1// Boost.Signals library
2
3// Copyright Douglas Gregor 2001-2004. Use, modification and
4// distribution is subject to the Boost Software License, Version
5// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
6// http://www.boost.org/LICENSE_1_0.txt)
7
8// For more information, see http://www.boost.org
9
10#ifndef BOOST_SIGNALS_CONNECTION_HPP
11#define BOOST_SIGNALS_CONNECTION_HPP
12
13#include <boost/signals/detail/signals_common.hpp>
14#include <boost/smart_ptr.hpp>
15#include <boost/operators.hpp>
16#include <boost/any.hpp>
17#include <list>
18#include <cassert>
19#include <utility>
20
21#ifdef BOOST_HAS_ABI_HEADERS
22# include BOOST_ABI_PREFIX
23#endif
24
25namespace boost {
26 namespace BOOST_SIGNALS_NAMESPACE {
27 class trackable;
28
29 namespace detail {
30 // Represents an object that has been bound as part of a slot, and how
31 // to notify that object of a disconnect
32 struct bound_object {
33 void* obj;
34 void* data;
35 void (*disconnect)(void*, void*);
36
37 bool operator==(const bound_object& other) const
38 { return obj == other.obj && data == other.data; }
39 bool operator<(const bound_object& other) const
40 { return obj < other.obj; }
41
42 // To support intel 80 compiler, 2004/03/18 (Mark Rodgers)
43 bool operator!=(const bound_object& other) const
44 { return !(*this==other); }
45 bool operator>(const bound_object& other) const
46 { return !(*this < other); }
47 };
48
49 // Describes the connection between a signal and the objects that are
50 // bound for a specific slot. Enables notification of the signal and the
51 // slots when a disconnect is requested.
52 struct basic_connection {
53 void* signal;
54 void* signal_data;
55 void (*signal_disconnect)(void*, void*);
56 bool blocked_;
57
58 std::list<bound_object> bound_objects;
59 };
60 } // end namespace detail
61
62 // The user may freely pass around the "connection" object and terminate
63 // the connection at any time using disconnect().
64 class BOOST_SIGNALS_DECL connection :
65 private less_than_comparable1<connection>,
66 private equality_comparable1<connection>
67 {
68 public:
69 connection() : con(), controlling_connection(false) {}
70 connection(const connection&);
71 ~connection();
72
73 // Block he connection: if the connection is still active, there
74 // will be no notification
75 void block(bool should_block = true) { con->blocked_ = should_block; }
76 void unblock() { con->blocked_ = false; }
77 bool blocked() const { return !connected() || con->blocked_; }
78
79 // Disconnect the signal and slot, if they are connected
80 void disconnect() const;
81
82 // Returns true if the signal and slot are connected
83 bool connected() const { return con.get() && con->signal_disconnect; }
84
85 // Comparison of connections
86 bool operator==(const connection& other) const;
87 bool operator<(const connection& other) const;
88
89 // Connection assignment
90 connection& operator=(const connection& other) ;
91
92 // Swap connections
93 void swap(connection& other);
94
95 public: // TBD: CHANGE THIS
96 // Set whether this connection object is controlling or not
97 void set_controlling(bool control = true)
98 { controlling_connection = control; }
99
100 shared_ptr<BOOST_SIGNALS_NAMESPACE::detail::basic_connection>
101 get_connection() const
102 { return con; }
103
104 private:
105 friend class detail::signal_base_impl;
106 friend class detail::slot_base;
107 friend class trackable;
108
109 // Reset this connection to refer to a different actual connection
110 void reset(BOOST_SIGNALS_NAMESPACE::detail::basic_connection*);
111
112 // Add a bound object to this connection (not for users)
113 void add_bound_object(const BOOST_SIGNALS_NAMESPACE::detail::bound_object& b);
114
115 friend class BOOST_SIGNALS_NAMESPACE::detail::bound_objects_visitor;
116
117 // Pointer to the actual contents of the connection
118 shared_ptr<BOOST_SIGNALS_NAMESPACE::detail::basic_connection> con;
119
120 // True if the destruction of this connection object should disconnect
121 bool controlling_connection;
122 };
123
124 // Similar to connection, but will disconnect the connection when it is
125 // destroyed unless release() has been called.
126 class BOOST_SIGNALS_DECL scoped_connection : public connection {
127 public:
128 scoped_connection() : connection(), released(false) {}
129 scoped_connection(const connection&);
130 scoped_connection(const scoped_connection&);
131 ~scoped_connection();
132
133 connection release();
134
135 void swap(scoped_connection&);
136
137 scoped_connection& operator=(const connection&);
138 scoped_connection& operator=(const scoped_connection&);
139
140 private:
141 bool released;
142 };
143
144 namespace detail {
145 struct connection_slot_pair {
146 connection first;
147 any second;
148
149 connection_slot_pair() {}
150
151 connection_slot_pair(const connection& c, const any& a)
152 : first(c), second(a)
153 {
154 }
155
156 // Dummys to allow explicit instantiation to work
157 bool operator==(const connection_slot_pair&) const { return false; }
158 bool operator<(const connection_slot_pair&) const { return false;}
159 };
160
161 // Determines if the underlying connection is disconnected
162 struct is_disconnected {
163 typedef connection_slot_pair argument_type;
164 typedef bool result_type;
165
166 inline bool operator()(const argument_type& c) const
167 {
168 return !c.first.connected();
169 }
170 };
171
172 // Determines if the underlying connection is callable, ie if
173 // it is connected and not blocked
174 struct is_callable {
175 typedef connection_slot_pair argument_type;
176 typedef bool result_type;
177
178 inline bool operator()(const argument_type& c) const
179 {
180 return c.first.connected() && !c.first.blocked() ;
181 }
182 };
183
184 // Autodisconnects the bound object when it is destroyed unless the
185 // release method is invoked.
186 class auto_disconnect_bound_object {
187 public:
188 auto_disconnect_bound_object(const bound_object& b) :
189 binding(b), auto_disconnect(true)
190 {
191 }
192
193 ~auto_disconnect_bound_object()
194 {
195 if (auto_disconnect)
196 binding.disconnect(binding.obj, binding.data);
197 }
198
199 void release() { auto_disconnect = false; }
200
201 private:
202 bound_object binding;
203 bool auto_disconnect;
204 };
205 } // end namespace detail
206 } // end namespace BOOST_SIGNALS_NAMESPACE
207} // end namespace boost
208
209#ifdef BOOST_HAS_ABI_HEADERS
210# include BOOST_ABI_SUFFIX
211#endif
212
213#endif // BOOST_SIGNALS_CONNECTION_HPP
214

source code of boost/boost/signals/connection.hpp