[Win, MediaGallery] Enumerate and handle mtp device attach/detach events.

chrome/browser/system_monitor/portable_device_watcher_win.h

+// Copyright (c) 2012 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.
+
+#ifndef CHROME_BROWSER_SYSTEM_MONITOR_PORTABLE_DEVICE_WATCHER_WIN_H_
+#define CHROME_BROWSER_SYSTEM_MONITOR_PORTABLE_DEVICE_WATCHER_WIN_H_
+
+#include <portabledeviceapi.h>
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/string16.h"
+#include "base/system_monitor/system_monitor.h"
+
+namespace base {
+class SequencedTaskRunner;
+}
+
+class FilePath;
+
+namespace chrome {
+
+// This class watches the portable device mount points and sends notifications
+// to base::SystemMonitor about the attached/detached Mtp devices. This is a
+// singleton class instantiated by RemovableDeviceNotificationsWindowWin. This
+// class is created, destroyed and operates on the UI thread, except for long
+// running tasks it spins off to a media task runner.

[Peter Kasting, 2012/10/26 23:46:23]

Nit: media task runner -> SequencedTaskRunner

[kmadhusu, 2012/10/28 22:57:16]

Done.

+class PortableDeviceWatcherWin {
+ public:
+  // Struct to store device storage information.

[Peter Kasting, 2012/10/26 23:46:23]

Nit: This comment doesn't add anything, remove.

[kmadhusu, 2012/10/28 22:57:16]

Done.

+  struct DeviceStorageObject {
+    // Storage object temporary identifier, e.g.: "s10001".

[Peter Kasting, 2012/10/26 23:46:23]

Tiny nit: ':' not necessary after "e.g." (2 places)

[kmadhusu, 2012/10/28 22:57:16]

Done.

+    string16 object_temporary_id;
+
+    // Storage object persistent identifier,
+    // e.g.: "StorageSerial:<SID-{10001,D,31080448}>:<123456789>"
+    std::string object_persistent_id;
+  };
+
+  // Vector of media transfer protocol(mtp) device storage objects.

[Peter Kasting, 2012/10/26 23:46:23]

Nit: Comment doesn't add anything, remove.  (Same as with next typedef.)

I would also eliminate the blank line between the struct and the typedef, which
makes it look less weird that you do struct, typedef, second struct.

[kmadhusu, 2012/10/28 22:57:16]

Done.

+  typedef std::vector<DeviceStorageObject> StorageObjects;
+
+  // Struct to store attached mtp device details.
+  struct DeviceDetails {
+    // Device name.
+    string16 name;
+
+    // Device interface path.
+    string16 location;
+
+    // Device storage details. A device can have multiple data partitions.
+    StorageObjects storage_objects;
+  };
+
+  // Vector of media transfer protocol devices.
+  typedef std::vector<DeviceDetails> DeviceDetailsVector;

[Peter Kasting, 2012/10/26 23:46:23]

Nit: How about just "Devices" as the type name?  (and the variable names, where
this is used)

[kmadhusu, 2012/10/28 22:57:16]

Done.

+
+  PortableDeviceWatcherWin();
+  virtual ~PortableDeviceWatcherWin();
+
+  // Must be called after the browser blocking pool is ready for use.
+  // RemovableDeviceNotificationsWindowsWin::Init() will call this function.
+  void Init();
+
+  // Processes DEV_BROADCAST_DEVICEINTERFACE messages and triggers a
+  // SystemMonitor notification if appropriate.
+  void OnWindowMessage(UINT event_type, LPARAM data);
+
+ private:
+  friend class TestPortableDeviceWatcherWin;
+
+  // Key: MTP device storage unique id.
+  // Value: Metadata for the given storage.
+  typedef std::map<std::string, base::SystemMonitor::RemovableStorageInfo>
+      MtpStorageMap;
+
+  // Key: Mtp device plug and play ID string.
+  // Value: Vector of device storage objects.
+  typedef std::map<string16, StorageObjects> MtpDeviceMap;
+
+  // Helpers to enumerate existing mtp storage devices.
+  virtual void EnumerateAttachedDevices();
+  virtual void OnDidEnumerateAttachedDevices(
+      const DeviceDetailsVector* device_details_vector);
+
+  // Helpers to handle device attach event.
+  virtual void HandleDeviceAttachEvent(const string16& pnp_device_id);
+  virtual void OnDidHandleDeviceAttachEvent(
+      const DeviceDetails* device_details);
+
+  //  Handles the detach event of the device specified by |pnp_device_id|.
+  void HandleDeviceDetachEvent(const string16& pnp_device_id);
+
+  // Attached media transfer protocol device map.
+  MtpDeviceMap device_map_;
+
+  // Attached media transfer protocol device storage objects map.
+  MtpStorageMap storage_map_;
+
+  // The task runner used to execute tasks that may take a long time and thus
+  // should not be performed on the UI thread.
+  scoped_refptr<base::SequencedTaskRunner> media_task_runner_;
+
+  // Used by |media_task_runner_| to create cancelable callbacks.
+  base::WeakPtrFactory<PortableDeviceWatcherWin> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(PortableDeviceWatcherWin);
+};
+
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_SYSTEM_MONITOR_PORTABLE_DEVICE_WATCHER_WIN_H_