatic`. }]; ``` ## Persisting the settings options with user defaults You can persist the settings options for your [`PDFSettingsViewController`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfsettingsviewcontroller) in your app’s [`UserDefaults`](https://developer.apple.com/documentation/foundation/userdefaults). ### Saving the settings options You can save the settings in your app’s user defaults in [`PDFViewControllerDelegate.pdfViewControllerDidDismiss(_:)`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfviewcontrollerdelegate/pdfviewcontrollerdiddismiss(_:)), like so: ### SWIFT ```swift func pdfViewControllerDidDismiss(_ pdfController: PDFViewController) { // Persist the settings options in the user defaults. let defaults = UserDefaults.standard defaults.set(pdfController.configuration.pageTransition.rawValue, forKey: "pageTransition") defaults.set(pdfController.configuration.pageMode.rawValue, forKey: "pageMode") defaults.set(pdfController.configuration.scrollDirection.rawValue, forKey: "scrollDirection") defaults.set(pdfController.configuration.spreadFitting.rawValue, forKey: "spreadFitting") } ``` ### OBJECTIVE-C ```objc - (void)pdfViewControllerDidDismiss:(PSPDFViewController *)pdfController { // Persist the settings options in the user defaults. NSUserDefaults *defaults = NSUserDefaults.standardUserDefaults; [defaults setInteger:pdfController.configuration.pageTransition forKey: @"pageTransition"]; [defaults setInteger:pdfController.configuration.pageMode forKey: @"pageMode"]; [defaults setInteger:pdfController.configuration.scrollDirection forKey: @"scrollDirection"]; [defaults setInteger:pdfController.configuration.spreadFitting forKey: @"spreadFitting"]; } ``` ### Restoring the settings options You can restore the saved settings options from your app’s user defaults in your [`PDFConfiguration`](https://www.nutrient.io/api/ios/documentation/pspdfkitui/pdfconfiguration), as seen below: ### SWIFT ```swift let configuration = PDFConfiguration { builder in // Restore the settings from the user defaults. let defaults = UserDefaults.standard builder.pageTransition = PageTransition(rawValue: UInt(defaults.integer(forKey: "pageTransition")))! builder.pageMode = PageMode(rawValue: UInt(defaults.integer(forKey: "pageMode")))! builder.scrollDirection = ScrollDirection(rawValue: UInt(defaults.integer(forKey: "scrollDirection")))! builder.spreadFitting = PDFConfiguration.SpreadFitting(rawValue: defaults.integer(forKey: "spreadFitting"))! } ``` ### OBJECTIVE-C ```objc PSPDFConfiguration *configuration = [PSPDFConfiguration configurationWithBuilder:^(PSPDFConfigurationBuilder *builder) { // Restore the settings from the user defaults. NSUserDefaults *defaults = NSUserDefaults.standardUserDefaults; builder.pageTransition = [defaults integerForKey:@"pageTransition"]; builder.pageMode = [defaults integerForKey:@"pageMode"]; builder.scrollDirection = [defaults integerForKey:@"scrollDirection"]; builder.spreadFitting = [defaults integerForKey:@"spreadFitting"]; }]; ``` For more details and sample code, take a look at [`PersistViewSettingsExample.swift`](https://github.com/PSPDFKit/pspdfkit-ios-catalog/blob/master/Catalog/Examples/ControllerCustomization/PersistViewSettingsExample.swift) from the [Catalog app](https://www.nutrient.io/../../getting-started/example-projects/#nutrient-catalog). --- ## Related pages - [iOS PDF viewer library](/guides/ios/viewer.md) - [Customizing page navigation in our iOS viewer](/guides/ios/getting-started/document-interactions.md) - [Embedded files and PDF portfolio collections](/guides/ios/features/embedded-files.md) - [Enhance your PDF workflow with JavaScript support](/guides/ios/features/javascript.md) - [iOS image viewer library](/guides/ios/viewer/images.md) - [Configure permissions for iOS PDF viewer](/guides/ios/features/document-permissions.md) - [Swift PDF viewer library](/guides/ios/viewer/swift.md) - [Troubleshooting](/guides/ios/viewer/troubleshooting.md) - [Display PDFs with the view state on iOS](/guides/ios/view-management/store-load-view-state.md) - [visionOS AR/VR PDF viewer](/guides/ios/viewer/visionos.md)