// Copyright (c) 2011 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_EXTENSIONS_EXTENSION_ACCESSIBILITY_API_H_
#define CHROME_BROWSER_EXTENSIONS_EXTENSION_ACCESSIBILITY_API_H_
#pragma once
#include <string>
#include <vector>
#include "base/callback.h"
#include "base/memory/singleton.h"
#include "base/values.h"
#include "chrome/browser/accessibility_events.h"
#include "chrome/browser/extensions/extension_function.h"
#include "content/common/notification_observer.h"
#include "content/common/notification_registrar.h"
// Observes the profile and routes accessibility notifications as events
// to the extension system.
class ExtensionAccessibilityEventRouter : public NotificationObserver {
public:
// Single instance of the event router.
static ExtensionAccessibilityEventRouter* GetInstance();
// Safe to call multiple times.
void ObserveProfile(Profile* profile);
// Get the dict representing the last control that received an
// OnControlFocus event.
DictionaryValue* last_focused_control_dict() {
return &last_focused_control_dict_;
}
// Accessibility support is disabled until an extension expicitly enables
// it, so that this extension api has no impact on Chrome's performance
// otherwise. These methods handle enabling, disabling, querying the
// status, and installing callbacks to execute when accessibility support
// is enabled or disabled.
void SetAccessibilityEnabled(bool enabled);
bool IsAccessibilityEnabled() const;
typedef Callback0::Type Callback;
void AddOnEnabledListener(Callback* callback);
void AddOnDisabledListener(Callback* callback);
private:
friend struct DefaultSingletonTraits<ExtensionAccessibilityEventRouter>;
ExtensionAccessibilityEventRouter();
virtual ~ExtensionAccessibilityEventRouter();
// NotificationObserver::Observe.
virtual void Observe(NotificationType type,
const NotificationSource& source,
const NotificationDetails& details);
void OnWindowOpened(const AccessibilityWindowInfo* details);
void OnWindowClosed(const AccessibilityWindowInfo* details);
void OnControlFocused(const AccessibilityControlInfo* details);
void OnControlAction(const AccessibilityControlInfo* details);
void OnTextChanged(const AccessibilityControlInfo* details);
void OnMenuOpened(const AccessibilityMenuInfo* details);
void OnMenuClosed(const AccessibilityMenuInfo* details);
void DispatchEvent(Profile* profile,
const char* event_name,
const std::string& json_args);
// Used for tracking registrations to history service notifications.
NotificationRegistrar registrar_;
DictionaryValue last_focused_control_dict_;
bool enabled_;
std::vector<Callback*> on_enabled_listeners_;
std::vector<Callback*> on_disabled_listeners_;
DISALLOW_COPY_AND_ASSIGN(ExtensionAccessibilityEventRouter);
};
// API function that enables or disables accessibility support. Event
// listeners are only installed when accessibility support is enabled, to
// minimize the impact.
class SetAccessibilityEnabledFunction : public SyncExtensionFunction {
virtual ~SetAccessibilityEnabledFunction() {}
virtual bool RunImpl();
DECLARE_EXTENSION_FUNCTION_NAME(
"experimental.accessibility.setAccessibilityEnabled")
};
// API function that returns the most recent focused control.
class GetFocusedControlFunction : public SyncExtensionFunction {
virtual ~GetFocusedControlFunction() {}
virtual bool RunImpl();
DECLARE_EXTENSION_FUNCTION_NAME(
"experimental.accessibility.getFocusedControl")
};
#endif // CHROME_BROWSER_EXTENSIONS_EXTENSION_ACCESSIBILITY_API_H_