ash: Add SessionController/Client mojo interfaces

ash/common/session/session_controller.cc

Index: ash/common/session/session_controller.cc
diff --git a/ash/common/session/session_controller.cc b/ash/common/session/session_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ee8f115a0c37064f532864b1b6fb213083874504
--- /dev/null
+++ b/ash/common/session/session_controller.cc
@@ -0,0 +1,152 @@
+// Copyright 2016 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 "ash/common/session/session_controller.h"
+
+#include <set>
+
+#include "ash/common/session/session_state_observer.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "components/signin/core/account_id/account_id.h"
+#include "services/service_manager/public/cpp/connector.h"
+
+namespace ash {
+
+SessionController::SessionController() {}
+
+SessionController::~SessionController() {}
+
+void SessionController::BindRequest(mojom::SessionControllerRequest request) {
+  bindings_.AddBinding(this, std::move(request));
+}
+
+int SessionController::GetMaximumNumberOfLoggedInUsers() const {
+  return static_cast<int>(max_users_);
+}
+
+int SessionController::NumberOfLoggedInUsers() const {
+  return static_cast<int>(user_sessions_.size());
+}
+
+AddUserSessionPolicy SessionController::GetAddUserPolicy() const {
+  return add_user_session_policy_;
+}
+
+bool SessionController::IsActiveUserSessionStarted() const {
+  return !user_sessions_.empty();
+}
+
+bool SessionController::CanLockScreen() const {
+  return can_lock_;
+}
+
+bool SessionController::IsScreenLocked() const {
+  return state_ == session_manager::SessionState::LOCKED;
+}
+
+bool SessionController::ShouldLockScreenAutomatically() const {
+  return should_lock_screen_automatically_;
+}
+
+bool SessionController::IsUserSessionBlocked() const {
+  return state_ != session_manager::SessionState::ACTIVE;
+}
+
+session_manager::SessionState SessionController::GetSessionState() const {
+  return state_;
+}
+
+const std::vector<mojom::UserSessionPtr>& SessionController::GetUserSessions()
+    const {
+  return user_sessions_;
+}
+
+void SessionController::LockScreen() {
+  client_->RequestLockScreen();

[James Cook, 2016/12/01 23:01:43]

Check if (client_) since it's possible someday we'll run without chrome.

[xiyuan, 2016/12/06 00:46:33]

Done.

+}
+
+void SessionController::SwitchActiveUser(const AccountId& account_id) {
+  client_->SwitchActiveUser(account_id.Serialize());
+}
+
+void SessionController::CycleActiveUser(bool next_user) {
+  client_->CycleActiveUser(next_user);
+}
+
+void SessionController::AddSessionStateObserver(
+    SessionStateObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void SessionController::RemoveSessionStateObserver(
+    SessionStateObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void SessionController::SetClient(mojom::SessionControllerClientPtr client) {
+  client_ = std::move(client);
+}
+
+void SessionController::SetMaxUsers(uint32_t max_users) {
+  max_users_ = max_users;
+}
+
+void SessionController::SetCanLockScreen(bool can_lock) {
+  can_lock_ = can_lock;
+}
+
+void SessionController::SetShouldLockScreenAutomatically(bool should_lock) {
+  should_lock_screen_automatically_ = should_lock;
+}
+
+void SessionController::SetAddUserSessionPolicy(
+    AddUserSessionPolicy add_user_session_policy) {
+  add_user_session_policy_ = add_user_session_policy;
+}
+
+void SessionController::SetSessionState(session_manager::SessionState state) {
+  if (state_ == state)
+    return;
+
+  state_ = state;
+  for (auto& observer : observers_)
+    observer.SessionStateChanged(state_);
+}
+
+void SessionController::SetUserSessions(
+    std::vector<mojom::UserSessionPtr> user_sessions) {
+  const std::string old_active_user =
+      user_sessions_.empty() ? std::string() : user_sessions_[0]->account_id;
+
+  std::set<std::string> existing_users;
+  for (auto& user_session : user_sessions_)

[James Cook, 2016/12/01 23:01:43]

const auto&, if possible, here and below

[xiyuan, 2016/12/06 00:46:33]

Code removed.

+    existing_users.insert(user_session->account_id);
+
+  user_sessions_ = std::move(user_sessions);
+
+  for (auto& user_session : user_sessions) {

[James Cook, 2016/12/01 23:01:43]

user_sessions_? isn't |user_sessions| empty now that you have moved it?

[xiyuan, 2016/12/06 00:46:33]

Right. The code is wrong. Removed in new patch since we get rid of
SetUserSessions.

+    if (existing_users.find(user_session->account_id) == existing_users.end()) {

[James Cook, 2016/12/01 23:01:43]

optional: if ( ... != end) continue; which would reduce indenting

[xiyuan, 2016/12/06 00:46:33]

Code removed.

+      AccountId account_id(EmptyAccountId());
+      if (!AccountId::Deserialize(user_session->account_id, &account_id)) {
+        LOG(ERROR) << "Failed to deserialize account id.";
+        continue;
+      }
+      for (auto& observer : observers_)
+        observer.UserAddedToSession(account_id);
+    }
+  }

[James Cook, 2016/12/01 23:01:43]

nit: this function could use some comments explaining what each block is doing

[xiyuan, 2016/12/06 00:46:33]

Acknowledged.

+
+  const std::string new_active_user =
+      user_sessions_.empty() ? std::string() : user_sessions_[0]->account_id;
+  if (new_active_user != old_active_user) {
+    AccountId account_id(EmptyAccountId());
+    if (AccountId::Deserialize(new_active_user, &account_id)) {
+      for (auto& observer : observers_)
+        observer.ActiveUserChanged(account_id);
+    }
+  }
+}

[James Cook, 2016/12/01 23:01:43]

Can you add a simple unit test for this class? Just enough to illustrate that
you can instantiate it by itself, and maybe exercise the SetUserSessions
function?

[xiyuan, 2016/12/06 00:46:33]

Done.

+
+}  // namespace ash