Resized thumbnails; async; extend MatrixCursor.

When requesting thumbnails, check if their dimensions are larger
than requested, and downscale to avoid memory pressure.  Load them
async and with LruCache.

Extend MatrixCursor so that RowBuilder can offer() columns without
requiring they know the projection map.  This makes it easier to
respond to query() calls, where the remote side controls the
projection map.  Use it to handle custom projections in external
storage backend.

Update date/time formatting to match spec.

Bug: 10333418, 10331689
Change-Id: I7e947a8e8068af8a39b55e6766b3241de4f3fc16

2 files changed, 57 insertions, 45 deletions

diff --git a/packages/ExternalStorageProvider/AndroidManifest.xml b/packages/ExternalStorageProvider/AndroidManifest.xml
index afdb6bb..5272166 100644
--- a/packages/ExternalStorageProvider/AndroidManifest.xml
+++ b/packages/ExternalStorageProvider/AndroidManifest.xml
@@ -7,7 +7,7 @@
     <application android:label="@string/app_label">
         <provider
             android:name=".ExternalStorageProvider"
-            android:authorities="com.android.externalstorage"
+            android:authorities="com.android.externalstorage.documents"
             android:grantUriPermissions="true"
             android:exported="true"
             android:permission="android.permission.MANAGE_DOCUMENTS">
diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
index 659139d..b4bf563 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
@@ -22,10 +22,10 @@ import android.content.ContentValues;
 import android.content.UriMatcher;
 import android.database.Cursor;
 import android.database.MatrixCursor;
+import android.database.MatrixCursor.RowBuilder;
 import android.net.Uri;
 import android.os.Environment;
 import android.os.ParcelFileDescriptor;
-import android.provider.BaseColumns;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.DocumentColumns;
 import android.provider.DocumentsContract.Documents;
@@ -45,7 +45,7 @@ import java.util.LinkedList;
 public class ExternalStorageProvider extends ContentProvider {
     private static final String TAG = "ExternalStorage";
 
-    private static final String AUTHORITY = "com.android.externalstorage";
+    private static final String AUTHORITY = "com.android.externalstorage.documents";
 
     // TODO: support multiple storage devices
 
@@ -57,6 +57,14 @@ public class ExternalStorageProvider extends ContentProvider {
     private static final int URI_DOCS_ID_CONTENTS = 4;
     private static final int URI_DOCS_ID_SEARCH = 5;
 
+    static {
+        sMatcher.addURI(AUTHORITY, "roots", URI_ROOTS);
+        sMatcher.addURI(AUTHORITY, "roots/*", URI_ROOTS_ID);
+        sMatcher.addURI(AUTHORITY, "roots/*/docs/*", URI_DOCS_ID);
+        sMatcher.addURI(AUTHORITY, "roots/*/docs/*/contents", URI_DOCS_ID_CONTENTS);
+        sMatcher.addURI(AUTHORITY, "roots/*/docs/*/search", URI_DOCS_ID_SEARCH);
+    }
+
     private HashMap<String, Root> mRoots = Maps.newHashMap();
 
     private static class Root {
@@ -68,13 +76,15 @@ public class ExternalStorageProvider extends ContentProvider {
         public File path;
     }
 
-    static {
-        sMatcher.addURI(AUTHORITY, "roots", URI_ROOTS);
-        sMatcher.addURI(AUTHORITY, "roots/*", URI_ROOTS_ID);
-        sMatcher.addURI(AUTHORITY, "roots/*/docs/*", URI_DOCS_ID);
-        sMatcher.addURI(AUTHORITY, "roots/*/docs/*/contents", URI_DOCS_ID_CONTENTS);
-        sMatcher.addURI(AUTHORITY, "roots/*/docs/*/search", URI_DOCS_ID_SEARCH);
-    }
+    private static final String[] ALL_ROOTS_COLUMNS = new String[] {
+            RootColumns.ROOT_ID, RootColumns.ROOT_TYPE, RootColumns.ICON, RootColumns.TITLE,
+            RootColumns.SUMMARY, RootColumns.AVAILABLE_BYTES
+    };
+
+    private static final String[] ALL_DOCUMENTS_COLUMNS = new String[] {
+            DocumentColumns.DOC_ID, DocumentColumns.DISPLAY_NAME, DocumentColumns.SIZE,
+            DocumentColumns.MIME_TYPE, DocumentColumns.LAST_MODIFIED, DocumentColumns.FLAGS
+    };
 
     @Override
     public boolean onCreate() {
@@ -93,64 +103,59 @@ public class ExternalStorageProvider extends ContentProvider {
     @Override
     public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
             String sortOrder) {
-
-        // TODO: support custom projections
-        final String[] rootsProjection = new String[] {
-                BaseColumns._ID, RootColumns.ROOT_ID, RootColumns.ROOT_TYPE, RootColumns.ICON,
-                RootColumns.TITLE, RootColumns.SUMMARY, RootColumns.AVAILABLE_BYTES };
-        final String[] docsProjection = new String[] {
-                BaseColumns._ID, DocumentColumns.DISPLAY_NAME, DocumentColumns.SIZE,
-                DocumentColumns.DOC_ID, DocumentColumns.MIME_TYPE, DocumentColumns.LAST_MODIFIED,
-                DocumentColumns.FLAGS };
-
         switch (sMatcher.match(uri)) {
             case URI_ROOTS: {
-                final MatrixCursor cursor = new MatrixCursor(rootsProjection);
+                final MatrixCursor result = new MatrixCursor(
+                        projection != null ? projection : ALL_ROOTS_COLUMNS);
                 for (Root root : mRoots.values()) {
-                    includeRoot(cursor, root);
+                    includeRoot(result, root);
                 }
-                return cursor;
+                return result;
             }
             case URI_ROOTS_ID: {
                 final Root root = mRoots.get(DocumentsContract.getRootId(uri));
 
-                final MatrixCursor cursor = new MatrixCursor(rootsProjection);
-                includeRoot(cursor, root);
-                return cursor;
+                final MatrixCursor result = new MatrixCursor(
+                        projection != null ? projection : ALL_ROOTS_COLUMNS);
+                includeRoot(result, root);
+                return result;
             }
             case URI_DOCS_ID: {
                 final Root root = mRoots.get(DocumentsContract.getRootId(uri));
                 final String docId = DocumentsContract.getDocId(uri);
 
-                final MatrixCursor cursor = new MatrixCursor(docsProjection);
+                final MatrixCursor result = new MatrixCursor(
+                        projection != null ? projection : ALL_DOCUMENTS_COLUMNS);
                 final File file = docIdToFile(root, docId);
-                includeFile(cursor, root, file);
-                return cursor;
+                includeFile(result, root, file);
+                return result;
             }
             case URI_DOCS_ID_CONTENTS: {
                 final Root root = mRoots.get(DocumentsContract.getRootId(uri));
                 final String docId = DocumentsContract.getDocId(uri);
 
-                final MatrixCursor cursor = new MatrixCursor(docsProjection);
+                final MatrixCursor result = new MatrixCursor(
+                        projection != null ? projection : ALL_DOCUMENTS_COLUMNS);
                 final File parent = docIdToFile(root, docId);
 
                 for (File file : parent.listFiles()) {
-                    includeFile(cursor, root, file);
+                    includeFile(result, root, file);
                 }
 
-                return cursor;
+                return result;
             }
             case URI_DOCS_ID_SEARCH: {
                 final Root root = mRoots.get(DocumentsContract.getRootId(uri));
                 final String docId = DocumentsContract.getDocId(uri);
                 final String query = DocumentsContract.getSearchQuery(uri).toLowerCase();
 
-                final MatrixCursor cursor = new MatrixCursor(docsProjection);
+                final MatrixCursor result = new MatrixCursor(
+                        projection != null ? projection : ALL_DOCUMENTS_COLUMNS);
                 final File parent = docIdToFile(root, docId);
 
                 final LinkedList<File> pending = new LinkedList<File>();
                 pending.add(parent);
-                while (!pending.isEmpty() && cursor.getCount() < 20) {
+                while (!pending.isEmpty() && result.getCount() < 20) {
                     final File file = pending.removeFirst();
                     if (file.isDirectory()) {
                         for (File child : file.listFiles()) {
@@ -158,12 +163,12 @@ public class ExternalStorageProvider extends ContentProvider {
                         }
                     } else {
                         if (file.getName().toLowerCase().contains(query)) {
-                            includeFile(cursor, root, file);
+                            includeFile(result, root, file);
                         }
                     }
                 }
 
-                return cursor;
+                return result;
             }
             default: {
                 throw new UnsupportedOperationException("Unsupported Uri " + uri);
@@ -196,13 +201,17 @@ public class ExternalStorageProvider extends ContentProvider {
         }
     }
 
-    private void includeRoot(MatrixCursor cursor, Root root) {
-        cursor.addRow(new Object[] {
-                root.name.hashCode(), root.name, root.rootType, root.icon, root.title, root.summary,
-                root.path.getFreeSpace() });
+    private void includeRoot(MatrixCursor result, Root root) {
+        final RowBuilder row = result.newRow();
+        row.offer(RootColumns.ROOT_ID, root.name);
+        row.offer(RootColumns.ROOT_TYPE, root.rootType);
+        row.offer(RootColumns.ICON, root.icon);
+        row.offer(RootColumns.TITLE, root.title);
+        row.offer(RootColumns.SUMMARY, root.summary);
+        row.offer(RootColumns.AVAILABLE_BYTES, root.path.getFreeSpace());
     }
 
-    private void includeFile(MatrixCursor cursor, Root root, File file) {
+    private void includeFile(MatrixCursor result, Root root, File file) {
         int flags = 0;
 
         if (file.isDirectory()) {
@@ -223,8 +232,6 @@ public class ExternalStorageProvider extends ContentProvider {
         }
 
         final String docId = fileToDocId(root, file);
-        final long id = docId.hashCode();
-
         final String displayName;
         if (Documents.DOC_ID_ROOT.equals(docId)) {
             displayName = root.title;
@@ -232,8 +239,13 @@ public class ExternalStorageProvider extends ContentProvider {
             displayName = file.getName();
         }
 
-        cursor.addRow(new Object[] {
-                id, displayName, file.length(), docId, mimeType, file.lastModified(), flags });
+        final RowBuilder row = result.newRow();
+        row.offer(DocumentColumns.DOC_ID, docId);
+        row.offer(DocumentColumns.DISPLAY_NAME, displayName);
+        row.offer(DocumentColumns.SIZE, file.length());
+        row.offer(DocumentColumns.MIME_TYPE, mimeType);
+        row.offer(DocumentColumns.LAST_MODIFIED, file.lastModified());
+        row.offer(DocumentColumns.FLAGS, flags);
     }
 
     @Override