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_X11_H
6#define BASE_MESSAGE_LOOP_MESSAGE_PUMP_X11_H
7
8#include <bitset>
9#include <map>
10
11#include "base/memory/scoped_ptr.h"
12#include "base/message_loop/message_pump.h"
13#include "base/message_loop/message_pump_dispatcher.h"
14#include "base/message_loop/message_pump_glib.h"
15#include "base/message_loop/message_pump_observer.h"
16#include "base/observer_list.h"
17
18// It would be nice to include the X11 headers here so that we use Window
19// instead of its typedef of unsigned long, but we can't because everything in
20// chrome includes us through base/message_loop/message_loop.h, and X11's crappy
21// #define heavy headers muck up half of chrome.
22
23typedef struct _GPollFD GPollFD;
24typedef struct _GSource GSource;
25typedef struct _XDisplay Display;
26
27namespace base {
28
29// This class implements a message-pump for dispatching X events.
30//
31// If there's a current dispatcher given through RunWithDispatcher(), that
32// dispatcher receives events. Otherwise, we route to messages to dispatchers
33// who have subscribed to messages from a specific X11 window.
34class BASE_EXPORT MessagePumpX11 : public MessagePumpGlib,
35                                   public MessagePumpDispatcher {
36 public:
37  MessagePumpX11();
38  virtual ~MessagePumpX11();
39
40  // Returns default X Display.
41  static Display* GetDefaultXDisplay();
42
43  // Returns the UI or GPU message pump.
44  static MessagePumpX11* Current();
45
46  // Adds/Removes |dispatcher| for the |xid|. This will route all messages from
47  // the window |xid| to |dispatcher.
48  void AddDispatcherForWindow(MessagePumpDispatcher* dispatcher,
49                              unsigned long xid);
50  void RemoveDispatcherForWindow(unsigned long xid);
51
52  // Adds/Removes |dispatcher| to receive all events sent to the X root
53  // window. A root window can have multiple dispatchers, and events on root
54  // windows will be dispatched to all.
55  void AddDispatcherForRootWindow(MessagePumpDispatcher* dispatcher);
56  void RemoveDispatcherForRootWindow(MessagePumpDispatcher* dispatcher);
57
58  // Adds an Observer, which will start receiving notifications immediately.
59  void AddObserver(MessagePumpObserver* observer);
60
61  // Removes an Observer.  It is safe to call this method while an Observer is
62  // receiving a notification callback.
63  void RemoveObserver(MessagePumpObserver* observer);
64
65  // Internal function. Called by the glib source dispatch function. Processes
66  // all available X events.
67  bool DispatchXEvents();
68
69  // Blocks on the X11 event queue until we receive notification from the
70  // xserver that |w| has been mapped; StructureNotifyMask events on |w| are
71  // pulled out from the queue and dispatched out of order.
72  //
73  // For those that know X11, this is really a wrapper around XWindowEvent
74  // which still makes sure the preempted event is dispatched instead of
75  // dropped on the floor. This method exists because mapping a window is
76  // asynchronous (and we receive an XEvent when mapped), while there are also
77  // functions which require a mapped window.
78  void BlockUntilWindowMapped(unsigned long xid);
79
80 private:
81  typedef std::map<unsigned long, MessagePumpDispatcher*> DispatchersMap;
82
83  // Initializes the glib event source for X.
84  void InitXSource();
85
86  // Dispatches the XEvent and returns true if we should exit the current loop
87  // of message processing.
88  bool ProcessXEvent(MessagePumpDispatcher* dispatcher, XEvent* event);
89
90  // Sends the event to the observers. If an observer returns true, then it does
91  // not send the event to any other observers and returns true. Returns false
92  // if no observer returns true.
93  bool WillProcessXEvent(XEvent* xevent);
94  void DidProcessXEvent(XEvent* xevent);
95
96  // Returns the Dispatcher based on the event's target window.
97  MessagePumpDispatcher* GetDispatcherForXEvent(const NativeEvent& xev) const;
98
99  ObserverList<MessagePumpObserver>& observers() { return observers_; }
100
101  // Overridden from MessagePumpDispatcher:
102  virtual bool Dispatch(const NativeEvent& event) OVERRIDE;
103
104  // The event source for X events.
105  GSource* x_source_;
106
107  // The poll attached to |x_source_|.
108  scoped_ptr<GPollFD> x_poll_;
109
110  DispatchersMap dispatchers_;
111
112  // Dispatch calls can cause addition of new dispatchers as we iterate
113  // through them. Use ObserverList to ensure the iterator remains valid across
114  // additions.
115  ObserverList<MessagePumpDispatcher> root_window_dispatchers_;
116
117  // List of observers.
118  ObserverList<MessagePumpObserver> observers_;
119
120  unsigned long x_root_window_;
121
122  DISALLOW_COPY_AND_ASSIGN(MessagePumpX11);
123};
124
125#if !defined(TOOLKIT_GTK)
126typedef MessagePumpX11 MessagePumpForUI;
127#endif
128
129}  // namespace base
130
131#endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_X11_H
132