jcs.org
Serenity Operating System
1/*
2 * Copyright (c) 2020, the SerenityOS developers.
3 *
4 * SPDX-License-Identifier: BSD-2-Clause
5 */
6
7#include <AK/Function.h>
8#include <LibLine/SuggestionManager.h>
9
10namespace Line {
11
12CompletionSuggestion::CompletionSuggestion(StringView completion, StringView trailing_trivia, StringView display_trivia, Style style)
13 : style(style)
14 , text_string(completion)
15 , display_trivia_string(display_trivia)
16 , is_valid(true)
17{
18 Utf8View text_u8 { completion };
19 Utf8View trivia_u8 { trailing_trivia };
20 Utf8View display_u8 { display_trivia };
21
22 for (auto cp : text_u8)
23 text.append(cp);
24
25 for (auto cp : trivia_u8)
26 this->trailing_trivia.append(cp);
27
28 for (auto cp : display_u8)
29 this->display_trivia.append(cp);
30
31 text_view = Utf32View { text.data(), text.size() };
32 trivia_view = Utf32View { this->trailing_trivia.data(), this->trailing_trivia.size() };
33 display_trivia_view = Utf32View { this->display_trivia.data(), this->display_trivia.size() };
34}
35
36void SuggestionManager::set_suggestions(Vector<CompletionSuggestion>&& suggestions)
37{
38 m_suggestions = move(suggestions);
39
40 // Set the views and make sure we were not given invalid suggestions
41 for (auto& suggestion : m_suggestions) {
42 VERIFY(suggestion.is_valid);
43 suggestion.text_view = { suggestion.text.data(), suggestion.text.size() };
44 suggestion.trivia_view = { suggestion.trailing_trivia.data(), suggestion.trailing_trivia.size() };
45 suggestion.display_trivia_view = { suggestion.display_trivia.data(), suggestion.display_trivia.size() };
46 }
47
48 size_t common_suggestion_prefix { 0 };
49 if (m_suggestions.size() == 1) {
50 m_largest_common_suggestion_prefix_length = m_suggestions[0].text_view.length();
51 } else if (m_suggestions.size()) {
52 u32 last_valid_suggestion_code_point;
53
54 for (;; ++common_suggestion_prefix) {
55 if (m_suggestions[0].text_view.length() <= common_suggestion_prefix)
56 goto no_more_commons;
57
58 last_valid_suggestion_code_point = m_suggestions[0].text_view.code_points()[common_suggestion_prefix];
59
60 for (auto& suggestion : m_suggestions) {
61 if (suggestion.text_view.length() <= common_suggestion_prefix || suggestion.text_view.code_points()[common_suggestion_prefix] != last_valid_suggestion_code_point) {
62 goto no_more_commons;
63 }
64 }
65 }
66 no_more_commons:;
67 m_largest_common_suggestion_prefix_length = common_suggestion_prefix;
68 } else {
69 m_largest_common_suggestion_prefix_length = 0;
70 }
71}
72
73void SuggestionManager::next()
74{
75 if (m_suggestions.size())
76 m_next_suggestion_index = (m_next_suggestion_index + 1) % m_suggestions.size();
77 else
78 m_next_suggestion_index = 0;
79}
80
81void SuggestionManager::previous()
82{
83 if (m_next_suggestion_index == 0)
84 m_next_suggestion_index = m_suggestions.size();
85 m_next_suggestion_index--;
86}
87
88CompletionSuggestion const& SuggestionManager::suggest()
89{
90 m_last_shown_suggestion = m_suggestions[m_next_suggestion_index];
91 m_selected_suggestion_index = m_next_suggestion_index;
92 return m_last_shown_suggestion;
93}
94
95void SuggestionManager::set_current_suggestion_initiation_index(size_t index)
96{
97 auto& suggestion = m_suggestions[m_next_suggestion_index];
98
99 if (m_last_shown_suggestion_display_length)
100 m_last_shown_suggestion.start_index = index - suggestion.static_offset - m_last_shown_suggestion_display_length;
101 else
102 m_last_shown_suggestion.start_index = index - suggestion.static_offset - suggestion.invariant_offset;
103
104 m_last_shown_suggestion_display_length = m_last_shown_suggestion.text_view.length();
105 m_last_shown_suggestion_was_complete = true;
106}
107
108SuggestionManager::CompletionAttemptResult SuggestionManager::attempt_completion(CompletionMode mode, size_t initiation_start_index)
109{
110 CompletionAttemptResult result { mode };
111
112 if (m_next_suggestion_index < m_suggestions.size()) {
113 auto& next_suggestion = m_suggestions[m_next_suggestion_index];
114
115 if (mode == CompletePrefix && !next_suggestion.allow_commit_without_listing) {
116 result.new_completion_mode = CompletionMode::ShowSuggestions;
117 result.avoid_committing_to_single_suggestion = true;
118 m_last_shown_suggestion_display_length = 0;
119 m_last_shown_suggestion_was_complete = false;
120 m_last_shown_suggestion = DeprecatedString::empty();
121 return result;
122 }
123
124 auto can_complete = next_suggestion.invariant_offset <= m_largest_common_suggestion_prefix_length;
125 ssize_t actual_offset;
126 size_t shown_length = m_last_shown_suggestion_display_length;
127 switch (mode) {
128 case CompletePrefix:
129 actual_offset = 0;
130 break;
131 case ShowSuggestions:
132 actual_offset = 0 - m_largest_common_suggestion_prefix_length + next_suggestion.invariant_offset;
133 if (can_complete && next_suggestion.allow_commit_without_listing)
134 shown_length = m_largest_common_suggestion_prefix_length + m_last_shown_suggestion.trivia_view.length();
135 break;
136 default:
137 if (m_last_shown_suggestion_display_length == 0)
138 actual_offset = 0;
139 else
140 actual_offset = 0 - m_last_shown_suggestion_display_length + next_suggestion.invariant_offset;
141 break;
142 }
143
144 auto& suggestion = suggest();
145 set_current_suggestion_initiation_index(initiation_start_index);
146
147 result.offset_region_to_remove = { next_suggestion.invariant_offset, shown_length };
148 result.new_cursor_offset = actual_offset;
149 result.static_offset_from_cursor = next_suggestion.static_offset;
150
151 if (mode == CompletePrefix) {
152 // Only auto-complete *if possible*.
153 if (can_complete) {
154 result.insert.append(suggestion.text_view.substring_view(suggestion.invariant_offset, m_largest_common_suggestion_prefix_length - suggestion.invariant_offset));
155 m_last_shown_suggestion_display_length = m_largest_common_suggestion_prefix_length;
156 // Do not increment the suggestion index, as the first tab should only be a *peek*.
157 if (m_suggestions.size() == 1) {
158 // If there's one suggestion, commit and forget.
159 result.new_completion_mode = DontComplete;
160 // Add in the trivia of the last selected suggestion.
161 result.insert.append(suggestion.trivia_view);
162 m_last_shown_suggestion_display_length = 0;
163 result.style_to_apply = suggestion.style;
164 m_last_shown_suggestion_was_complete = true;
165 return result;
166 }
167 } else {
168 m_last_shown_suggestion_display_length = 0;
169 }
170 result.new_completion_mode = CompletionMode::ShowSuggestions;
171 m_last_shown_suggestion_was_complete = false;
172 m_last_shown_suggestion = DeprecatedString::empty();
173 } else {
174 result.insert.append(suggestion.text_view.substring_view(suggestion.invariant_offset, suggestion.text_view.length() - suggestion.invariant_offset));
175 // Add in the trivia of the last selected suggestion.
176 result.insert.append(suggestion.trivia_view);
177 m_last_shown_suggestion_display_length += suggestion.trivia_view.length();
178 }
179 } else {
180 m_next_suggestion_index = 0;
181 }
182 return result;
183}
184
185ErrorOr<size_t> SuggestionManager::for_each_suggestion(Function<ErrorOr<IterationDecision>(CompletionSuggestion const&, size_t)> callback) const
186{
187 size_t start_index { 0 };
188 for (auto& suggestion : m_suggestions) {
189 if (start_index++ < m_last_displayed_suggestion_index)
190 continue;
191 if (TRY(callback(suggestion, start_index - 1)) == IterationDecision::Break)
192 break;
193 }
194 return start_index;
195}
196
197}