1// Copyright (c) 2011 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 CHROME_BROWSER_UI_LIBGTK2UI_GTK2_SIGNAL_REGISTRAR_H_
6#define CHROME_BROWSER_UI_LIBGTK2UI_GTK2_SIGNAL_REGISTRAR_H_
7
8#include <glib.h>
9#include <map>
10#include <vector>
11
12#include "base/basictypes.h"
13
14typedef void (*GCallback) (void);
15typedef struct _GObject GObject;
16typedef struct _GtkWidget GtkWidget;
17
18namespace libgtk2ui {
19
20// A class that ensures that callbacks don't run on stale owner objects. Similar
21// in spirit to NotificationRegistrar. Use as follows:
22//
23//   class ChromeObject {
24//    public:
25//     ChromeObject() {
26//       ...
27//
28//       signals_.Connect(widget, "event", CallbackThunk, this);
29//     }
30//
31//     ...
32//
33//    private:
34//     Gtk2SignalRegistrar signals_;
35//   };
36//
37// When |signals_| goes down, it will disconnect the handlers connected via
38// Connect.
39class Gtk2SignalRegistrar {
40 public:
41  Gtk2SignalRegistrar();
42  ~Gtk2SignalRegistrar();
43
44  // Connect before the default handler. Returns the handler id.
45  glong Connect(gpointer instance, const gchar* detailed_signal,
46                GCallback signal_handler, gpointer data);
47  // Connect after the default handler. Returns the handler id.
48  glong ConnectAfter(gpointer instance, const gchar* detailed_signal,
49                     GCallback signal_handler, gpointer data);
50
51  // Disconnects all signal handlers connected to |instance|.
52  void DisconnectAll(gpointer instance);
53
54 private:
55  typedef std::vector<glong> HandlerList;
56  typedef std::map<GObject*, HandlerList> HandlerMap;
57
58  static void WeakNotifyThunk(gpointer data, GObject* where_the_object_was) {
59    reinterpret_cast<Gtk2SignalRegistrar*>(data)->WeakNotify(
60        where_the_object_was);
61  }
62  void WeakNotify(GObject* where_the_object_was);
63
64  glong ConnectInternal(gpointer instance, const gchar* detailed_signal,
65                        GCallback signal_handler, gpointer data, bool after);
66
67  HandlerMap handler_lists_;
68
69  DISALLOW_COPY_AND_ASSIGN(Gtk2SignalRegistrar);
70};
71
72}  // namespace libgtk2ui
73
74#endif  // CHROME_BROWSER_UI_LIBGTK2UI_GTK2_SIGNAL_REGISTRAR_H_
75