gecko/dom/bindings/CallbackFunction.h

56 lines
1.5 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* 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/. */
/**
* A common base class for representing WebIDL callback function types in C++.
*
* This class implements common functionality like lifetime
* management, initialization with the callable, and setup of the call
* environment. Subclasses corresponding to particular callback
* function types should provide a Call() method that actually does
* the call.
*/
#ifndef mozilla_dom_CallbackFunction_h
#define mozilla_dom_CallbackFunction_h
#include "mozilla/dom/CallbackObject.h"
namespace mozilla {
namespace dom {
class CallbackFunction : public CallbackObject
{
public:
explicit CallbackFunction(JSObject* aCallable)
: CallbackObject(aCallable)
{
MOZ_ASSERT(JS_ObjectIsCallable(nullptr, aCallable));
}
JS::Handle<JSObject*> Callable() const
{
return Callback();
}
bool HasGrayCallable() const
{
// Play it safe in case this gets called after unlink.
return mCallback && xpc_IsGrayGCThing(mCallback);
}
protected:
explicit CallbackFunction(CallbackFunction* aCallbackFunction)
: CallbackObject(aCallbackFunction)
{
}
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_CallbackFunction_h