1 | // Copyright (C) 2024 The Qt Company Ltd. |
2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
3 | |
4 | #ifndef QGLIST_HELPER_P_H |
5 | #define QGLIST_HELPER_P_H |
6 | |
7 | // |
8 | // W A R N I N G |
9 | // ------------- |
10 | // |
11 | // This file is not part of the Qt API. It exists purely as an |
12 | // implementation detail. This header file may change from version to |
13 | // version without notice, or even be removed. |
14 | // |
15 | // We mean it. |
16 | // |
17 | |
18 | #include <QtCore/qtconfigmacros.h> |
19 | |
20 | #include <glib.h> |
21 | #include <iterator> |
22 | |
23 | QT_BEGIN_NAMESPACE |
24 | |
25 | namespace QGstUtils { |
26 | |
27 | template <typename ListType, bool IsConst> |
28 | struct GListIterator |
29 | { |
30 | using GListType = std::conditional_t<IsConst, const GList *, GList *>; |
31 | |
32 | explicit GListIterator(GListType element = nullptr) : element(element) { } |
33 | |
34 | const ListType &operator*() const noexcept { return *operator->(); } |
35 | const ListType *operator->() const noexcept |
36 | { |
37 | return reinterpret_cast<const ListType *>(&element->data); |
38 | } |
39 | |
40 | GListIterator &operator++() noexcept |
41 | { |
42 | if (element) |
43 | element = element->next; |
44 | |
45 | return *this; |
46 | } |
47 | GListIterator operator++(int n) noexcept |
48 | { |
49 | for (int i = 0; i != n; ++i) |
50 | operator++(); |
51 | |
52 | return *this; |
53 | } |
54 | |
55 | bool operator==(const GListIterator &r) const noexcept { return element == r.element; } |
56 | bool operator!=(const GListIterator &r) const noexcept { return element != r.element; } |
57 | |
58 | using difference_type = std::ptrdiff_t; |
59 | using value_type = ListType; |
60 | using pointer = value_type *; |
61 | using reference = value_type &; |
62 | using iterator_category = std::input_iterator_tag; |
63 | |
64 | GListType element = nullptr; |
65 | }; |
66 | |
67 | template <typename ListType, bool IsConst> |
68 | struct GListRangeAdaptorImpl |
69 | { |
70 | static_assert(std::is_pointer_v<ListType>); |
71 | |
72 | using GListType = std::conditional_t<IsConst, const GList *, GList *>; |
73 | |
74 | explicit GListRangeAdaptorImpl(GListType list) : head(list) { } |
75 | |
76 | auto begin() { return GListIterator<ListType, IsConst>(head); } |
77 | auto end() { return GListIterator<ListType, IsConst>(nullptr); } |
78 | |
79 | GListType head; |
80 | }; |
81 | |
82 | template <typename ListType> |
83 | using GListRangeAdaptor = GListRangeAdaptorImpl<ListType, false>; |
84 | template <typename ListType> |
85 | using GListConstRangeAdaptor = GListRangeAdaptorImpl<ListType, true>; |
86 | |
87 | } // namespace QGstUtils |
88 | |
89 | QT_END_NAMESPACE |
90 | |
91 | #endif |
92 | |