Introduce ash mojo interface for lock screen action handlers

ash/tray_action_handler/tray_action_handler_controller.cc

+// Copyright 2017 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/tray_action_handler/tray_action_handler_controller.h"
+
+#include <utility>
+
+#include "ash/tray_action_handler/tray_action_handler_observer.h"
+#include "base/logging.h"
+
+namespace ash {
+
+TrayActionHandlerController::TrayActionHandlerController() {}

[James Cook, 2017/05/03 23:31:51]

optional: = default

[tbarzic, 2017/05/04 20:58:30]

Done.

+
+TrayActionHandlerController::~TrayActionHandlerController() {}
+
+void TrayActionHandlerController::AddObserver(
+    TrayActionHandlerObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void TrayActionHandlerController::RemoveObserver(
+    TrayActionHandlerObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void TrayActionHandlerController::BindRequest(
+    mojom::TrayActionHandlerControllerRequest request) {
+  bindings_.AddBinding(this, std::move(request));
+}
+
+mojom::TrayActionHandlerState TrayActionHandlerController::GetState(
+    mojom::TrayActionHandlerAction action) {
+  DCHECK_EQ(mojom::TrayActionHandlerAction::kNewLockScreenNote, action);
+
+  if (!action_handler_client_)
+    return mojom::TrayActionHandlerState::kNotSupported;
+  return new_note_state_;
+}
+
+void TrayActionHandlerController::SetClient(
+    mojom::TrayActionHandlerClientPtr action_handler_client) {
+  mojom::TrayActionHandlerState old_effective_new_note_state =

[James Cook, 2017/05/03 23:31:50]

What does "effective" mean here? Isn't this just "old_state"?

[tbarzic, 2017/05/04 20:58:30]

yeah, pretty much

+      GetState(mojom::TrayActionHandlerAction::kNewLockScreenNote);
+
+  action_handler_client_ = std::move(action_handler_client);
+
+  // Setting action handler value can change effective state - notify observers
+  // if that was the case.
+  if (GetState(mojom::TrayActionHandlerAction::kNewLockScreenNote) !=
+      old_effective_new_note_state) {
+    NotifyActionStateChanged(
+        mojom::TrayActionHandlerAction::kNewLockScreenNote);
+  }
+}
+
+void TrayActionHandlerController::UpdateActionHandlerState(
+    mojom::TrayActionHandlerAction action,
+    mojom::TrayActionHandlerState state) {
+  if (action != mojom::TrayActionHandlerAction::kNewLockScreenNote) {
+    LOG(ERROR) << "Unexpected action " << action;
+    return;
+  }
+
+  if (state == new_note_state_)
+    return;
+
+  new_note_state_ = state;
+
+  if (action_handler_client_)
+    NotifyActionStateChanged(action);
+}
+
+void TrayActionHandlerController::RequestHandleAction(
+    mojom::TrayActionHandlerAction action) {
+  if (!action_handler_client_)
+    return;
+
+  action_handler_client_->RequestHandleAction(action);
+}
+
+void TrayActionHandlerController::NotifyActionStateChanged(
+    mojom::TrayActionHandlerAction action) {
+  for (auto& observer : observers_)
+    observer.OnActionStateChanged(action, GetState(action));
+}
+
+}  // namespace ash