| // 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 <functional> |
| #include <ostream> |
| #include <string> |
| |
| #include "ax/ax_enums.h" |
| #include "ax/ax_export.h" |
| #include "ax/ax_mode.h" |
| #include "ax/ax_mode_observer.h" |
| #include "ax_build/build_config.h" |
| #include "base/macros.h" |
| #include "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: |
| typedef AXPlatformNode* NativeWindowHandlerCallback(gfx::NativeWindow); |
| |
| // 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 nullptr if it's not an instance of this class. |
| static AXPlatformNode* FromNativeViewAccessible( |
| gfx::NativeViewAccessible accessible); |
| |
| // Return the AXPlatformNode at the root of the tree for a native window. |
| static AXPlatformNode* FromNativeWindow(gfx::NativeWindow native_window); |
| |
| // Provide a function that returns the AXPlatformNode at the root of the |
| // tree for a native window. |
| static void RegisterNativeWindowHandler( |
| std::function<NativeWindowHandlerCallback> handler); |
| |
| // Register and unregister to receive notifications about AXMode changes |
| // for this node. |
| static void AddAXModeObserver(AXModeObserver* observer); |
| static void RemoveAXModeObserver(AXModeObserver* observer); |
| |
| // Convenience method to get the current accessibility mode. |
| static AXMode GetAccessibilityMode() { return ax_mode_; } |
| |
| // Helper static function to notify all global observers about |
| // the addition of an AXMode flag. |
| static void NotifyAddAXModeFlags(AXMode mode_flags); |
| |
| // Return the focused object in any UI popup overlaying content, or null. |
| static gfx::NativeViewAccessible GetPopupFocusOverride(); |
| |
| // Set the focused object withn any UI popup overlaying content, or null. |
| // The focus override is the perceived focus within the popup, and it changes |
| // each time a user navigates to a new item within the popup. |
| static void SetPopupFocusOverride(gfx::NativeViewAccessible focus_override); |
| |
| // 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(ax::mojom::Event event_type) = 0; |
| |
| #if defined(OS_APPLE) |
| // Fire a platform-specific notification to announce |text|. |
| virtual void AnnounceText(const std::u16string& text) = 0; |
| #endif |
| |
| // Return this object's delegate. |
| virtual AXPlatformNodeDelegate* GetDelegate() const = 0; |
| |
| // Return true if this object is equal to or a descendant of |ancestor|. |
| virtual bool IsDescendantOf(AXPlatformNode* ancestor) const = 0; |
| |
| // Set |this| as the primary web contents for the window. |
| void SetIsPrimaryWebContentsForWindow(bool is_primary); |
| bool IsPrimaryWebContentsForWindow() const; |
| |
| // Return the unique ID. |
| int32_t GetUniqueId() const; |
| |
| // Creates a string representation of this node's data. |
| std::string ToString(); |
| |
| // Returns a string representation of the subtree of nodes rooted at this |
| // node. |
| std::string SubtreeToString(); |
| |
| friend std::ostream& operator<<(std::ostream& stream, AXPlatformNode& node); |
| virtual ~AXPlatformNode(); |
| |
| protected: |
| AXPlatformNode(); |
| |
| private: |
| static std::vector<AXModeObserver*> ax_mode_observers_; |
| static std::function<NativeWindowHandlerCallback> native_window_handler_; |
| |
| static AXMode ax_mode_; |
| |
| // This allows UI menu popups like to act as if they are focused in the |
| // exposed platform accessibility API, even though actual focus remains in |
| // underlying content. |
| static gfx::NativeViewAccessible popup_focus_override_; |
| |
| bool is_primary_web_contents_for_window_ = false; |
| |
| BASE_DISALLOW_COPY_AND_ASSIGN(AXPlatformNode); |
| }; |
| |
| } // namespace ui |
| |
| #endif // UI_ACCESSIBILITY_PLATFORM_AX_PLATFORM_NODE_H_ |