1/**************************************************************************/
2/* self_list.h */
3/**************************************************************************/
4/* This file is part of: */
5/* GODOT ENGINE */
6/* https://godotengine.org */
7/**************************************************************************/
8/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
9/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
10/* */
11/* Permission is hereby granted, free of charge, to any person obtaining */
12/* a copy of this software and associated documentation files (the */
13/* "Software"), to deal in the Software without restriction, including */
14/* without limitation the rights to use, copy, modify, merge, publish, */
15/* distribute, sublicense, and/or sell copies of the Software, and to */
16/* permit persons to whom the Software is furnished to do so, subject to */
17/* the following conditions: */
18/* */
19/* The above copyright notice and this permission notice shall be */
20/* included in all copies or substantial portions of the Software. */
21/* */
22/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
23/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
24/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
25/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
26/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
27/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
28/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
29/**************************************************************************/
30
31#ifndef SELF_LIST_H
32#define SELF_LIST_H
33
34#include "core/error/error_macros.h"
35#include "core/typedefs.h"
36
37template <class T>
38class SelfList {
39public:
40 class List {
41 SelfList<T> *_first = nullptr;
42 SelfList<T> *_last = nullptr;
43
44 public:
45 void add(SelfList<T> *p_elem) {
46 ERR_FAIL_COND(p_elem->_root);
47
48 p_elem->_root = this;
49 p_elem->_next = _first;
50 p_elem->_prev = nullptr;
51
52 if (_first) {
53 _first->_prev = p_elem;
54
55 } else {
56 _last = p_elem;
57 }
58
59 _first = p_elem;
60 }
61
62 void add_last(SelfList<T> *p_elem) {
63 ERR_FAIL_COND(p_elem->_root);
64
65 p_elem->_root = this;
66 p_elem->_next = nullptr;
67 p_elem->_prev = _last;
68
69 if (_last) {
70 _last->_next = p_elem;
71
72 } else {
73 _first = p_elem;
74 }
75
76 _last = p_elem;
77 }
78
79 void remove(SelfList<T> *p_elem) {
80 ERR_FAIL_COND(p_elem->_root != this);
81 if (p_elem->_next) {
82 p_elem->_next->_prev = p_elem->_prev;
83 }
84
85 if (p_elem->_prev) {
86 p_elem->_prev->_next = p_elem->_next;
87 }
88
89 if (_first == p_elem) {
90 _first = p_elem->_next;
91 }
92
93 if (_last == p_elem) {
94 _last = p_elem->_prev;
95 }
96
97 p_elem->_next = nullptr;
98 p_elem->_prev = nullptr;
99 p_elem->_root = nullptr;
100 }
101
102 void clear() {
103 while (_first) {
104 remove(_first);
105 }
106 }
107
108 _FORCE_INLINE_ SelfList<T> *first() { return _first; }
109 _FORCE_INLINE_ const SelfList<T> *first() const { return _first; }
110
111 _FORCE_INLINE_ List() {}
112 _FORCE_INLINE_ ~List() {
113 // A self list must be empty on destruction.
114 DEV_ASSERT(_first == nullptr);
115 }
116 };
117
118private:
119 List *_root = nullptr;
120 T *_self = nullptr;
121 SelfList<T> *_next = nullptr;
122 SelfList<T> *_prev = nullptr;
123
124public:
125 _FORCE_INLINE_ bool in_list() const { return _root; }
126 _FORCE_INLINE_ void remove_from_list() {
127 if (_root) {
128 _root->remove(this);
129 }
130 }
131 _FORCE_INLINE_ SelfList<T> *next() { return _next; }
132 _FORCE_INLINE_ SelfList<T> *prev() { return _prev; }
133 _FORCE_INLINE_ const SelfList<T> *next() const { return _next; }
134 _FORCE_INLINE_ const SelfList<T> *prev() const { return _prev; }
135 _FORCE_INLINE_ T *self() const { return _self; }
136
137 _FORCE_INLINE_ SelfList(T *p_self) {
138 _self = p_self;
139 }
140
141 _FORCE_INLINE_ ~SelfList() {
142 if (_root) {
143 _root->remove(this);
144 }
145 }
146};
147
148#endif // SELF_LIST_H
149