Extract colors from wallpaper and dynamically update login screen overlay

chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc

 // Copyright (c) 2013 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 "chrome/browser/ui/webui/chromeos/login/signin_screen_handler.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/public/interfaces/constants.mojom.h"
 #include "ash/public/interfaces/tray_action.mojom.h"
+#include "ash/shelf/shelf_constants.h"
 #include "ash/shell.h"
 #include "ash/system/devicetype_utils.h"
 #include "ash/wm/lock_state_controller.h"
 #include "base/bind.h"
 #include "base/i18n/number_formatting.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 20 matching lines @@
 #include "chrome/browser/chromeos/login/quick_unlock/quick_unlock_storage.h"
 #include "chrome/browser/chromeos/login/reauth_stats.h"
 #include "chrome/browser/chromeos/login/screens/core_oobe_view.h"
 #include "chrome/browser/chromeos/login/screens/network_error.h"
 #include "chrome/browser/chromeos/login/startup_utils.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host.h"
 #include "chrome/browser/chromeos/login/ui/login_display_host_impl.h"
 #include "chrome/browser/chromeos/login/ui/login_feedback.h"
 #include "chrome/browser/chromeos/login/ui/webui_login_display.h"
 #include "chrome/browser/chromeos/login/users/multi_profile_user_controller.h"
-#include "chrome/browser/chromeos/login/users/wallpaper/wallpaper_manager.h"
 #include "chrome/browser/chromeos/login/wizard_controller.h"
 #include "chrome/browser/chromeos/policy/browser_policy_connector_chromeos.h"
 #include "chrome/browser/chromeos/policy/device_local_account.h"
 #include "chrome/browser/chromeos/profiles/profile_helper.h"
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #include "chrome/browser/chromeos/system/system_clock.h"
 #include "chrome/browser/io_thread.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_metrics.h"
 #include "chrome/browser/signin/easy_unlock_service.h"
@@ skipping 29 matching lines @@
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/service_manager_connection.h"
 #include "google_apis/gaia/gaia_auth_util.h"
 #include "services/service_manager/public/cpp/connector.h"
 #include "third_party/cros_system_api/dbus/service_constants.h"
 #include "ui/base/ime/chromeos/ime_keyboard.h"
 #include "ui/base/ime/chromeos/input_method_descriptor.h"
 #include "ui/base/ime/chromeos/input_method_manager.h"
 #include "ui/base/ime/chromeos/input_method_util.h"
 #include "ui/base/webui/web_ui_util.h"
+#include "ui/gfx/color_utils.h"
 
 namespace {
 
 // Max number of users to show.
 const size_t kMaxUsers = 18;
 
 // Timeout to delay first notification about offline state for a
 // current network.
 const int kOfflineTimeoutSec = 5;
 
@@ skipping 231 matching lines @@
   content::ServiceManagerConnection::GetForProcess()
       ->GetConnector()
       ->BindInterface(ash::mojom::kServiceName, &touch_view_manager_ptr_);
   ash::mojom::TouchViewObserverPtr observer;
   touch_view_binding_.Bind(mojo::MakeRequest(&observer));
   touch_view_manager_ptr_->AddObserver(std::move(observer));
   if (ScreenLocker::default_screen_locker() &&
       lock_screen_apps::StateController::IsEnabled()) {
     lock_screen_apps_observer_.Add(lock_screen_apps::StateController::Get());
   }
+  WallpaperManager::Get()->AddObserver(this);
 }
 
 SigninScreenHandler::~SigninScreenHandler() {
   OobeUI* oobe_ui = GetOobeUI();
   if (oobe_ui && oobe_ui_observer_added_)
     oobe_ui->RemoveObserver(this);
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(
       this);
   chromeos::input_method::ImeKeyboard* keyboard =
       chromeos::input_method::InputMethodManager::Get()->GetImeKeyboard();
   if (keyboard)
     keyboard->RemoveObserver(this);
   StopEnforcingPolicyInputMethods();
   weak_factory_.InvalidateWeakPtrs();
   if (delegate_)
     delegate_->SetWebUIHandler(nullptr);
   network_state_informer_->RemoveObserver(this);
   proximity_auth::ScreenlockBridge::Get()->SetLockHandler(nullptr);
   proximity_auth::ScreenlockBridge::Get()->SetFocusedUser(EmptyAccountId());
+  WallpaperManager::Get()->RemoveObserver(this);
 }
 
 // static
 std::string SigninScreenHandler::GetUserLastInputMethod(
     const std::string& username) {
   PrefService* const local_state = g_browser_process->local_state();
   const base::DictionaryValue* users_last_input_methods =
       local_state->GetDictionary(prefs::kUsersLastInputMethod);
 
   if (!users_last_input_methods) {
@@ skipping 586 matching lines @@
 
   // Forces a reload for Gaia screen on hiding error message.
   if (IsGaiaVisible() || IsGaiaHiddenByError())
     ReloadGaia(reason == NetworkError::ERROR_REASON_NETWORK_STATE_CHANGED);
 }
 
 void SigninScreenHandler::ReloadGaia(bool force_reload) {
   gaia_screen_handler_->ReloadGaia(force_reload);
 }
 
+void SigninScreenHandler::SetSigninScreenColors(const SkColor& dm_color) {

[jdufault, 2017/06/12 21:37:28]

Just pass a SkColor dm_color parameter and mutate it. FYI, SkColor is an int so
no performance penalty.

[Wenzhao (Colin) Zang, 2017/06/12 23:40:35]

Done. Originally I wanted to prevent mistakenly changing this value but it seems
not necessary.

+  // The dark muted color should have 100% opacity.
+  SkColor dm_sk_color = dm_color;

[jdufault, 2017/06/12 21:37:29]

avoid non-obvious acronyms (dm). It makes the code harder to quickly parse/read.

[Wenzhao (Colin) Zang, 2017/06/12 23:40:34]

Done.

+  dm_sk_color = SkColorSetA(dm_sk_color, 0xFF);

[jdufault, 2017/06/12 21:37:29]

FYI: naming here is confusing; what is the difference between dm_sk_color and
dm_color? This should get cleaned up by mutating param directly.

[Wenzhao (Colin) Zang, 2017/06/12 23:40:35]

Done.

+  SkColor base_sk_color = color_utils::GetResultingPaintColor(
+      SkColorSetA(ash::kShelfDefaultBaseColor,
+                  ash::kShelfTranslucentColorDarkenAlpha),
+      dm_sk_color);
+  SkColor background_sk_color =

[jdufault, 2017/06/12 21:37:29]

background_sk_color -> background_color

[Wenzhao (Colin) Zang, 2017/06/12 23:40:34]

Done.

+      SkColorSetA(base_sk_color, ash::kShelfTranslucentAlpha);
+  // The alpha value for the signin screen background. This constant will be
+  // moved to a separate file when views-based signin screen is being

[jdufault, 2017/06/12 21:37:29]

Add TODO and file a bug.

[Wenzhao (Colin) Zang, 2017/06/12 23:40:34]

Done.

+  // developed.
+  constexpr int kLoginTranslucentAlpha = 76;

[jdufault, 2017/06/12 21:37:29]

move to anonymous namespace

[Wenzhao (Colin) Zang, 2017/06/12 23:40:34]

Done.

+  SkColor scroll_sk_color = SkColorSetA(base_sk_color, kLoginTranslucentAlpha);

[jdufault, 2017/06/12 21:37:29]

scroll_sk_color -> scroll_color

[Wenzhao (Colin) Zang, 2017/06/12 23:40:35]

Done.

+  // Transform SkColor values to rgba strings.

[jdufault, 2017/06/12 21:37:28]

Remove comment, it is immediately obvious.

[Wenzhao (Colin) Zang, 2017/06/12 23:40:34]

Done.

+  CallJS("login.AccountPickerScreen.setOverlayColors",
+         color_utils::SkColorToRgbaString(dm_sk_color),
+         color_utils::SkColorToRgbaString(scroll_sk_color),
+         color_utils::SkColorToRgbaString(background_sk_color));
+}
+
 void SigninScreenHandler::Initialize() {
   // Preload PIN keyboard if any of the users can authenticate via PIN.
   if (user_manager::UserManager::IsInitialized()) {
     for (user_manager::User* user :
          user_manager::UserManager::Get()->GetUnlockUsers()) {
       chromeos::quick_unlock::QuickUnlockStorage* quick_unlock_storage =
           chromeos::quick_unlock::QuickUnlockFactory::GetForUser(user);
       if (quick_unlock_storage &&
           quick_unlock_storage->IsPinAuthenticationAvailable()) {
         CallJS("cr.ui.Oobe.preloadPinKeyboard");
@@ skipping 20 matching lines @@
 }
 
 void SigninScreenHandler::OnCurrentScreenChanged(OobeScreen current_screen,
                                                  OobeScreen new_screen) {
   if (new_screen == OobeScreen::SCREEN_ACCOUNT_PICKER) {
     // Restore active IME state if returning to user pod row screen.
     input_method::InputMethodManager::Get()->SetState(ime_state_);
   }
 }
 
+void SigninScreenHandler::OnColorCalculationComplete() {
+  SkColor dm_color = WallpaperManager::Get()->prominent_color();
+  SetSigninScreenColors(dm_color);
+}
+
+void SigninScreenHandler::OnWallpaperAnimationFinished(
+    const AccountId& account_id) {}
+
 void SigninScreenHandler::ClearAndEnablePassword() {
   core_oobe_view_->ResetSignInUI(false);
 }
 
 void SigninScreenHandler::ClearUserPodPassword() {
   core_oobe_view_->ClearUserPodPassword();
 }
 
 void SigninScreenHandler::RefocusCurrentPod() {
   core_oobe_view_->RefocusCurrentPod();
@@ skipping 677 matching lines @@
   rate.initial_delay_in_ms = auto_repeat_delay;
   rate.repeat_interval_in_ms = auto_repeat_interval;
   input_method::InputMethodManager::Get()
       ->GetImeKeyboard()
       ->SetAutoRepeatEnabled(true);
   input_method::InputMethodManager::Get()->GetImeKeyboard()->SetAutoRepeatRate(
       rate);
 }
 
 }  // namespace chromeos