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#ifndef nsIJSEventListener_h__
#define nsIJSEventListener_h__

#include "nsIScriptContext.h"

class nsIScriptObjectOwner;
class nsIDOMEventListener;
class nsIAtom;
struct JSObject;

#define NS_IJSEVENTLISTENER_IID     \
{ 0xa6cf9118, 0x15b3, 0x11d2,       \
{0x93, 0x2e, 0x00, 0x80, 0x5f, 0x8a, 0xdd, 0x32} }

// Implemented by JS event listeners. Used to retrieve the
// JSObject corresponding to the event target.
class nsIJSEventListener : public nsISupports
{
public:
  NS_DEFINE_STATIC_IID_ACCESSOR(NS_IJSEVENTLISTENER_IID)

  nsIJSEventListener(nsIScriptContext *aContext, JSObject *aScopeObject,
                     nsISupports *aTarget)
    : mContext(aContext), mScopeObject(aScopeObject), mTarget(aTarget)
  {
    // mTarget is a weak reference. We are guaranteed because of the
    // ownership model that the target will be freed (and the
    // references dropped) before either the context or the owner goes
    // away.

    NS_IF_ADDREF(mContext);
  }

  nsIScriptContext *GetEventContext()
  {
    return mContext;
  }

  nsISupports *GetEventTarget()
  {
    return mTarget;
  }

  JSObject *GetEventScope()
  {
    return mScopeObject;
  }

  virtual void SetEventName(nsIAtom* aName) = 0;

protected:
  ~nsIJSEventListener()
  {
    NS_IF_RELEASE(mContext);
  }

  nsIScriptContext *mContext;
  JSObject *mScopeObject;
  nsISupports *mTarget;
};

/* factory function */
nsresult NS_NewJSEventListener(nsIScriptContext *aContext,
                               JSObject *aScopeObject, nsISupports *aObject,
                               nsIDOMEventListener **aReturn);

#endif // nsIJSEventListener_h__
