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// Copyright (c) 2010 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_VIEWS_ACCESSIBILITY_EVENT_ROUTER_VIEWS_H_
#define CHROME_BROWSER_VIEWS_ACCESSIBILITY_EVENT_ROUTER_VIEWS_H_
#include <string>
#include "base/basictypes.h"
#include "base/hash_tables.h"
#include "base/singleton.h"
#include "base/task.h"
#include "chrome/browser/accessibility_events.h"
#include "views/view.h"
#include "views/widget/root_view.h"
class Profile;
// Allows us to use (View*) and (FocusManager*) in a hash_map with gcc.
#if defined(COMPILER_GCC)
namespace __gnu_cxx {
template<>
struct hash<views::FocusManager*> {
size_t operator()(views::FocusManager* focus_manager) const {
return reinterpret_cast<size_t>(focus_manager);
}
};
template<>
struct hash<views::View*> {
size_t operator()(views::View* view) const {
return reinterpret_cast<size_t>(view);
}
};
} // namespace __gnu_cxx
#endif // defined(COMPILER_GCC)
// NOTE: This class is part of the Accessibility Extension API, which lets
// extensions receive accessibility events. It's distinct from code that
// implements platform accessibility APIs like MSAA or ATK.
//
// Singleton class that adds listeners to many views, then sends an
// accessibility notification whenever a relevant event occurs in an
// accessible view.
//
// Views are not accessible by default. When you register a root widget,
// that widget and all of its descendants will start sending accessibility
// event notifications. You can then override the default behavior for
// specific descendants using other methods.
//
// You can use Profile::PauseAccessibilityEvents to prevent a flurry
// of accessibility events when a window is being created or initialized.
class AccessibilityEventRouterViews
: public views::FocusChangeListener {
public:
// Internal information about a particular view to override the
// information we get directly from the view.
struct ViewInfo {
ViewInfo() : ignore(false), focus_manager(NULL) {}
// If nonempty, will use this name instead of the view's label.
std::string name;
// If true, will ignore this widget and not send accessibility events.
bool ignore;
// The focus manager that this view is part of - saved because
// GetFocusManager may not succeed while a view is being deleted.
views::FocusManager* focus_manager;
};
// Get the single instance of this class.
static AccessibilityEventRouterViews* GetInstance();
// Start sending accessibility events for this view and all of its
// descendants. Notifications will go to the specified profile.
// Returns true on success, false if "view" was already registered.
// It is the responsibility of the caller to call RemoveViewTree if
// this view is ever deleted; consider using AccessibleViewHelper.
bool AddViewTree(views::View* view, Profile* profile);
// Stop sending accessibility events for this view and all of its
// descendants.
void RemoveViewTree(views::View* view);
// Don't send any events for this view.
void IgnoreView(views::View* view);
// Use the following string as the name of this view, instead of the
// gtk label associated with the view.
void SetViewName(views::View* view, std::string name);
// Forget all information about this view.
void RemoveView(views::View* view);
// Implementation of views::FocusChangeListener:
virtual void FocusWillChange(
views::View* focused_before, views::View* focused_now);
private:
// Given a view, determine if it's part of a view tree that's mapped to
// a profile and if so, if it's marked as accessible.
void FindView(views::View* view, Profile** profile, bool* is_accessible);
// Checks the type of the view and calls one of the more specific
// Send*Notification methods, below.
void DispatchAccessibilityNotification(
views::View* view, NotificationType type);
// Return the name of a view.
std::string GetViewName(views::View* view);
// Each of these methods constructs an AccessibilityControlInfo object
// and sends a notification of a specific accessibility event.
void SendButtonNotification(
views::View* view, NotificationType type, Profile* profile);
void SendLinkNotification(
views::View* view, NotificationType type, Profile* profile);
void SendMenuNotification(
views::View* view, NotificationType type, Profile* profile);
private:
AccessibilityEventRouterViews();
virtual ~AccessibilityEventRouterViews();
friend struct DefaultSingletonTraits<AccessibilityEventRouterViews>;
// The set of all view tree roots; only descendants of these will generate
// accessibility notifications.
base::hash_map<views::View*, Profile*> view_tree_profile_map_;
// Extra information about specific views.
base::hash_map<views::View*, ViewInfo> view_info_map_;
// Count of the number of references to each focus manager.
base::hash_map<views::FocusManager*, int> focus_manager_ref_count_;
// Used to defer handling of some events until the next time
// through the event loop.
ScopedRunnableMethodFactory<AccessibilityEventRouterViews> method_factory_;
};
#endif // CHROME_BROWSER_VIEWS_ACCESSIBILITY_EVENT_ROUTER_VIEWS_H_
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