// Copyright 2014 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.
#ifndef UI_EVENTS_PLATFORM_PLATFORM_EVENT_DISPATCHER_H_
#define UI_EVENTS_PLATFORM_PLATFORM_EVENT_DISPATCHER_H_
#include "base/basictypes.h"
#include "ui/events/events_export.h"
#include "ui/events/platform/platform_event_types.h"
namespace ui {
// See documentation for |PlatformEventDispatcher::DispatchEvent()| for
// explanation of the meaning of the flags.
enum PostDispatchAction {
POST_DISPATCH_NONE = 0x0,
POST_DISPATCH_QUIT_LOOP = 0x1,
POST_DISPATCH_PERFORM_DEFAULT = 0x2,
POST_DISPATCH_STOP_PROPAGATION = 0x4,
};
// PlatformEventDispatcher receives events from a PlatformEventSource and
// dispatches them.
class EVENTS_EXPORT PlatformEventDispatcher {
public:
// Returns whether this dispatcher wants to dispatch |event|.
virtual bool CanDispatchEvent(const PlatformEvent& event) = 0;
// Dispatches |event|. If this is not the default dispatcher, then the
// dispatcher can request that the default dispatcher gets a chance to
// dispatch the event by setting POST_DISPATCH_PERFORM_DEFAULT to the return
// value. If a nested message-loop is active, then the dispatcher can signal
// that the nested message-loop should be terminated by setting
// POST_DISPATCH_QUIT_LOOP flag on the return value. If the dispatcher has
// processed the event, and no other dispatcher should be allowed to dispatch
// the event, then the dispatcher should set POST_DISPATCH_STOP_PROPAGATION
// flag on the return value.
virtual uint32_t DispatchEvent(const PlatformEvent& event) = 0;
protected:
virtual ~PlatformEventDispatcher() {}
};
} // namespace ui
#endif // UI_EVENTS_PLATFORM_PLATFORM_EVENT_DISPATCHER_H_