| // 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. |
| |
| #ifndef UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_H_ |
| #define UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_H_ |
| |
| #include "base/lazy_instance.h" |
| #include "base/observer_list.h" |
| #include "build/build_config.h" |
| #include "ui/accessibility/ax_enums.h" |
| #include "ui/accessibility/ax_export.h" |
| #include "ui/accessibility/ax_mode_observer.h" |
| #include "ui/gfx/native_widget_types.h" |
| |
| namespace ui { |
| |
| class AXPlatformNodeDelegate; |
| |
| // AXPlatformNode is the abstract base class for an implementation of |
| // native accessibility APIs on supported platforms (e.g. Windows, Mac OS X). |
| // An object that wants to be accessible can derive from AXPlatformNodeDelegate |
| // and then call AXPlatformNode::Create. The delegate implementation should |
| // own the AXPlatformNode instance (or otherwise manage its lifecycle). |
| class AX_EXPORT AXPlatformNode { |
| public: |
| // Create an appropriate platform-specific instance. The delegate owns the |
| // AXPlatformNode instance (or manages its lifecycle in some other way). |
| static AXPlatformNode* Create(AXPlatformNodeDelegate* delegate); |
| |
| // Cast a gfx::NativeViewAccessible to an AXPlatformNode if it is one, |
| // or return NULL if it's not an instance of this class. |
| static AXPlatformNode* FromNativeViewAccessible( |
| gfx::NativeViewAccessible accessible); |
| |
| // Register and unregister to receive notifications about AXMode changes |
| // for this node. |
| static void AddAXModeObserver(ui::AXModeObserver* observer); |
| static void RemoveAXModeObserver(ui::AXModeObserver* observer); |
| |
| // Helper static function to notify all global observers about |
| // the addition of an AXMode flag. |
| static void NotifyAddAXModeFlags(ui::AXMode mode_flags); |
| |
| // Call Destroy rather than deleting this, because the subclass may |
| // use reference counting. |
| virtual void Destroy(); |
| |
| // Get the platform-specific accessible object type for this instance. |
| // On some platforms this is just a type cast, on others it may be a |
| // wrapper object or handle. |
| virtual gfx::NativeViewAccessible GetNativeViewAccessible() = 0; |
| |
| // Fire a platform-specific notification that an event has occurred on |
| // this object. |
| virtual void NotifyAccessibilityEvent(ui::AXEvent event_type) = 0; |
| |
| // Return this object's delegate. |
| virtual AXPlatformNodeDelegate* GetDelegate() const = 0; |
| |
| protected: |
| AXPlatformNode(); |
| virtual ~AXPlatformNode(); |
| |
| private: |
| // Global ObserverList for AXMode changes. |
| static base::LazyInstance<base::ObserverList<AXModeObserver>>::Leaky |
| ax_mode_observers_; |
| }; |
| |
| } // namespace ui |
| |
| #endif // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_H_ |