| /* |
| * 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 |
| |
| /** |
| * This component creates a scope which will be the root of recomposition for any reads or writes to |
| * [Model] classes that happen inside of it. This can be used to improve performance in situations |
| * where you know that a specific [Model] object will need to change at high frequencies, and you |
| * want to reduce the burden of recomposition. It is recommended that you not introduce [Observe] |
| * into the composition until it is clear that is necessary to improve performance. |
| * |
| * @param body The composable content to observe |
| * |
| * @see Model |
| * @see invalidate |
| * @see Recompose |
| */ |
| @Composable |
| @Suppress("PLUGIN_ERROR") |
| fun Observe(@Children body: @Composable() () -> Unit) = |
| currentComposerNonNull.let { composer -> |
| composer.startGroup(observer) |
| composer.startJoin(false) { body() } |
| body() |
| composer.doneJoin(false) |
| composer.endGroup() |
| } |
| |
| private val observer = Object() |
