tests/common/com/android/documentsui/DocumentsProviderHelper.java - platform/packages/apps/DocumentsUI - Git at Google

 /*
  * Copyright (C) 2015 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.documentsui;

 import static android.provider.DocumentsContract.buildChildDocumentsUri;
 import static android.provider.DocumentsContract.buildDocumentUri;
 import static android.provider.DocumentsContract.buildRootsUri;
 import static com.android.documentsui.base.DocumentInfo.getCursorString;
 import static com.android.internal.util.Preconditions.checkArgument;
 import static junit.framework.Assert.assertEquals;
 import static junit.framework.Assert.assertNotNull;
 import static junit.framework.Assert.fail;

 import android.content.ContentProviderClient;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.ParcelFileDescriptor;
 import android.os.ParcelFileDescriptor.AutoCloseInputStream;
 import android.os.ParcelFileDescriptor.AutoCloseOutputStream;
 import android.os.RemoteException;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
 import android.provider.DocumentsContract.Root;
 import android.support.annotation.Nullable;
 import android.test.MoreAsserts;
 import android.text.TextUtils;

 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.RootInfo;
 import com.android.documentsui.roots.RootCursorWrapper;

 import com.google.android.collect.Lists;

 import libcore.io.IoUtils;
 import libcore.io.Streams;

 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;

 /**
  * Provides support for creation of documents in a test settings.
  */
 public class DocumentsProviderHelper {

     private final String mAuthority;
     private final ContentProviderClient mClient;

     public DocumentsProviderHelper(String authority, ContentProviderClient client) {
         checkArgument(!TextUtils.isEmpty(authority));
         mAuthority = authority;
         mClient = client;
     }

     public RootInfo getRoot(String documentId) throws RemoteException {
         final Uri rootsUri = buildRootsUri(mAuthority);
         Cursor cursor = null;
         try {
             cursor = mClient.query(rootsUri, null, null, null, null);
             while (cursor.moveToNext()) {
                 if (documentId.equals(getCursorString(cursor, Root.COLUMN_ROOT_ID))) {
                     return RootInfo.fromRootsCursor(mAuthority, cursor);
                 }
             }
             throw new IllegalArgumentException("Can't find matching root for id=" + documentId);
         } catch (Exception e) {
             throw new RuntimeException("Can't load root for id=" + documentId , e);
         } finally {
             IoUtils.closeQuietly(cursor);
         }
     }

     public Uri createDocument(Uri parentUri, String mimeType, String name) {
         if (name.contains("/")) {
             throw new IllegalArgumentException("Name and mimetype probably interposed.");
         }
         try {
             Uri uri = DocumentsContract.createDocument(mClient, parentUri, mimeType, name);
             return uri;
         } catch (RemoteException e) {
             throw new RuntimeException("Couldn't create document: " + name + " with mimetype "
                     + mimeType, e);
         }
     }

     public Uri createDocument(String parentId, String mimeType, String name) {
         Uri parentUri = buildDocumentUri(mAuthority, parentId);
         return createDocument(parentUri, mimeType, name);
     }

     public Uri createDocument(RootInfo root, String mimeType, String name) {
         return createDocument(root.documentId, mimeType, name);
     }

     public Uri createDocumentWithFlags(String documentId, String mimeType, String name, int flags,
             String... streamTypes)
             throws RemoteException {
         Bundle in = new Bundle();
         in.putInt(StubProvider.EXTRA_FLAGS, flags);
         in.putString(StubProvider.EXTRA_PARENT_ID, documentId);
         in.putString(Document.COLUMN_MIME_TYPE, mimeType);
         in.putString(Document.COLUMN_DISPLAY_NAME, name);
         in.putStringArrayList(StubProvider.EXTRA_STREAM_TYPES, Lists.newArrayList(streamTypes));

         Bundle out = mClient.call("createDocumentWithFlags", null, in);
         Uri uri = out.getParcelable(DocumentsContract.EXTRA_URI);
         return uri;
     }

     public Uri createFolder(Uri parentUri, String name) {
         return createDocument(parentUri, Document.MIME_TYPE_DIR, name);
     }

     public Uri createFolder(String parentId, String name) {
         Uri parentUri = buildDocumentUri(mAuthority, parentId);
         return createDocument(parentUri, Document.MIME_TYPE_DIR, name);
     }

     public Uri createFolder(RootInfo root, String name) {
         return createDocument(root, Document.MIME_TYPE_DIR, name);
     }

     public void writeDocument(Uri documentUri, byte[] contents)
             throws RemoteException, IOException {
         ParcelFileDescriptor file = mClient.openFile(documentUri, "w", null);
         try (AutoCloseOutputStream out = new AutoCloseOutputStream(file)) {
             out.write(contents, 0, contents.length);
         }
         waitForWrite();
     }

     public void writeAppendDocument(Uri documentUri, byte[] contents)
             throws RemoteException, IOException {
         ParcelFileDescriptor file = mClient.openFile(documentUri, "wa", null);
         try (AutoCloseOutputStream out = new AutoCloseOutputStream(file)) {
             out.write(contents);
         }
         waitForWrite();
     }

     public void waitForWrite() throws RemoteException {
         mClient.call("waitForWrite", null, null);
     }

     public byte[] readDocument(Uri documentUri) throws RemoteException, IOException {
         ParcelFileDescriptor file = mClient.openFile(documentUri, "r", null);
         byte[] buf = null;
         try (AutoCloseInputStream in = new AutoCloseInputStream(file)) {
             buf = Streams.readFully(in);
         }
         return buf;
     }

     public void assertChildCount(Uri parentUri, int expected) throws Exception {
         List<DocumentInfo> children = listChildren(parentUri);
         assertEquals("Incorrect file count after copy", expected, children.size());
     }

     public void assertChildCount(String parentId, int expected) throws Exception {
         List<DocumentInfo> children = listChildren(parentId, -1);
         assertEquals("Incorrect file count after copy", expected, children.size());
     }

     public void assertChildCount(RootInfo root, int expected) throws Exception {
         assertChildCount(root.documentId, expected);
     }

     public void assertHasFile(Uri parentUri, String name) throws Exception {
         List<DocumentInfo> children = listChildren(parentUri);
         for (DocumentInfo child : children) {
             if (name.equals(child.displayName) && !child.isDirectory()) {
                 return;
             }
         }
         fail("Could not find file named=" + name + " in children " + children);
     }

     public void assertHasFile(String parentId, String name) throws Exception {
         Uri parentUri = buildDocumentUri(mAuthority, parentId);
         assertHasFile(parentUri, name);
     }

     public void assertHasFile(RootInfo root, String name) throws Exception {
         assertHasFile(root.documentId, name);
     }

     public void assertHasDirectory(Uri parentUri, String name) throws Exception {
         List<DocumentInfo> children = listChildren(parentUri);
         for (DocumentInfo child : children) {
             if (name.equals(child.displayName) && child.isDirectory()) {
                 return;
             }
         }
         fail("Could not find name=" + name + " in children " + children);
     }

     public void assertHasDirectory(String parentId, String name) throws Exception {
         Uri parentUri = buildDocumentUri(mAuthority, parentId);
         assertHasDirectory(parentUri, name);
     }

     public void assertHasDirectory(RootInfo root, String name) throws Exception {
         assertHasDirectory(root.documentId, name);
     }

     public void assertDoesNotExist(Uri parentUri, String name) throws Exception {
         List<DocumentInfo> children = listChildren(parentUri);
         for (DocumentInfo child : children) {
             if (name.equals(child.displayName)) {
                 fail("Found name=" + name + " in children " + children);
             }
         }
     }

     public void assertDoesNotExist(String parentId, String name) throws Exception {
         Uri parentUri = buildDocumentUri(mAuthority, parentId);
         assertDoesNotExist(parentUri, name);
     }

     public void assertDoesNotExist(RootInfo root, String name) throws Exception {
         assertDoesNotExist(root.getUri(), name);
     }

     public @Nullable DocumentInfo findFile(String parentId, String name)
             throws Exception {
         List<DocumentInfo> children = listChildren(parentId);
         for (DocumentInfo child : children) {
             if (name.equals(child.displayName)) {
                 return child;
             }
         }
         return null;
     }

     public DocumentInfo findDocument(String parentId, String name) throws Exception {
         List<DocumentInfo> children = listChildren(parentId);
         for (DocumentInfo child : children) {
             if (name.equals(child.displayName)) {
                 return child;
             }
         }
         return null;
     }

     public DocumentInfo findDocument(Uri parentUri, String name) throws Exception {
         List<DocumentInfo> children = listChildren(parentUri);
         for (DocumentInfo child : children) {
             if (name.equals(child.displayName)) {
                 return child;
             }
         }
         return null;
     }

     public List<DocumentInfo> listChildren(Uri parentUri) throws Exception {
         String id = DocumentsContract.getDocumentId(parentUri);
         return listChildren(id);
     }

     public List<DocumentInfo> listChildren(String documentId) throws Exception {
         return listChildren(documentId, 100);
     }

     public List<DocumentInfo> listChildren(Uri parentUri, int maxCount) throws Exception {
         String id = DocumentsContract.getDocumentId(parentUri);
         return listChildren(id, maxCount);
     }

     public List<DocumentInfo> listChildren(String documentId, int maxCount) throws Exception {
         Uri uri = buildChildDocumentsUri(mAuthority, documentId);
         List<DocumentInfo> children = new ArrayList<>();
         try (Cursor cursor = mClient.query(uri, null, null, null, null, null)) {
             Cursor wrapper = new RootCursorWrapper(mAuthority, "totally-fake", cursor, maxCount);
             while (wrapper.moveToNext()) {
                 children.add(DocumentInfo.fromDirectoryCursor(wrapper));
             }
         }
         return children;
     }

     public void assertFileContents(Uri documentUri, byte[] expected) throws Exception {
         MoreAsserts.assertEquals(
                 "Copied file contents differ",
                 expected, readDocument(documentUri));
     }

     public void assertFileContents(String parentId, String fileName, byte[] expected)
             throws Exception {
         DocumentInfo file = findFile(parentId, fileName);
         assertNotNull(file);
         assertFileContents(file.derivedUri, expected);
     }

     /**
      * A helper method for StubProvider only. Won't work with other providers.
      * @throws RemoteException
      */
     public Uri createVirtualFile(
             RootInfo root, String path, String mimeType, byte[] content, String... streamTypes)
                     throws RemoteException {

         Bundle args = new Bundle();
         args.putString(StubProvider.EXTRA_ROOT, root.rootId);
         args.putString(StubProvider.EXTRA_PATH, path);
         args.putString(Document.COLUMN_MIME_TYPE, mimeType);
         args.putStringArrayList(StubProvider.EXTRA_STREAM_TYPES, Lists.newArrayList(streamTypes));
         args.putByteArray(StubProvider.EXTRA_CONTENT, content);

         Bundle result = mClient.call("createVirtualFile", null, args);
         String documentId = result.getString(Document.COLUMN_DOCUMENT_ID);

         return DocumentsContract.buildDocumentUri(mAuthority, documentId);
     }

     public void setLoadingDuration(long duration) throws RemoteException {
         final Bundle extra = new Bundle();
         extra.putLong(DocumentsContract.EXTRA_LOADING, duration);
         mClient.call("setLoadingDuration", null, extra);
     }

     public void configure(String args, Bundle configuration) throws RemoteException {
         mClient.call("configure", args, configuration);
     }

     public List<RootInfo> getRootList() throws RemoteException {
         List<RootInfo> list = new ArrayList<>();
         final Uri rootsUri = DocumentsContract.buildRootsUri(mAuthority);
         Cursor cursor = null;
         try {
             cursor = mClient.query(rootsUri, null, null, null, null);
             while (cursor.moveToNext()) {
                 RootInfo rootInfo = RootInfo.fromRootsCursor(mAuthority, cursor);
                 if (rootInfo != null) {
                     list.add(rootInfo);
                 }
             }
         } catch (Exception e) {
             throw new RuntimeException("Can't load rootInfo list", e);
         } finally {
             IoUtils.closeQuietly(cursor);
         }
         return list;
     }
 }
	/*
	* Copyright (C) 2015 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.documentsui;

	import static android.provider.DocumentsContract.buildChildDocumentsUri;
	import static android.provider.DocumentsContract.buildDocumentUri;
	import static android.provider.DocumentsContract.buildRootsUri;
	import static com.android.documentsui.base.DocumentInfo.getCursorString;
	import static com.android.internal.util.Preconditions.checkArgument;
	import static junit.framework.Assert.assertEquals;
	import static junit.framework.Assert.assertNotNull;
	import static junit.framework.Assert.fail;

	import android.content.ContentProviderClient;
	import android.database.Cursor;
	import android.net.Uri;
	import android.os.Bundle;
	import android.os.ParcelFileDescriptor;
	import android.os.ParcelFileDescriptor.AutoCloseInputStream;
	import android.os.ParcelFileDescriptor.AutoCloseOutputStream;
	import android.os.RemoteException;
	import android.provider.DocumentsContract;
	import android.provider.DocumentsContract.Document;
	import android.provider.DocumentsContract.Root;
	import android.support.annotation.Nullable;
	import android.test.MoreAsserts;
	import android.text.TextUtils;

	import com.android.documentsui.base.DocumentInfo;
	import com.android.documentsui.base.RootInfo;
	import com.android.documentsui.roots.RootCursorWrapper;

	import com.google.android.collect.Lists;

	import libcore.io.IoUtils;
	import libcore.io.Streams;

	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.List;

	/**
	* Provides support for creation of documents in a test settings.
	*/
	public class DocumentsProviderHelper {

	private final String mAuthority;
	private final ContentProviderClient mClient;

	public DocumentsProviderHelper(String authority, ContentProviderClient client) {
	checkArgument(!TextUtils.isEmpty(authority));
	mAuthority = authority;
	mClient = client;
	}

	public RootInfo getRoot(String documentId) throws RemoteException {
	final Uri rootsUri = buildRootsUri(mAuthority);
	Cursor cursor = null;
	try {
	cursor = mClient.query(rootsUri, null, null, null, null);
	while (cursor.moveToNext()) {
	if (documentId.equals(getCursorString(cursor, Root.COLUMN_ROOT_ID))) {
	return RootInfo.fromRootsCursor(mAuthority, cursor);
	}
	}
	throw new IllegalArgumentException("Can't find matching root for id=" + documentId);
	} catch (Exception e) {
	throw new RuntimeException("Can't load root for id=" + documentId , e);
	} finally {
	IoUtils.closeQuietly(cursor);
	}
	}

	public Uri createDocument(Uri parentUri, String mimeType, String name) {
	if (name.contains("/")) {
	throw new IllegalArgumentException("Name and mimetype probably interposed.");
	}
	try {
	Uri uri = DocumentsContract.createDocument(mClient, parentUri, mimeType, name);
	return uri;
	} catch (RemoteException e) {
	throw new RuntimeException("Couldn't create document: " + name + " with mimetype "
	+ mimeType, e);
	}
	}

	public Uri createDocument(String parentId, String mimeType, String name) {
	Uri parentUri = buildDocumentUri(mAuthority, parentId);
	return createDocument(parentUri, mimeType, name);
	}

	public Uri createDocument(RootInfo root, String mimeType, String name) {
	return createDocument(root.documentId, mimeType, name);
	}

	public Uri createDocumentWithFlags(String documentId, String mimeType, String name, int flags,
	String... streamTypes)
	throws RemoteException {
	Bundle in = new Bundle();
	in.putInt(StubProvider.EXTRA_FLAGS, flags);
	in.putString(StubProvider.EXTRA_PARENT_ID, documentId);
	in.putString(Document.COLUMN_MIME_TYPE, mimeType);
	in.putString(Document.COLUMN_DISPLAY_NAME, name);
	in.putStringArrayList(StubProvider.EXTRA_STREAM_TYPES, Lists.newArrayList(streamTypes));

	Bundle out = mClient.call("createDocumentWithFlags", null, in);
	Uri uri = out.getParcelable(DocumentsContract.EXTRA_URI);
	return uri;
	}

	public Uri createFolder(Uri parentUri, String name) {
	return createDocument(parentUri, Document.MIME_TYPE_DIR, name);
	}

	public Uri createFolder(String parentId, String name) {
	Uri parentUri = buildDocumentUri(mAuthority, parentId);
	return createDocument(parentUri, Document.MIME_TYPE_DIR, name);
	}

	public Uri createFolder(RootInfo root, String name) {
	return createDocument(root, Document.MIME_TYPE_DIR, name);
	}

	public void writeDocument(Uri documentUri, byte[] contents)
	throws RemoteException, IOException {
	ParcelFileDescriptor file = mClient.openFile(documentUri, "w", null);
	try (AutoCloseOutputStream out = new AutoCloseOutputStream(file)) {
	out.write(contents, 0, contents.length);
	}
	waitForWrite();
	}

	public void writeAppendDocument(Uri documentUri, byte[] contents)
	throws RemoteException, IOException {
	ParcelFileDescriptor file = mClient.openFile(documentUri, "wa", null);
	try (AutoCloseOutputStream out = new AutoCloseOutputStream(file)) {
	out.write(contents);
	}
	waitForWrite();
	}

	public void waitForWrite() throws RemoteException {
	mClient.call("waitForWrite", null, null);
	}

	public byte[] readDocument(Uri documentUri) throws RemoteException, IOException {
	ParcelFileDescriptor file = mClient.openFile(documentUri, "r", null);
	byte[] buf = null;
	try (AutoCloseInputStream in = new AutoCloseInputStream(file)) {
	buf = Streams.readFully(in);
	}
	return buf;
	}

	public void assertChildCount(Uri parentUri, int expected) throws Exception {
	List<DocumentInfo> children = listChildren(parentUri);
	assertEquals("Incorrect file count after copy", expected, children.size());
	}

	public void assertChildCount(String parentId, int expected) throws Exception {
	List<DocumentInfo> children = listChildren(parentId, -1);
	assertEquals("Incorrect file count after copy", expected, children.size());
	}

	public void assertChildCount(RootInfo root, int expected) throws Exception {
	assertChildCount(root.documentId, expected);
	}

	public void assertHasFile(Uri parentUri, String name) throws Exception {
	List<DocumentInfo> children = listChildren(parentUri);
	for (DocumentInfo child : children) {
	if (name.equals(child.displayName) && !child.isDirectory()) {
	return;
	}
	}
	fail("Could not find file named=" + name + " in children " + children);
	}

	public void assertHasFile(String parentId, String name) throws Exception {
	Uri parentUri = buildDocumentUri(mAuthority, parentId);
	assertHasFile(parentUri, name);
	}

	public void assertHasFile(RootInfo root, String name) throws Exception {
	assertHasFile(root.documentId, name);
	}

	public void assertHasDirectory(Uri parentUri, String name) throws Exception {
	List<DocumentInfo> children = listChildren(parentUri);
	for (DocumentInfo child : children) {
	if (name.equals(child.displayName) && child.isDirectory()) {
	return;
	}
	}
	fail("Could not find name=" + name + " in children " + children);
	}

	public void assertHasDirectory(String parentId, String name) throws Exception {
	Uri parentUri = buildDocumentUri(mAuthority, parentId);
	assertHasDirectory(parentUri, name);
	}

	public void assertHasDirectory(RootInfo root, String name) throws Exception {
	assertHasDirectory(root.documentId, name);
	}

	public void assertDoesNotExist(Uri parentUri, String name) throws Exception {
	List<DocumentInfo> children = listChildren(parentUri);
	for (DocumentInfo child : children) {
	if (name.equals(child.displayName)) {
	fail("Found name=" + name + " in children " + children);
	}
	}
	}

	public void assertDoesNotExist(String parentId, String name) throws Exception {
	Uri parentUri = buildDocumentUri(mAuthority, parentId);
	assertDoesNotExist(parentUri, name);
	}

	public void assertDoesNotExist(RootInfo root, String name) throws Exception {
	assertDoesNotExist(root.getUri(), name);
	}

	public @Nullable DocumentInfo findFile(String parentId, String name)
	throws Exception {
	List<DocumentInfo> children = listChildren(parentId);
	for (DocumentInfo child : children) {
	if (name.equals(child.displayName)) {
	return child;
	}
	}
	return null;
	}

	public DocumentInfo findDocument(String parentId, String name) throws Exception {
	List<DocumentInfo> children = listChildren(parentId);
	for (DocumentInfo child : children) {
	if (name.equals(child.displayName)) {
	return child;
	}
	}
	return null;
	}

	public DocumentInfo findDocument(Uri parentUri, String name) throws Exception {
	List<DocumentInfo> children = listChildren(parentUri);
	for (DocumentInfo child : children) {
	if (name.equals(child.displayName)) {
	return child;
	}
	}
	return null;
	}

	public List<DocumentInfo> listChildren(Uri parentUri) throws Exception {
	String id = DocumentsContract.getDocumentId(parentUri);
	return listChildren(id);
	}

	public List<DocumentInfo> listChildren(String documentId) throws Exception {
	return listChildren(documentId, 100);
	}

	public List<DocumentInfo> listChildren(Uri parentUri, int maxCount) throws Exception {
	String id = DocumentsContract.getDocumentId(parentUri);
	return listChildren(id, maxCount);
	}

	public List<DocumentInfo> listChildren(String documentId, int maxCount) throws Exception {
	Uri uri = buildChildDocumentsUri(mAuthority, documentId);
	List<DocumentInfo> children = new ArrayList<>();
	try (Cursor cursor = mClient.query(uri, null, null, null, null, null)) {
	Cursor wrapper = new RootCursorWrapper(mAuthority, "totally-fake", cursor, maxCount);
	while (wrapper.moveToNext()) {
	children.add(DocumentInfo.fromDirectoryCursor(wrapper));
	}
	}
	return children;
	}

	public void assertFileContents(Uri documentUri, byte[] expected) throws Exception {
	MoreAsserts.assertEquals(
	"Copied file contents differ",
	expected, readDocument(documentUri));
	}

	public void assertFileContents(String parentId, String fileName, byte[] expected)
	throws Exception {
	DocumentInfo file = findFile(parentId, fileName);
	assertNotNull(file);
	assertFileContents(file.derivedUri, expected);
	}

	/**
	* A helper method for StubProvider only. Won't work with other providers.
	* @throws RemoteException
	*/
	public Uri createVirtualFile(
	RootInfo root, String path, String mimeType, byte[] content, String... streamTypes)
	throws RemoteException {

	Bundle args = new Bundle();
	args.putString(StubProvider.EXTRA_ROOT, root.rootId);
	args.putString(StubProvider.EXTRA_PATH, path);
	args.putString(Document.COLUMN_MIME_TYPE, mimeType);
	args.putStringArrayList(StubProvider.EXTRA_STREAM_TYPES, Lists.newArrayList(streamTypes));
	args.putByteArray(StubProvider.EXTRA_CONTENT, content);

	Bundle result = mClient.call("createVirtualFile", null, args);
	String documentId = result.getString(Document.COLUMN_DOCUMENT_ID);

	return DocumentsContract.buildDocumentUri(mAuthority, documentId);
	}

	public void setLoadingDuration(long duration) throws RemoteException {
	final Bundle extra = new Bundle();
	extra.putLong(DocumentsContract.EXTRA_LOADING, duration);
	mClient.call("setLoadingDuration", null, extra);
	}

	public void configure(String args, Bundle configuration) throws RemoteException {
	mClient.call("configure", args, configuration);
	}

	public List<RootInfo> getRootList() throws RemoteException {
	List<RootInfo> list = new ArrayList<>();
	final Uri rootsUri = DocumentsContract.buildRootsUri(mAuthority);
	Cursor cursor = null;
	try {
	cursor = mClient.query(rootsUri, null, null, null, null);
	while (cursor.moveToNext()) {
	RootInfo rootInfo = RootInfo.fromRootsCursor(mAuthority, cursor);
	if (rootInfo != null) {
	list.add(rootInfo);
	}
	}
	} catch (Exception e) {
	throw new RuntimeException("Can't load rootInfo list", e);
	} finally {
	IoUtils.closeQuietly(cursor);
	}
	return list;
	}
	}