Implement a policy to autologin a public account.

chrome/browser/chromeos/login/existing_user_controller.cc

Index: chrome/browser/chromeos/login/existing_user_controller.cc
diff --git a/chrome/browser/chromeos/login/existing_user_controller.cc b/chrome/browser/chromeos/login/existing_user_controller.cc
index 06f697ec7906a033097dec31addf20cbb4040189..82479f7aa14a12b447d37e30f65431bfe7774efd 100644
--- a/chrome/browser/chromeos/login/existing_user_controller.cc
+++ b/chrome/browser/chromeos/login/existing_user_controller.cc
@@ -6,6 +6,8 @@
 
 #include <vector>
 
+#include "ash/shell.h"
+#include "ash/wm/user_activity_detector.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
@@ -143,7 +145,8 @@ ExistingUserController::ExistingUserController(LoginDisplayHost* host)
       offline_failed_(false),
       is_login_in_progress_(false),
       password_changed_(false),
-      do_auto_enrollment_(false) {
+      do_auto_enrollment_(false),
+      signin_screen_ready_(false) {
   DCHECK(current_controller_ == NULL);
   current_controller_ = this;
 
@@ -163,11 +166,18 @@ ExistingUserController::ExistingUserController(LoginDisplayHost* host)
   cros_settings_->AddSettingsObserver(kAccountsPrefAllowNewUser, this);
   cros_settings_->AddSettingsObserver(kAccountsPrefAllowGuest, this);
   cros_settings_->AddSettingsObserver(kAccountsPrefUsers, this);
+  cros_settings_->AddSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginId,
+      this);
+  cros_settings_->AddSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginDelay,
+      this);
 }
 
 void ExistingUserController::Init(const UserList& users) {
   time_init_ = base::Time::Now();
   UpdateLoginDisplay(users);
+  ConfigurePublicSessionAutoLogin();
 
   LoginUtils::Get()->PrewarmAuthentication();
   DBusThreadManager::Get()->GetSessionManagerClient()->EmitLoginPromptReady();
@@ -228,6 +238,13 @@ void ExistingUserController::Observe(
     registrar_.RemoveAll();
     return;
   }
+  if (type == chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED) {
+    std::string setting = *content::Details<const std::string>(details).ptr();

[bartfab (slow), 2013/02/25 16:51:23]

Nit: I would make this a "const std::string"

[dconnelly, 2013/02/26 18:04:15]

Done.

+    if (setting == kAccountsPrefDeviceLocalAccountAutoLoginId ||
+        setting == kAccountsPrefDeviceLocalAccountAutoLoginDelay) {
+      ConfigurePublicSessionAutoLogin();
+    }
+  }
   if (type == chrome::NOTIFICATION_SYSTEM_SETTING_CHANGED ||
       type == chrome::NOTIFICATION_USER_LIST_CHANGED) {
     if (host_ != NULL) {
@@ -277,6 +294,15 @@ ExistingUserController::~ExistingUserController() {
   cros_settings_->RemoveSettingsObserver(kAccountsPrefAllowNewUser, this);
   cros_settings_->RemoveSettingsObserver(kAccountsPrefAllowGuest, this);
   cros_settings_->RemoveSettingsObserver(kAccountsPrefUsers, this);
+  cros_settings_->RemoveSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginId,
+      this);
+  cros_settings_->RemoveSettingsObserver(
+      kAccountsPrefDeviceLocalAccountAutoLoginDelay,
+      this);
+
+  if (ash::Shell::HasInstance())
+    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
 
   if (current_controller_ == this) {
     current_controller_ = NULL;
@@ -331,6 +357,9 @@ void ExistingUserController::CompleteLogin(const std::string& username,
     return;
   }
 
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable UI while loading user profile.
   login_display_->SetUIEnabled(false);
 
@@ -387,6 +416,10 @@ void ExistingUserController::Login(const std::string& username,
                                    const std::string& password) {
   if (username.empty() || password.empty())
     return;
+
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
 
@@ -434,6 +467,9 @@ void ExistingUserController::PerformLogin(
 }
 
 void ExistingUserController::LoginAsRetailModeUser() {
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
   // TODO(rkc): Add a CHECK to make sure retail mode logins are allowed once
@@ -449,6 +485,9 @@ void ExistingUserController::LoginAsRetailModeUser() {
 }
 
 void ExistingUserController::LoginAsGuest() {
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
 
@@ -462,11 +501,13 @@ void ExistingUserController::LoginAsGuest() {
                               HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
     // Reenable clicking on other windows and status area.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     display_email_.clear();
     return;
   } else if (status != CrosSettingsProvider::TRUSTED) {
     // Value of AllowNewUser setting is still not verified.
     // Another attempt will be invoked after verification completion.
+    StartPublicSessionAutoLoginTimer();

[bartfab (slow), 2013/02/25 16:51:23]

Notice that we end up here if the policy subsystem is not quite ready yet and we
need to wait for a callback before continuing with the login. In such a case,
the login attempt is still pending and the timer should not be restarted.

[dconnelly, 2013/02/26 18:04:15]

Done.

     return;
   }
 
@@ -480,6 +521,7 @@ void ExistingUserController::LoginAsGuest() {
                               HelpAppLauncher::HELP_CANT_ACCESS_ACCOUNT);
     // Reenable clicking on other windows and status area.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     display_email_.clear();
     return;
   }
@@ -501,6 +543,9 @@ void ExistingUserController::MigrateUserData(const std::string& old_password) {
 
 void ExistingUserController::LoginAsPublicAccount(
     const std::string& username) {
+  // Stop the auto-login timer when attempting login.
+  StopPublicSessionAutoLoginTimer();
+
   // Disable clicking on other windows.
   login_display_->SetUIEnabled(false);
 
@@ -521,8 +566,10 @@ void ExistingUserController::LoginAsPublicAccount(
 
   // If device policy is not verified yet, this function will be called again
   // when verification finishes.
-  if (status != CrosSettingsProvider::TRUSTED)
+  if (status != CrosSettingsProvider::TRUSTED) {
+    StartPublicSessionAutoLoginTimer();

[bartfab (slow), 2013/02/25 16:51:23]

Notice that we end up here if the policy subsystem is not quite ready yet and we
need to wait for a callback before continuing with the login. In such a case,
the login attempt is still pending and the timer should not be restarted.

[dconnelly, 2013/02/26 18:04:15]

Done.

     return;
+  }
 
   // If there is no public account with the given |username|, logging in is not
   // possible.
@@ -530,6 +577,7 @@ void ExistingUserController::LoginAsPublicAccount(
   if (!user || user->GetType() != User::USER_TYPE_PUBLIC_ACCOUNT) {
     // Re-enable clicking on other windows.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
     return;
   }
 
@@ -542,6 +590,11 @@ void ExistingUserController::LoginAsPublicAccount(
       l10n_util::GetStringUTF8(IDS_CHROMEOS_ACC_LOGIN_SIGNIN_PUBLIC_ACCOUNT));
 }
 
+void ExistingUserController::OnSigninScreenReady() {
+  signin_screen_ready_ = true;
+  StartPublicSessionAutoLoginTimer();
+}
+
 void ExistingUserController::OnUserSelected(const std::string& username) {
   login_performer_.reset(NULL);
   num_login_attempts_ = 0;
@@ -680,6 +733,7 @@ void ExistingUserController::OnLoginFailure(const LoginFailure& failure) {
     }
     // Reenable clicking on other windows and status area.
     login_display_->SetUIEnabled(true);
+    StartPublicSessionAutoLoginTimer();
   }
 
   // Reset user flow to default, so that special flow will not affect next
@@ -701,6 +755,8 @@ void ExistingUserController::OnLoginSuccess(
   is_login_in_progress_ = false;
   offline_failed_ = false;
 
+  StopPublicSessionAutoLoginTimer();
+
   bool has_cookies =
       login_performer_->auth_mode() == LoginPerformer::AUTH_MODE_EXTENSION;
 
@@ -825,6 +881,8 @@ void ExistingUserController::WhiteListCheckFailed(const std::string& email) {
   }
 
   display_email_.clear();
+
+  StartPublicSessionAutoLoginTimer();
 }
 
 void ExistingUserController::PolicyLoadFailed() {
@@ -834,6 +892,9 @@ void ExistingUserController::PolicyLoadFailed() {
   login_display_->SetUIEnabled(true);
 
   display_email_.clear();
+
+  // Policy load failure stops login attempts---restart the timer.

[bartfab (slow), 2013/02/25 16:51:23]

Nit: I am still bothered by these triple dashes and the lack of spaces around
them :).

[dconnelly, 2013/02/26 18:04:15]

Done.  But I'm going to make sure that every email I send you has three dashes
and no spaces around them.

+  StartPublicSessionAutoLoginTimer();
 }
 
 void ExistingUserController::OnOnlineChecked(const std::string& username,
@@ -858,6 +919,67 @@ void ExistingUserController::ActivateWizard(const std::string& screen_name) {
   host_->StartWizard(screen_name, params);
 }
 
+void ExistingUserController::ConfigurePublicSessionAutoLogin() {
+  if (!cros_settings_->GetString(
+          kAccountsPrefDeviceLocalAccountAutoLoginId,
+          &public_session_auto_login_username_) ||
+      public_session_auto_login_username_.empty()) {
+    public_session_auto_login_username_ = "";

[bartfab (slow), 2013/02/25 16:51:23]

You can simplify this to:

if (!cros_settings_->GetString(
        kAccountsPrefDeviceLocalAccountAutoLoginId,
        &public_session_auto_login_username_)) {
  public_session_auto_login_username_ = "";
}

[dconnelly, 2013/02/26 18:04:15]

Done.

+  }
+  if (!cros_settings_->GetInteger(
+          kAccountsPrefDeviceLocalAccountAutoLoginDelay,
+          &public_session_auto_login_delay_)) {
+    public_session_auto_login_delay_ = 0;
+  }
+
+  ash::UserActivityDetector* detector = ash::Shell::HasInstance()
+      ? ash::Shell::GetInstance()->user_activity_detector() : NULL;

[bartfab (slow), 2013/02/25 16:51:23]

I think it is allowed to put the |?| at the start of the line but it is very
uncommon. Better put it at the end of the previous line.

[dconnelly, 2013/02/26 18:04:15]

Done.

+  if (!public_session_auto_login_username_.empty()) {
+    StartPublicSessionAutoLoginTimer();
+    if (detector && !detector->HasObserver(this))
+      detector->AddObserver(this);
+  } else {
+    if (detector)
+      detector->RemoveObserver(this);
+    StopPublicSessionAutoLoginTimer();
+  }
+}
+
+void ExistingUserController::OnUserActivity() {
+  if (auto_login_timer_.IsRunning()) {

[bartfab (slow), 2013/02/25 16:51:23]

It is pretty obvious what this function is doing but I think that a comment
would still be useful here: Document the fact that this restarts the timer but
only if it is currently running.

[dconnelly, 2013/02/26 18:04:15]

Done.

+    StopPublicSessionAutoLoginTimer();
+    StartPublicSessionAutoLoginTimer();
+  }
+}
+
+void ExistingUserController::OnPublicSessionAutoLoginTimerFire() {
+  DCHECK(signin_screen_ready_ &&
+         !is_login_in_progress_ &&
+         !public_session_auto_login_username_.empty());
+  LoginAsPublicAccount(public_session_auto_login_username_);
+}
+
+void ExistingUserController::StopPublicSessionAutoLoginTimer() {
+  auto_login_timer_.Stop();
+}
+
+void ExistingUserController::StartPublicSessionAutoLoginTimer() {
+  if (!signin_screen_ready_ ||
+      public_session_auto_login_username_.empty() ||
+      is_login_in_progress_) {

[bartfab (slow), 2013/02/25 16:51:23]

Nit: The conditions in lines 956-958 and 967-969 are the exact logical inverses
of each other but they are arranged in different order. Could you arrange them
in the same order for consistency?

[dconnelly, 2013/02/26 18:04:15]

Done.

+    return;
+  }
+
+  // Start the auto-login timer.
+  auto_login_timer_.Start(
+      FROM_HERE,
+      base::TimeDelta::FromMilliseconds(
+          public_session_auto_login_delay_),
+      base::Bind(
+          &ExistingUserController::OnPublicSessionAutoLoginTimerFire,
+          weak_factory_.GetWeakPtr()));
+}
+
 gfx::NativeWindow ExistingUserController::GetNativeWindow() const {
   return host_->GetNativeWindow();
 }