tree 3cadec8c73dd2ea2ed4cbe5744a52128e5d24a8a
parent 846318a3250fa95f47a9decfbffb05a31dbd0006
author Jeff Sharkey <jsharkey@android.com> 1396749924 -0700
committer Jeff Sharkey <jsharkey@android.com> 1398230301 -0700

Add directory selection to DocumentsProvider.

Introduce new ACTION_PICK_DIRECTORY that allows users to grant access
to an entire document subtree.  Instead of requiring grants for each
individual document, this leverages new prefix URI permission grants
by defining new "via"-style URIs:

content://com.example/via/12/document/24/

This references document 24 by using a prefix grant given for
document 12.  Internally, we use isChildDocument() to enforce that
24 is actually a descendant (child, grandchild, etc) of 12.  Since
this is an optional API, providers indicate support with
Root.FLAG_SUPPORTS_DIR_SELECTION.

Extend DocumentsUI to support picking directories.  Expose
createDocument() API to work with returned directories.

Offer to canonicalize via-style URIs into direct URIs, generating
exact permission grants along the way.  Override openAssetFile()
to pass through CancellationSignal.  Move testing code into ApiDemos.

Bug: 10607375
Change-Id: Ifffc1cff878870f8152eb6ca0199c5d014b9cb07