gecko-dev/accessible/xpcom/xpcAccessibilityService.h

67 lines
1.9 KiB
C++

/* 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 nsIAccessibleRetrieval
{
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIACCESSIBILITYSERVICE
NS_DECL_NSIACCESSIBLERETRIEVAL
/**
* 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