LibLine: Implement ^R searching

This commit adds searching in the editor history with ^R.
It does so by instantiating...another Line::Editor inside the current
Line::Editor :^)
This commit is contained in:
AnotherTest 2020-04-19 23:34:58 +04:30 committed by Andreas Kling
parent df6696f576
commit 58912994ab
Notes: sideshowbarker 2024-07-19 07:26:33 +09:00
2 changed files with 167 additions and 20 deletions

View file

@ -33,8 +33,9 @@
namespace Line {
Editor::Editor()
Editor::Editor(bool always_refresh)
{
m_always_refresh = always_refresh;
m_pending_chars = ByteBuffer::create_uninitialized(0);
struct winsize ws;
if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) < 0) {
@ -126,7 +127,17 @@ String Editor::get_line(const String& prompt)
m_history_cursor = m_history.size();
for (;;) {
if (m_always_refresh)
m_refresh_needed = true;
refresh_display();
if (m_finish) {
m_finish = false;
printf("\n");
fflush(stdout);
auto string = String::copy(m_buffer);
m_buffer.clear();
return string;
}
char keybuf[16];
ssize_t nread = read(0, keybuf, sizeof(keybuf));
// FIXME: exit()ing here is a bit off. Should communicate failure to caller somehow instead.
@ -138,13 +149,17 @@ String Editor::get_line(const String& prompt)
m_was_interrupted = false;
if (!m_buffer.is_empty())
printf("^C");
if (m_is_searching) {
end_search();
continue;
}
}
if (m_was_resized)
continue;
m_buffer.clear();
putchar('\n');
return String::empty();
finish();
continue;
}
perror("read failed");
// FIXME: exit()ing here is a bit off. Should communicate failure to caller somehow instead.
@ -500,6 +515,9 @@ String Editor::get_line(const String& prompt)
m_times_tab_pressed = 0; // Safe to say if we get here, the user didn't press TAB
auto do_backspace = [&] {
if (m_is_searching) {
return;
}
if (m_cursor == 0) {
fputc('\a', stdout);
fflush(stdout);
@ -549,10 +567,110 @@ String Editor::get_line(const String& prompt)
m_cursor = 0;
continue;
}
// ^R
if (ch == 0x12) {
if (m_is_searching) {
// how did we get here?
ASSERT_NOT_REACHED();
} else {
m_is_searching = true;
m_search_offset = 0;
m_pre_search_buffer = m_buffer;
m_pre_search_cursor = m_cursor;
m_search_editor = make<Editor>(true); // Has anyone seen 'Inception'?
m_search_editor->initialize();
m_search_editor->on_display_refresh = [this](Editor& search_editor) {
int last_matching_offset = -1;
// do not search for empty strings
if (search_editor.buffer().size() > 0) {
size_t search_offset = m_search_offset;
StringView search_term { search_editor.buffer().data(), search_editor.buffer().size() };
for (size_t i = m_history_cursor; i > 0; --i) {
if (m_history[i - 1].contains(search_term)) {
last_matching_offset = i - 1;
if (search_offset == 0)
break;
--search_offset;
}
}
if (last_matching_offset == -1) {
fputc('\a', stdout);
fflush(stdout);
return;
}
}
m_buffer.clear();
m_cursor = 0;
if (last_matching_offset >= 0)
insert(m_history[last_matching_offset]);
// always needed
m_refresh_needed = true;
refresh_display();
return;
};
// whenever the search editor gets a ^R, cycle between history entries
m_search_editor->register_character_input_callback(0x12, [this](Editor& search_editor) {
++m_search_offset;
search_editor.m_refresh_needed = true;
return false; // Do not process this key event
});
// whenever the search editor gets a backspace, cycle back between history entries
// unless we're at the zeroth entry, in which case, allow the deletion
m_search_editor->register_character_input_callback(m_termios.c_cc[VERASE], [this](Editor& search_editor) {
if (m_search_offset > 0) {
--m_search_offset;
search_editor.m_refresh_needed = true;
return false; // Do not process this key event
}
return true;
});
// quit without clearing the current buffer
m_search_editor->register_character_input_callback('\t', [this](Editor& search_editor) {
search_editor.finish();
m_reset_buffer_on_search_end = false;
return false;
});
printf("\n");
fflush(stdout);
auto search_prompt = "\x1b[32msearch:\x1b[0m ";
auto search_string = m_search_editor->get_line(search_prompt);
m_search_editor = nullptr;
m_is_searching = false;
m_search_offset = 0;
// manually cleanup the search line
reposition_cursor();
vt_clear_lines(0, (search_string.length() + actual_rendered_string_length(search_prompt) + m_num_columns - 1) / m_num_columns);
reposition_cursor();
if (!m_reset_buffer_on_search_end || search_string.length() == 0) {
// if the entry was empty, or we purposely quit without a newline,
// do not return anything
// instead, just end the search
end_search();
continue;
}
// return the string
finish();
continue;
}
continue;
}
// Normally ^D
if (ch == m_termios.c_cc[VEOF]) {
if (m_buffer.is_empty()) {
printf("<EOF>\n");
if (!m_always_refresh) // this is a little off, but it'll do for now
exit(0);
}
continue;
@ -564,11 +682,8 @@ String Editor::get_line(const String& prompt)
continue;
}
if (ch == '\n') {
putchar('\n');
fflush(stdout);
auto string = String::copy(m_buffer);
m_buffer.clear();
return string;
finish();
continue;
}
insert(ch);
@ -591,15 +706,17 @@ void Editor::recalculate_origin()
// but that will be calculated and applied at the next
// refresh cycle
}
void Editor::refresh_display()
void Editor::cleanup()
{
auto cleanup = [&] {
vt_move_relative(0, m_pending_chars.size() - m_chars_inserted_in_the_middle);
auto current_line = cursor_line();
vt_clear_lines(current_line - 1, num_lines() - current_line);
vt_move_relative(-num_lines() + 1, -offset_in_line() - m_old_prompt_length - m_pending_chars.size() + m_chars_inserted_in_the_middle);
};
};
void Editor::refresh_display()
{
auto has_cleaned_up = false;
// someone changed the window size, figure it out
// and react to it, we might need to redraw

View file

@ -77,7 +77,7 @@ struct CompletionSuggestion {
class Editor {
public:
Editor();
explicit Editor(bool always_refresh = false);
~Editor();
void initialize()
@ -143,6 +143,11 @@ public:
const struct termios& termios() const { return m_termios; }
const struct termios& default_termios() const { return m_default_termios; }
void finish()
{
m_finish = true;
}
private:
void vt_save_cursor();
void vt_restore_cursor();
@ -155,6 +160,19 @@ private:
Style find_applicable_style(size_t offset) const;
inline void end_search()
{
m_is_searching = false;
m_refresh_needed = true;
m_search_offset = 0;
if (m_reset_buffer_on_search_end) {
m_buffer = m_pre_search_buffer;
m_cursor = m_pre_search_cursor;
}
m_reset_buffer_on_search_end = false;
m_search_editor = nullptr;
}
void reset()
{
m_origin_x = 0;
@ -165,6 +183,7 @@ private:
}
void refresh_display();
void cleanup();
size_t current_prompt_length() const
{
@ -197,6 +216,15 @@ private:
void recalculate_origin();
void reposition_cursor();
bool m_finish { false };
OwnPtr<Editor> m_search_editor;
bool m_is_searching { false };
bool m_reset_buffer_on_search_end { true };
size_t m_search_offset { 0 };
size_t m_pre_search_cursor { 0 };
Vector<char, 1024> m_pre_search_buffer;
Vector<char, 1024> m_buffer;
ByteBuffer m_pending_chars;
size_t m_cursor { 0 };
@ -225,6 +253,8 @@ private:
size_t m_next_suggestion_invariant_offset { 0 };
size_t m_largest_common_suggestion_prefix_length { 0 };
bool m_always_refresh { false };
enum class TabDirection {
Forward,
Backward,
@ -235,8 +265,8 @@ private:
// TODO: handle signals internally
struct termios m_termios, m_default_termios;
bool m_was_interrupted = false;
bool m_was_resized = false;
bool m_was_interrupted { false };
bool m_was_resized { false };
// FIXME: This should be something more take_first()-friendly.
Vector<String> m_history;