What needs to be done to animate transitions between…

For transition animations between screens in Android, several approaches can be used:

Activity Animations: Defined in themes or programmatically. They allow setting default enter and exit animations for activities.

override fun startActivity(intent: Intent) {
    super.startActivity(intent)
    overridePendingTransition(R.anim.slide_in_right, R.anim.slide_out_left)
}

override fun finish() {
    super.finish()
    overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right)
}

Animation files (e.g., res/anim/slide_in_right.xml):

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate
        android:fromXDelta="100%"
        android:toXDelta="0%"
        android:duration="@android:integer/config_shortAnimTime" />
</set>

Fragment Animations: Defined during fragment transactions.

supportFragmentManager.beginTransaction()
    .setCustomAnimations(R.anim.fade_in, R.anim.fade_out, R.anim.fade_in, R.anim.fade_out)
    .replace(R.id.container, fragment)
    .commit()

Shared Element Transitions: Allow animating the transition of one or multiple Views between screens, creating a seamless effect. Transition support must be enabled in the theme.

In the source activity:

val options = ActivityOptionsCompat.makeSceneTransitionAnimation(
    this,
    sharedView, // View for animation
    ViewCompat.getTransitionName(sharedView) // Name for linking
)
startActivity(intent, options.toBundle())

In the receiving activity:

// In onCreate or onViewCreated (for fragment)
supportPostponeEnterTransition() // Delay the enter animation until Views are ready
// When Views are ready (e.g., after image load),
supportStartPostponedEnterTransition()

In the XML layout of both screens:

<ImageView
    android:id="@+id/imageView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:transitionName="image_transition" /> <!-- Name for linking -->

Component Animations (Navigation Component): If using the Navigation Component, transition animations can be set directly in the navigation graph.

<action
    android:id="@+id/action_fragmentA_to_fragmentB"
    app:destination="@id/fragmentB"
    app:enterAnim="@anim/slide_in_right"
    app:exitAnim="@anim/slide_out_left"
    app:popEnterAnim="@anim/slide_in_left"
    app:popExitAnim="@anim/slide_out_right" />

The choice of method depends on the architecture used (Activity, Fragments, Navigation Component) and the desired effect.

What needs to be done to animate transitions between screens?