253 lines
7.4 KiB
C
253 lines
7.4 KiB
C
/****************************************************************************
|
|
* libs/libc/misc/lib_kbddecode.c
|
|
*
|
|
* Licensed to the Apache Software Foundation (ASF) under one or more
|
|
* contributor license agreements. See the NOTICE file distributed with
|
|
* this work for additional information regarding copyright ownership. The
|
|
* ASF licenses this file to you under the Apache License, Version 2.0 (the
|
|
* "License"); you may not use this file except in compliance with the
|
|
* License. You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
* License for the specific language governing permissions and limitations
|
|
* under the License.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <nuttx/config.h>
|
|
|
|
#include <stdint.h>
|
|
#include <assert.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/streams.h>
|
|
#include <nuttx/ascii.h>
|
|
#include <nuttx/input/kbd_codec.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
|
|
#define NDX_ESC 0
|
|
#define NDX_BRACKET 1
|
|
#define NDX_CODE 2
|
|
#define NDX_TERMINATOR 3
|
|
|
|
#define NCH_ESC 1
|
|
#define NCH_BRACKET 2
|
|
#define NCH_CODE 3
|
|
#define NCH_TERMINATOR 4
|
|
|
|
#define TERM_MIN ('a' + KBD_RELEASE)
|
|
#define TERM_MAX ('a' + KBD_SPECREL)
|
|
#define TERM_RETURN(a) ((a) - 'a')
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: kbd_reget
|
|
*
|
|
* Description:
|
|
* We have unused characters from the last, unsuccessful decode attempt.
|
|
* Return one of these instead of the new character from the stream.
|
|
*
|
|
* Input Parameters:
|
|
* stream - An instance of lib_instream_s to do the low-level get
|
|
* operation.
|
|
* pch - The location character to save the returned value. This may be
|
|
* either a normal, character code or a special command from enum
|
|
* kbd_keycode_e
|
|
*
|
|
* Returned Value:
|
|
* KBD_PRESS - Indicates the successful receipt of norma keyboard data.
|
|
*
|
|
****************************************************************************/
|
|
|
|
static int kbd_reget(FAR struct kbd_getstate_s *state, FAR uint8_t *pch)
|
|
{
|
|
/* Return the next character */
|
|
|
|
*pch = state->buf[state->ndx];
|
|
state->ndx++;
|
|
state->nch--;
|
|
return KBD_PRESS;
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: kbd_decode
|
|
*
|
|
* Description:
|
|
* Get one byte of data or special command from the driver provided input
|
|
* buffer.
|
|
*
|
|
* Input Parameters:
|
|
* stream - An instance of lib_instream_s to do the low-level get
|
|
* operation.
|
|
* pch - The location to save the returned value. This may be
|
|
* either a normal, character code or a special command from enum
|
|
* kbd_keycode_e
|
|
* state - A user provided buffer to support parsing. This structure
|
|
* should be cleared the first time that kbd_decode is called.
|
|
*
|
|
* Returned Value:
|
|
*
|
|
* KBD_PRESS - Indicates the successful receipt of normal, keyboard data.
|
|
* This corresponds to a keypress event. The returned value in pch is a
|
|
* simple byte of text or control data corresponding to the pressed key.
|
|
* KBD_RELEASE - Indicates a key release event. The returned value in pch
|
|
* is the byte of text or control data corresponding to the released key.
|
|
* KBD_SPECPRESS - Indicates the successful receipt of a special keyboard
|
|
* command. The returned value in pch is a value from enum kbd_getstate_s.
|
|
* KBD_SPECREL - Indicates a special key release event. The returned value
|
|
* in pch is a value from enum kbd_getstate_s.
|
|
* EOF - An error has getting the next character (reported by the stream).
|
|
* Normally indicates the end of file.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int kbd_decode(FAR struct lib_instream_s *stream,
|
|
FAR struct kbd_getstate_s *state, FAR uint8_t *pch)
|
|
{
|
|
int ch;
|
|
|
|
DEBUGASSERT(stream && state && pch);
|
|
|
|
/* Are their ungotten characters from the last, failed parse? */
|
|
|
|
if (state->nch > 0)
|
|
{
|
|
/* Yes, return the next ungotten character */
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
|
|
state->ndx = 0;
|
|
|
|
/* No, ungotten characters. Check for the beginning of an ESC sequence. */
|
|
|
|
ch = lib_stream_getc(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream */
|
|
|
|
return KBD_ERROR;
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_ESC] = (uint8_t)ch;
|
|
state->nch = NCH_ESC;
|
|
|
|
if (ch != ASCII_ESC)
|
|
{
|
|
/* Not the beginning of an escape sequence.
|
|
* Return the character.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* Check for ESC-[ */
|
|
|
|
ch = lib_stream_getc(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Return the escape character now. We will
|
|
* return the EOF indication next time.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_BRACKET] = ch;
|
|
state->nch = NCH_BRACKET;
|
|
|
|
if (ch != '[')
|
|
{
|
|
/* Not the beginning of an escape sequence. Return the ESC now,
|
|
* return the following character later.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* Get and verify the special keyboard data to decode */
|
|
|
|
ch = lib_stream_getc(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Unget everything and return the ESC character.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_CODE] = (uint8_t)ch;
|
|
state->nch = NCH_CODE;
|
|
|
|
/* Check for a valid special command code */
|
|
|
|
if (ch < FIRST_KEYCODE || ch > LAST_KEYCODE)
|
|
{
|
|
/* Not a special command code, return the ESC now and the next two
|
|
* characters later.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* Check for the final semicolon */
|
|
|
|
ch = lib_stream_getc(stream);
|
|
if (ch == EOF)
|
|
{
|
|
/* End of file/stream. Unget everything and return the ESC character.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
else
|
|
{
|
|
state->buf[NDX_TERMINATOR] = (uint8_t)ch;
|
|
state->nch = NCH_TERMINATOR;
|
|
|
|
/* Check for a valid special command code */
|
|
|
|
if (ch < TERM_MIN || ch > TERM_MAX)
|
|
{
|
|
/* Not a special command code, return the ESC now and the next two
|
|
* characters later.
|
|
*/
|
|
|
|
return kbd_reget(state, pch);
|
|
}
|
|
}
|
|
|
|
/* We have successfully parsed the entire escape sequence. Return the
|
|
* keyboard value in pch and the value an indication determined by the
|
|
* terminating character.
|
|
*/
|
|
|
|
*pch = state->buf[NDX_CODE];
|
|
state->nch = 0;
|
|
return TERM_RETURN(state->buf[NDX_TERMINATOR]);
|
|
}
|