1 // Document/View sample for Boost.Signals2.
2 // Expands on doc_view_acm.cpp example by using boost::signals2::deconstruct
3 // as a post-constructing factory function.
4 //
5 // Copyright Keith MacDonald 2005.
6 // Copyright Frank Mori Hess 2009.
7 //
8 // Use, modification and
9 // distribution is subject to the Boost Software License, Version
10 // 1.0. (See accompanying file LICENSE_1_0.txt or copy at
11 // http://www.boost.org/LICENSE_1_0.txt)
12 // For more information, see http://www.boost.org
13
14 #include <iostream>
15 #include <string>
16 #include <boost/bind.hpp>
17 #include <boost/ref.hpp>
18 #include <boost/signals2/deconstruct.hpp>
19 #include <boost/signals2/signal.hpp>
20 #include <boost/shared_ptr.hpp>
21
22 class Document
23 {
24 public:
25 typedef boost::signals2::signal<void ()> signal_t;
26
27 public:
Document()28 Document()
29 {}
30
31 /* Connect a slot to the signal which will be emitted whenever
32 text is appended to the document. */
connect(const signal_t::slot_type & subscriber)33 boost::signals2::connection connect(const signal_t::slot_type &subscriber)
34 {
35 return m_sig.connect(subscriber);
36 }
37
append(const char * s)38 void append(const char* s)
39 {
40 m_text += s;
41 m_sig();
42 }
43
getText() const44 const std::string& getText() const
45 {
46 return m_text;
47 }
48
49 private:
50 signal_t m_sig;
51 std::string m_text;
52 };
53
54 class TextView
55 {
56 public:
57 /* This adl_postconstruct function will be found
58 via argument-dependent lookup when using boost::signals2::deconstruct. */
59 template<typename T>
adl_postconstruct(const boost::shared_ptr<T> & view_sp,TextView * view,Document & doc)60 friend void adl_postconstruct(const boost::shared_ptr<T> &view_sp, TextView *view, Document& doc)
61 {
62 view->m_document = &doc;
63 {
64 typedef Document::signal_t::slot_type slot_type;
65 slot_type myslot(&TextView::refresh, view);
66 doc.connect(myslot.track(view_sp));
67 }
68 }
69
refresh() const70 void refresh() const
71 {
72 std::cout << "TextView: " << m_document->getText() << std::endl;
73 }
74 private:
75 // give boost::signals2::deconstruct access to private constructor
76 friend class boost::signals2::deconstruct_access;
77 // private constructor to force use of deconstruct
TextView()78 TextView() : m_document(0)
79 {}
80
81 Document* m_document;
82 };
83
84 class HexView
85 {
86 public:
87 /* This adl_postconstruct function will be found
88 via argument-dependent lookup when using boost::signals2::deconstruct. */
89 template<typename T>
adl_postconstruct(const boost::shared_ptr<T> & view_sp,HexView * view,Document & doc)90 friend void adl_postconstruct(const boost::shared_ptr<T> &view_sp, HexView *view, Document& doc)
91 {
92 view->m_document = &doc;
93 {
94 typedef Document::signal_t::slot_type slot_type;
95 slot_type myslot(&HexView::refresh, view);
96 doc.connect(myslot.track(view_sp));
97 }
98 }
99
refresh() const100 void refresh() const
101 {
102 const std::string& s = m_document->getText();
103
104 std::cout << "HexView:";
105
106 for (std::string::const_iterator it = s.begin(); it != s.end(); ++it)
107 std::cout << ' ' << std::hex << static_cast<int>(*it);
108
109 std::cout << std::endl;
110 }
111 private:
112 // give boost::signals2::deconstruct access to private constructor
113 friend class boost::signals2::deconstruct_access;
114 // private constructor to force use of deconstruct
HexView()115 HexView(): m_document(0)
116 {}
117
118 Document* m_document;
119 };
120
121 namespace bs2 = boost::signals2;
122
main(int argc,char * argv[])123 int main(int argc, char* argv[])
124 {
125 Document doc;
126 boost::shared_ptr<TextView> v1 = bs2::deconstruct<TextView>().postconstruct(boost::ref(doc));
127 boost::shared_ptr<HexView> v2 = bs2::deconstruct<HexView>().postconstruct(boost::ref(doc));
128
129 doc.append(argc >= 2 ? argv[1] : "Hello world!");
130
131 v2.reset(); // destroy the HexView, automatically disconnecting
132 doc.append(" HexView should no longer be connected.");
133
134 return 0;
135 }
136