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Serenity Operating System
1/*
2 * Copyright (c) 2020, the SerenityOS developers.
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/SyntaxHighlighter.h>
28#include <LibGUI/TextEditor.h>
29
30namespace GUI {
31
32SyntaxHighlighter::~SyntaxHighlighter()
33{
34}
35
36void SyntaxHighlighter::highlight_matching_token_pair()
37{
38 ASSERT(m_editor);
39 auto& document = m_editor->document();
40
41 enum class Direction {
42 Forward,
43 Backward,
44 };
45
46 auto find_span_of_type = [&](auto i, void* type, void* not_type, Direction direction) -> Optional<size_t> {
47 size_t nesting_level = 0;
48 bool forward = direction == Direction::Forward;
49
50 if (forward) {
51 ++i;
52 if (i >= document.spans().size())
53 return {};
54 } else {
55 if (i == 0)
56 return {};
57 --i;
58 }
59
60 for (;;) {
61 auto& span = document.spans().at(i);
62 auto span_token_type = span.data;
63 if (token_types_equal(span_token_type, not_type)) {
64 ++nesting_level;
65 } else if (token_types_equal(span_token_type, type)) {
66 if (nesting_level-- <= 0)
67 return i;
68 }
69
70 if (forward) {
71 ++i;
72 if (i >= document.spans().size())
73 return {};
74 } else {
75 if (i == 0)
76 return {};
77 --i;
78 }
79 }
80
81 return {};
82 };
83
84 auto make_buddies = [&](int index0, int index1) {
85 auto& buddy0 = document.spans()[index0];
86 auto& buddy1 = document.spans()[index1];
87 m_has_brace_buddies = true;
88 m_brace_buddies[0].index = index0;
89 m_brace_buddies[1].index = index1;
90 m_brace_buddies[0].span_backup = buddy0;
91 m_brace_buddies[1].span_backup = buddy1;
92 buddy0.background_color = Color::DarkCyan;
93 buddy1.background_color = Color::DarkCyan;
94 buddy0.color = Color::White;
95 buddy1.color = Color::White;
96 m_editor->update();
97 };
98
99 auto pairs = matching_token_pairs();
100
101 for (size_t i = 0; i < document.spans().size(); ++i) {
102 auto& span = const_cast<GUI::TextDocumentSpan&>(document.spans().at(i));
103 auto token_type = span.data;
104
105 for (auto& pair : pairs) {
106 if (token_types_equal(token_type, pair.open) && span.range.start() == m_editor->cursor()) {
107 auto buddy = find_span_of_type(i, pair.close, pair.open, Direction::Forward);
108 if (buddy.has_value())
109 make_buddies(i, buddy.value());
110 return;
111 }
112 }
113
114 auto right_of_end = span.range.end();
115 right_of_end.set_column(right_of_end.column() + 1);
116
117 for (auto& pair : pairs) {
118 if (token_types_equal(token_type, pair.close) && right_of_end == m_editor->cursor()) {
119 auto buddy = find_span_of_type(i, pair.open, pair.close, Direction::Backward);
120 if (buddy.has_value())
121 make_buddies(i, buddy.value());
122 return;
123 }
124 }
125 }
126}
127
128void SyntaxHighlighter::attach(TextEditor& editor)
129{
130 ASSERT(!m_editor);
131 m_editor = editor.make_weak_ptr();
132}
133
134void SyntaxHighlighter::detach()
135{
136 ASSERT(m_editor);
137 m_editor = nullptr;
138}
139
140void SyntaxHighlighter::cursor_did_change()
141{
142 ASSERT(m_editor);
143 auto& document = m_editor->document();
144 if (m_has_brace_buddies) {
145 if (m_brace_buddies[0].index >= 0 && m_brace_buddies[0].index < static_cast<int>(document.spans().size()))
146 document.set_span_at_index(m_brace_buddies[0].index, m_brace_buddies[0].span_backup);
147 if (m_brace_buddies[1].index >= 0 && m_brace_buddies[1].index < static_cast<int>(document.spans().size()))
148 document.set_span_at_index(m_brace_buddies[1].index, m_brace_buddies[1].span_backup);
149 m_has_brace_buddies = false;
150 m_editor->update();
151 }
152 highlight_matching_token_pair();
153}
154
155}