UiApplier.android.kt
/*
* Copyright 2020 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.runtime.AbstractApplier
import androidx.compose.ui.platform.AndroidComposeView
internal class UiApplier(
root: LayoutNode
) : AbstractApplier<LayoutNode>(root) {
override fun insertTopDown(index: Int, instance: LayoutNode) {
// Ignored. Insert is performed in [insertBottomUp] to build the tree bottom-up to avoid
// duplicate notification when the child nodes enter the tree.
}
override fun insertBottomUp(index: Int, instance: LayoutNode) {
current.insertAt(index, instance)
}
override fun remove(index: Int, count: Int) {
current.removeAt(index, count)
}
override fun move(from: Int, to: Int, count: Int) {
current.move(from, to, count)
}
override fun onClear() {
root.removeAll()
}
override fun onEndChanges() {
super.onEndChanges()
(root.owner as? AndroidComposeView)?.clearInvalidObservations()
}
}