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// 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_MANAGER_H_
#define CHROME_BROWSER_BROWSER_ACCESSIBILITY_MANAGER_H_
#include <oaidl.h> // Needed for VARIANT structure.
#include <hash_map>
#include "base/singleton.h"
#include "chrome/common/accessibility.h"
#include "chrome/common/notification_observer.h"
class BrowserAccessibility;
class RenderProcessHost;
class RenderWidgetHost;
////////////////////////////////////////////////////////////////////////////////
//
// BrowserAccessibilityManager
//
// Used to manage instance creation and memory handling for browser side
// accessibility. A singleton class. It implements NotificationObserver to
// ensure that a termination of a renderer process gets propagated to the
// active BrowserAccessibility instances calling into it. Each such instance
// will upon such an event be set to an inactive state, failing calls from the
// assistive technology gracefully.
////////////////////////////////////////////////////////////////////////////////
class BrowserAccessibilityManager : public NotificationObserver {
public:
// Gets the singleton BrowserAccessibilityManager object. The first time this
// method is called, a CacheManagerHost object is constructed and returned.
// Subsequent calls will return the same object.
static BrowserAccessibilityManager* GetInstance();
// Creates an instance of BrowserAccessibility, initializes it and sets the
// iaccessible_id and parent_id.
STDMETHODIMP CreateAccessibilityInstance(REFIID iid,
int iaccessible_id,
int instance_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_id,
int instance_id,
int iaccessible_func_id,
VARIANT var_id,
LONG input1,
LONG input2);
// Wrapper function, for cleaner code.
const AccessibilityOutParams& response();
// Retrieves the parent HWND connected to the provided id.
HWND parent_hwnd(int id);
// Mutator, needed since constructor does not take any arguments, and to keep
// instance accessor clean.
int SetMembers(BrowserAccessibility* browser_acc,
HWND parent_hwnd,
RenderWidgetHost* render_widget_host);
// NotificationObserver implementation.
virtual void Observe(NotificationType type,
const NotificationSource& source,
const NotificationDetails& details);
protected:
// This class is a singleton. Do not instantiate directly.
BrowserAccessibilityManager();
friend struct DefaultSingletonTraits<BrowserAccessibilityManager>;
~BrowserAccessibilityManager();
private:
// Member variable structure, used in instance hashmap.
struct UniqueMembers {
RenderWidgetHost* render_widget_host_;
HWND parent_hwnd_;
UniqueMembers(HWND parent_hwnd, RenderWidgetHost* render_widget_host)
: parent_hwnd_(parent_hwnd),
render_widget_host_(render_widget_host) {
}
};
typedef stdext::hash_map<int, UniqueMembers*> InstanceMap;
typedef stdext::hash_map<RenderProcessHost*, BrowserAccessibility*>
RenderProcessHostMap;
// Caching of the unique member variables used to handle browser accessibility
// requests from multiple processes.
InstanceMap instance_map_;
int instance_id_;
// Reverse mapping to track which RenderProcessHosts are active. If a
// RenderProcessHost is found to be terminated, it should be removed from this
// mapping, and the connected BrowserAccessibility ids/instances invalidated.
RenderProcessHostMap render_process_host_map_;
AccessibilityOutParams out_params_;
DISALLOW_COPY_AND_ASSIGN(BrowserAccessibilityManager);
};
#endif // CHROME_BROWSER_BROWSER_ACCESSIBILITY_MANAGER_H_
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