UserSwitchingDialog.java revision 5e5cb463b6e2540a7ef6c261ba5fed074be536e1
1/* 2 * Copyright (C) 2014 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 17package com.android.server.am; 18 19import android.app.AlertDialog; 20import android.content.Context; 21import android.content.res.Resources; 22import android.os.Handler; 23import android.os.Message; 24import android.view.LayoutInflater; 25import android.view.View; 26import android.view.ViewTreeObserver; 27import android.view.WindowManager; 28import android.widget.TextView; 29 30import com.android.internal.R; 31import com.android.internal.annotations.GuardedBy; 32 33/** 34 * Dialog to show when a user switch it about to happen. The intent is to snapshot the screen 35 * immediately after the dialog shows so that the user is informed that something is happening 36 * in the background rather than just freeze the screen and not know if the user-switch affordance 37 * was being handled. 38 */ 39final class UserSwitchingDialog extends AlertDialog 40 implements ViewTreeObserver.OnWindowShownListener { 41 private static final String TAG = "ActivityManagerUserSwitchingDialog"; 42 43 // Time to wait for the onWindowShown() callback before continuing the user switch 44 private static final int WINDOW_SHOWN_TIMEOUT_MS = 3000; 45 46 private final ActivityManagerService mService; 47 private final int mUserId; 48 private static final int MSG_START_USER = 1; 49 @GuardedBy("this") 50 private boolean mStartedUser; 51 52 public UserSwitchingDialog(ActivityManagerService service, Context context, 53 int userId, String userName, boolean aboveSystem) { 54 super(context); 55 56 mService = service; 57 mUserId = userId; 58 59 // Set up the dialog contents 60 setCancelable(false); 61 Resources res = getContext().getResources(); 62 // Custom view due to alignment and font size requirements 63 View view = LayoutInflater.from(getContext()).inflate(R.layout.user_switching_dialog, null); 64 ((TextView) view.findViewById(R.id.message)).setText( 65 res.getString(com.android.internal.R.string.user_switching_message, userName)); 66 setView(view); 67 68 if (aboveSystem) { 69 getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ERROR); 70 } 71 WindowManager.LayoutParams attrs = getWindow().getAttributes(); 72 attrs.privateFlags = WindowManager.LayoutParams.PRIVATE_FLAG_SYSTEM_ERROR | 73 WindowManager.LayoutParams.PRIVATE_FLAG_SHOW_FOR_ALL_USERS; 74 getWindow().setAttributes(attrs); 75 } 76 77 @Override 78 public void show() { 79 // Slog.v(TAG, "show called"); 80 super.show(); 81 final View decorView = getWindow().getDecorView(); 82 if (decorView != null) { 83 decorView.getViewTreeObserver().addOnWindowShownListener(this); 84 } 85 // Add a timeout as a safeguard, in case a race in screen on/off causes the window 86 // callback to never come. 87 mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_START_USER), 88 WINDOW_SHOWN_TIMEOUT_MS); 89 } 90 91 @Override 92 public void onWindowShown() { 93 // Slog.v(TAG, "onWindowShown called"); 94 startUser(); 95 } 96 97 void startUser() { 98 synchronized (this) { 99 if (!mStartedUser) { 100 mService.startUserInForeground(mUserId, this); 101 mStartedUser = true; 102 final View decorView = getWindow().getDecorView(); 103 if (decorView != null) { 104 decorView.getViewTreeObserver().removeOnWindowShownListener(this); 105 } 106 mHandler.removeMessages(MSG_START_USER); 107 } 108 } 109 } 110 111 private final Handler mHandler = new Handler() { 112 @Override 113 public void handleMessage(Message msg) { 114 switch (msg.what) { 115 case MSG_START_USER: 116 startUser(); 117 break; 118 } 119 } 120 }; 121} 122