blob: 9faaae7f295ea5b55f018853000c26666617c9a1 [file] [log] [blame]
* Copyright (C) 2006, 2008, 2009 Apple Inc. All rights reserved.
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* Library General Public License for more details.
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
#include "base/macros.h"
#include "third_party/blink/renderer/core/core_export.h"
#include "third_party/blink/renderer/core/probe/async_task_id.h"
#include "third_party/blink/renderer/platform/bindings/name_client.h"
#include "third_party/blink/renderer/platform/heap/handle.h"
#include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
namespace blink {
class Event;
class ExecutionContext;
// EventListener represents 'callback' in 'event listener' in DOM standard.
// While RegisteredEventListener represents 'event listener', which consists of
// - type
// - callback
// - capture
// - passive
// - once
// - removed
// EventListener represents 'callback' part.
class CORE_EXPORT EventListener : public GarbageCollected<EventListener>,
public NameClient {
virtual ~EventListener() = default;
// Invokes this event listener.
virtual void Invoke(ExecutionContext*, Event*) = 0;
// Returns true if this implements IDL EventHandler family.
virtual bool IsEventHandler() const { return false; }
// Returns true if this implements IDL EventHandler family and the value is
// a content attribute (or compiled from a content attribute).
virtual bool IsEventHandlerForContentAttribute() const { return false; }
// Returns an uncompiled script body.
virtual const String& ScriptBody() const { return g_empty_string; }
// Returns true if this event listener was created in the current world.
virtual bool BelongsToTheCurrentWorld(ExecutionContext*) const {
return false;
// Returns true if this event listener is considered as the same with the
// other event listener (in context of EventTarget.removeEventListener).
// See also |RegisteredEventListener::Matches|.
// This function must satisfy the symmetric property; a.Matches(b) must
// produce the same result as b.Matches(a).
virtual bool Matches(const EventListener&) const = 0;
virtual void Trace(Visitor*) {}
const char* NameInHeapSnapshot() const override { return "EventListener"; }
// Helper functions for DowncastTraits.
virtual bool IsJSBasedEventListener() const { return false; }
virtual bool IsNativeEventListener() const { return false; }
probe::AsyncTaskId* async_task_id() { return &async_task_id_; }
EventListener() = default;
probe::AsyncTaskId async_task_id_;
// Only these two classes are direct subclasses of EventListener. Other
// subclasses must inherit from either of them.
friend class JSBasedEventListener;
friend class NativeEventListener;
} // namespace blink