1 files changed, 68 insertions, 0 deletions
diff --git a/accessible/xpcom/xpcAccessibilityService.h b/accessible/xpcom/xpcAccessibilityService.h
new file mode 100644
index 0000000000..04c23e7075
--- /dev/null
+++ b/accessible/xpcom/xpcAccessibilityService.h
@@ -0,0 +1,68 @@
+/* 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"
+#include "nsITimer.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() = default;
+
+  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