/core/java/android/os/UserManager.java

/*
 * Copyright (C) 2012 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package android.os;

import com.android.internal.R;

import android.app.ActivityManagerNative;
import android.content.Context;
import android.content.pm.UserInfo;
import android.graphics.Bitmap;
import android.content.res.Resources;
import android.util.Log;

import java.util.List;

/**
 * Manages users and user details on a multi-user system.
 */
public class UserManager {

    private static String TAG = "UserManager";
    private final IUserManager mService;
    private final Context mContext;

    /** @hide */
    public UserManager(Context context, IUserManager service) {
        mService = service;
        mContext = context;
    }

    /**
     * Returns whether the system supports multiple users.
     * @return true if multiple users can be created, false if it is a single user device.
     * @hide
     */
    public static boolean supportsMultipleUsers() {
        return getMaxSupportedUsers() > 1;
    }

    /** 
     * Returns the user handle for the user that this application is running for.
     * @return the user handle of the user making this call.
     * @hide
     * */
    public int getUserHandle() {
        return UserHandle.myUserId();
    }

    /**
     * Returns the user name of the user making this call.  This call is only
     * available to applications on the system image; it requires the
     * MANAGE_USERS permission.
     * @return the user name
     */
    public String getUserName() {
        try {
            return mService.getUserInfo(getUserHandle()).name;
        } catch (RemoteException re) {
            Log.w(TAG, "Could not get user name", re);
            return "";
        }
    }

   /**
     * Used to determine whether the user making this call is subject to
     * teleportations.
     * @return whether the user making this call is a goat 
     */
    public boolean isUserAGoat() {
        return false;
    }
 
    /**
     * Return whether the given user is actively running.  This means that
     * the user is in the "started" state, not "stopped" -- it is currently
     * allowed to run code through scheduled alarms, receiving broadcasts,
     * etc.  A started user may be either the current foreground user or a
     * background user; the result here does not distinguish between the two.
     * @param user The user to retrieve the running state for.
     */
    public boolean isUserRunning(UserHandle user) {
        try {
            return ActivityManagerNative.getDefault().isUserRunning(
                    user.getIdentifier(), false);
        } catch (RemoteException e) {
            return false;
        }
    }

    /**
     * Return whether the given user is actively running <em>or</em> stopping.
     * This is like {@link #isUserRunning(UserHandle)}, but will also return
     * true if the user had been running but is in the process of being stopped
     * (but is not yet fully stopped, and still running some code).
     * @param user The user to retrieve the running state for.
     */
    public boolean isUserRunningOrStopping(UserHandle user) {
        try {
            return ActivityManagerNative.getDefault().isUserRunning(
                    user.getIdentifier(), true);
        } catch (RemoteException e) {
            return false;
        }
    }

    /**
     * Returns the UserInfo object describing a specific user.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     * @param userHandle the user handle of the user whose information is being requested.
     * @return the UserInfo object for a specific user.
     * @hide
     */
    public UserInfo getUserInfo(int userHandle) {
        try {
            return mService.getUserInfo(userHandle);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not get user info", re);
            return null;
        }
    }

    /**
     * Return the serial number for a user.  This is a device-unique
     * number assigned to that user; if the user is deleted and then a new
     * user created, the new users will not be given the same serial number.
     * @param user The user whose serial number is to be retrieved.
     * @return The serial number of the given user; returns -1 if the
     * given UserHandle does not exist.
     * @see #getUserForSerialNumber(long)
     */
    public long getSerialNumberForUser(UserHandle user) {
        return getUserSerialNumber(user.getIdentifier());
    }

    /**
     * Return the user associated with a serial number previously
     * returned by {@link #getSerialNumberForUser(UserHandle)}.
     * @param serialNumber The serial number of the user that is being
     * retrieved.
     * @return Return the user associated with the serial number, or null
     * if there is not one.
     * @see #getSerialNumberForUser(UserHandle)
     */
    public UserHandle getUserForSerialNumber(long serialNumber) {
        int ident = getUserHandle((int)serialNumber);
        return ident >= 0 ? new UserHandle(ident) : null;
    }

    /**
     * Creates a user with the specified name and options.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     *
     * @param name the user's name
     * @param flags flags that identify the type of user and other properties.
     * @see UserInfo
     *
     * @return the UserInfo object for the created user, or null if the user could not be created.
     * @hide
     */
    public UserInfo createUser(String name, int flags) {
        try {
            return mService.createUser(name, flags);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not create a user", re);
            return null;
        }
    }

    /**
     * Return the number of users currently created on the device.
     */
    public int getUserCount() {
        List<UserInfo> users = getUsers();
        return users != null ? users.size() : 1;
    }

    /**
     * Returns information for all users on this device.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     * @return the list of users that were created.
     * @hide
     */
    public List<UserInfo> getUsers() {
        try {
            return mService.getUsers(false);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not get user list", re);
            return null;
        }
    }

    /**
     * Returns information for all users on this device.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     * @param excludeDying specify if the list should exclude users being removed.
     * @return the list of users that were created.
     * @hide
     */
    public List<UserInfo> getUsers(boolean excludeDying) {
        try {
            return mService.getUsers(excludeDying);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not get user list", re);
            return null;
        }
    }

    /**
     * Removes a user and all associated data.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     * @param userHandle the integer handle of the user, where 0 is the primary user.
     * @hide
     */
    public boolean removeUser(int userHandle) {
        try {
            return mService.removeUser(userHandle);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not remove user ", re);
            return false;
        }
    }

    /**
     * Updates the user's name.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     *
     * @param userHandle the user's integer handle
     * @param name the new name for the user
     * @hide
     */
    public void setUserName(int userHandle, String name) {
        try {
            mService.setUserName(userHandle, name);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not set the user name ", re);
        }
    }

    /**
     * Sets the user's photo.
     * @param userHandle the user for whom to change the photo.
     * @param icon the bitmap to set as the photo.
     * @hide
     */
    public void setUserIcon(int userHandle, Bitmap icon) {
        try {
            mService.setUserIcon(userHandle, icon);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not set the user icon ", re);
        }
    }

    /**
     * Returns a file descriptor for the user's photo. PNG data can be read from this file.
     * @param userHandle the user whose photo we want to read.
     * @return a {@link Bitmap} of the user's photo, or null if there's no photo.
     * @hide
     */
    public Bitmap getUserIcon(int userHandle) {
        try {
            return mService.getUserIcon(userHandle);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not get the user icon ", re);
            return null;
        }
    }

    /**
     * Enable or disable the use of a guest account. If disabled, the existing guest account
     * will be wiped.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     * @param enable whether to enable a guest account.
     * @hide
     */
    public void setGuestEnabled(boolean enable) {
        try {
            mService.setGuestEnabled(enable);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not change guest account availability to " + enable);
        }
    }

    /**
     * Checks if a guest user is enabled for this device.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     * @return whether a guest user is enabled
     * @hide
     */
    public boolean isGuestEnabled() {
        try {
            return mService.isGuestEnabled();
        } catch (RemoteException re) {
            Log.w(TAG, "Could not retrieve guest enabled state");
            return false;
        }
    }

    /**
     * Wipes all the data for a user, but doesn't remove the user.
     * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
     * @param userHandle
     * @hide
     */
    public void wipeUser(int userHandle) {
        try {
            mService.wipeUser(userHandle);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not wipe user " + userHandle);
        }
    }

    /**
     * Returns the maximum number of users that can be created on this device. A return value
     * of 1 means that it is a single user device.
     * @hide
     * @return a value greater than or equal to 1 
     */
    public static int getMaxSupportedUsers() {
        // Don't allow multiple users on certain builds
        if (android.os.Build.ID.startsWith("JVP")) return 1;
        return SystemProperties.getInt("fw.max_users",
                Resources.getSystem().getInteger(R.integer.config_multiuserMaximumUsers));
    }

    /**
     * Returns a serial number on this device for a given userHandle. User handles can be recycled
     * when deleting and creating users, but serial numbers are not reused until the device is wiped.
     * @param userHandle
     * @return a serial number associated with that user, or -1 if the userHandle is not valid.
     * @hide
     */
    public int getUserSerialNumber(int userHandle) {
        try {
            return mService.getUserSerialNumber(userHandle);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not get serial number for user " + userHandle);
        }
        return -1;
    }

    /**
     * Returns a userHandle on this device for a given user serial number. User handles can be
     * recycled when deleting and creating users, but serial numbers are not reused until the device
     * is wiped.
     * @param userSerialNumber
     * @return the userHandle associated with that user serial number, or -1 if the serial number
     * is not valid.
     * @hide
     */
    public int getUserHandle(int userSerialNumber) {
        try {
            return mService.getUserHandle(userSerialNumber);
        } catch (RemoteException re) {
            Log.w(TAG, "Could not get userHandle for user " + userSerialNumber);
        }
        return -1;
    }
}