Use androidx SavedStateHandle.saveable

Change-Id: Ifdae07c5b3731c4d67f348a01652cf3aec00b234

feature-foryou/src/main/java/com/google/samples/apps/nowinandroid/feature/foryou/util/SavedStateHandleExtensions.kt

@@ -16,40 +16,33 @@
 
 package com.google.samples.apps.nowinandroid.feature.foryou.util
 
-import android.os.Binder
-import android.os.Bundle
-import android.os.Parcelable
-import android.util.Size
-import android.util.SizeF
-import android.util.SparseArray
 import androidx.compose.runtime.MutableState
 import androidx.compose.runtime.SnapshotMutationPolicy
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.neverEqualPolicy
-import androidx.compose.runtime.referentialEqualityPolicy
 import androidx.compose.runtime.saveable.Saver
-import androidx.compose.runtime.saveable.SaverScope
 import androidx.compose.runtime.saveable.autoSaver
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.runtime.snapshots.SnapshotMutableState
-import androidx.compose.runtime.structuralEqualityPolicy
-import androidx.core.os.bundleOf
 import androidx.lifecycle.SavedStateHandle
-import java.io.Serializable
+import androidx.lifecycle.viewmodel.compose.SavedStateHandleSaveableApi
+import androidx.lifecycle.viewmodel.compose.saveable
 import kotlin.properties.PropertyDelegateProvider
 import kotlin.properties.ReadOnlyProperty
 import kotlin.properties.ReadWriteProperty
 import kotlin.reflect.KProperty
 
-// These are placeholder solutions for https://issuetracker.google.com/issues/195689777
+// These are placeholder solutions for https://issuetracker.google.com/issues/224565154 and
+// https://issuetracker.google.com/issues/225014345.
 // With the following, it is possible to use the Compose Saver APIs to back values in the
 // SavedStateHandle to persist through process death, in a similar form as rememberSaveable
 
 /**
  * A [PropertyDelegateProvider] allowing the use of [saveable] with the key provided by the name
  * of the property.
+ *
+ * https://issuetracker.google.com/issues/225014345
  */
 fun <T : Any> SavedStateHandle.saveable(
     saver: Saver<T, out Any> = autoSaver(),
@@ -75,6 +68,9 @@ fun <T : Any> SavedStateHandle.saveable(
  * ```
  * val value by savedStateHandle.saveable { mutableStateOf("initialValue") }
  * ```
+ *
+ * https://issuetracker.google.com/issues/224565154 and
+ * https://issuetracker.google.com/issues/225014345
  */
 @JvmName("saveableMutableState")
 fun <T : Any> SavedStateHandle.saveable(
@@ -97,35 +93,6 @@ fun <T : Any> SavedStateHandle.saveable(
         }
     }
 
-/**
- * A basic interop between [SavedStateHandle] and [Saver], so the latter can be used to save
- * state holders into the [SavedStateHandle].
- *
- * This implementation is based on [rememberSaveable], [SaveableStateRegistry] and
- * [DisposableSaveableStateRegistry], with some simplifications since there will be exactly one
- * state provider storing exactly one value.
- *
- * This implementation makes use of [SavedStateHandle.setSavedStateProvider], so this
- * state will not be kept in sync with any other way to change the internal state
- * of the [SavedStateHandle].
- */
-fun <T : Any> SavedStateHandle.saveable(
-    key: String,
-    saver: Saver<T, out Any> = autoSaver(),
-    init: () -> T,
-): T {
-    @Suppress("UNCHECKED_CAST")
-    saver as Saver<T, Any>
-    // value is restored using the SavedStateHandle or created via [init] lambda
-    val value = get<Bundle?>(key)?.get("value")?.let(saver::restore) ?: init()
-
-    // Hook up saving the state to the SavedStateHandle
-    setSavedStateProvider(key) {
-        bundleOf("value" to with(saver) { SaverScope(::canBeSavedToBundle).save(value) })
-    }
-    return value
-}
-
 /**
  * A basic interop between [SavedStateHandle] and [Saver], so the latter can be used to save
  * state holders into the [SavedStateHandle].
@@ -140,7 +107,10 @@ fun <T : Any> SavedStateHandle.saveable(
  *
  * Use this overload if you remember a mutable state with a type which can't be stored in the
  * Bundle so you have to provide a custom saver object.
+ *
+ * https://issuetracker.google.com/issues/224565154
  */
+@OptIn(SavedStateHandleSaveableApi::class)
 fun <T> SavedStateHandle.saveable(
     key: String,
     stateSaver: Saver<T, out Any>,
@@ -173,57 +143,3 @@ private fun <T> mutableStateSaver(inner: Saver<T, out Any>) = with(inner as Save
         }
     )
 }
-
-/**
- * Checks that [value] can be stored inside [Bundle].
- *
- * Copied from DisposableSaveableStateRegistry.android.kt
- */
-private fun canBeSavedToBundle(value: Any): Boolean {
-    // SnapshotMutableStateImpl is Parcelable, but we do extra checks
-    if (value is SnapshotMutableState<*>) {
-        if (value.policy === neverEqualPolicy<Any?>() ||
-            value.policy === structuralEqualityPolicy<Any?>() ||
-            value.policy === referentialEqualityPolicy<Any?>()
-        ) {
-            val stateValue = value.value
-            return if (stateValue == null) true else canBeSavedToBundle(stateValue)
-        } else {
-            return false
-        }
-    }
-    for (cl in AcceptableClasses) {
-        if (cl.isInstance(value)) {
-            return true
-        }
-    }
-    return false
-}
-
-/**
- * Contains Classes which can be stored inside [Bundle].
- *
- * Some of the classes are not added separately because:
- *
- * This classes implement Serializable:
- * - Arrays (DoubleArray, BooleanArray, IntArray, LongArray, ByteArray, FloatArray, ShortArray,
- * CharArray, Array<Parcelable, Array<String>)
- * - ArrayList
- * - Primitives (Boolean, Int, Long, Double, Float, Byte, Short, Char) will be boxed when casted
- * to Any, and all the boxed classes implements Serializable.
- * This class implements Parcelable:
- * - Bundle
- *
- * Note: it is simplified copy of the array from SavedStateHandle (lifecycle-viewmodel-savedstate).
- *
- * Copied from DisposableSaveableStateRegistry.android.kt
- */
-private val AcceptableClasses = arrayOf(
-    Serializable::class.java,
-    Parcelable::class.java,
-    String::class.java,
-    SparseArray::class.java,
-    Binder::class.java,
-    Size::class.java,
-    SizeF::class.java
-)

gradle/libs.versions.toml

@@ -11,7 +11,7 @@ androidxCore = "1.7.0"
 androidxDataStore = "1.0.0"
 androidxEspresso = "3.3.0"
 androidxHiltNavigationCompose = "1.0.0-rc01"
-androidxLifecycle = "2.4.0"
+androidxLifecycle = "2.5.0-alpha05"
 androidxMacroBenchmark = "1.1.0-beta04"
 androidxNavigation = "2.4.0-rc01"
 androidxProfileinstaller = "1.2.0-alpha02"