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Serenity Operating System
1/*
2 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <LibGUI/Command.h>
28#include <LibGUI/UndoStack.h>
29
30namespace GUI {
31
32UndoStack::UndoStack()
33{
34}
35
36UndoStack::~UndoStack()
37{
38}
39
40void UndoStack::undo()
41{
42 if (!can_undo())
43 return;
44
45 auto& undo_container = m_stack[m_stack_index];
46 auto& undo_vector = undo_container.m_undo_vector;
47
48 //If we try to undo a empty vector, delete it and skip over.
49 if (undo_vector.is_empty()) {
50 m_stack.remove(m_stack_index);
51 undo();
52 return;
53 }
54
55 for (size_t i = 0; i < undo_vector.size(); i++) {
56 auto& undo_command = undo_vector[i];
57 undo_command.undo();
58 }
59
60 m_stack_index++;
61}
62
63void UndoStack::redo()
64{
65 if (!can_redo())
66 return;
67
68 auto& undo_container = m_stack[m_stack_index - 1];
69 auto& redo_vector = undo_container.m_undo_vector;
70
71 for (int i = static_cast<int>(redo_vector.size()) - 1; i >= 0; i--) {
72 auto& undo_command = redo_vector[i];
73 undo_command.redo();
74 }
75
76 m_stack_index--;
77}
78
79void UndoStack::push(NonnullOwnPtr<Command>&& command)
80{
81 if (m_stack.is_empty()) {
82 auto undo_commands_container = make<UndoCommandsContainer>();
83 m_stack.prepend(move(undo_commands_container));
84 }
85
86 // Clear the elements of the stack before the m_undo_stack_index (Excluding our new element)
87 for (size_t i = 1; i < m_stack_index; i++)
88 m_stack.remove(1);
89
90 if (m_stack_index > 0 && !m_stack.is_empty())
91 m_stack[0].m_undo_vector.clear();
92
93 m_stack_index = 0;
94
95 m_stack[0].m_undo_vector.prepend(move(command));
96}
97
98void UndoStack::finalize_current_combo()
99{
100 if (m_stack.is_empty())
101 return;
102
103 auto& undo_vector = m_stack[0].m_undo_vector;
104
105 if (undo_vector.size() == m_last_updated_undo_vector_size && !undo_vector.is_empty()) {
106 auto undo_commands_container = make<UndoCommandsContainer>();
107 m_stack.prepend(move(undo_commands_container));
108 // Note: Remove dbg() if we're 100% sure there are no bugs left.
109 dbg() << "Undo stack increased to " << m_stack.size();
110
111 // Shift the index to the left since we're adding an empty container.
112 if (m_stack_index > 0)
113 m_stack_index++;
114 }
115
116 m_last_updated_undo_vector_size = undo_vector.size();
117}
118
119}