[ash] Switch the theme on the login screen based on the focused pod

Also switch the theme to light when the OOBE WebUI is shown

Bug: 1143060
Change-Id: If4e981e8b8ef65b80ee886300536c0f7f7d75534
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3565367
Reviewed-by: Min Chen <minch@chromium.org>
Reviewed-by: Toni Barzic <tbarzic@chromium.org>
Commit-Queue: Roman Sorokin <rsorokin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#988877}

ash/login/login_screen_controller.cc

@@ -30,6 +30,7 @@
 #include "base/debug/alias.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "components/account_id/account_id.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/session_manager/session_manager_types.h"
 
@@ -182,18 +183,21 @@ bool LoginScreenController::GetSecurityTokenPinRequestCanceled() const {
 }
 
 void LoginScreenController::HardlockPod(const AccountId& account_id) {
+  GetModel()->NotifyFocusPod(account_id);
   if (!client_)
     return;
   client_->HardlockPod(account_id);
 }
 
 void LoginScreenController::OnFocusPod(const AccountId& account_id) {
+  GetModel()->NotifyFocusPod(account_id);
   if (!client_)
     return;
   client_->OnFocusPod(account_id);
 }
 
 void LoginScreenController::OnNoPodFocused() {
+  GetModel()->NotifyFocusPod(EmptyAccountId());
   if (!client_)
     return;
   client_->OnNoPodFocused();

ash/login/login_screen_controller_unittest.cc

@@ -21,14 +21,21 @@
 #include "base/test/bind.h"
 #include "components/prefs/pref_service.h"
 #include "components/session_manager/session_manager_types.h"
+#include "components/user_manager/known_user.h"
 
 using session_manager::SessionState;
 using ::testing::_;
 
 namespace ash {
 
 namespace {
-using LoginScreenControllerTest = AshTestBase;
+class LoginScreenControllerTest : public AshTestBase {
+ public:
+  LoginScreenControllerTest() {
+    user_manager::KnownUser::RegisterPrefs(local_state()->registry());
+  }
+};
+
 using LoginScreenControllerNoSessionTest = NoSessionAshTestBase;
 
 // Enum instead of enum class, because it is used for indexing.

ash/login/ui/login_data_dispatcher.cc

@@ -5,6 +5,8 @@
 #include "ash/login/ui/login_data_dispatcher.h"
 #include "ash/constants/ash_features.h"
 
+class AccountId;
+
 namespace ash {
 
 LoginDataDispatcher::Observer::~Observer() = default;
@@ -105,6 +107,8 @@ void LoginDataDispatcher::Observer::OnFocusLeavingLockScreenApps(bool reverse) {
 void LoginDataDispatcher::Observer::OnOobeDialogStateChanged(
     OobeDialogState state) {}
 
+void LoginDataDispatcher::Observer::OnFocusPod(const AccountId& account_id) {}
+
 LoginDataDispatcher::LoginDataDispatcher() = default;
 
 LoginDataDispatcher::~LoginDataDispatcher() = default;
@@ -284,4 +288,9 @@ void LoginDataDispatcher::NotifyOobeDialogState(OobeDialogState state) {
     observer.OnOobeDialogStateChanged(state);
 }
 
+void LoginDataDispatcher::NotifyFocusPod(const AccountId& account_id) {
+  for (auto& observer : observers_)
+    observer.OnFocusPod(account_id);
+}
+
 }  // namespace ash

ash/login/ui/login_data_dispatcher.h

@@ -16,6 +16,8 @@
 #include "base/observer_list.h"
 #include "base/time/time.h"
 
+class AccountId;
+
 namespace ash {
 
 // Provides access to data needed by the lock/login screen. The login UI will
@@ -155,6 +157,11 @@ class ASH_EXPORT LoginDataDispatcher : public LoginScreenModel {
 
     // Called when the state of the OOBE dialog is changed.
     virtual void OnOobeDialogStateChanged(OobeDialogState state);
+
+    // Called when the focused pod is changed on the login screen with the
+    // corresponding `account_id`. In case all the pods lost focus the
+    // `EmptyAccountId` passed as the argument.
+    virtual void OnFocusPod(const AccountId& account_id);
   };
 
   LoginDataDispatcher();
@@ -223,6 +230,7 @@ class ASH_EXPORT LoginDataDispatcher : public LoginScreenModel {
       DetachableBasePairingStatus pairing_status);
   void HandleFocusLeavingLockScreenApps(bool reverse) override;
   void NotifyOobeDialogState(OobeDialogState state) override;
+  void NotifyFocusPod(const AccountId& account_id) override;
 
  private:
   base::ObserverList<Observer>::Unchecked observers_;

ash/public/cpp/login_screen_model.h

@@ -156,6 +156,8 @@ class ASH_PUBLIC_EXPORT LoginScreenModel {
   // as add user or powerwash.
   virtual void NotifyOobeDialogState(OobeDialogState state) = 0;
 
+  virtual void NotifyFocusPod(const AccountId& account_id) = 0;
+
  protected:
   virtual ~LoginScreenModel();
 };

ash/style/ash_color_provider.cc

@@ -9,18 +9,25 @@
 #include "ash/constants/ash_constants.h"
 #include "ash/constants/ash_features.h"
 #include "ash/constants/ash_pref_names.h"
+#include "ash/login/login_screen_controller.h"
+#include "ash/login_status.h"
+#include "ash/public/cpp/login_types.h"
 #include "ash/public/cpp/style/color_mode_observer.h"
 #include "ash/session/session_controller_impl.h"
 #include "ash/shell.h"
 #include "ash/wallpaper/wallpaper_controller_impl.h"
 #include "base/bind.h"
+#include "base/callback_helpers.h"
 #include "base/check_op.h"
 #include "base/feature_list.h"
 #include "base/metrics/histogram_functions.h"
 #include "base/strings/string_number_conversions.h"
+#include "components/account_id/account_id.h"
 #include "components/prefs/pref_change_registrar.h"
 #include "components/prefs/pref_registry_simple.h"
 #include "components/prefs/pref_service.h"
+#include "components/session_manager/session_manager_types.h"
+#include "components/user_manager/known_user.h"
 #include "ui/chromeos/styles/cros_styles.h"
 #include "ui/gfx/color_analysis.h"
 #include "ui/gfx/color_utils.h"
@@ -115,8 +122,11 @@ AshColorProvider::AshColorProvider() {
   g_instance = this;
 
   // May be null in unit tests.
-  if (Shell::HasInstance())
+  if (Shell::HasInstance()) {
     Shell::Get()->session_controller()->AddObserver(this);
+    Shell::Get()->login_screen_controller()->data_dispatcher()->AddObserver(
+        this);
+  }
 
   cros_styles::SetDebugColorsEnabled(base::FeatureList::IsEnabled(
       ash::features::kSemanticColorsDebugOverride));
@@ -127,8 +137,16 @@ AshColorProvider::~AshColorProvider() {
   g_instance = nullptr;
 
   // May be null in unit tests.
-  if (Shell::HasInstance())
+  if (Shell::HasInstance()) {
     Shell::Get()->session_controller()->RemoveObserver(this);
+    if (Shell::Get()->login_screen_controller() &&
+        Shell::Get()->login_screen_controller()->data_dispatcher()) {
+      Shell::Get()
+          ->login_screen_controller()
+          ->data_dispatcher()
+          ->RemoveObserver(this);
+    }
+  }
 
   cros_styles::SetDebugColorsEnabled(false);
   cros_styles::SetDarkModeEnabled(false);
@@ -272,12 +290,19 @@ bool AshColorProvider::IsDarkModeEnabled() const {
   if (!features::IsDarkLightModeEnabled() && override_light_mode_as_default_)
     return false;
 
-  // Keep colors in OOBE as LIGHT when D/L is enabled. When the feature is
-  // disabled, lots of colors are hard coded in OOBE for now.
-  if (features::IsDarkLightModeEnabled() &&
-      Shell::Get()->session_controller()->GetSessionState() ==
-          session_manager::SessionState::OOBE) {
-    return false;
+  if (features::IsDarkLightModeEnabled()) {
+    // Always use the LIGHT theme when OOBE WebUI is show (either as out-of-box
+    // or the WebUI dialog on the login screen). Lots of colors are hard coded
+    // in OOBE WebUI for now.
+    if (is_oobe_webui_shown_)
+      return false;
+
+    // On the login screen use the preference of the focused pod's user if they
+    // had the preference stored in the known_user and the pod is focused.
+    if (!active_user_pref_service_ &&
+        is_dark_mode_enabled_for_focused_pod_.has_value()) {
+      return is_dark_mode_enabled_for_focused_pod_.value();
+    }
   }
 
   // Keep the color mode as DARK in login screen or when dark/light mode feature
@@ -294,6 +319,23 @@ void AshColorProvider::SetDarkModeEnabledForTest(bool enabled) {
   }
 }
 
+void AshColorProvider::OnOobeDialogStateChanged(OobeDialogState state) {
+  auto closure = GetNotifyOnDarkModeChangeClosure();
+  is_oobe_webui_shown_ = state != OobeDialogState::HIDDEN;
+}
+
+void AshColorProvider::OnFocusPod(const AccountId& account_id) {
+  auto closure = GetNotifyOnDarkModeChangeClosure();
+
+  if (!account_id.is_valid()) {
+    is_dark_mode_enabled_for_focused_pod_.reset();
+    return;
+  }
+  is_dark_mode_enabled_for_focused_pod_ =
+      user_manager::KnownUser(ash::Shell::Get()->local_state())
+          .FindBoolPath(account_id, prefs::kDarkModeEnabled);
+}
+
 bool AshColorProvider::IsThemed() const {
   if (!active_user_pref_service_)
     return kDefaultColorModeThemed;
@@ -501,4 +543,19 @@ void AshColorProvider::NotifyColorModeThemedPrefChange() {
   NotifyColorModeAndThemeChanges(IsDarkModeEnabled());
 }
 
+base::ScopedClosureRunner AshColorProvider::GetNotifyOnDarkModeChangeClosure() {
+  return base::ScopedClosureRunner(
+      // Unretained is safe here because GetNotifyOnDarkModeChangeClosure is a
+      // private function and callback should be called on going out of scope of
+      // the calling method.
+      base::BindOnce(&AshColorProvider::NotifyIfDarkModeChanged,
+                     base::Unretained(this), IsDarkModeEnabled()));
+}
+
+void AshColorProvider::NotifyIfDarkModeChanged(bool old_is_dark_mode_enabled) {
+  if (old_is_dark_mode_enabled == IsDarkModeEnabled())
+    return;
+  NotifyDarkModeEnabledPrefChange();
+}
+
 }  // namespace ash

ash/style/ash_color_provider.h

@@ -6,12 +6,15 @@
 #define ASH_STYLE_ASH_COLOR_PROVIDER_H_
 
 #include "ash/ash_export.h"
+#include "ash/login/ui/login_data_dispatcher.h"
 #include "ash/public/cpp/session/session_observer.h"
 #include "ash/public/cpp/style/color_provider.h"
+#include "base/callback_helpers.h"
 #include "base/observer_list.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/color_palette.h"
 
+class AccountId;
 class PrefChangeRegistrar;
 class PrefRegistrySimple;
 class PrefService;
@@ -30,7 +33,8 @@ class ColorModeObserver;
 // the UI elements, e.g., separator, text, icon. The color of an element in
 // system UI will be the combination of the colors of the four layers.
 class ASH_EXPORT AshColorProvider : public SessionObserver,
-                                    public ColorProvider {
+                                    public ColorProvider,
+                                    public LoginDataDispatcher::Observer {
  public:
   AshColorProvider();
   AshColorProvider(const AshColorProvider& other) = delete;
@@ -68,6 +72,10 @@ class ASH_EXPORT AshColorProvider : public SessionObserver,
   bool IsDarkModeEnabled() const override;
   void SetDarkModeEnabledForTest(bool enabled) override;
 
+  // LoginDataDispatcher::Observer:
+  void OnOobeDialogStateChanged(OobeDialogState state) override;
+  void OnFocusPod(const AccountId& account_id) override;
+
   // Gets the color of |type| of the corresponding layer based on the current
   // inverted color mode. For views that need LIGHT colors while DARK mode is
   // active, and vice versa.
@@ -134,6 +142,11 @@ class ASH_EXPORT AshColorProvider : public SessionObserver,
   // Notifies all the observers on |kColorModeThemed|'s change.
   void NotifyColorModeThemedPrefChange();
 
+  // Returns a closure which calls `NotifyIfDarkModeChanged` if the dark mode
+  // changed between creation and getting out of scope.
+  base::ScopedClosureRunner GetNotifyOnDarkModeChangeClosure();
+  void NotifyIfDarkModeChanged(bool old_is_dark_mode_enabled);
+
   // The default color is DARK when the DarkLightMode feature is disabled. But
   // we can also override it to LIGHT through ScopedLightModeAsDefault. This is
   // done to help keeping some of the UI elements as LIGHT by default before
@@ -142,6 +155,12 @@ class ASH_EXPORT AshColorProvider : public SessionObserver,
   // DarkLightMode feature.
   bool override_light_mode_as_default_ = false;
 
+  // True if we're in the OOBE state or OOBE WebUI dialog is open (e.g. for the
+  // "Add person" flow).
+  bool is_oobe_webui_shown_ = false;
+  // absl::nullopt in case no user pod is focused.
+  absl::optional<bool> is_dark_mode_enabled_for_focused_pod_;
+
   base::ObserverList<ColorModeObserver> observers_;
   std::unique_ptr<PrefChangeRegistrar> pref_change_registrar_;
   PrefService* active_user_pref_service_ = nullptr;  // Not owned.

ash/style/ash_color_provider_unittests.cc

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "ash/login/ui/login_test_base.h"
+#include "ash/public/cpp/login_types.h"
 #include "ash/style/ash_color_provider.h"
 
 #include "ash/session/test_session_controller_client.h"
@@ -11,7 +13,7 @@
 
 namespace ash {
 
-using AshColorProviderTest = AshTestBase;
+using AshColorProviderTest = LoginTestBase;
 
 // Tests the color mode in non-active user sessions.
 TEST_F(AshColorProviderTest, ColorModeInNonActiveUserSessions) {
@@ -24,7 +26,16 @@ TEST_F(AshColorProviderTest, ColorModeInNonActiveUserSessions) {
   enable_dark_light.InitAndEnableFeature(chromeos::features::kDarkLightMode);
   client->SetSessionState(session_manager::SessionState::UNKNOWN);
   EXPECT_TRUE(color_provider->IsDarkModeEnabled());
+
   client->SetSessionState(session_manager::SessionState::OOBE);
+  DataDispatcher()->NotifyOobeDialogState(OobeDialogState::USER_CREATION);
+  EXPECT_FALSE(color_provider->IsDarkModeEnabled());
+
+  client->SetSessionState(session_manager::SessionState::LOGIN_PRIMARY);
+  DataDispatcher()->NotifyOobeDialogState(OobeDialogState::HIDDEN);
+  EXPECT_TRUE(color_provider->IsDarkModeEnabled());
+
+  DataDispatcher()->NotifyOobeDialogState(OobeDialogState::GAIA_SIGNIN);
   EXPECT_FALSE(color_provider->IsDarkModeEnabled());
 
   // When dark/light mode is disabled. Color mode in non-active user sessions
@@ -34,6 +45,7 @@ TEST_F(AshColorProviderTest, ColorModeInNonActiveUserSessions) {
   client->SetSessionState(session_manager::SessionState::UNKNOWN);
   EXPECT_TRUE(color_provider->IsDarkModeEnabled());
   client->SetSessionState(session_manager::SessionState::OOBE);
+  DataDispatcher()->NotifyOobeDialogState(OobeDialogState::USER_CREATION);
   EXPECT_TRUE(color_provider->IsDarkModeEnabled());
 }