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Merged
ngxson merged 3 commits into from
Dec 7, 2025
Merged

Xsn/cli arrow left right #53

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75a412e
console: fix arrow keys on Windows using private-use Unicode
ServeurpersoCom Dec 7, 2025
5e19ce2
console: add Home/End key support for Windows and Linux
ServeurpersoCom Dec 7, 2025
6e67dd3
console: add basic Up/Down history navigation
ServeurpersoCom Dec 7, 2025
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203 changes: 202 additions & 1 deletion common/console.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@
#include <vector>
#include <iostream>
#include <cassert>
#include <cstddef>

#if defined(_WIN32)
#define WIN32_LEAN_AND_MEAN
Expand Down Expand Up @@ -36,6 +37,18 @@

namespace console {

namespace {
// Use private-use unicode values to represent special keys that are not reported
// as characters (e.g. arrows on Windows). These values should never clash with
// real input and let the rest of the code handle navigation uniformly.
static constexpr char32_t KEY_ARROW_LEFT = 0xE000;
static constexpr char32_t KEY_ARROW_RIGHT = 0xE001;
static constexpr char32_t KEY_ARROW_UP = 0xE002;
static constexpr char32_t KEY_ARROW_DOWN = 0xE003;
static constexpr char32_t KEY_HOME = 0xE004;
static constexpr char32_t KEY_END = 0xE005;
}

//
// Console state
//
Expand All @@ -44,6 +57,8 @@ namespace console {
static bool simple_io = true;
static display_t current_display = reset;

static std::vector<std::string> history;

static FILE* out = stdout;

#if defined (_WIN32)
Expand Down Expand Up @@ -176,6 +191,17 @@ namespace console {

if (record.EventType == KEY_EVENT && record.Event.KeyEvent.bKeyDown) {
wchar_t wc = record.Event.KeyEvent.uChar.UnicodeChar;
if (wc == 0) {
switch (record.Event.KeyEvent.wVirtualKeyCode) {
case VK_LEFT: return KEY_ARROW_LEFT;
case VK_RIGHT: return KEY_ARROW_RIGHT;
case VK_UP: return KEY_ARROW_UP;
case VK_DOWN: return KEY_ARROW_DOWN;
case VK_HOME: return KEY_HOME;
case VK_END: return KEY_END;
default: continue;
}
}
if (wc == 0) {
continue;
}
Expand Down Expand Up @@ -316,6 +342,34 @@ namespace console {
#endif
}

static char32_t decode_utf8(const std::string & input, size_t pos, size_t & advance) {
unsigned char c = static_cast<unsigned char>(input[pos]);
if ((c & 0x80u) == 0u) {
advance = 1;
return c;
}
if ((c & 0xE0u) == 0xC0u && pos + 1 < input.size()) {
advance = 2;
return ((c & 0x1Fu) << 6) | (static_cast<unsigned char>(input[pos + 1]) & 0x3Fu);
}
if ((c & 0xF0u) == 0xE0u && pos + 2 < input.size()) {
advance = 3;
return ((c & 0x0Fu) << 12) |
((static_cast<unsigned char>(input[pos + 1]) & 0x3Fu) << 6) |
(static_cast<unsigned char>(input[pos + 2]) & 0x3Fu);
}
if ((c & 0xF8u) == 0xF0u && pos + 3 < input.size()) {
advance = 4;
return ((c & 0x07u) << 18) |
((static_cast<unsigned char>(input[pos + 1]) & 0x3Fu) << 12) |
((static_cast<unsigned char>(input[pos + 2]) & 0x3Fu) << 6) |
(static_cast<unsigned char>(input[pos + 3]) & 0x3Fu);
}

advance = 1;
return 0xFFFD; // replacement character for invalid input
}

static void append_utf8(char32_t ch, std::string & out) {
if (ch <= 0x7F) {
out.push_back(static_cast<unsigned char>(ch));
Expand Down Expand Up @@ -355,6 +409,67 @@ namespace console {
return pos;
}

static void move_cursor(int delta);
static void move_to_line_start(size_t & char_pos, size_t & byte_pos, const std::vector<int> & widths);
static void move_to_line_end(size_t & char_pos, size_t & byte_pos, const std::vector<int> & widths, const std::string & line);

static void clear_current_line(const std::vector<int> & widths) {
int total_width = 0;
for (int w : widths) {
total_width += (w > 0 ? w : 1);
}

if (total_width > 0) {
std::string spaces(total_width, ' ');
fwrite(spaces.c_str(), 1, total_width, out);
move_cursor(-total_width);
}
}

static void set_line_contents(std::string new_line, std::string & line, std::vector<int> & widths, size_t & char_pos,
size_t & byte_pos) {
move_to_line_start(char_pos, byte_pos, widths);
clear_current_line(widths);

line = std::move(new_line);
widths.clear();
byte_pos = 0;
char_pos = 0;

size_t idx = 0;
while (idx < line.size()) {
size_t advance = 0;
char32_t cp = decode_utf8(line, idx, advance);
int expected_width = estimateWidth(cp);
int real_width = put_codepoint(line.c_str() + idx, advance, expected_width);
if (real_width < 0) real_width = 0;
widths.push_back(real_width);
idx += advance;
++char_pos;
byte_pos = idx;
}
}

static void move_to_line_start(size_t & char_pos, size_t & byte_pos, const std::vector<int> & widths) {
int back_width = 0;
for (size_t i = 0; i < char_pos; ++i) {
back_width += widths[i];
}
move_cursor(-back_width);
char_pos = 0;
byte_pos = 0;
}

static void move_to_line_end(size_t & char_pos, size_t & byte_pos, const std::vector<int> & widths, const std::string & line) {
int forward_width = 0;
for (size_t i = char_pos; i < widths.size(); ++i) {
forward_width += widths[i];
}
move_cursor(forward_width);
char_pos = widths.size();
byte_pos = line.length();
}

static void move_cursor(int delta) {
if (delta == 0) return;
#if defined(_WIN32)
Expand Down Expand Up @@ -397,6 +512,7 @@ namespace console {
std::vector<int> widths;
bool is_special_char = false;
bool end_of_stream = false;
size_t history_index = history.size();

size_t byte_pos = 0; // current byte index
size_t char_pos = 0; // current character index (one char can be multiple bytes)
Expand Down Expand Up @@ -442,9 +558,48 @@ namespace console {
char_pos++;
byte_pos = next_utf8_char_pos(line, byte_pos);
}
} else if (code == 'H') { // home
move_to_line_start(char_pos, byte_pos, widths);
} else if (code == 'F') { // end
move_to_line_end(char_pos, byte_pos, widths, line);
} else if (code == 'A' || code == 'B') {
// up/down
// TODO: Implement history navigation
if (!history.empty()) {
if (code == 'A' && history_index > 0) {
history_index--;
set_line_contents(history[history_index], line, widths, char_pos, byte_pos);
is_special_char = false;
} else if (code == 'B') {
if (history_index + 1 < history.size()) {
history_index++;
set_line_contents(history[history_index], line, widths, char_pos, byte_pos);
is_special_char = false;
} else if (history_index < history.size()) {
history_index = history.size();
set_line_contents("", line, widths, char_pos, byte_pos);
is_special_char = false;
}
}
}
} else if (code >= '0' && code <= '9') {
std::string digits;
digits.push_back(static_cast<char>(code));
while (true) {
code = getchar32();
if (code >= '0' && code <= '9') {
digits.push_back(static_cast<char>(code));
continue;
}
break;
}

if (code == '~') {
if (digits == "1" || digits == "7") {
move_to_line_start(char_pos, byte_pos, widths);
} else if (digits == "4" || digits == "8") {
move_to_line_end(char_pos, byte_pos, widths, line);
}
}
} else {
// Discard the rest of the escape sequence
while ((code = getchar32()) != (char32_t) WEOF) {
Expand All @@ -462,6 +617,44 @@ namespace console {
}
}
}
#if defined(_WIN32)
} else if (input_char == KEY_ARROW_LEFT) {
if (char_pos > 0) {
int w = widths[char_pos - 1];
move_cursor(-w);
char_pos--;
byte_pos = prev_utf8_char_pos(line, byte_pos);
}
} else if (input_char == KEY_ARROW_RIGHT) {
if (char_pos < widths.size()) {
int w = widths[char_pos];
move_cursor(w);
char_pos++;
byte_pos = next_utf8_char_pos(line, byte_pos);
}
} else if (input_char == KEY_HOME) {
move_to_line_start(char_pos, byte_pos, widths);
} else if (input_char == KEY_END) {
move_to_line_end(char_pos, byte_pos, widths, line);
} else if (input_char == KEY_ARROW_UP || input_char == KEY_ARROW_DOWN) {
if (!history.empty()) {
if (input_char == KEY_ARROW_UP && history_index > 0) {
history_index--;
set_line_contents(history[history_index], line, widths, char_pos, byte_pos);
is_special_char = false;
} else if (input_char == KEY_ARROW_DOWN) {
if (history_index + 1 < history.size()) {
history_index++;
set_line_contents(history[history_index], line, widths, char_pos, byte_pos);
is_special_char = false;
} else if (history_index < history.size()) {
history_index = history.size();
set_line_contents("", line, widths, char_pos, byte_pos);
is_special_char = false;
}
}
}
#endif
} else if (input_char == 0x08 || input_char == 0x7F) { // Backspace
if (char_pos > 0) {
int w = widths[char_pos - 1];
Expand Down Expand Up @@ -566,6 +759,14 @@ namespace console {
}
}

if (!end_of_stream && !line.empty()) {
std::string history_entry = line;
if (!history_entry.empty() && history_entry.back() == '\n') {
history_entry.pop_back();
}
history.push_back(std::move(history_entry));
}

fflush(out);
return has_more;
}
Expand Down