android: commonize shared animation code

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/decorations/ClawFab.kt

@@ -2,11 +2,6 @@ package dev.msfjarvis.claw.android.ui.decorations
 
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.ExperimentalAnimationApi
-import androidx.compose.animation.core.FastOutLinearInEasing
-import androidx.compose.animation.core.LinearOutSlowInEasing
-import androidx.compose.animation.core.tween
-import androidx.compose.animation.slideInVertically
-import androidx.compose.animation.slideOutVertically
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.material3.FloatingActionButton
 import androidx.compose.material3.Icon
@@ -15,7 +10,8 @@ import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.painterResource
 import dev.msfjarvis.claw.android.R
-import dev.msfjarvis.claw.android.ui.AnimationDuration
+import dev.msfjarvis.claw.android.ui.slideInAnimation
+import dev.msfjarvis.claw.android.ui.slideOutAnimation
 import kotlinx.coroutines.launch
 
 @OptIn(ExperimentalAnimationApi::class)
@@ -28,18 +24,8 @@ fun ClawFab(
   val coroutineScope = rememberCoroutineScope()
   AnimatedVisibility(
     visible = isFabVisible,
-    enter =
+    enter = slideInAnimation(),
-      slideInVertically(
+    exit = slideOutAnimation(),
-        // Enters by sliding up from offset 0 to fullHeight.
-        initialOffsetY = { fullHeight -> fullHeight },
-        animationSpec = tween(durationMillis = AnimationDuration, easing = LinearOutSlowInEasing),
-      ),
-    exit =
-      slideOutVertically(
-        // Exits by sliding up from offset 0 to -fullHeight.
-        targetOffsetY = { fullHeight -> fullHeight },
-        animationSpec = tween(durationMillis = AnimationDuration, easing = FastOutLinearInEasing),
-      ),
     modifier = modifier,
   ) {
     FloatingActionButton(onClick = { coroutineScope.launch { listState.animateScrollToItem(0) } }) {

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/decorations/ClawNavigationBar.kt

@@ -1,11 +1,6 @@
 package dev.msfjarvis.claw.android.ui.decorations
 
 import androidx.compose.animation.AnimatedVisibility
-import androidx.compose.animation.core.FastOutLinearInEasing
-import androidx.compose.animation.core.LinearOutSlowInEasing
-import androidx.compose.animation.core.tween
-import androidx.compose.animation.slideInVertically
-import androidx.compose.animation.slideOutVertically
 import androidx.compose.material3.Icon
 import androidx.compose.material3.NavigationBar
 import androidx.compose.material3.NavigationBarItem
@@ -14,8 +9,9 @@ import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.painter.Painter
 import androidx.navigation.NavController
-import dev.msfjarvis.claw.android.ui.AnimationDuration
 import dev.msfjarvis.claw.android.ui.navigation.Destinations
+import dev.msfjarvis.claw.android.ui.slideInAnimation
+import dev.msfjarvis.claw.android.ui.slideOutAnimation
 
 @Composable
 fun ClawNavigationBar(
@@ -26,18 +22,8 @@ fun ClawNavigationBar(
 ) {
   AnimatedVisibility(
     visible = isVisible,
-    enter =
+    enter = slideInAnimation(),
-      slideInVertically(
+    exit = slideOutAnimation(),
-        // Enters by sliding up from offset 0 to fullHeight.
-        initialOffsetY = { fullHeight -> fullHeight },
-        animationSpec = tween(durationMillis = AnimationDuration, easing = LinearOutSlowInEasing),
-      ),
-    exit =
-      slideOutVertically(
-        // Exits by sliding up from offset 0 to -fullHeight.
-        targetOffsetY = { fullHeight -> fullHeight },
-        animationSpec = tween(durationMillis = AnimationDuration, easing = FastOutLinearInEasing),
-      ),
     modifier = Modifier,
   ) {
     NavigationBar(modifier = modifier) {

android/src/main/kotlin/dev/msfjarvis/claw/android/ui/ext.kt

@@ -2,6 +2,13 @@ package dev.msfjarvis.claw.android.ui
 
 import android.content.Context
 import android.os.Build
+import androidx.compose.animation.EnterTransition
+import androidx.compose.animation.ExitTransition
+import androidx.compose.animation.core.FastOutLinearInEasing
+import androidx.compose.animation.core.LinearOutSlowInEasing
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.slideInVertically
+import androidx.compose.animation.slideOutVertically
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.material3.ColorScheme
 import androidx.compose.material3.LocalAbsoluteTonalElevation
@@ -27,7 +34,23 @@ import dev.msfjarvis.claw.common.urllauncher.UrlLauncher
 import dev.msfjarvis.claw.database.local.SavedPost
 import kotlin.math.ln
 
-const val AnimationDuration = 100
+private const val AnimationDuration = 100
+
+fun slideInAnimation(): EnterTransition {
+  return slideInVertically(
+    // Enters by sliding up from offset 0 to fullHeight.
+    initialOffsetY = { fullHeight -> fullHeight },
+    animationSpec = tween(durationMillis = AnimationDuration, easing = LinearOutSlowInEasing),
+  )
+}
+
+fun slideOutAnimation(): ExitTransition {
+  return slideOutVertically(
+    // Exits by sliding up from offset 0 to -fullHeight.
+    targetOffsetY = { fullHeight -> fullHeight },
+    animationSpec = tween(durationMillis = AnimationDuration, easing = FastOutLinearInEasing),
+  )
+}
 
 // The destination needs to be tracked like this rather than used directly since
 // `NavController#currentDestination` is not a Composable state.