| // Copyright (c) 2006-2008 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_BROWSER_ACCESSIBILITY_H_ |
| #define CHROME_BROWSER_BROWSER_ACCESSIBILITY_H_ |
| |
| #include <atlbase.h> |
| #include <atlcom.h> |
| |
| #include <oleacc.h> |
| |
| #include "chrome/common/render_messages.h" |
| |
| //////////////////////////////////////////////////////////////////////////////// |
| // |
| // BrowserAccessibility |
| // |
| // Class implementing the MSAA IAccessible COM interface for the |
| // Browser-Renderer communication of MSAA information, providing accessibility |
| // to be used by screen readers and other assistive technology (AT). |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| class ATL_NO_VTABLE BrowserAccessibility |
| : public CComObjectRootEx<CComMultiThreadModel>, |
| public IDispatchImpl<IAccessible, &IID_IAccessible, &LIBID_Accessibility> { |
| public: |
| BEGIN_COM_MAP(BrowserAccessibility) |
| COM_INTERFACE_ENTRY2(IDispatch, IAccessible) |
| COM_INTERFACE_ENTRY(IAccessible) |
| END_COM_MAP() |
| |
| BrowserAccessibility(); |
| ~BrowserAccessibility() {} |
| |
| // Supported IAccessible methods. |
| |
| // Performs the default action on a given object. |
| STDMETHODIMP accDoDefaultAction(VARIANT var_id); |
| |
| // Retrieves the child element or child object at a given point on the screen. |
| STDMETHODIMP accHitTest(LONG x_left, LONG y_top, VARIANT* child); |
| |
| // Retrieves the specified object's current screen location. |
| STDMETHODIMP accLocation(LONG* x_left, |
| LONG* y_top, |
| LONG* width, |
| LONG* height, |
| VARIANT var_id); |
| |
| // Traverses to another UI element and retrieves the object. |
| STDMETHODIMP accNavigate(LONG nav_dir, VARIANT start, VARIANT* end); |
| |
| // Retrieves an IDispatch interface pointer for the specified child. |
| STDMETHODIMP get_accChild(VARIANT var_child, IDispatch** disp_child); |
| |
| // Retrieves the number of accessible children. |
| STDMETHODIMP get_accChildCount(LONG* child_count); |
| |
| // Retrieves a string that describes the object's default action. |
| STDMETHODIMP get_accDefaultAction(VARIANT var_id, BSTR* default_action); |
| |
| // Retrieves the object's description. |
| STDMETHODIMP get_accDescription(VARIANT var_id, BSTR* desc); |
| |
| // Retrieves the object that has the keyboard focus. |
| STDMETHODIMP get_accFocus(VARIANT* focus_child); |
| |
| // Retrieves the help information associated with the object. |
| STDMETHODIMP get_accHelp(VARIANT var_id, BSTR* help); |
| |
| // Retrieves the specified object's shortcut. |
| STDMETHODIMP get_accKeyboardShortcut(VARIANT var_id, BSTR* access_key); |
| |
| // Retrieves the name of the specified object. |
| STDMETHODIMP get_accName(VARIANT var_id, BSTR* name); |
| |
| // Retrieves the IDispatch interface of the object's parent. |
| STDMETHODIMP get_accParent(IDispatch** disp_parent); |
| |
| // Retrieves information describing the role of the specified object. |
| STDMETHODIMP get_accRole(VARIANT var_id, VARIANT* role); |
| |
| // Retrieves the current state of the specified object. |
| STDMETHODIMP get_accState(VARIANT var_id, VARIANT* state); |
| |
| // Returns the value associated with the object. |
| STDMETHODIMP get_accValue(VARIANT var_id, BSTR* value); |
| |
| // Non-supported (by WebKit) IAccessible methods. |
| STDMETHODIMP accSelect(LONG flags_sel, VARIANT var_id); |
| |
| STDMETHODIMP get_accHelpTopic(BSTR* help_file, |
| VARIANT var_id, |
| LONG* topic_id); |
| |
| STDMETHODIMP get_accSelection(VARIANT* selected); |
| |
| // Deprecated functions, not implemented here. |
| STDMETHODIMP put_accName(VARIANT var_id, BSTR put_name); |
| STDMETHODIMP put_accValue(VARIANT var_id, BSTR put_val); |
| |
| // Modify/retrieve the unique id of this IAccessible instance. |
| void set_iaccessible_id(int iaccessible_id) { |
| iaccessible_id_ = iaccessible_id; |
| } |
| int iaccessible_id() const { return iaccessible_id_; } |
| |
| // Modify/retrieve the unique id of this IAccessible's routing variables. |
| void set_instance_id(int instance_id) { |
| instance_id_ = instance_id; |
| } |
| int instance_id() const { return instance_id_; } |
| |
| // Modify/retrieve the state (active/inactive) of this instance. |
| void set_instance_active(bool instance_active) { |
| instance_active_ = instance_active; |
| } |
| int instance_active() const { return instance_active_; } |
| |
| private: |
| // Creates an empty VARIANT. Used as the equivalent of a NULL (unused) input |
| // parameter. |
| VARIANT EmptyVariant() const { |
| VARIANT empty; |
| empty.vt = VT_EMPTY; |
| return empty; |
| } |
| |
| // Wrapper functions, calling through to singleton instance of |
| // BrowserAccessibilityManager. |
| |
| // Creates an instance of BrowserAccessibility, initializes it and sets the |
| // |iaccessible_id| and |parent_id|. |
| STDMETHODIMP CreateInstance(REFIID iid, |
| int iaccessible_id, |
| void** interface_ptr); |
| |
| // Composes and sends a message for requesting needed accessibility |
| // information. Unused LONG input parameters should be NULL, and the VARIANT |
| // an empty, valid instance. |
| bool RequestAccessibilityInfo(int iaccessible_func_id, |
| VARIANT var_id, |
| LONG input1, LONG input2); |
| |
| // Accessors. |
| ViewHostMsg_Accessibility_Out_Params response(); |
| HWND parent_hwnd(); |
| |
| // Id to uniquely distinguish this instance in the render-side caching, |
| // mapping it to the correct IAccessible on that side. Initialized to -1. |
| int iaccessible_id_; |
| |
| // The unique id of this IAccessible instance. Used to help |
| // BrowserAccessibilityManager instance retrieve the correct member |
| // variables for this process. |
| int instance_id_; |
| |
| // The instance should only be active if there is a non-terminated |
| // RenderProcessHost associated with it. The BrowserAccessibilityManager keeps |
| // track of this state, and sets it to false to disable all calls into the |
| // renderer from this instance of BroweserAccessibility, and have all |
| // IAccessible functions return E_FAIL. |
| bool instance_active_; |
| |
| DISALLOW_COPY_AND_ASSIGN(BrowserAccessibility); |
| }; |
| #endif // CHROME_BROWSER_BROWSER_ACCESSIBILITY_H_ |
| |