Add UserManager.getUserIcon()

So that we don't abuse the setUserIcon() for reading. So the new method won't try
to create the file, only return it if it exists.

Change-Id: I7a81d3f1b29d14d37e71f531744ce39f21d827ac

Author: Amith Yamasani

core/java/android/os/IUserManager.aidl

@@ -28,6 +28,7 @@ interface IUserManager {
     boolean removeUser(int userHandle);
     void setUserName(int userHandle, String name);
     ParcelFileDescriptor setUserIcon(int userHandle);
+    ParcelFileDescriptor getUserIcon(int userHandle);
     List<UserInfo> getUsers();
     UserInfo getUserInfo(int userHandle);
     void setGuestEnabled(boolean enable);

core/java/android/os/UserManager.java

@@ -165,6 +165,22 @@ public ParcelFileDescriptor setUserIcon(int userHandle) {
         }
     }
 
+    /**
+     * 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 ParcelFileDescriptor} from which to read the file, or null if there's no
+     * photo.
+     * @hide
+     */
+    public ParcelFileDescriptor getUserIcon(int userHandle) {
+        try {
+            return mService.getUserIcon(userHandle);
+        } catch (RemoteException re) {
+            Log.w(TAG, "Could not set the user icon ", re);
+            return null;
+        }
+    }
+
     /**
      * Enable or disable the use of a guest account. If disabled, the existing guest account
      * will be wiped.

services/java/com/android/server/pm/UserManagerService.java

@@ -196,14 +196,25 @@ public ParcelFileDescriptor setUserIcon(int userId) {
         synchronized (mPackagesLock) {
             UserInfo info = mUsers.get(userId);
             if (info == null) return null;
-            ParcelFileDescriptor fd = updateIconBitmapLocked(info);
+            ParcelFileDescriptor fd = openIconBitmapLocked(info, true /* write */);
             if (fd != null) {
                 writeUserLocked(info);
             }
             return fd;
         }
     }
 
+    @Override
+    public ParcelFileDescriptor getUserIcon(int userId) {
+        checkManageUsersPermission("read users");
+        synchronized (mPackagesLock) {
+            UserInfo info = mUsers.get(userId);
+            if (info == null || info.iconPath == null) return null;
+            ParcelFileDescriptor fd = openIconBitmapLocked(info, false /* read */);
+            return fd;
+        }
+    }
+
     @Override
     public void setGuestEnabled(boolean enable) {
         checkManageUsersPermission("enable guest users");
@@ -278,7 +289,7 @@ private static final void checkManageUsersPermission(String message) {
         }
     }
 
-    private ParcelFileDescriptor updateIconBitmapLocked(UserInfo info) {
+    private ParcelFileDescriptor openIconBitmapLocked(UserInfo info, boolean toWrite) {
         try {
             File dir = new File(mUsersDir, Integer.toString(info.id));
             File file = new File(dir, USER_PHOTO_FILENAME);
@@ -290,8 +301,10 @@ private ParcelFileDescriptor updateIconBitmapLocked(UserInfo info) {
                         -1, -1);
             }
             ParcelFileDescriptor fd = ParcelFileDescriptor.open(file,
-                    MODE_CREATE|MODE_READ_WRITE);
-            info.iconPath = file.getAbsolutePath();
+                    toWrite ? MODE_CREATE|MODE_READ_WRITE : MODE_READ_WRITE);
+            if (toWrite) {
+                info.iconPath = file.getAbsolutePath();
+            }
             return fd;
         } catch (FileNotFoundException e) {
             Slog.w(LOG_TAG, "Error setting photo for user ", e);