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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef BASE_MESSAGE_LOOP_MESSAGE_PUMP_GLIB_H_
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#define BASE_MESSAGE_LOOP_MESSAGE_PUMP_GLIB_H_
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#include "base/base_export.h"
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#include "base/memory/scoped_ptr.h"
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#include "base/message_loop/message_pump.h"
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#include "base/observer_list.h"
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#include "base/time/time.h"
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typedef struct _GMainContext GMainContext;
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typedef struct _GPollFD GPollFD;
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typedef struct _GSource GSource;
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// MessagePumpObserver is notified prior to an event being dispatched. As
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// Observers are notified of every change, they have to be FAST! The platform
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// specific implementation of the class is in message_pump_gtk/message_pump_x.
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class MessagePumpObserver;
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// MessagePumpDispatcher is used during a nested invocation of Run to dispatch
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// events. If Run is invoked with a non-NULL MessagePumpDispatcher, MessageLoop
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// does not dispatch events (or invoke gtk_main_do_event), rather every event is
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// passed to Dispatcher's Dispatch method for dispatch. It is up to the
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// Dispatcher to dispatch, or not, the event. The platform specific
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// implementation of the class is in message_pump_gtk/message_pump_x.
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class MessagePumpDispatcher;
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// This class implements a base MessagePump needed for TYPE_UI MessageLoops on
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// platforms using GLib.
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class BASE_EXPORT MessagePumpGlib : public MessagePump {
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virtual ~MessagePumpGlib();
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// Like MessagePump::Run, but events are routed through dispatcher.
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virtual void RunWithDispatcher(Delegate* delegate,
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MessagePumpDispatcher* dispatcher);
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// Internal methods used for processing the pump callbacks. They are
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// public for simplicity but should not be used directly. HandlePrepare
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// is called during the prepare step of glib, and returns a timeout that
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// will be passed to the poll. HandleCheck is called after the poll
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// has completed, and returns whether or not HandleDispatch should be called.
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// HandleDispatch is called if HandleCheck returned true.
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void HandleDispatch();
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// Overridden from MessagePump:
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virtual void Run(Delegate* delegate) OVERRIDE;
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virtual void Quit() OVERRIDE;
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virtual void ScheduleWork() OVERRIDE;
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virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) OVERRIDE;
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// Returns the dispatcher for the current run state (|state_->dispatcher|).
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MessagePumpDispatcher* GetDispatcher();
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bool ShouldQuit() const;
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// We may make recursive calls to Run, so we save state that needs to be
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// separate between them in this structure type.
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// This is a GLib structure that we can add event sources to. We use the
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// default GLib context, which is the one to which all GTK events are
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GMainContext* context_;
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// This is the time when we need to do delayed work.
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TimeTicks delayed_work_time_;
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// The work source. It is shared by all calls to Run and destroyed when
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// the message pump is destroyed.
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GSource* work_source_;
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// We use a wakeup pipe to make sure we'll get out of the glib polling phase
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// when another thread has scheduled us to do some work. There is a glib
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// mechanism g_main_context_wakeup, but this won't guarantee that our event's
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// Dispatch() will be called.
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int wakeup_pipe_read_;
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int wakeup_pipe_write_;
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// Use a scoped_ptr to avoid needing the definition of GPollFD in the header.
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scoped_ptr<GPollFD> wakeup_gpollfd_;
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DISALLOW_COPY_AND_ASSIGN(MessagePumpGlib);
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#endif // BASE_MESSAGE_LOOP_MESSAGE_PUMP_GLIB_H_