1 /*
2  * Copyright 2024 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package androidx.xr.compose.subspace.node
18 
19 import androidx.compose.runtime.AbstractApplier
20 
21 /**
22  * Node applier for subspace compositions.
23  *
24  * See [androidx.compose.ui.node.UiApplier]
25  */
26 internal class SubspaceNodeApplier(private val owner: SubspaceOwner) :
27     AbstractApplier<SubspaceLayoutNode>(owner.root) {
28 
29     init {
30         owner.root.measurePolicy = SubspaceLayoutNode.RootMeasurePolicy
31     }
32 
insertTopDownnull33     override fun insertTopDown(index: Int, instance: SubspaceLayoutNode) {
34         // Ignored. Insert is performed in [insertBottomUp] to build the tree bottom-up to avoid
35         // duplicate notification when the child nodes enter the tree.
36     }
37 
insertBottomUpnull38     override fun insertBottomUp(index: Int, instance: SubspaceLayoutNode) {
39         current.insertAt(index, instance)
40     }
41 
removenull42     override fun remove(index: Int, count: Int) {
43         current.removeAt(index, count)
44     }
45 
movenull46     override fun move(from: Int, to: Int, count: Int) {
47         current.move(from, to, count)
48     }
49 
onClearnull50     override fun onClear() {
51         owner.root.removeAll()
52     }
53 
onEndChangesnull54     override fun onEndChanges() {
55         owner.requestRelayout()
56     }
57 }
58