Example of usage of new features of context and screen.

chrome/browser/chromeos/login/screens/controller_pairing_screen.cc

+// Copyright 2014 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/chromeos/login/screens/controller_pairing_screen.h"
+
+#include "base/values.h"
+#include "base/strings/string_util.h"
+#include "chrome/browser/chromeos/login/auth/user_context.h"
+#include "chrome/browser/chromeos/login/wizard_controller.h"
+#include "chromeos/pairing/fake_controller_pairing_flow.h"
+
+namespace chromeos {
+
+ControllerPairingScreen::ControllerPairingScreen(
+    ScreenObserver* observer,
+    ControllerPairingScreenActor* actor)
+    : WizardScreen(observer),
+      actor_(actor),
+      flow_(new FakeControllerPairingFlow()),
+      current_stage_(ControllerPairingFlow::STAGE_NONE),
+      device_preselected_(false) {
+  actor_->SetDelegate(this);
+  flow_->AddObserver(this);
+}
+
+ControllerPairingScreen::~ControllerPairingScreen() {
+  if (actor_)
+    actor_->SetDelegate(NULL);
+  flow_->RemoveObserver(this);
+}
+
+void ControllerPairingScreen::CommitContextChanges() {
+  base::DictionaryValue diff;
+  context_.GetChangesAndReset(&diff);
+  if (actor_)
+    actor_->OnContextChanged(diff);
+}
+
+bool ControllerPairingScreen::ExpectStageIs(Stage stage) const {
+  DCHECK(stage == current_stage_);
+  if (current_stage_ != stage)
+    LOG(ERROR) << "Incorrect stage. Expected: " << stage
+               << ", current stage: " << current_stage_;
+  return stage == current_stage_;
+}
+
+void ControllerPairingScreen::PrepareToShow() {
+}
+
+void ControllerPairingScreen::Show() {
+  if (actor_)
+    actor_->Show();
+  flow_->StartFlow();
+}
+
+void ControllerPairingScreen::Hide() {
+  if (actor_)
+    actor_->Hide();
+}
+
+std::string ControllerPairingScreen::GetName() const {
+  return WizardController::kControllerPairingScreenName;
+}
+
+// Overridden from ControllerPairingFlow::Observer:
+void ControllerPairingScreen::PairingStageChanged(Stage new_stage) {
+  using namespace chromeos::controller_pairing;
+  DCHECK(new_stage != current_stage_);
+
+  std::string desired_page;
+  switch (new_stage) {
+    case Stage::STAGE_DEVICES_DISCOVERY: {
+      desired_page = kPageDevicesDiscovery;
+      context_.SetString(kContextKeySelectedDevice, "");
+      device_preselected_ = false;
+      break;
+    }
+    case Stage::STAGE_DEVICE_NOT_FOUND: {
+      desired_page = kPageDeviceNotFound;
+      break;
+    }
+    case Stage::STAGE_ESTABLISHING_CONNECTION: {
+      desired_page = kPageEstablishingConnection;
+      break;
+    }
+    case Stage::STAGE_ESTABLISHING_CONNECTION_ERROR: {
+      desired_page = kPageEstablishingConnectionError;
+      break;
+    }
+    case Stage::STAGE_WAITING_FOR_CODE_CONFIRMATION: {
+      desired_page = kPageCodeConfirmation;
+      context_.SetString(kContextKeyConfirmationCode,
+                         flow_->GetConfirmationCode());
+      break;
+    }
+    case Stage::STAGE_HOST_UPDATE_IN_PROGRESS: {
+      desired_page = kPageHostUpdate;
+      break;
+    }
+    case Stage::STAGE_HOST_CONNECTION_LOST: {
+      desired_page = kPageHostConnectionLost;
+      break;
+    }
+    case Stage::STAGE_WAITING_FOR_CREDENTIALS: {
+      desired_page = kPageEnrlollmentIntroduction;
+      break;
+    }
+    case Stage::STAGE_HOST_ENROLLMENT_IN_PROGRESS: {
+      desired_page = kPageHostEnrollment;
+      break;
+    }
+    case Stage::STAGE_HOST_ENROLLMENT_ERROR: {
+      desired_page = kPageHostEnrollmentError;
+      break;
+    }
+    case Stage::STAGE_PAIRING_DONE: {
+      desired_page = kPagePairingDone;
+      break;
+    }
+    case Stage::STAGE_STARTING_SESSION: {
+      // TODO(dzhioev): Is it needed?
+      break;
+    }
+    case Stage::STAGE_FINISHED: {
+      get_screen_observer()->OnExit(
+          WizardController::CONTROLLER_PAIRING_FINISHED);
+      break;
+    }
+    default:
+      NOTREACHED();
+  }
+  current_stage_ = new_stage;
+  context_.SetString(controller_pairing::kContextKeyPage, desired_page);
+  context_.SetBoolean(controller_pairing::kContextKeyControlsDisabled, false);
+  CommitContextChanges();
+}
+
+void ControllerPairingScreen::DiscoveredDevicesListChanged() {
+  if (!ExpectStageIs(Stage::STAGE_DEVICES_DISCOVERY))
+    return;
+  ControllerPairingFlow::DeviceIdList devices = flow_->GetDiscoveredDevices();
+  std::sort(devices.begin(), devices.end());
+  std::string list = JoinString(devices, '\0');
+  context_.SetString(controller_pairing::kContextKeyDevices, list);
+  context_.SetString(controller_pairing::kContextKeyPage,
+                     devices.empty() ? controller_pairing::kPageDevicesDiscovery
+                                     : controller_pairing::kPageDeviceSelect);
+  if (devices.empty()) {
+    device_preselected_ = false;
+  } else if (!device_preselected_) {
+    context_.SetString(controller_pairing::kContextKeySelectedDevice,
+                       devices.front());
+    device_preselected_ = true;
+  }
+  CommitContextChanges();
+}
+
+void ControllerPairingScreen::OnActorDestroyed(
+    ControllerPairingScreenActor* actor) {
+  if (actor_ == actor)
+    actor_ = NULL;
+}
+
+// Overridden from ControllerPairingView::Delegate:
+void ControllerPairingScreen::OnButtonClicked(const std::string& action) {
+  using namespace controller_pairing;
+
+  bool disable_controls = true;
+  if (action == kActionChooseDevice) {
+    flow_->ChooseDeviceForPairing(
+        context_.GetString(kContextKeySelectedDevice));
+  } else if (action == kActionRepeatDiscovery) {
+    flow_->RepeatDiscovery();
+  } else if (action == kActionAcceptCode) {
+    flow_->SetConfirmationCodeIsCorrect(true);
+  } else if (action == kActionRejectCode) {
+    flow_->SetConfirmationCodeIsCorrect(false);
+  } else if (action == kActionProceedToAuthentication) {
+    context_.SetString(kContextKeyPage, kPageAuthentication);
+    disable_controls = false;
+  } else if (action == kActionEnroll) {
+    UserContext user_context(context_.GetString(kContextKeyAccountId));
+    flow_->OnAuthenticationDone(user_context, actor_->GetBrowserContext());
+  } else if (action == kActionStartSession) {
+    flow_->StartSession();
+  }
+  context_.SetBoolean(kContextKeyControlsDisabled, disable_controls);
+  CommitContextChanges();
+}
+
+void ControllerPairingScreen::OnScreenContextChanged(
+    const base::DictionaryValue& diff) {
+  context_.ApplyChanges(diff, NULL);
+}
+
+}  // namespace chromeos