/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this file,

 * You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_a11y_xpcAccessibilityService_h_

#define mozilla_a11y_xpcAccessibilityService_h_

#include "nsIAccessibilityService.h"

class xpcAccessibilityService : public nsIAccessibilityService

{

public:

  NS_DECL_ISUPPORTS

  NS_DECL_NSIACCESSIBILITYSERVICE

  /**

   * Return true if xpc accessibility service is in use.

   */

  static bool IsInUse() {

    // When ref count goes down to 1 (held internally as a static reference),

    // it means that there are no more external references and thus it is not in

    // use.

    return gXPCAccessibilityService ? gXPCAccessibilityService->mRefCnt > 1 : false;

  }

protected:

  virtual ~xpcAccessibilityService() {

    if (mShutdownTimer) {

      mShutdownTimer->Cancel();

      mShutdownTimer = nullptr;

    }

    gXPCAccessibilityService = nullptr;

  }

private:

  // xpcAccessibilityService creation is controlled by friend

  // NS_GetAccessibilityService, keep constructor private.

  xpcAccessibilityService() { };

  nsCOMPtr<nsITimer> mShutdownTimer;

  /**

   * Reference for xpc accessibility service instance.

   */

  static xpcAccessibilityService* gXPCAccessibilityService;

  /**

   * Used to shutdown nsAccessibilityService if xpcom accessible service is not

   * in use any more.

   */

  static void ShutdownCallback(nsITimer* aTimer, void* aClosure);

  friend nsresult NS_GetAccessibilityService(nsIAccessibilityService** aResult);

};

// for component registration

// {3b265b69-f813-48ff-880d-d88d101af404}

#define NS_ACCESSIBILITY_SERVICE_CID \

{ 0x3b265b69, 0xf813, 0x48ff, { 0x88, 0x0d, 0xd8, 0x8d, 0x10, 0x1a, 0xf4, 0x04 } }

extern nsresult

NS_GetAccessibilityService(nsIAccessibilityService** aResult);

#endif