ClickHouse/base/poco/XML/include/Poco/DOM/EventTarget.h

//
// EventTarget.h
//
// Library: XML
// Package: DOM
// Module:  DOMEvents
//
// Definition of the DOM EventTarget interface.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef DOM_EventTarget_INCLUDED
#define DOM_EventTarget_INCLUDED


#include "Poco/DOM/DOMObject.h"
#include "Poco/XML/XML.h"
#include "Poco/XML/XMLString.h"


namespace Poco
{
namespace XML
{


    class EventListener;
    class Event;


    class XML_API EventTarget : public DOMObject
    /// The EventTarget interface is implemented by all Nodes in an implementation
    /// which supports the DOM Event Model. Therefore, this interface can be obtained
    /// by using binding-specific casting methods on an instance of the Node interface.
    /// The interface allows registration and removal of EventListeners on an EventTarget
    /// and dispatch of events to that EventTarget.
    {
    public:
        virtual void addEventListener(const XMLString & type, EventListener * listener, bool useCapture) = 0;
        /// This method allows the registration of event listeners on
        /// the event target. If an EventListener is added to an
        /// EventTarget while it is processing an event, it will not
        /// be triggered by the current actions but may be triggered
        /// during a later stage of event flow, such as the bubbling phase.
        /// If multiple identical EventListeners are registered on the same
        /// EventTarget with the same parameters the duplicate instances are
        /// discarded. They do not cause the EventListener to be called twice and since they are
        /// discarded they do not need to be removed with the removeEventListener method.

        virtual void removeEventListener(const XMLString & type, EventListener * listener, bool useCapture) = 0;
        /// This method allows the removal of event listeners from the event
        /// target. If an EventListener is removed from an EventTarget while it is
        /// processing an event, it will not be triggered by the current actions.
        /// EventListeners can never be invoked after being removed.
        /// Calling removeEventListener with arguments which do not identify
        /// any currently registered EventListener on the EventTarget has no effect.

        virtual bool dispatchEvent(Event * evt) = 0;
        /// This method allows the dispatch of events into the implementations
        /// event model. Events dispatched in this manner will have the same capturing and
        /// bubbling behavior as events dispatched directly by the
        /// implementation. The target of the event is the EventTarget on
        /// which dispatchEvent is called.

    protected:
        virtual ~EventTarget();
    };


}
} // namespace Poco::XML


#endif // DOM_EventTarget_INCLUDED