Work on issue #10130785: Restore silence and vibrate settings...

...in settings > sound

Add a new ContentProvider API to canonicalize URIs, so they can
be transported across backup/restore.

Change-Id: Ie5af3662f6822a32310e49c7f1e1ff084986c56e

1 files changed, 80 insertions, 0 deletions

diff --git a/core/java/android/content/ContentResolver.java b/core/java/android/content/ContentResolver.java
index 8a5a56c..9f462aa 100644
--- a/core/java/android/content/ContentResolver.java
+++ b/core/java/android/content/ContentResolver.java
@@ -497,6 +497,86 @@ public abstract class ContentResolver {
     }
 
     /**
+     * Transform the given <var>url</var> to a canonical representation of
+     * its referenced resource, which can be used across devices, persisted,
+     * backed up and restored, etc.  The returned Uri is still a fully capable
+     * Uri for use with its content provider, allowing you to do all of the
+     * same content provider operations as with the original Uri --
+     * {@link #query}, {@link #openInputStream(android.net.Uri)}, etc.  The
+     * only difference in behavior between the original and new Uris is that
+     * the content provider may need to do some additional work at each call
+     * using it to resolve it to the correct resource, especially if the
+     * canonical Uri has been moved to a different environment.
+     *
+     * <p>If you are moving a canonical Uri between environments, you should
+     * perform another call to {@link #canonicalize} with that original Uri to
+     * re-canonicalize it for the current environment.  Alternatively, you may
+     * want to use {@link #uncanonicalize} to transform it to a non-canonical
+     * Uri that works only in the current environment but potentially more
+     * efficiently than the canonical representation.</p>
+     *
+     * @param url The {@link Uri} that is to be transformed to a canonical
+     * representation.  Like all resolver calls, the input can be either
+     * a non-canonical or canonical Uri.
+     *
+     * @return Returns the official canonical representation of <var>url</var>,
+     * or null if the content provider does not support a canonical representation
+     * of the given Uri.  Many providers may not support canonicalization of some
+     * or all of their Uris.
+     *
+     * @see #uncanonicalize
+     */
+    public final Uri canonicalize(Uri url) {
+        IContentProvider provider = acquireProvider(url);
+        if (provider == null) {
+            return null;
+        }
+
+        try {
+            return provider.canonicalize(mPackageName, url);
+        } catch (RemoteException e) {
+            // Arbitrary and not worth documenting, as Activity
+            // Manager will kill this process shortly anyway.
+            return null;
+        } finally {
+            releaseProvider(provider);
+        }
+    }
+
+    /**
+     * Given a canonical Uri previously generated by {@link #canonicalize}, convert
+     * it to its local non-canonical form.  This can be useful in some cases where
+     * you know that you will only be using the Uri in the current environment and
+     * want to avoid any possible overhead when using it with the content
+     * provider.
+     *
+     * @param url The canonical {@link Uri} that is to be convered back to its
+     * non-canonical form.
+     *
+     * @return Returns the non-canonical representation of <var>url</var>.  This
+     * function never returns null; if there is no conversion to be done, it returns
+     * the same Uri that was provided.
+     *
+     * @see #canonicalize
+     */
+    public final Uri uncanonicalize(Uri url) {
+        IContentProvider provider = acquireProvider(url);
+        if (provider == null) {
+            return null;
+        }
+
+        try {
+            return provider.uncanonicalize(mPackageName, url);
+        } catch (RemoteException e) {
+            // Arbitrary and not worth documenting, as Activity
+            // Manager will kill this process shortly anyway.
+            return null;
+        } finally {
+            releaseProvider(provider);
+        }
+    }
+
+    /**
      * Open a stream on to the content associated with a content URI.  If there
      * is no data associated with the URI, FileNotFoundException is thrown.
      *