Files.app: Add FileSystemMetadataModel.

ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_model.js

Index: ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_model.js
diff --git a/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_model.js b/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_model.js
new file mode 100644
index 0000000000000000000000000000000000000000..06302fe39bc7e2834cc4ce94ac53988965a774d8
--- /dev/null
+++ b/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_model.js
@@ -0,0 +1,92 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @param {!MetadataProviderCache} cache
+ * @param {!FileSystemMetadataProvider} fileSystemMetadataProvider
+ * @param {!ExternalMetadataProvider} externalMetadataProvider
+ * @param {!VolumeManagerWrapper} volumeManager
+ * @constructor
+ * @struct
+ */
+function FileSystemMetadataModel(
+    cache,
+    fileSystemMetadataProvider,
+    externalMetadataProvider,
+    volumeManager) {
+  /**
+   * @private {!MetadataProviderCache}
+   * @const
+   */
+  this.cache_ = cache;
+
+  /**
+   * @private {!FileSystemMetadataProvider}
+   * @const
+   */
+  this.fileSystemMetadataProvider_ = fileSystemMetadataProvider;
+
+  /**
+   * @private {!ExternalMetadataProvider}
+   * @const
+   */
+  this.externalMetadataProvider_ = externalMetadataProvider;
+
+  /**
+   * @private {!VolumeManagerWrapper}
+   * @const
+   */
+  this.volumeManager_ = volumeManager;
+}
+
+/**
+ * Obtains metadata for entries.
+ * @param {!Array<!FileEntry>} entries Entries.
+ * @param {!Array<string>} names Metadata property names to be obtained.
+ * @return {!Promise<!Array<!ExternalMetadata>>}
+ */
+FileSystemMetadataModel.prototype.get = function(entries, names) {
+  var localEntries = [];
+  var localEntryIndexes = [];
+  var externalEntries = [];
+  var externalEntryIndexes = [];
+  for (var i = 0; i < entries.length; i++) {
+    var volumeInfo = this.volumeManager_.getVolumeInfo(entries[i]);
+    if (volumeInfo &&
+        (volumeInfo.volumeType === VolumeManagerCommon.VolumeType.DRIVE ||
+         volumeInfo.volumeType === VolumeManagerCommon.VolumeType.PROVIDED)) {
+      externalEntries.push(entries[i]);
+      externalEntryIndexes.push(i);
+    } else {
+      localEntries.push(entries[i]);
+      localEntryIndexes.push(i);
+    }
+  }
+
+  return Promise.all([
+    this.fileSystemMetadataProvider_.get(localEntries, names),
+    this.externalMetadataProvider_.get(externalEntries, names)
+  ]).then(function(results) {
+    var integratedResults = [];
+    var localResults = results[0];
+    for (var i = 0; i < localResults.length; i++) {
+      integratedResults[localEntryIndexes[i]] = localResults[i];
+    }
+    var externalResults = results[1];
+    for (var i = 0; i < externalResults.length; i++) {
+      integratedResults[externalEntryIndexes[i]] = externalResults[i];
+    }
+    return integratedResults;
+  });
+};
+
+/**
+ * Obtains metadata cache for entries.
+ * @param {!Array<!FileEntry>} entries Entries.
+ * @param {!Array<string>} names Metadata property names to be obtained.
+ * @return {!Array<!FileSystemMetadata>}
+ */
+FileSystemMetadataModel.prototype.getCache = function(entries, names) {
+  return this.cache_.get(entries, names);
+};