Fix wrong animation direction when child replaced

badoo · Mar 29, 2021 · 325fccc · 325fccc
1 parent 18f5e4b
commit 325fccc
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Showing 4 changed files with 21 additions and 9 deletions.
diff --git a/...in/com/arkivanov/decompose/extensions/compose/jetbrains/animation/child/ChildAnimation.kt b/...in/com/arkivanov/decompose/extensions/compose/jetbrains/animation/child/ChildAnimation.kt
@@ -2,17 +2,19 @@ package com.arkivanov.decompose.extensions.compose.jetbrains.animation.child
 
 import androidx.compose.animation.core.FiniteAnimationSpec
 import androidx.compose.animation.core.tween
+import androidx.compose.runtime.remember
 import com.arkivanov.decompose.Child
 import com.arkivanov.decompose.ExperimentalDecomposeApi
 import com.arkivanov.decompose.extensions.compose.jetbrains.ChildAnimation
 import com.arkivanov.decompose.extensions.compose.jetbrains.animation.page.PageAnimation
 import com.arkivanov.decompose.extensions.compose.jetbrains.animation.page.PageAnimator
 import com.arkivanov.decompose.extensions.compose.jetbrains.animation.page.PageArrangement
+import java.util.WeakHashMap
 
 internal val defaultChildAnimationSpec: FiniteAnimationSpec<Float> = tween()
 
 /**
- * A handy API for the [Children][com.arkivanov.decompose.extensions.compose.jetbrains.Children] animations
+ * A handy API for the [Children][com.arkivanov.decompose.extensions.compose.jetpack.Children] animations
  *
  * @param animationSpec a [FiniteAnimationSpec] to configure the animation
  * @param animator see [PageAnimator] for details
@@ -23,14 +25,18 @@ fun <C : Any, T : Any> childAnimation(
     animator: PageAnimator<Child.Created<C, T>>
 ): ChildAnimation<C, T> =
     { routerState, content ->
-        val stack = routerState.backStack + routerState.activeChild
+        val indicesMap: MutableMap<Child<C, T>, Int> = remember(::WeakHashMap)
+        routerState.backStack.forEachIndexed { index, child ->
+            indicesMap[child] = index
+        }
+        indicesMap[routerState.activeChild] = routerState.backStack.size
 
         PageAnimation(
             key = routerState.activeChild,
             animationSpec = animationSpec,
             arranger = { new, old ->
-                val indexOfNew = stack.indexOf(new).takeIf { it >= 0 } ?: Int.MAX_VALUE
-                val indexOfOld = stack.indexOf(old).takeIf { it >= 0 } ?: Int.MAX_VALUE
+                val indexOfNew = indicesMap[new] ?: Int.MAX_VALUE
+                val indexOfOld = indicesMap[old] ?: Int.MAX_VALUE
                 if (indexOfNew >= indexOfOld) PageArrangement.FOLLOWING else PageArrangement.PREVIOUS
             },
             animator = animator,

diff --git a/...tlin/com/arkivanov/decompose/extensions/compose/jetbrains/animation/page/PageAnimation.kt b/...tlin/com/arkivanov/decompose/extensions/compose/jetbrains/animation/page/PageAnimation.kt
@@ -128,7 +128,7 @@ private fun <T : Any> PageAnimationFrame(
     }
 }
 
-private class AnimationItem<T>(
+private class AnimationItem<out T>(
     val key: T,
     val arrangement: PageArrangement,
     val direction: PageAnimationDirection

diff --git a/...java/com/arkivanov/decompose/extensions/compose/jetpack/animation/child/ChildAnimation.kt b/...java/com/arkivanov/decompose/extensions/compose/jetpack/animation/child/ChildAnimation.kt
@@ -2,12 +2,14 @@ package com.arkivanov.decompose.extensions.compose.jetpack.animation.child
 
 import androidx.compose.animation.core.FiniteAnimationSpec
 import androidx.compose.animation.core.tween
+import androidx.compose.runtime.remember
 import com.arkivanov.decompose.Child
 import com.arkivanov.decompose.ExperimentalDecomposeApi
 import com.arkivanov.decompose.extensions.compose.jetpack.ChildAnimation
 import com.arkivanov.decompose.extensions.compose.jetpack.animation.page.PageAnimation
 import com.arkivanov.decompose.extensions.compose.jetpack.animation.page.PageAnimator
 import com.arkivanov.decompose.extensions.compose.jetpack.animation.page.PageArrangement
+import java.util.WeakHashMap
 
 internal val defaultChildAnimationSpec: FiniteAnimationSpec<Float> = tween()
 
@@ -23,14 +25,18 @@ fun <C : Any, T : Any> childAnimation(
     animator: PageAnimator<Child.Created<C, T>>
 ): ChildAnimation<C, T> =
     { routerState, content ->
-        val stack = routerState.backStack + routerState.activeChild
+        val indicesMap: MutableMap<Child<C, T>, Int> = remember(::WeakHashMap)
+        routerState.backStack.forEachIndexed { index, child ->
+            indicesMap[child] = index
+        }
+        indicesMap[routerState.activeChild] = routerState.backStack.size
 
         PageAnimation(
             key = routerState.activeChild,
             animationSpec = animationSpec,
             arranger = { new, old ->
-                val indexOfNew = stack.indexOf(new).takeIf { it >= 0 } ?: Int.MAX_VALUE
-                val indexOfOld = stack.indexOf(old).takeIf { it >= 0 } ?: Int.MAX_VALUE
+                val indexOfNew = indicesMap[new] ?: Int.MAX_VALUE
+                val indexOfOld = indicesMap[old] ?: Int.MAX_VALUE
                 if (indexOfNew >= indexOfOld) PageArrangement.FOLLOWING else PageArrangement.PREVIOUS
             },
             animator = animator,

diff --git a/...n/java/com/arkivanov/decompose/extensions/compose/jetpack/animation/page/PageAnimation.kt b/...n/java/com/arkivanov/decompose/extensions/compose/jetpack/animation/page/PageAnimation.kt
@@ -128,7 +128,7 @@ private fun <T : Any> PageAnimationFrame(
     }
 }
 
-private class AnimationItem<T>(
+private class AnimationItem<out T>(
     val key: T,
     val arrangement: PageArrangement,
     val direction: PageAnimationDirection