photopicker/src/com/android/photopicker/core/selection/LocalSelection.kt

/*
 * 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
 *
 *      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 com.android.photopicker.core.selection

import androidx.compose.runtime.staticCompositionLocalOf
import com.android.photopicker.data.model.Media

/**
 * Provider for fetching [Selection] inside of composables. [staticCompositionLocalOf] is used here
 * because the actual selection object is unlikely to change or be reassigned, and there are
 * performance benefits for not having to keep track of consumers to apply recompositions. The
 * drawback is that the content this CompositionLocal wraps will be recalculated if the value is
 * changed. Since it's not expected for the Selection reference to be updated (this is being
 * provided by the ActivityRetainedComponent), and is injected via Hilt, this value should be very
 * stable.
 */
val LocalSelection = staticCompositionLocalOf<Selection<Media>> { error("No Selection provided") }