blob: fbe7a0e0e7b0a8b7563c064244c6e4a0fd06bedf [file] [log] [blame]
// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "base/compiler_specific.h"
#include "ui/events/events_export.h"
namespace ui {
class Event;
class EventTarget;
class EVENTS_EXPORT EventTargeter {
virtual ~EventTargeter() {}
// Returns the target |event| should be dispatched to. If there is no such
// target, return NULL. If |event| is a located event, the location of |event|
// is in the coordinate space of |root|. Furthermore, the targeter can mutate
// the event (e.g., by changing the location of the event to be in the
// returned target's coordinate space) so that it can be dispatched to the
// target without any further modification.
virtual EventTarget* FindTargetForEvent(EventTarget* root, Event* event) = 0;
// Returns the next best target for |event| as compared to |previous_target|.
// |event| is in the local coordinate space of |previous_target|.
// Also mutates |event| so that it can be dispatched to the returned target
// (e.g., by changing |event|'s location to be in the returned target's
// coordinate space).
virtual EventTarget* FindNextBestTarget(EventTarget* previous_target,
Event* event) = 0;
} // namespace ui