1 /*
2  * Copyright (C) 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 com.android.quickstep
18 
19 import android.os.RemoteException
20 import android.util.Log
21 import android.view.Display.DEFAULT_DISPLAY
22 import com.android.launcher3.util.Executors
23 import com.android.wm.shell.shared.IFocusTransitionListener.Stub
24 import com.android.wm.shell.shared.IShellTransitions
25 
26 /** Class to track focus state of displays and windows */
27 class FocusState {
28 
29     var focusedDisplayId = DEFAULT_DISPLAY
30         private set
31 
32     private var listeners = mutableSetOf<FocusChangeListener>()
33 
addListenernull34     fun addListener(l: FocusChangeListener) = listeners.add(l)
35 
36     fun removeListener(l: FocusChangeListener) = listeners.remove(l)
37 
38     fun init(transitions: IShellTransitions?) {
39         try {
40             transitions?.setFocusTransitionListener(
41                 object : Stub() {
42                     override fun onFocusedDisplayChanged(displayId: Int) {
43                         Executors.MAIN_EXECUTOR.execute {
44                             listeners.forEach { it.onFocusedDisplayChanged(displayId) }
45                         }
46                     }
47                 }
48             )
49         } catch (e: RemoteException) {
50             Log.w(TAG, "Failed call setFocusTransitionListener", e)
51         }
52     }
53 
54     interface FocusChangeListener {
onFocusedDisplayChangednull55         fun onFocusedDisplayChanged(displayId: Int)
56     }
57 
58     override fun toString() = "{FocusState focusedDisplayId=$focusedDisplayId}"
59 
60     companion object {
61         private const val TAG = "FocusState"
62     }
63 }
64