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.pm.UserInfo;
22import android.content.res.Resources;
23import android.os.Handler;
24import android.os.Message;
25import android.os.UserHandle;
26import android.os.UserManager;
27import android.view.LayoutInflater;
28import android.view.View;
29import android.view.ViewTreeObserver;
30import android.view.WindowManager;
31import android.widget.TextView;
32
33import com.android.internal.R;
34import com.android.internal.annotations.GuardedBy;
35
36/**
37 * Dialog to show when a user switch it about to happen. The intent is to snapshot the screen
38 * immediately after the dialog shows so that the user is informed that something is happening
39 * in the background rather than just freeze the screen and not know if the user-switch affordance
40 * was being handled.
41 */
42class UserSwitchingDialog extends AlertDialog
43        implements ViewTreeObserver.OnWindowShownListener {
44    private static final String TAG = "ActivityManagerUserSwitchingDialog";
45
46    // Time to wait for the onWindowShown() callback before continuing the user switch
47    private static final int WINDOW_SHOWN_TIMEOUT_MS = 3000;
48
49    private final ActivityManagerService mService;
50    private final int mUserId;
51    private static final int MSG_START_USER = 1;
52    @GuardedBy("this")
53    private boolean mStartedUser;
54    final protected UserInfo mOldUser;
55    final protected UserInfo mNewUser;
56    final private String mSwitchingFromSystemUserMessage;
57    final private String mSwitchingToSystemUserMessage;
58    final protected Context mContext;
59
60    public UserSwitchingDialog(ActivityManagerService service, Context context, UserInfo oldUser,
61            UserInfo newUser, boolean aboveSystem, String switchingFromSystemUserMessage,
62            String switchingToSystemUserMessage) {
63        super(context);
64
65        mContext = context;
66        mService = service;
67        mUserId = newUser.id;
68        mOldUser = oldUser;
69        mNewUser = newUser;
70        mSwitchingFromSystemUserMessage = switchingFromSystemUserMessage;
71        mSwitchingToSystemUserMessage = switchingToSystemUserMessage;
72
73        inflateContent();
74
75        if (aboveSystem) {
76            getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ERROR);
77        }
78
79        WindowManager.LayoutParams attrs = getWindow().getAttributes();
80        attrs.privateFlags = WindowManager.LayoutParams.PRIVATE_FLAG_SYSTEM_ERROR |
81            WindowManager.LayoutParams.PRIVATE_FLAG_SHOW_FOR_ALL_USERS;
82        getWindow().setAttributes(attrs);
83    }
84
85    void inflateContent() {
86        // Set up the dialog contents
87        setCancelable(false);
88        Resources res = getContext().getResources();
89        // Custom view due to alignment and font size requirements
90        View view = LayoutInflater.from(getContext()).inflate(R.layout.user_switching_dialog,
91            null);
92
93        String viewMessage = null;
94        if (UserManager.isSplitSystemUser() && mNewUser.id == UserHandle.USER_SYSTEM) {
95            viewMessage = res.getString(R.string.user_logging_out_message, mOldUser.name);
96        } else if (UserManager.isDeviceInDemoMode(mContext)) {
97            if (mOldUser.isDemo()) {
98                viewMessage = res.getString(R.string.demo_restarting_message);
99            } else {
100                viewMessage = res.getString(R.string.demo_starting_message);
101            }
102        } else {
103            if (mOldUser.id == UserHandle.USER_SYSTEM) {
104                viewMessage = mSwitchingFromSystemUserMessage;
105            } else if (mNewUser.id == UserHandle.USER_SYSTEM) {
106                viewMessage = mSwitchingToSystemUserMessage;
107            }
108
109            // If switchingFromSystemUserMessage or switchingToSystemUserMessage is null, fallback
110            // to system message.
111            if (viewMessage == null) {
112                viewMessage = res.getString(R.string.user_switching_message, mNewUser.name);
113            }
114        }
115        ((TextView) view.findViewById(R.id.message)).setText(viewMessage);
116        setView(view);
117    }
118
119    @Override
120    public void show() {
121        // Slog.v(TAG, "show called");
122        super.show();
123        final View decorView = getWindow().getDecorView();
124        if (decorView != null) {
125            decorView.getViewTreeObserver().addOnWindowShownListener(this);
126        }
127        // Add a timeout as a safeguard, in case a race in screen on/off causes the window
128        // callback to never come.
129        mHandler.sendMessageDelayed(mHandler.obtainMessage(MSG_START_USER),
130                WINDOW_SHOWN_TIMEOUT_MS);
131    }
132
133    @Override
134    public void onWindowShown() {
135        // Slog.v(TAG, "onWindowShown called");
136        startUser();
137    }
138
139    void startUser() {
140        synchronized (this) {
141            if (!mStartedUser) {
142                mService.mUserController.startUserInForeground(mUserId);
143                dismiss();
144                mStartedUser = true;
145                final View decorView = getWindow().getDecorView();
146                if (decorView != null) {
147                    decorView.getViewTreeObserver().removeOnWindowShownListener(this);
148                }
149                mHandler.removeMessages(MSG_START_USER);
150            }
151        }
152    }
153
154    private final Handler mHandler = new Handler() {
155        @Override
156        public void handleMessage(Message msg) {
157            switch (msg.what) {
158                case MSG_START_USER:
159                    startUser();
160                    break;
161            }
162        }
163    };
164}
165