1 /*
<lambda>null2  * Copyright (C) 2023 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 android.tools.traces.wm
18 
19 object Utils {
20     internal fun WindowContainer.traverseTopDown(): List<WindowContainer> {
21         val traverseList = mutableListOf(this)
22 
23         this.children.reversed().forEach { childLayer ->
24             traverseList.addAll(childLayer.traverseTopDown())
25         }
26 
27         return traverseList
28     }
29 
30     /**
31      * For a given WindowContainer, traverse down the hierarchy and collect all children of type [T]
32      * if the child passes the test [predicate].
33      *
34      * @param predicate Filter function
35      */
36     internal inline fun <reified T : WindowContainer> WindowContainer.collectDescendants(
37         predicate: (T) -> Boolean = { true }
38     ): Collection<T> {
39         val traverseList = traverseTopDown()
40 
41         return traverseList.filterIsInstance<T>().filter { predicate(it) }
42     }
43 }
44