1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROME_BROWSER_ACCESSIBILITY_ACCESSIBILITY_EXTENSION_API_H_ 6 #define CHROME_BROWSER_ACCESSIBILITY_ACCESSIBILITY_EXTENSION_API_H_ 7 8 #include <string> 9 10 #include "base/compiler_specific.h" 11 #include "base/memory/singleton.h" 12 #include "base/values.h" 13 #include "chrome/browser/accessibility/accessibility_events.h" 14 #include "chrome/browser/extensions/extension_function.h" 15 #include "content/public/browser/notification_observer.h" 16 #include "content/public/browser/notification_registrar.h" 17 18 // Observes the profile and routes accessibility notifications as events 19 // to the extension system. 20 class ExtensionAccessibilityEventRouter : public content::NotificationObserver { 21 public: 22 // Single instance of the event router. 23 static ExtensionAccessibilityEventRouter* GetInstance(); 24 25 // Get the dict representing the last control that received an 26 // OnControlFocus event. 27 DictionaryValue* last_focused_control_dict() { 28 return &last_focused_control_dict_; 29 } 30 31 // Accessibility support is disabled until an extension expicitly enables 32 // it, so that this extension api has no impact on Chrome's performance 33 // otherwise. These methods handle enabling, disabling, and querying the 34 // status. 35 void SetAccessibilityEnabled(bool enabled); 36 bool IsAccessibilityEnabled() const; 37 38 private: 39 friend struct DefaultSingletonTraits<ExtensionAccessibilityEventRouter>; 40 41 ExtensionAccessibilityEventRouter(); 42 virtual ~ExtensionAccessibilityEventRouter(); 43 44 // content::NotificationObserver::Observe. 45 virtual void Observe(int type, 46 const content::NotificationSource& source, 47 const content::NotificationDetails& details) OVERRIDE; 48 49 void OnWindowOpened(const AccessibilityWindowInfo* details); 50 void OnWindowClosed(const AccessibilityWindowInfo* details); 51 void OnControlFocused(const AccessibilityControlInfo* details); 52 void OnControlAction(const AccessibilityControlInfo* details); 53 void OnTextChanged(const AccessibilityControlInfo* details); 54 void OnMenuOpened(const AccessibilityMenuInfo* details); 55 void OnMenuClosed(const AccessibilityMenuInfo* details); 56 57 void DispatchEvent(Profile* profile, 58 const char* event_name, 59 scoped_ptr<base::ListValue> event_args); 60 61 // Used for tracking registrations to history service notifications. 62 content::NotificationRegistrar registrar_; 63 64 DictionaryValue last_focused_control_dict_; 65 66 bool enabled_; 67 68 DISALLOW_COPY_AND_ASSIGN(ExtensionAccessibilityEventRouter); 69 }; 70 71 // API function that enables or disables accessibility support. Event 72 // listeners are only installed when accessibility support is enabled, to 73 // minimize the impact. 74 class AccessibilitySetAccessibilityEnabledFunction 75 : public SyncExtensionFunction { 76 virtual ~AccessibilitySetAccessibilityEnabledFunction() {} 77 virtual bool RunImpl() OVERRIDE; 78 DECLARE_EXTENSION_FUNCTION( 79 "experimental.accessibility.setAccessibilityEnabled", 80 EXPERIMENTAL_ACCESSIBILITY_SETACCESSIBILITYENABLED) 81 }; 82 83 // API function that enables or disables web content accessibility support. 84 class AccessibilitySetNativeAccessibilityEnabledFunction 85 : public SyncExtensionFunction { 86 virtual ~AccessibilitySetNativeAccessibilityEnabledFunction() {} 87 virtual bool RunImpl() OVERRIDE; 88 DECLARE_EXTENSION_FUNCTION( 89 "experimental.accessibility.setNativeAccessibilityEnabled", 90 EXPERIMENTAL_ACCESSIBILITY_SETNATIVEACCESSIBILITYENABLED) 91 }; 92 93 // API function that returns the most recent focused control. 94 class AccessibilityGetFocusedControlFunction : public SyncExtensionFunction { 95 virtual ~AccessibilityGetFocusedControlFunction() {} 96 virtual bool RunImpl() OVERRIDE; 97 DECLARE_EXTENSION_FUNCTION( 98 "experimental.accessibility.getFocusedControl", 99 EXPERIMENTAL_ACCESSIBILITY_GETFOCUSEDCONTROL) 100 }; 101 102 // API function that returns alerts being shown on the give tab. 103 class AccessibilityGetAlertsForTabFunction : public SyncExtensionFunction { 104 virtual ~AccessibilityGetAlertsForTabFunction() {} 105 virtual bool RunImpl() OVERRIDE; 106 DECLARE_EXTENSION_FUNCTION( 107 "experimental.accessibility.getAlertsForTab", 108 EXPERIMENTAL_ACCESSIBILITY_GETALERTSFORTAB) 109 }; 110 111 #endif // CHROME_BROWSER_ACCESSIBILITY_ACCESSIBILITY_EXTENSION_API_H_ 112