| /* |
| * Copyright 2019 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 |
| |
| /** |
| * [StableMarker] marks an annotation as indicating a type is stable. A stable type obeys the |
| * following assumptions, |
| * |
| * 1) The result of [equals] will always return the same result for the same two instances. |
| * 2) When a public property of the type changes, composition will be notified. |
| * 3) All public property types are stable. |
| * |
| * A type that is immutable obeys the above assumptions because the public values will never |
| * change. The [Immutable] annotation is provided to mark immutable types as stable. |
| * |
| * An object whose public properties do not change but is not immutable (for example, it has |
| * private mutable state or uses property delegation to a [MutableState] object, but is otherwise |
| * immutable), should use the [Stable] annotation. |
| * |
| * Mutable object that do not notify composition when they changed should not be marked as stable. |
| * |
| * When all types passed as parameters to a [Composable] function are marked as stable then the |
| * parameter values are compared for equality based on positional memoization and the call is |
| * skipped if all the values are the equal to the previous call. |
| * |
| * Primitive value types (such as Int, Float, etc), String and enum types are considered, a |
| * priori, stable. |
| * |
| * @see Immutable |
| * @see Stable |
| */ |
| @MustBeDocumented |
| @Target(AnnotationTarget.ANNOTATION_CLASS, AnnotationTarget.CLASS) |
| @Retention(AnnotationRetention.BINARY) |
| annotation class StableMarker |