Centralize the creation of the user system directory

Environment.getUserSystemDirectory(int userId)

Use it all relevant places that was hardcoding it.
Also, wipe out the user's system directory when user is removed, otherwise old state
might be transferred to a new user.

Change-Id: I788ce9c4cf9624229e65efa7047bc0c019ccef0a
diff --git a/services/java/com/android/server/AppWidgetServiceImpl.java b/services/java/com/android/server/AppWidgetServiceImpl.java
index 79dabee..57ab921 100644
--- a/services/java/com/android/server/AppWidgetServiceImpl.java
+++ b/services/java/com/android/server/AppWidgetServiceImpl.java
@@ -40,6 +40,7 @@
 import android.net.Uri;
 import android.os.Binder;
 import android.os.Bundle;
+import android.os.Environment;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.SystemClock;
@@ -1634,11 +1635,11 @@
     }
 
     static File getSettingsFile(int userId) {
-        return new File("/data/system/users/" + userId + "/" + SETTINGS_FILENAME);
+        return new File(Environment.getUserSystemDirectory(userId), SETTINGS_FILENAME);
     }
 
     AtomicFile savedStateFile() {
-        File dir = new File("/data/system/users/" + mUserId);
+        File dir = Environment.getUserSystemDirectory(mUserId);
         File settingsFile = getSettingsFile(mUserId);
         if (!settingsFile.exists() && mUserId == 0) {
             if (!dir.exists()) {
diff --git a/services/java/com/android/server/SystemBackupAgent.java b/services/java/com/android/server/SystemBackupAgent.java
index a7a583c..8cf273d 100644
--- a/services/java/com/android/server/SystemBackupAgent.java
+++ b/services/java/com/android/server/SystemBackupAgent.java
@@ -24,8 +24,10 @@
 import android.app.backup.FullBackupDataOutput;
 import android.app.backup.WallpaperBackupHelper;
 import android.content.Context;
+import android.os.Environment;
 import android.os.ParcelFileDescriptor;
 import android.os.ServiceManager;
+import android.os.UserHandle;
 import android.util.Slog;
 
 
@@ -45,11 +47,13 @@
     private static final String WALLPAPER_INFO_FILENAME = "wallpaper_info.xml";
 
     // TODO: Will need to change if backing up non-primary user's wallpaper
-    private static final String WALLPAPER_IMAGE_DIR = "/data/system/users/0";
+    private static final String WALLPAPER_IMAGE_DIR =
+            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
     private static final String WALLPAPER_IMAGE = WallpaperBackupHelper.WALLPAPER_IMAGE;
 
     // TODO: Will need to change if backing up non-primary user's wallpaper
-    private static final String WALLPAPER_INFO_DIR = "/data/system/users/0";
+    private static final String WALLPAPER_INFO_DIR =
+            Environment.getUserSystemDirectory(UserHandle.USER_OWNER).getAbsolutePath();
     private static final String WALLPAPER_INFO = WallpaperBackupHelper.WALLPAPER_INFO;
     // Use old keys to keep legacy data compatibility and avoid writing two wallpapers
     private static final String WALLPAPER_IMAGE_KEY = WallpaperBackupHelper.WALLPAPER_IMAGE_KEY;
diff --git a/services/java/com/android/server/WallpaperManagerService.java b/services/java/com/android/server/WallpaperManagerService.java
index 643e937..b8a37cf 100644
--- a/services/java/com/android/server/WallpaperManagerService.java
+++ b/services/java/com/android/server/WallpaperManagerService.java
@@ -92,8 +92,6 @@
      * restarting it vs. just reverting to the static wallpaper.
      */
     static final long MIN_WALLPAPER_CRASH_TIME = 10000;
-    
-    static final File WALLPAPER_BASE_DIR = new File("/data/system/users");
     static final String WALLPAPER = "wallpaper";
     static final String WALLPAPER_INFO = "wallpaper_info.xml";
 
@@ -395,12 +393,12 @@
         mIPackageManager = AppGlobals.getPackageManager();
         mMonitor = new MyPackageMonitor();
         mMonitor.register(context, null, true);
-        WALLPAPER_BASE_DIR.mkdirs();
-        loadSettingsLocked(0);
+        getWallpaperDir(UserHandle.USER_OWNER).mkdirs();
+        loadSettingsLocked(UserHandle.USER_OWNER);
     }
     
     private static File getWallpaperDir(int userId) {
-        return new File(WALLPAPER_BASE_DIR + "/" + userId);
+        return Environment.getUserSystemDirectory(userId);
     }
 
     @Override
@@ -414,7 +412,7 @@
 
     public void systemReady() {
         if (DEBUG) Slog.v(TAG, "systemReady");
-        WallpaperData wallpaper = mWallpaperMap.get(0);
+        WallpaperData wallpaper = mWallpaperMap.get(UserHandle.USER_OWNER);
         switchWallpaper(wallpaper);
         wallpaper.wallpaperObserver = new WallpaperObserver(wallpaper);
         wallpaper.wallpaperObserver.startWatching();
@@ -880,7 +878,7 @@
     }
 
     private static JournaledFile makeJournaledFile(int userId) {
-        final String base = getWallpaperDir(userId) + "/" + WALLPAPER_INFO;
+        final String base = new File(getWallpaperDir(userId), WALLPAPER_INFO).getAbsolutePath();
         return new JournaledFile(new File(base), new File(base + ".tmp"));
     }
 
diff --git a/services/java/com/android/server/pm/Settings.java b/services/java/com/android/server/pm/Settings.java
index 68b594a..5f10d44 100644
--- a/services/java/com/android/server/pm/Settings.java
+++ b/services/java/com/android/server/pm/Settings.java
@@ -745,13 +745,12 @@
     }
 
     private File getUserPackagesStateFile(int userId) {
-        return new File(mSystemDir,
-                "users/" + userId + "/package-restrictions.xml");
+        return new File(Environment.getUserSystemDirectory(userId), "package-restrictions.xml");
     }
 
     private File getUserPackagesStateBackupFile(int userId) {
-        return new File(mSystemDir,
-                "users/" + userId + "/package-restrictions-backup.xml");
+        return new File(Environment.getUserSystemDirectory(userId),
+                "package-restrictions-backup.xml");
     }
 
     void writeAllUsersPackageRestrictionsLPr() {
diff --git a/services/java/com/android/server/pm/UserManagerService.java b/services/java/com/android/server/pm/UserManagerService.java
index 492158d..a13c16e 100644
--- a/services/java/com/android/server/pm/UserManagerService.java
+++ b/services/java/com/android/server/pm/UserManagerService.java
@@ -594,6 +594,7 @@
                 // Update the user list
                 writeUserListLocked();
                 updateUserIdsLocked();
+                removeDirectoryRecursive(Environment.getUserSystemDirectory(userHandle));
             }
         }
 
@@ -603,6 +604,17 @@
         mContext.sendBroadcast(addedIntent, android.Manifest.permission.MANAGE_USERS);
     }
 
+    private void removeDirectoryRecursive(File parent) {
+        if (parent.isDirectory()) {
+            String[] files = parent.list();
+            for (String filename : files) {
+                File child = new File(parent, filename);
+                removeDirectoryRecursive(child);
+            }
+        }
+        parent.delete();
+    }
+
     @Override
     public int getUserSerialNumber(int userHandle) {
         synchronized (mPackagesLock) {