Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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
#ifndef mozilla_JSEventHandler_h_
#define mozilla_JSEventHandler_h_
#include "mozilla/Attributes.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/dom/EventHandlerBinding.h"
#include "nsCOMPtr.h"
#include "nsCycleCollectionParticipant.h"
#include "nsAtom.h"
#include "nsIDOMEventListener.h"
#include "nsIScriptContext.h"
namespace mozilla {
namespace dom {
class EventTarget;
} // namespace dom
class TypedEventHandler {
public:
enum HandlerType {
eUnset = 0,
eNormal = 0x1,
eOnError = 0x2,
eOnBeforeUnload = 0x3,
eTypeBits = 0x3
};
TypedEventHandler() : mBits(0) {}
explicit TypedEventHandler(dom::EventHandlerNonNull* aHandler) : mBits(0) {
Assign(aHandler, eNormal);
}
explicit TypedEventHandler(dom::OnErrorEventHandlerNonNull* aHandler)
: mBits(0) {
Assign(aHandler, eOnError);
}
explicit TypedEventHandler(dom::OnBeforeUnloadEventHandlerNonNull* aHandler)
: mBits(0) {
Assign(aHandler, eOnBeforeUnload);
}
TypedEventHandler(const TypedEventHandler& aOther) {
if (aOther.HasEventHandler()) {
// Have to make sure we take our own ref
Assign(aOther.Ptr(), aOther.Type());
} else {
mBits = 0;
}
}
~TypedEventHandler() { ReleaseHandler(); }
HandlerType Type() const { return HandlerType(mBits & eTypeBits); }
bool HasEventHandler() const { return !!Ptr(); }
void SetHandler(const TypedEventHandler& aHandler) {
if (aHandler.HasEventHandler()) {
ReleaseHandler();
Assign(aHandler.Ptr(), aHandler.Type());
} else {
ForgetHandler();
}
}
dom::EventHandlerNonNull* NormalEventHandler() const {
MOZ_ASSERT(Type() == eNormal && Ptr());
return reinterpret_cast<dom::EventHandlerNonNull*>(Ptr());
}
void SetHandler(dom::EventHandlerNonNull* aHandler) {
ReleaseHandler();
Assign(aHandler, eNormal);
}
dom::OnBeforeUnloadEventHandlerNonNull* OnBeforeUnloadEventHandler() const {
MOZ_ASSERT(Type() == eOnBeforeUnload);
return reinterpret_cast<dom::OnBeforeUnloadEventHandlerNonNull*>(Ptr());
}
void SetHandler(dom::OnBeforeUnloadEventHandlerNonNull* aHandler) {
ReleaseHandler();
Assign(aHandler, eOnBeforeUnload);
}
dom::OnErrorEventHandlerNonNull* OnErrorEventHandler() const {
MOZ_ASSERT(Type() == eOnError);
return reinterpret_cast<dom::OnErrorEventHandlerNonNull*>(Ptr());
}
void SetHandler(dom::OnErrorEventHandlerNonNull* aHandler) {
ReleaseHandler();
Assign(aHandler, eOnError);
}
dom::CallbackFunction* Ptr() const {
// Have to cast eTypeBits so we don't have to worry about
// promotion issues after the bitflip.
return reinterpret_cast<dom::CallbackFunction*>(mBits &
~uintptr_t(eTypeBits));
}
void ForgetHandler() {
ReleaseHandler();
mBits = 0;
}
bool operator==(const TypedEventHandler& aOther) const {
return Ptr() && aOther.Ptr() &&
Ptr()->CallbackPreserveColor() ==
aOther.Ptr()->CallbackPreserveColor();
}
private:
void operator=(const TypedEventHandler&) = delete;
void ReleaseHandler() {
nsISupports* ptr = Ptr();
NS_IF_RELEASE(ptr);
}
void Assign(nsISupports* aHandler, HandlerType aType) {
MOZ_ASSERT(aHandler, "Must have handler");
NS_ADDREF(aHandler);
mBits = uintptr_t(aHandler) | uintptr_t(aType);
}
uintptr_t mBits;
};
/**
* Implemented by script event listeners. Used to retrieve the script object
* corresponding to the event target and the handler itself.
*
* Note, mTarget is a raw pointer and the owner of the JSEventHandler object
* is expected to call Disconnect()!
*/
#define NS_JSEVENTHANDLER_IID \
{ \
0x4f486881, 0x1956, 0x4079, { \
0x8c, 0xa0, 0xf3, 0xbd, 0x60, 0x5c, 0xc2, 0x79 \
} \
}
class JSEventHandler : public nsIDOMEventListener {
public:
NS_DECLARE_STATIC_IID_ACCESSOR(NS_JSEVENTHANDLER_IID)
JSEventHandler(dom::EventTarget* aTarget, nsAtom* aType,
const TypedEventHandler& aTypedHandler);
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
// nsIDOMEventListener interface
NS_DECL_NSIDOMEVENTLISTENER
void Disconnect() { mTarget = nullptr; }
const TypedEventHandler& GetTypedEventHandler() const {
return mTypedHandler;
}
void ForgetHandler() { mTypedHandler.ForgetHandler(); }
nsAtom* EventName() const { return mEventName; }
// Set a handler for this event listener. The handler must already
// be bound to the right target.
void SetHandler(const TypedEventHandler& aTypedHandler) {
mTypedHandler.SetHandler(aTypedHandler);
}
void SetHandler(dom::EventHandlerNonNull* aHandler) {
mTypedHandler.SetHandler(aHandler);
}
void SetHandler(dom::OnBeforeUnloadEventHandlerNonNull* aHandler) {
mTypedHandler.SetHandler(aHandler);
}
void SetHandler(dom::OnErrorEventHandlerNonNull* aHandler) {
mTypedHandler.SetHandler(aHandler);
}
size_t SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
return 0;
// Measurement of the following members may be added later if DMD finds it
// is worthwhile:
// - mTarget
//
// The following members are not measured:
// - mTypedHandler: may be shared with others
// - mEventName: shared with others
}
size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) {
return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}
NS_DECL_CYCLE_COLLECTION_SKIPPABLE_CLASS(JSEventHandler)
bool IsBlackForCC();
protected:
virtual ~JSEventHandler();
dom::EventTarget* mTarget;
RefPtr<nsAtom> mEventName;
TypedEventHandler mTypedHandler;
};
NS_DEFINE_STATIC_IID_ACCESSOR(JSEventHandler, NS_JSEVENTHANDLER_IID)
} // namespace mozilla
/**
* Factory function. aHandler must already be bound to aTarget.
* aContext is allowed to be null if aHandler is already set up.
*/
nsresult NS_NewJSEventHandler(mozilla::dom::EventTarget* aTarget, nsAtom* aType,
const mozilla::TypedEventHandler& aTypedHandler,
mozilla::JSEventHandler** aReturn);
#endif // mozilla_JSEventHandler_h_