Improve pane transitions in bank auth flow

financial-connections/src/main/java/com/stripe/android/financialconnections/ui/FinancialConnectionsSheetNativeActivity.kt

@@ -201,6 +201,10 @@ internal class FinancialConnectionsSheetNativeActivity : AppCompatActivity() {
                     NavHost(
                         navController = navController,
                         startDestination = initialDestination.fullRoute,
+                        enterTransition = enterTransition(),
+                        exitTransition = pauseTransition(),
+                        popEnterTransition = resumeTransition(),
+                        popExitTransition = exitTransition(),
                     ) {
                         composable(Destination.Consent)
                         composable(Destination.ManualEntry)

financial-connections/src/main/java/com/stripe/android/financialconnections/ui/Transitions.kt

@@ -0,0 +1,91 @@
+package com.stripe.android.financialconnections.ui
+
+import androidx.compose.animation.AnimatedContentTransitionScope
+import androidx.compose.animation.EnterTransition
+import androidx.compose.animation.ExitTransition
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.slideInHorizontally
+import androidx.compose.animation.slideOutHorizontally
+import androidx.navigation.NavBackStackEntry
+import com.stripe.android.financialconnections.model.FinancialConnectionsSessionManifest.Pane.ATTACH_LINKED_PAYMENT_ACCOUNT
+import com.stripe.android.financialconnections.navigation.pane
+
+private const val TransitionDurationMillis = 300
+
+private val FADE_IN_TRANSITION = fadeIn(
+    animationSpec = tween(TransitionDurationMillis)
+)
+
+private val FADE_OUT_TRANSITION = fadeOut(
+    animationSpec = tween(TransitionDurationMillis)
+)
+
+internal fun enterTransition(): AnimatedContentTransitionScope<NavBackStackEntry>.() -> EnterTransition {
+    return {
+        if (initialState.skipTransition) {
+            FADE_IN_TRANSITION
+        } else {
+            FADE_IN_TRANSITION + slideInHorizontally(
+                animationSpec = tween(TransitionDurationMillis),
+                initialOffsetX = { fullWidth ->
+                    fullWidth / 2
+                },
+            )
+        }
+    }
+}
+
+internal fun resumeTransition(): AnimatedContentTransitionScope<NavBackStackEntry>.() -> EnterTransition {
+    return {
+        if (initialState.skipTransition) {
+            FADE_IN_TRANSITION
+        } else {
+            FADE_IN_TRANSITION + slideInHorizontally(
+                animationSpec = tween(TransitionDurationMillis),
+                initialOffsetX = { fullWidth ->
+                    -fullWidth / 2
+                },
+            )
+        }
+    }
+}
+
+internal fun pauseTransition(): AnimatedContentTransitionScope<NavBackStackEntry>.() -> ExitTransition {
+    return {
+        if (initialState.skipTransition) {
+            FADE_OUT_TRANSITION
+        } else {
+            FADE_OUT_TRANSITION + slideOutHorizontally(
+                animationSpec = tween(TransitionDurationMillis),
+                targetOffsetX = { fullWidth ->
+                    -fullWidth / 2
+                },
+            )
+        }
+    }
+}
+
+internal fun exitTransition(): AnimatedContentTransitionScope<NavBackStackEntry>.() -> ExitTransition {
+    return {
+        if (initialState.skipTransition) {
+            FADE_OUT_TRANSITION
+        } else {
+            FADE_OUT_TRANSITION + slideOutHorizontally(
+                animationSpec = tween(TransitionDurationMillis),
+                targetOffsetX = { fullWidth ->
+                    fullWidth / 2
+                },
+            )
+        }
+    }
+}
+
+/**
+ * We want to skip the transition for some screens and use a simple fade instead. This currently only applies
+ * to transitions starting from the attach linked payment account screen, which only ever shows a loading indicator.
+ * We wouldn't want to show a slide transition from one loading indicator to another, therefore we use a fade.
+ */
+private val NavBackStackEntry.skipTransition: Boolean
+    get() = destination.pane == ATTACH_LINKED_PAYMENT_ACCOUNT

financial-connections/src/main/java/com/stripe/android/financialconnections/ui/components/TopAppBar.kt

@@ -2,7 +2,11 @@ package com.stripe.android.financialconnections.ui.components
 
 import androidx.activity.OnBackPressedDispatcher
 import androidx.activity.compose.LocalOnBackPressedDispatcherOwner
+import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.padding
@@ -179,13 +183,18 @@ private fun Title(hideStripeLogo: Boolean, testmode: Boolean) = Row(
     verticalAlignment = Alignment.CenterVertically,
     horizontalArrangement = Arrangement.spacedBy(8.dp)
 ) {
-    if (hideStripeLogo.not()) {
+    AnimatedVisibility(
+        visible = !hideStripeLogo,
+        enter = fadeIn(animationSpec = tween()),
+        exit = fadeOut(animationSpec = tween()),
+    ) {
         Icon(
             modifier = Modifier.size(width = LOGO_WIDTH, height = LOGO_HEIGHT),
             painter = painterResource(id = R.drawable.stripe_logo),
             contentDescription = null // decorative element
         )
     }
+
     // show a test mode pill if in test mode
     if (testmode) {
         Text(