ModifiedRelocationNode.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.ui.node
import androidx.compose.ui.ExperimentalComposeUiApi
import androidx.compose.ui.geometry.Rect
import androidx.compose.ui.layout.RelocationModifier
import kotlinx.coroutines.currentCoroutineContext
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
@ExperimentalComposeUiApi
internal class ModifiedRelocationNode(
wrapped: LayoutNodeWrapper,
modifier: RelocationModifier
) : DelegatingLayoutNodeWrapper<RelocationModifier>(wrapped, modifier) {
override suspend fun propagateRelocationRequest(rect: Rect) {
// Compute the position of the item after it is brought within this node's bounding box.
val destinationRect = modifier.computeDestination(rect, this)
// Perform the relocation for this node, and send a relocation request to its parents.
//
// Note: For now we run both of these in parallel, but in the future we could make this
// configurable. (The child relocation could be executed before the parent, or parent before
// the child).
withContext(currentCoroutineContext()) {
launch { modifier.performRelocation(rect, destinationRect) }
launch { super.propagateRelocationRequest(destinationRect) }
}
}
}