Introduce AcccessibilityManager

chrome/browser/chromeos/accessibility/accessibility_manager.h

+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
+#define CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_
+
+#include "ash/shell_delegate.h"
+#include "base/prefs/pref_change_registrar.h"
+#include "chrome/browser/chromeos/accessibility/accessibility_util.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+
+class Profile;
+
+namespace content {
+class WebUI;
+}
+
+namespace chromeos {
+
+struct AccessibilityStatusEventDetails {
+  AccessibilityStatusEventDetails(
+      bool enabled,
+      ash::AccessibilityNotificationVisibility notify);
+
+  AccessibilityStatusEventDetails(
+      bool enabled,
+      ash::MagnifierType magnifier_type,
+      ash::AccessibilityNotificationVisibility notify);
+
+  bool enabled;
+  ash::MagnifierType magnifier_type;
+  ash::AccessibilityNotificationVisibility notify;
+};
+
+// AccessibilityManager changes the statuses of accessibility features
+// watching profile notifications and pref-changes.
+// TODO(yoshiki): merge MagnificationManager with AccessibilityManager.
+class AccessibilityManager : public content::NotificationObserver {
+ public:
+  // Creates an instance of AccessibilityManager, this should be called once,
+  // because only one instance should exist at the same time.
+  static void Initialize();
+  // Deletes the existing instance of AccessibilityManager.
+  static void Shutdown();
+  // Returns the existing instance. If there is no instance, returns NULL.
+  static AccessibilityManager* Get();
+
+  // Enables or disables spoken feedback. Enabling spoken feedback installs the
+  // ChromeVox component extension.  If this is being called in a login/oobe
+  // login screen, pass the WebUI object in login_web_ui so that ChromeVox
+  // can be injected directly into that screen, otherwise it should be NULL.
+  void EnableSpokenFeedback(bool enabled,
+                            content::WebUI* login_web_ui,
+                            ash::AccessibilityNotificationVisibility notify);
+
+  // Returns true if spoken feedback is enabled, or false if not.
+  bool IsSpokenFeedbackEnabled();
+
+  // Toggles whether Chrome OS spoken feedback is on or off. See docs for
+  // EnableSpokenFeedback, above.
+  void ToggleSpokenFeedback(content::WebUI* login_web_ui,
+                            ash::AccessibilityNotificationVisibility notify);
+
+  // Speaks the specified string.
+  void Speak(const std::string& text);
+
+  // Speaks the given text if the accessibility pref is already set.
+  void MaybeSpeak(const std::string& text);
+
+  // Enables or disables the high contrast mode for Chrome.
+  void EnableHighContrast(bool enabled);
+
+  // Returns true if High Contrast is enabled, or false if not.
+  bool IsHighContrastEnabled();
+
+  void SetProfileForTest(Profile* profile);
+
+ protected:
+  AccessibilityManager();
+  virtual ~AccessibilityManager();
+
+ private:
+  void UpdateSpokenFeedbackStatusFromPref();
+  void UpdateHighContrastStatusFromPref();
+
+  void SetProfile(Profile* profile);
+
+  void UpdateChromeOSAccessibilityHistograms();
+
+  // content::NotificationObserver implementation:
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  Profile* profile_;
+  content::NotificationRegistrar notification_registrar_;
+  scoped_ptr<PrefChangeRegistrar> pref_change_registrar_;
+
+  bool spoken_feedback_enabled_;
+  bool high_contrast_enabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(AccessibilityManager);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_ACCESSIBILITY_ACCESSIBILITY_MANAGER_H_