New roots UX, async, performance, docs.

Yet another iteration from UX on how roots should be ordered.  Since
we no longer categorize by type, remove from public API.  Updated
asset drop with new dividers.

Update public API docs to be explicit about required columns.  Hide
flags and columns that aren't required for third-party apps.

Move remainder of potentially blocking work to AsyncTasks, including
creating directories, picked root resolution, and creation of new
documents once picked.

Improve performance of layouts by removing baseline alignment and
reduce hierarchy depth.  Set alpha on ImageViews directly to avoid
offscreen rendering hit.

Limit returned recents to 45 days.  Show load in recents when still
waiting for backends.  Show empty message when no recents stacks to
create from.  Use unique key when saving recent stacks.

Bug: 10941423, 10819454, 10964412, 10960718
Change-Id: I08cf589dcda7e203acf67928f4d30322ae36ee94

2 files changed, 3 insertions, 8 deletions

diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
index ed28da5..9328b33 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
@@ -47,9 +47,8 @@ public class ExternalStorageProvider extends DocumentsProvider {
     // docId format: root:path/to/file
 
     private static final String[] DEFAULT_ROOT_PROJECTION = new String[] {
-            Root.COLUMN_ROOT_ID, Root.COLUMN_ROOT_TYPE, Root.COLUMN_FLAGS, Root.COLUMN_ICON,
-            Root.COLUMN_TITLE, Root.COLUMN_SUMMARY, Root.COLUMN_DOCUMENT_ID,
-            Root.COLUMN_AVAILABLE_BYTES,
+            Root.COLUMN_ROOT_ID, Root.COLUMN_FLAGS, Root.COLUMN_ICON, Root.COLUMN_TITLE,
+            Root.COLUMN_DOCUMENT_ID, Root.COLUMN_AVAILABLE_BYTES,
     };
 
     private static final String[] DEFAULT_DOCUMENT_PROJECTION = new String[] {
@@ -59,7 +58,6 @@ public class ExternalStorageProvider extends DocumentsProvider {
 
     private static class RootInfo {
         public String rootId;
-        public int rootType;
         public int flags;
         public String title;
         public String docId;
@@ -84,7 +82,6 @@ public class ExternalStorageProvider extends DocumentsProvider {
 
             final RootInfo root = new RootInfo();
             root.rootId = rootId;
-            root.rootType = Root.ROOT_TYPE_DEVICE;
             root.flags = Root.FLAG_SUPPORTS_CREATE | Root.FLAG_LOCAL_ONLY | Root.FLAG_ADVANCED
                     | Root.FLAG_SUPPORTS_SEARCH;
             root.title = getContext().getString(R.string.root_internal_storage);
@@ -198,7 +195,6 @@ public class ExternalStorageProvider extends DocumentsProvider {
 
             final RowBuilder row = result.newRow();
             row.add(Root.COLUMN_ROOT_ID, root.rootId);
-            row.add(Root.COLUMN_ROOT_TYPE, root.rootType);
             row.add(Root.COLUMN_FLAGS, root.flags);
             row.add(Root.COLUMN_TITLE, root.title);
             row.add(Root.COLUMN_DOCUMENT_ID, root.docId);
diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java
index e6fbb1b..5a15cd2 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java
@@ -65,7 +65,7 @@ public class TestDocumentsProvider extends DocumentsProvider {
     private static final String MY_DOC_NULL = "myNull";
 
     private static final String[] DEFAULT_ROOT_PROJECTION = new String[] {
-            Root.COLUMN_ROOT_ID, Root.COLUMN_ROOT_TYPE, Root.COLUMN_FLAGS, Root.COLUMN_ICON,
+            Root.COLUMN_ROOT_ID, Root.COLUMN_FLAGS, Root.COLUMN_ICON,
             Root.COLUMN_TITLE, Root.COLUMN_SUMMARY, Root.COLUMN_DOCUMENT_ID,
             Root.COLUMN_AVAILABLE_BYTES,
     };
@@ -114,7 +114,6 @@ public class TestDocumentsProvider extends DocumentsProvider {
         final MatrixCursor result = new MatrixCursor(resolveRootProjection(projection));
         final RowBuilder row = result.newRow();
         row.add(Root.COLUMN_ROOT_ID, MY_ROOT_ID);
-        row.add(Root.COLUMN_ROOT_TYPE, Root.ROOT_TYPE_SERVICE);
         row.add(Root.COLUMN_FLAGS, Root.FLAG_SUPPORTS_RECENTS);
         row.add(Root.COLUMN_TITLE, "_Test title which is really long");
         row.add(Root.COLUMN_SUMMARY,