ARC Media View: Mojo definitions.

BUG=chromium:671511
TEST=trybot

Review-Url: https://codereview.chromium.org/2559643002
Cr-Commit-Position: refs/heads/master@{#437511}

components/arc/common/file_system.mojom

@@ -2,14 +2,67 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Next MinVersion: 2
+// Next MinVersion: 3
 
 module arc.mojom;
 
-// Next method ID: 3
+// Represents a document in Android DocumentsProvider.
+// See Android docs of DocumentsContract.Document for details.
+struct Document {
+  // Opaque ID of the document.
+  string document_id;
+
+  // Display name of the document.
+  string display_name;
+
+  // MIME type of the document.
+  // A directory is represented by a document having MIME_TYPE_DIR MIME type.
+  string mime_type;
+
+  // Size of the document in bytes. If the size is unknown, -1 is set.
+  int64 size;
+
+  // Timestamp when the document was modified last time, in milliseconds
+  // since UNIX epoch.
+  // TODO(crbug.com/672737): Use mojo.common.mojom.Time once the type is
+  // converted to a non-native type so that it can be used from Java.
+  uint64 last_modified;
+};
+
+// Next method ID: 5
 interface FileSystemInstance {
+  // Notes about Android Documents Provider:
+  //
+  // In Android Storage Access Framework, a document is uniquely identified by
+  // a pair of "authority" and "document ID".
+  //
+  // - An authority specifies a Documents Provider that serves a document.
+  //   It is the origin part of a content:// URI used to access the Documents
+  //   Provider via Content Resolver protocol.
+  //   Example: "com.android.providers.media.documents"
+  // - A document ID is an opaque string that specifies a particular document
+  //   in a documents provider. Its format varies by providers.
+  //
+  // See the following documents for details about Documents Provider:
+  // https://developer.android.com/guide/topics/providers/document-provider.html
+  // https://developer.android.com/reference/android/provider/DocumentsContract.html
+
+  // Queries child documents of the directory specified by |authority| and
+  // |parent_document_id| in Documents Provider.
+  // If such a directory does not exist, null is returned.
+  [MinVersion=2] GetChildDocuments@4(string authority,
+                                     string parent_document_id) =>
+      (array<Document>? documents);
+
+  // Queries the document specified by |authority| and |document_id| in
+  // Documents Provider.
+  // If such a document does not exist, null is returned.
+  [MinVersion=2] GetDocument@3(string authority, string document_id) =>
+      (Document? document);
+
   // Asks the ContentResolver for the size of the file specified by the URL.
-  // If the file does not exist or the size is unknown, -1 is returned.
+  // If the file does not exist or the size is unknown (e.g. directories and
+  // streams), -1 is returned.
   [MinVersion=1] GetFileSize@1(string url) => (int64 size);
 
   // Asks the ContentResolver to get a FD to read the file specified by the

components/arc/test/fake_file_system_instance.cc

@@ -10,6 +10,15 @@ FakeFileSystemInstance::FakeFileSystemInstance() = default;
 
 FakeFileSystemInstance::~FakeFileSystemInstance() = default;
 
+void FakeFileSystemInstance::GetChildDocuments(
+    const std::string& authority,
+    const std::string& document_id,
+    const GetChildDocumentsCallback& callback) {}
+
+void FakeFileSystemInstance::GetDocument(const std::string& authority,
+                                         const std::string& document_id,
+                                         const GetDocumentCallback& callback) {}
+
 void FakeFileSystemInstance::GetFileSize(const std::string& url,
                                          const GetFileSizeCallback& callback) {}
 

components/arc/test/fake_file_system_instance.h

@@ -20,6 +20,14 @@ class FakeFileSystemInstance : public mojom::FileSystemInstance {
   // mojom::FileSystemInstance:
   ~FakeFileSystemInstance() override;
 
+  void GetChildDocuments(const std::string& authority,
+                         const std::string& document_id,
+                         const GetChildDocumentsCallback& callback) override;
+
+  void GetDocument(const std::string& authority,
+                   const std::string& document_id,
+                   const GetDocumentCallback& callback) override;
+
   void GetFileSize(const std::string& url,
                    const GetFileSizeCallback& callback) override;