/****************************************************************************
* interpreters/micropython/py_readline.c
*
* This file originated from the Micro Python project, http://micropython.org/
* It has been hacked around to fit into Nuttx
*
* The MIT License (MIT)
*
* Copyright (c) 2013, 2014 Damien P. George
* Further edits (c) 2015 Dave Marples
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include "py/mpconfig.h"
#include "py/misc.h"
#include "py_readline.h"
#if 0 /* print debugging info */
# define DEBUG_PRINT (1)
# define DEBUG_printf printf
#else /* don't print debugging info */
# define DEBUG_printf(...) (void)0
#endif
#define READLINE_HIST_SIZE (8)
#define CURSOR_BACK ('\b')
#define KEY_TAB ('\t')
/****************************************************************************
* Private Types
****************************************************************************/
enum
{
ESEQ_NONE,
ESEQ_ESC,
ESEQ_ESC_BRACKET,
ESEQ_ESC_BRACKET_DIGIT,
ESEQ_ESC_O
};
/****************************************************************************
* Private Data
****************************************************************************/
static const char *readline_hist[READLINE_HIST_SIZE];
/****************************************************************************
* Private Functions
****************************************************************************/
STATIC char *str_dup_maybe(const char *str)
{
uint32_t len = strlen(str);
char *s2 = m_new_maybe(char, len + 1);
if (s2 == NULL)
{
return NULL;
}
memcpy(s2, str, len + 1);
return s2;
}
/****************************************************************************
* Public Functions
****************************************************************************/
void readline_init0(void)
{
memset(readline_hist, 0, READLINE_HIST_SIZE * sizeof(const char *));
}
int py_readline(vstr_t * line, const char *prompt)
{
fprintf(stdout, prompt);
fflush(stdout);
int orig_line_len = line->len;
int escape_seq = ESEQ_NONE;
char escape_seq_buf[1] = { 0 };
int hist_cur = -1;
int cursor_pos = orig_line_len;
for (;;)
{
int c = getc(stdin);
int last_line_len = line->len;
int redraw_step_back = 0;
bool redraw_from_cursor = false;
int redraw_step_forward = 0;
if (escape_seq == ESEQ_NONE)
{
if (CHAR_CTRL_A <= c && c <= CHAR_CTRL_D &&
vstr_len(line) == orig_line_len)
{
/* control character with empty line */
return c;
}
else if (c == CHAR_CTRL_A)
{
/* CTRL-A with non-empty line is go-to-start-of-line */
goto home_key;
}
else if (c == CHAR_CTRL_C)
{
/* CTRL-C with non-empty line is cancel */
return c;
}
else if (c == CHAR_CTRL_E)
{
/* CTRL-E is go-to-end-of-line */
goto end_key;
}
else if (c == '\r')
{
/* newline */
fputs("\r\n", stdout);
if (line->len > orig_line_len &&
(readline_hist[0] == NULL ||
strcmp(readline_hist[0], line->buf + orig_line_len) != 0))
{
/* a line which is not empty and different from the last one
* so update the history
*/
char *most_recent_hist =
str_dup_maybe(line->buf + orig_line_len);
if (most_recent_hist != NULL)
{
for (int i = READLINE_HIST_SIZE - 1; i > 0; i--)
{
readline_hist[i] = readline_hist[i - 1];
}
readline_hist[0] = most_recent_hist;
}
}
return 0;
}
else if (c == 27)
{
/* escape sequence */
escape_seq = ESEQ_ESC;
}
else if (c == 8 || c == 127)
{
/* backspace/delete */
if (cursor_pos > orig_line_len)
{
vstr_cut_out_bytes(line, cursor_pos - 1, 1);
/* set redraw parameters */
redraw_step_back = 1;
redraw_from_cursor = true;
}
}
else if ((KEY_TAB == c) || (32 <= c && c <= 126))
{
/* printable character */
vstr_ins_char(line, cursor_pos, c);
/* set redraw parameters */
redraw_from_cursor = true;
redraw_step_forward = 1;
}
}
else if (escape_seq == ESEQ_ESC)
{
switch (c)
{
case '[':
escape_seq = ESEQ_ESC_BRACKET;
break;
case 'O':
escape_seq = ESEQ_ESC_O;
break;
default:
DEBUG_printf("(ESC %d)", c);
escape_seq = ESEQ_NONE;
}
}
else if (escape_seq == ESEQ_ESC_BRACKET)
{
if ('0' <= c && c <= '9')
{
escape_seq = ESEQ_ESC_BRACKET_DIGIT;
escape_seq_buf[0] = c;
}
else
{
escape_seq = ESEQ_NONE;
if (c == 'A')
{
/* up arrow */
if (hist_cur + 1 < READLINE_HIST_SIZE &&
readline_hist[hist_cur + 1] != NULL)
{
/* increase hist num */
hist_cur += 1;
/* set line to history */
line->len = orig_line_len;
vstr_add_str(line, readline_hist[hist_cur]);
/* set redraw parameters */
redraw_step_back = cursor_pos - orig_line_len;
redraw_from_cursor = true;
redraw_step_forward = line->len - orig_line_len;
}
}
else if (c == 'B')
{
/* down arrow */
if (hist_cur >= 0)
{
/* decrease hist num */
hist_cur -= 1;
/* set line to history */
vstr_cut_tail_bytes(line, line->len - orig_line_len);
if (hist_cur >= 0)
{
vstr_add_str(line, readline_hist[hist_cur]);
}
/* set redraw parameters */
redraw_step_back = cursor_pos - orig_line_len;
redraw_from_cursor = true;
redraw_step_forward = line->len - orig_line_len;
}
}
else if (c == 'C')
{
/* right arrow */
if (cursor_pos < line->len)
{
redraw_step_forward = 1;
}
}
else if (c == 'D')
{
/* left arrow */
if (cursor_pos > orig_line_len)
{
redraw_step_back = 1;
}
}
else if (c == 'H')
{
/* home */
goto home_key;
}
else if (c == 'F')
{
/* end */
goto end_key;
}
else
{
DEBUG_printf("(ESC [ %d)", c);
}
}
}
else if (escape_seq == ESEQ_ESC_BRACKET_DIGIT)
{
if (c == '~')
{
if (escape_seq_buf[0] == '1' || escape_seq_buf[0] == '7')
{
home_key:
redraw_step_back = cursor_pos - orig_line_len;
}
else if (escape_seq_buf[0] == '4' || escape_seq_buf[0] == '8')
{
end_key:
redraw_step_forward = line->len - cursor_pos;
}
else
{
DEBUG_printf("(ESC [ %c %d)", escape_seq_buf[0], c);
}
}
else
{
DEBUG_printf("(ESC [ %c %d)", escape_seq_buf[0], c);
}
escape_seq = ESEQ_NONE;
}
else if (escape_seq == ESEQ_ESC_O)
{
switch (c)
{
case 'H':
goto home_key;
case 'F':
goto end_key;
default:
DEBUG_printf("(ESC O %d)", c);
escape_seq = ESEQ_NONE;
}
}
else
{
escape_seq = ESEQ_NONE;
}
/* redraw command prompt, efficiently
* TODO we can probably use some more sophisticated VT100 commands here
*/
if (redraw_step_back > 0)
{
for (int i = 0; i < redraw_step_back; i++)
{
fputc(CURSOR_BACK, stdout);
}
cursor_pos -= redraw_step_back;
}
if (redraw_from_cursor)
{
if (line->len < last_line_len)
{
/* erase old chars */
for (int i = cursor_pos; i < last_line_len; i++)
{
fputc(' ', stdout);
}
/* step back */
for (int i = cursor_pos; i < last_line_len; i++)
{
fputc(CURSOR_BACK, stdout);
}
}
/* draw new chars */
int charCount = 0;
do
{
fputc(*(line->buf + cursor_pos + charCount), stdout);
}
while (charCount++ < (line->len - cursor_pos));
/* move cursor forward if needed (already moved forward by length of
* line, so move it back)
*/
for (int i = cursor_pos + redraw_step_forward; i < line->len; i++)
{
fputc(CURSOR_BACK, stdout);
}
cursor_pos += redraw_step_forward;
}
else if (redraw_step_forward > 0)
{
/* draw over old chars to move cursor forwards */
int charCount = 0;
do
{
fputc(*(line->buf + cursor_pos + charCount), stdout);
}
while (charCount++ < redraw_step_forward);
cursor_pos += redraw_step_forward;
}
fflush(stdout);
}
}