1 /****************************************************************************
2 **
3 ** Copyright (C) 2016 The Qt Company Ltd.
4 ** Contact: https://www.qt.io/licensing/
5 **
6 ** This file is part of the QtCore module of the Qt Toolkit.
7 **
8 ** $QT_BEGIN_LICENSE:LGPL$
9 ** Commercial License Usage
10 ** Licensees holding valid commercial Qt licenses may use this file in
11 ** accordance with the commercial license agreement provided with the
12 ** Software or, alternatively, in accordance with the terms contained in
13 ** a written agreement between you and The Qt Company. For licensing terms
14 ** and conditions see https://www.qt.io/terms-conditions. For further
15 ** information use the contact form at https://www.qt.io/contact-us.
16 **
17 ** GNU Lesser General Public License Usage
18 ** Alternatively, this file may be used under the terms of the GNU Lesser
19 ** General Public License version 3 as published by the Free Software
20 ** Foundation and appearing in the file LICENSE.LGPL3 included in the
21 ** packaging of this file. Please review the following information to
22 ** ensure the GNU Lesser General Public License version 3 requirements
23 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
24 **
25 ** GNU General Public License Usage
26 ** Alternatively, this file may be used under the terms of the GNU
27 ** General Public License version 2.0 or (at your option) the GNU General
28 ** Public license version 3 or any later version approved by the KDE Free
29 ** Qt Foundation. The licenses are as published by the Free Software
30 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
31 ** included in the packaging of this file. Please review the following
32 ** information to ensure the GNU General Public License requirements will
33 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and
34 ** https://www.gnu.org/licenses/gpl-3.0.html.
35 **
36 ** $QT_END_LICENSE$
37 **
38 ****************************************************************************/
39 
40 #ifndef Q_QDOC
41 
42 #ifndef QOBJECT_H
43 #error Do not include qobject_impl.h directly
44 #endif
45 
46 #if 0
47 #pragma qt_sync_skip_header_check
48 #pragma qt_sync_stop_processing
49 #endif
50 
51 QT_BEGIN_NAMESPACE
52 
53 
54 namespace QtPrivate {
55     /*
56         Logic to statically generate the array of qMetaTypeId
57         ConnectionTypes<FunctionPointer<Signal>::Arguments>::types() returns an array
58         of int that is suitable for the types arguments of the connection functions.
59 
60         The array only exist of all the types are declared as a metatype
61         (detected using the TypesAreDeclaredMetaType helper struct)
62         If one of the type is not declared, the function return 0 and the signal
63         cannot be used in queued connection.
64     */
65     template <typename ArgList> struct TypesAreDeclaredMetaType { enum { Value = false }; };
66     template <> struct TypesAreDeclaredMetaType<List<>> { enum { Value = true }; };
67     template <typename Arg, typename... Tail> struct TypesAreDeclaredMetaType<List<Arg, Tail...> >
68     { enum { Value = QMetaTypeId2<Arg>::Defined && TypesAreDeclaredMetaType<List<Tail...>>::Value }; };
69 
70     template <typename ArgList, bool Declared = TypesAreDeclaredMetaType<ArgList>::Value > struct ConnectionTypes
71     { static const int *types() { return nullptr; } };
72     template <> struct ConnectionTypes<List<>, true>
73     { static const int *types() { return nullptr; } };
74     template <typename... Args> struct ConnectionTypes<List<Args...>, true>
75     { static const int *types() { static const int t[sizeof...(Args) + 1] = { (QtPrivate::QMetaTypeIdHelper<Args>::qt_metatype_id())..., 0 }; return t; } };
76 
77     // implementation of QSlotObjectBase for which the slot is a static function
78     // Args and R are the List of arguments and the return type of the signal to which the slot is connected.
79     template<typename Func, typename Args, typename R> class QStaticSlotObject : public QSlotObjectBase
80     {
81         typedef QtPrivate::FunctionPointer<Func> FuncType;
82         Func function;
83         static void impl(int which, QSlotObjectBase *this_, QObject *r, void **a, bool *ret)
84         {
85             switch (which) {
86             case Destroy:
87                 delete static_cast<QStaticSlotObject*>(this_);
88                 break;
89             case Call:
90                 FuncType::template call<Args, R>(static_cast<QStaticSlotObject*>(this_)->function, r, a);
91                 break;
92             case Compare:   // not implemented
93             case NumOperations:
94                 Q_UNUSED(ret);
95             }
96         }
97     public:
98         explicit QStaticSlotObject(Func f) : QSlotObjectBase(&impl), function(f) {}
99     };
100 }
101 
102 
103 QT_END_NAMESPACE
104 
105 #endif
106