1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#ifndef BASE_MESSAGE_LOOP_MESSAGE_PUMP_DISPATCHER_H 6#define BASE_MESSAGE_LOOP_MESSAGE_PUMP_DISPATCHER_H 7 8#include <stdint.h> 9 10#include "base/base_export.h" 11#include "base/event_types.h" 12 13namespace base { 14 15// Dispatcher is used during a nested invocation of Run to dispatch events when 16// |RunLoop(dispatcher).Run()| is used. If |RunLoop().Run()| is invoked, 17// MessageLoop does not dispatch events (or invoke TranslateMessage), rather 18// every message is passed to Dispatcher's Dispatch method for dispatch. It is 19// up to the Dispatcher whether or not to dispatch the event. 20// 21// The nested loop is exited by either posting a quit, or setting the 22// POST_DISPATCH_QUIT_LOOP flag on the return value from Dispatch. 23class BASE_EXPORT MessagePumpDispatcher { 24 public: 25 enum PostDispatchAction { 26 POST_DISPATCH_NONE = 0x0, 27 POST_DISPATCH_QUIT_LOOP = 0x1, 28 POST_DISPATCH_PERFORM_DEFAULT = 0x2, 29 }; 30 31 virtual ~MessagePumpDispatcher() {} 32 33 // Dispatches the event. The return value can have more than one 34 // PostDispatchAction flags OR'ed together. If POST_DISPATCH_PERFORM_DEFAULT 35 // is set in the returned value, then the message-pump performs the default 36 // action. If POST_DISPATCH_QUIT_LOOP is set, in the return value, then the 37 // nested loop exits immediately. 38 virtual uint32_t Dispatch(const NativeEvent& event) = 0; 39}; 40 41} // namespace base 42 43#endif // BASE_MESSAGE_LOOP_MESSAGE_PUMP_DISPATCHER_H 44