Serialize state to parcel for state restoration tester

kmp-state-restoration-tester/build.gradle.kts

@@ -35,7 +35,12 @@ kotlin {
     jvm("desktop")
 
     sourceSets {
-        val commonMain by getting {}
+        val commonMain by getting {
+            dependencies {
+                implementation(libs.jetbrains.compose.runtime)
+                implementation(libs.jetbrains.compose.runtime.saveable)
+            }
+        }
         val jbMain by creating {
             dependsOn(commonMain)
             dependencies {

kmp-state-restoration-tester/src/androidMain/kotlin/com/alexvanyo/composelife/kmpstaterestorationtester/KmpStateRestorationTester.android.kt

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alexvanyo.composelife.kmpstaterestorationtester
+
+import android.os.Bundle
+import android.os.Parcel
+import android.os.Parcelable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.saveable.SaveableStateRegistry
+import androidx.compose.runtime.setValue
+
+private class RestorationRegistryImpl(private val original: SaveableStateRegistry) :
+    RestorationRegistry {
+
+    override var shouldEmitChildren by mutableStateOf(true)
+        private set
+    private var currentRegistry: SaveableStateRegistry = original
+    private lateinit var savedParcel: Parcel
+
+    override fun saveStateAndDisposeChildren() {
+        savedParcel = Parcel.obtain().also {
+            currentRegistry.performSave().toBundle().writeToParcel(it, Parcelable.PARCELABLE_WRITE_RETURN_VALUE)
+        }
+        shouldEmitChildren = false
+    }
+
+    override fun emitChildrenWithRestoredState() {
+        savedParcel.setDataPosition(0)
+        val restoredValues = Bundle.CREATOR.createFromParcel(savedParcel).apply {
+            classLoader = this@RestorationRegistryImpl.javaClass.classLoader
+        }.toMap()
+        savedParcel.recycle()
+        currentRegistry = SaveableStateRegistry(
+            restoredValues = restoredValues,
+            canBeSaved = { original.canBeSaved(it) },
+        )
+        shouldEmitChildren = true
+    }
+
+    override fun consumeRestored(key: String) = currentRegistry.consumeRestored(key)
+
+    override fun registerProvider(key: String, valueProvider: () -> Any?) =
+        currentRegistry.registerProvider(key, valueProvider)
+
+    override fun canBeSaved(value: Any) = currentRegistry.canBeSaved(value)
+
+    override fun performSave() = currentRegistry.performSave()
+}
+
+internal actual fun RestorationRegistry(
+    original: SaveableStateRegistry,
+): RestorationRegistry = RestorationRegistryImpl(original)
+
+// Copied from DisposableSaveableStateRegistry.android.kt
+@Suppress("DEPRECATION", "UNCHECKED_CAST")
+private fun Bundle.toMap(): Map<String, List<Any?>>? {
+    val map = mutableMapOf<String, List<Any?>>()
+    this.keySet().forEach { key ->
+        val list = getParcelableArrayList<Parcelable?>(key) as ArrayList<Any?>
+        map[key] = list
+    }
+    return map
+}
+
+// Copied from DisposableSaveableStateRegistry.android.kt
+@Suppress("UNCHECKED_CAST")
+private fun Map<String, List<Any?>>.toBundle(): Bundle {
+    val bundle = Bundle()
+    forEach { (key, list) ->
+        val arrayList = if (list is ArrayList<Any?>) list else ArrayList(list)
+        bundle.putParcelableArrayList(
+            key,
+            arrayList as ArrayList<Parcelable?>,
+        )
+    }
+    return bundle
+}

kmp-state-restoration-tester/src/desktopMain/kotlin/com/alexvanyo/composelife/kmpstaterestorationtester/KmpStateRestorationTester.desktop.kt

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.alexvanyo.composelife.kmpstaterestorationtester
+
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.saveable.SaveableStateRegistry
+import androidx.compose.runtime.setValue
+
+private class RestorationRegistryImpl(private val original: SaveableStateRegistry) :
+    RestorationRegistry {
+
+    override var shouldEmitChildren by mutableStateOf(true)
+        private set
+    private var currentRegistry: SaveableStateRegistry = original
+    private var savedMap: Map<String, List<Any?>> = emptyMap()
+
+    override fun saveStateAndDisposeChildren() {
+        savedMap = currentRegistry.performSave()
+        shouldEmitChildren = false
+    }
+
+    override fun emitChildrenWithRestoredState() {
+        currentRegistry = SaveableStateRegistry(
+            restoredValues = savedMap,
+            canBeSaved = { original.canBeSaved(it) },
+        )
+        shouldEmitChildren = true
+    }
+
+    override fun consumeRestored(key: String) = currentRegistry.consumeRestored(key)
+
+    override fun registerProvider(key: String, valueProvider: () -> Any?) =
+        currentRegistry.registerProvider(key, valueProvider)
+
+    override fun canBeSaved(value: Any) = currentRegistry.canBeSaved(value)
+
+    override fun performSave() = currentRegistry.performSave()
+}
+
+internal actual fun RestorationRegistry(
+    original: SaveableStateRegistry,
+): RestorationRegistry = RestorationRegistryImpl(original)

kmp-state-restoration-tester/src/jbMain/kotlin/com/alexvanyo/composelife/kmpstaterestorationtester/KmpStateRestorationTester.kt

@@ -19,7 +19,6 @@ package com.alexvanyo.composelife.kmpstaterestorationtester
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.LocalSaveableStateRegistry
 import androidx.compose.runtime.saveable.SaveableStateRegistry
@@ -95,35 +94,14 @@ class KmpStateRestorationTester(private val composeUiTest: ComposeUiTest) {
             }
         }
     }
+}
 
-    private class RestorationRegistry(private val original: SaveableStateRegistry) :
-        SaveableStateRegistry {
-
-        var shouldEmitChildren by mutableStateOf(true)
-            private set
-        private var currentRegistry: SaveableStateRegistry = original
-        private var savedMap: Map<String, List<Any?>> = emptyMap()
-
-        fun saveStateAndDisposeChildren() {
-            savedMap = currentRegistry.performSave()
-            shouldEmitChildren = false
-        }
-
-        fun emitChildrenWithRestoredState() {
-            currentRegistry = SaveableStateRegistry(
-                restoredValues = savedMap,
-                canBeSaved = { original.canBeSaved(it) },
-            )
-            shouldEmitChildren = true
-        }
-
-        override fun consumeRestored(key: String) = currentRegistry.consumeRestored(key)
-
-        override fun registerProvider(key: String, valueProvider: () -> Any?) =
-            currentRegistry.registerProvider(key, valueProvider)
+internal interface RestorationRegistry : SaveableStateRegistry {
+    val shouldEmitChildren: Boolean
 
-        override fun canBeSaved(value: Any) = currentRegistry.canBeSaved(value)
+    fun saveStateAndDisposeChildren()
 
-        override fun performSave() = currentRegistry.performSave()
-    }
+    fun emitChildrenWithRestoredState()
 }
+
+internal expect fun RestorationRegistry(original: SaveableStateRegistry): RestorationRegistry