The Battle for Wesnoth  1.17.6+dev
walker_container.cpp
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1 /*
2  Copyright (C) 2011 - 2022
3  by Mark de Wever <koraq@xs4all.nl>
4  Part of the Battle for Wesnoth Project https://www.wesnoth.org/
5 
6  This program is free software; you can redistribute it and/or modify
7  it under the terms of the GNU General Public License as published by
8  the Free Software Foundation; either version 2 of the License, or
9  (at your option) any later version.
10  This program is distributed in the hope that it will be useful,
11  but WITHOUT ANY WARRANTY.
12 
13  See the COPYING file for more details.
14 */
15 
16 #define GETTEXT_DOMAIN "wesnoth-lib"
17 
19 
20 #include <cassert>
21 
22 namespace gui2::iteration
23 {
24 
26  : container_(container), widget_(&container), itor_(container.begin())
27 {
28 }
29 
31 {
32  if(at_end(level)) {
33  return fail;
34  }
35 
36  switch(level) {
37  case self:
38  if(widget_) {
39  widget_ = nullptr;
40  return invalid;
41  }
42  assert(false);
43  return fail;
44  case internal:
45  if(!entered_grid) {
46  entered_grid = true;
47  in_grid = true;
48  return valid;
49  }
50  if(in_grid) {
51  in_grid = false;
52  return invalid;
53  }
54  assert(false);
55  return fail;
56  case child:
57  if(itor_ != container_.end()) {
58  ++itor_;
59  return itor_ == container_.end() ? invalid : valid;
60  }
61  }
62 
63  assert(false);
64  return fail;
65 }
66 
67 bool container::at_end(const level level) const
68 {
69  switch(level) {
70  case self:
71  return widget_ == nullptr;
72  case internal:
73  return entered_grid && !in_grid;
74  case child:
75  return (itor_ == container_.end());
76  }
77 
78  assert(false);
79  return true;
80 }
81 
83 {
84  switch(level) {
85  case self:
86  return widget_;
87  case internal:
88  return &container_.get_grid();
89  case child:
90  if(itor_ == container_.end()) {
91  return nullptr;
92  } else {
93  return *itor_;
94  }
95  }
96 
97  assert(false);
98  return nullptr;
99 }
100 
101 } // namespace gui2::iteration
When calling next the following it has the following results.
Definition: walker.hpp:69
When calling next the following it has the following results.
Definition: walker.hpp:58
level
The level to walk at.
Definition: walker.hpp:35
grid::iterator end()
const grid & get_grid() const
gui2::container_base & container_
The container which the walker is attached to.
gui2::grid::iterator itor_
The iterator to the children of container_.
Base class for all widgets.
Definition: widget.hpp:53
virtual gui2::widget * get(const level level)
Inherited from gui2::iteration::walker_base.
state_t
The state of the walker.
Definition: walker.hpp:49
virtual bool at_end(const level level) const
Inherited from gui2::iteration::walker_base.
gui2::widget * widget_
The widget which the walker is attached to.
virtual state_t next(const level level)
Inherited from gui2::iteration::walker_base.
A walker for a gui2::container_base.
bool entered_grid
Whether the grid has been yielded.
A generic container base class.
container(gui2::container_base &container)
Constructor.
Visit the children of its nested grid.
Definition: walker.hpp:41