ParcelableSnapshotMutableState.kt
/*
* Copyright 2021 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
*
* http://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 androidx.compose.runtime
import android.annotation.SuppressLint
import android.os.Parcel
import android.os.Parcelable
@SuppressLint("BanParcelableUsage")
internal class ParcelableSnapshotMutableState<T>(
value: T,
policy: SnapshotMutationPolicy<T>
) : SnapshotMutableStateImpl<T>(value, policy), Parcelable {
override fun writeToParcel(parcel: Parcel, flags: Int) {
parcel.writeValue(value)
parcel.writeInt(
when (policy) {
neverEqualPolicy<Any?>() -> PolicyNeverEquals
structuralEqualityPolicy<Any?>() -> PolicyStructuralEquality
referentialEqualityPolicy<Any?>() -> PolicyReferentialEquality
else -> throw IllegalStateException(
"Only known types of MutableState's SnapshotMutationPolicy are supported"
)
}
)
}
override fun describeContents(): Int {
return 0
}
companion object {
private const val PolicyNeverEquals = 0
private const val PolicyStructuralEquality = 1
private const val PolicyReferentialEquality = 2
@Suppress("unused")
@JvmField
val CREATOR: Parcelable.Creator<ParcelableSnapshotMutableState<Any?>> =
object : Parcelable.ClassLoaderCreator<ParcelableSnapshotMutableState<Any?>> {
override fun createFromParcel(
parcel: Parcel,
loader: ClassLoader?
): ParcelableSnapshotMutableState<Any?> {
val value = parcel.readValue(loader ?: javaClass.classLoader)
val policyIndex = parcel.readInt()
return ParcelableSnapshotMutableState(
value,
when (policyIndex) {
PolicyNeverEquals -> neverEqualPolicy()
PolicyStructuralEquality -> structuralEqualityPolicy()
PolicyReferentialEquality -> referentialEqualityPolicy()
else -> throw IllegalStateException(
"Unsupported MutableState policy $policyIndex was restored"
)
}
)
}
override fun createFromParcel(parcel: Parcel) = createFromParcel(parcel, null)
override fun newArray(size: Int) =
arrayOfNulls<ParcelableSnapshotMutableState<Any?>?>(size)
}
}
}