Add media device attach notification mechanism.

Split out from https://chromiumcodereview.appspot.com/9363008/

BUG=110400
TEST=NONE


Review URL: http://codereview.chromium.org/9580018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@124763 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 135 insertions, 28 deletions

diff --git a/base/base.gyp b/base/base.gyp
index c13a93e..1a1caee 100644
--- a/base/base.gyp
+++ b/base/base.gyp
@@ -409,6 +409,8 @@
         'perftimer.cc',
         'test/mock_chrome_application_mac.h',
         'test/mock_chrome_application_mac.mm',
+        'test/mock_devices_changed_observer.cc',
+        'test/mock_devices_changed_observer.h',
         'test/mock_time_provider.cc',
         'test/mock_time_provider.h',
         'test/multiprocess_test.cc',
diff --git a/base/system_monitor/system_monitor.cc b/base/system_monitor/system_monitor.cc
index 28fc70b..afca3fc 100644
--- a/base/system_monitor/system_monitor.cc
+++ b/base/system_monitor/system_monitor.cc
@@ -1,9 +1,10 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
 #include "base/system_monitor/system_monitor.h"
 
+#include "base/file_path.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/time.h"
@@ -83,6 +84,16 @@ void SystemMonitor::ProcessDevicesChanged() {
   NotifyDevicesChanged();
 }
 
+void SystemMonitor::ProcessMediaDeviceAttached(const DeviceIdType& id,
+                                               const std::string& name,
+                                               const FilePath& path) {
+  NotifyMediaDeviceAttached(id, name, path);
+}
+
+void SystemMonitor::ProcessMediaDeviceDetached(const DeviceIdType& id) {
+  NotifyMediaDeviceDetached(id);
+}
+
 void SystemMonitor::AddPowerObserver(PowerObserver* obs) {
   power_observer_list_->AddObserver(obs);
 }
@@ -105,6 +116,20 @@ void SystemMonitor::NotifyDevicesChanged() {
     &DevicesChangedObserver::OnDevicesChanged);
 }
 
+void SystemMonitor::NotifyMediaDeviceAttached(const DeviceIdType& id,
+                                              const std::string& name,
+                                              const FilePath& path) {
+  DVLOG(1) << "MediaDeviceAttached with name " << name << " and id " << id;
+  devices_changed_observer_list_->Notify(
+    &DevicesChangedObserver::OnMediaDeviceAttached, id, name, path);
+}
+
+void SystemMonitor::NotifyMediaDeviceDetached(const DeviceIdType& id) {
+  DVLOG(1) << "MediaDeviceDetached for id " << id;
+  devices_changed_observer_list_->Notify(
+    &DevicesChangedObserver::OnMediaDeviceDetached, id);
+}
+
 void SystemMonitor::NotifyPowerStateChange() {
   DVLOG(1) << "PowerStateChange: " << (BatteryPower() ? "On" : "Off")
            << " battery";
diff --git a/base/system_monitor/system_monitor.h b/base/system_monitor/system_monitor.h
index 7684523..3f73b15 100644
--- a/base/system_monitor/system_monitor.h
+++ b/base/system_monitor/system_monitor.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
@@ -6,6 +6,8 @@
 #define BASE_SYSTEM_MONITOR_SYSTEM_MONITOR_H_
 #pragma once
 
+#include <string>
+
 #include "base/base_export.h"
 #include "base/basictypes.h"
 #include "build/build_config.h"
@@ -28,6 +30,8 @@
 #include <IOKit/IOMessage.h>
 #endif  // OS_MACOSX
 
+class FilePath;
+
 namespace base {
 
 // Class for monitoring various system-related subsystems
@@ -42,6 +46,8 @@ class BASE_EXPORT SystemMonitor {
     RESUME_EVENT        // The system is being resumed.
   };
 
+  typedef unsigned int DeviceIdType;
+
   // Create SystemMonitor. Only one SystemMonitor instance per application
   // is allowed.
   SystemMonitor();
@@ -93,8 +99,19 @@ class BASE_EXPORT SystemMonitor {
   class BASE_EXPORT DevicesChangedObserver {
    public:
     // Notification that the devices connected to the system have changed.
+    // This is only implemented on Windows currently.
     virtual void OnDevicesChanged() {}
 
+    // When a media device is attached or detached, one of these two events
+    // is triggered.
+    // TODO(vandebo) Pass an appropriate device identifier or way to interact
+    // with the devices instead of FilePath.
+    virtual void OnMediaDeviceAttached(const DeviceIdType& id,
+                                       const std::string& name,
+                                       const FilePath& path) {}
+
+    virtual void OnMediaDeviceDetached(const DeviceIdType& id) {}
+
    protected:
     virtual ~DevicesChangedObserver() {}
   };
@@ -123,6 +140,10 @@ class BASE_EXPORT SystemMonitor {
 
   // Cross-platform handling of a device change event.
   void ProcessDevicesChanged();
+  void ProcessMediaDeviceAttached(const DeviceIdType& id,
+                                  const std::string& name,
+                                  const FilePath& path);
+  void ProcessMediaDeviceDetached(const DeviceIdType& id);
 
  private:
 #if defined(OS_MACOSX)
@@ -141,6 +162,10 @@ class BASE_EXPORT SystemMonitor {
 
   // Functions to trigger notifications.
   void NotifyDevicesChanged();
+  void NotifyMediaDeviceAttached(const DeviceIdType& id,
+                                 const std::string& name,
+                                 const FilePath& path);
+  void NotifyMediaDeviceDetached(const DeviceIdType& id);
   void NotifyPowerStateChange();
   void NotifySuspend();
   void NotifyResume();
diff --git a/base/system_monitor/system_monitor_unittest.cc b/base/system_monitor/system_monitor_unittest.cc
index 1d5d6af..eaed974 100644
--- a/base/system_monitor/system_monitor_unittest.cc
+++ b/base/system_monitor/system_monitor_unittest.cc
@@ -1,8 +1,11 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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.
 
+#include "base/file_path.h"
+#include "base/test/mock_devices_changed_observer.h"
 #include "base/system_monitor/system_monitor.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
@@ -90,26 +93,6 @@ TEST(SystemMonitor, PowerNotifications) {
   EXPECT_EQ(test[0].resumes(), 1);
 }
 
-class DevicesChangedTest : public SystemMonitor::DevicesChangedObserver {
- public:
-  DevicesChangedTest()
-      : changes_(0) {
-  }
-
-  // DevicesChangedObserver callbacks.
-  virtual void OnDevicesChanged() OVERRIDE {
-    changes_++;
-  }
-
-  // Test status counts.
-  int changes() const { return changes_; }
-
- private:
-  int changes_;  // Count of OnDevicesChanged notifications.
-
-  DISALLOW_COPY_AND_ASSIGN(DevicesChangedTest);
-};
-
 TEST(SystemMonitor, DeviceChangeNotifications) {
   const int kObservers = 5;
 
@@ -120,19 +103,38 @@ TEST(SystemMonitor, DeviceChangeNotifications) {
   SystemMonitor::AllocateSystemIOPorts();
 #endif
 
+  testing::Sequence mock_sequencer[kObservers];
   SystemMonitor system_monitor;
-  DevicesChangedTest test[kObservers];
-  for (int index = 0; index < kObservers; ++index)
-    system_monitor.AddDevicesChangedObserver(&test[index]);
+  MockDevicesChangedObserver observers[kObservers];
+  for (int index = 0; index < kObservers; ++index) {
+    system_monitor.AddDevicesChangedObserver(&observers[index]);
+
+    EXPECT_CALL(observers[index], OnDevicesChanged())
+        .Times(3)
+        .InSequence(mock_sequencer[index]);
+    EXPECT_CALL(observers[index], OnMediaDeviceAttached(1, "media device",
+                                                        testing::_))
+        .InSequence(mock_sequencer[index]);
+    EXPECT_CALL(observers[index], OnMediaDeviceDetached(1))
+        .InSequence(mock_sequencer[index]);
+    EXPECT_CALL(observers[index], OnMediaDeviceDetached(2))
+        .InSequence(mock_sequencer[index]);
+  }
 
   system_monitor.ProcessDevicesChanged();
   loop.RunAllPending();
-  EXPECT_EQ(1, test[0].changes());
 
   system_monitor.ProcessDevicesChanged();
   system_monitor.ProcessDevicesChanged();
   loop.RunAllPending();
-  EXPECT_EQ(3, test[0].changes());
+
+  system_monitor.ProcessMediaDeviceAttached(
+      1, "media device", FilePath(FILE_PATH_LITERAL("path")));
+  loop.RunAllPending();
+
+  system_monitor.ProcessMediaDeviceDetached(1);
+  system_monitor.ProcessMediaDeviceDetached(2);
+  loop.RunAllPending();
 }
 
 }  // namespace base
diff --git a/base/test/mock_devices_changed_observer.cc b/base/test/mock_devices_changed_observer.cc
new file mode 100644
index 0000000..25ff613
--- /dev/null
+++ b/base/test/mock_devices_changed_observer.cc
@@ -0,0 +1,17 @@
+// 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.
+
+#include "base/test/mock_devices_changed_observer.h"
+
+#include "base/file_path.h"
+
+namespace base {
+
+MockDevicesChangedObserver::MockDevicesChangedObserver() {
+}
+
+MockDevicesChangedObserver::~MockDevicesChangedObserver() {
+}
+
+}  // namespace base
diff --git a/base/test/mock_devices_changed_observer.h b/base/test/mock_devices_changed_observer.h
new file mode 100644
index 0000000..9964f06
--- /dev/null
+++ b/base/test/mock_devices_changed_observer.h
@@ -0,0 +1,36 @@
+// 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 BASE_TEST_MOCK_DEVICES_CHANGED_OBSERVER_H_
+#define BASE_TEST_MOCK_DEVICES_CHANGED_OBSERVER_H_
+
+#include <string>
+
+#include "base/system_monitor/system_monitor.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+class FilePath;
+
+namespace base {
+
+class MockDevicesChangedObserver
+  : public base::SystemMonitor::DevicesChangedObserver {
+ public:
+  MockDevicesChangedObserver();
+  ~MockDevicesChangedObserver();
+
+  MOCK_METHOD0(OnDevicesChanged, void());
+  MOCK_METHOD3(OnMediaDeviceAttached,
+               void(const base::SystemMonitor::DeviceIdType& id,
+                    const std::string& name,
+                    const FilePath& path));
+  MOCK_METHOD1(OnMediaDeviceDetached,
+               void(const base::SystemMonitor::DeviceIdType& id));
+
+  DISALLOW_COPY_AND_ASSIGN(MockDevicesChangedObserver);
+};
+
+}  // namespace base
+
+#endif  // BASE_TEST_MOCK_DEVICES_CHANGED_OBSERVER_H_