dom/bindings/CallbackFunction.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim:set ts=2 sw=2 sts=2 et cindent: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 /**
   8  * A common base class for representing WebIDL callback function types in C++.
   9  *
  10  * This class implements common functionality like lifetime
  11  * management, initialization with the callable, and setup of the call
  12  * environment.  Subclasses corresponding to particular callback
  13  * function types should provide a Call() method that actually does
  14  * the call.
  15  */
  16
  17 #ifndef mozilla_dom_CallbackFunction_h
  18 #define mozilla_dom_CallbackFunction_h
  19
  20 #include "mozilla/dom/CallbackObject.h"
  21
  22 namespace mozilla {
  23 namespace dom {
  24
  25 class CallbackFunction : public CallbackObject
  26 {
  27 public:
  28   explicit CallbackFunction(JS::Handle<JSObject*> aCallable,
  29                             nsIGlobalObject* aIncumbentGlobal)
  30     : CallbackObject(aCallable, aIncumbentGlobal)
  31   {
  32   }
  33
  34   JS::Handle<JSObject*> Callable() const
  35   {
  36     return Callback();
  37   }
  38
  39   bool HasGrayCallable() const
  40   {
  41     // Play it safe in case this gets called after unlink.
  42     return mCallback && JS::ObjectIsMarkedGray(mCallback);
  43   }
  44
  45 protected:
  46   explicit CallbackFunction(CallbackFunction* aCallbackFunction)
  47     : CallbackObject(aCallbackFunction)
  48   {
  49   }
  50 };
  51
  52 } // namespace dom
  53 } // namespace mozilla
  54
  55 #endif // mozilla_dom_CallbackFunction_h