The primary milestone is to improve to Kotlin 1.8.0 or larger, which is required for different Predictive Again dependencies.
Again-to-home animation milestone
The back-to-home animation is the keystone predictive again animation.
To get this animation, add android:enableOnBackInvokedCallback=true in your AndroidManifest.xml to your root exercise if you’re a multi-activity app (see per-activity opt-in) or on the utility degree if you’re a single-activity app. After this, you’ll see each the back-to-home animation and a cross-task animation the place relevant, that are seen to customers in Android 15+ and behind a developer possibility in Android 13 and 14.
If you’re intercepting again occasions in your root exercise (e.g. MainActivity), you may proceed to take action however you’ll want to make use of supported APIs and also you gained’t get the back-to-home animation. Because of this, we usually advocate you solely intercept again occasions for UI logic; for instance, to point out a dialog asking the person to avoid wasting earlier than they stop.
See the Add support for the predictive back gesture information for extra particulars.
Migrate all actions milestone
If you’re a multi-activity app, you’ll have to opt-in and deal with again occasions inside these actions too to get a system managed cross-activity animation. Be taught extra about per-activity opt-in, accessible for units operating Android 14+. The cross-activity animation is seen to customers in Android 15+ and behind a developer possibility in Android 13 and 14.
Customized cross exercise animations are additionally accessible with overrideActivityTransition.
Fragment milestone
Subsequent, you’ll wish to focus in your fragment animations and transitions. This requires updating to AndroidX fragment 1.7.0 and transition 1.5.0 or later and utilizing Animator or AndroidX Transitions. Assuming these necessities are met, your current fragment animations and transitions will animate consistent with the again gesture. You can even use material motion with fragments. Most materials motions assist predictive again as of 1.12.02-alpha02 or larger, together with MaterialFadeThrough, MaterialSharedAxis and MaterialFade.
Don’t attempt to make your fragment transitions seem like the system’s cross-activity transition. We advocate this full screen surface transition as a substitute.
Be taught extra about Fragments and Predictive Back.
Materials Parts milestone
Lastly, you’ll wish to make the most of the Materials Part View animations accessible for Predictive Again. Be taught extra about available components.
After this, you’ve accomplished your quest to assist Predictive Again animations in your view primarily based app.
[Optional] AndroidX Transitions milestone
If you happen to’re up for extra, you may also guarantee your AndroidX transitions are supported with Predictive Again. Learn extra about AndroidX Transitions and the Predictive Again Progress APIs.
