[hackers] [st] Add parsing of DCS q sequences || Roberto E. Vargas Caballero

From: <git_AT_suckless.org>
Date: Wed, 14 Sep 2016 08:37:45 +0200 (CEST)

commit f7398434b8fa949af7bf43472caaefdd97eed0f3
Author: Roberto E. Vargas Caballero <roberto.vargas_AT_igrid-td.com>
AuthorDate: Wed Sep 14 08:27:32 2016 +0200
Commit: Roberto E. Vargas Caballero <roberto.vargas_AT_igrid-td.com>
CommitDate: Wed Sep 14 08:27:32 2016 +0200

    Add parsing of DCS q sequences
    
    These sequences are used to operate with sixels, but they are still
    str sequences, so they are finished with \a, ST or with a C1 control
    code. This patch also disables utf8 handling for the case of sixels.

diff --git a/st.c b/st.c
index ebbd7ca..6c16386 100644
--- a/st.c
+++ b/st.c
_AT_@ -138,6 +138,7 @@ enum term_mode {
         MODE_BRCKTPASTE = 1 << 19,
         MODE_PRINT = 1 << 20,
         MODE_UTF8 = 1 << 21,
+ MODE_SIXEL = 1 << 22,
         MODE_MOUSE = MODE_MOUSEBTN|MODE_MOUSEMOTION|MODE_MOUSEX10\
                           |MODE_MOUSEMANY,
 };
_AT_@ -155,11 +156,12 @@ enum charset {
 enum escape_state {
         ESC_START = 1,
         ESC_CSI = 2,
- ESC_STR = 4, /* DCS, OSC, PM, APC */
+ ESC_STR = 4, /* OSC, PM, APC */
         ESC_ALTCHARSET = 8,
         ESC_STR_END = 16, /* a final string was encountered */
         ESC_TEST = 32, /* Enter in test mode */
         ESC_UTF8 = 64,
+ ESC_DCS =128,
 };
 
 enum window_state {
_AT_@ -1485,7 +1487,7 @@ ttyread(void)
         ptr = buf;
 
         for (;;) {
- if (IS_SET(MODE_UTF8)) {
+ if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
                         /* process a complete utf8 char */
                         charsize = utf8decode(ptr, &unicodep, buflen);
                         if (charsize == 0)
_AT_@ -1578,7 +1580,7 @@ ttysend(char *s, size_t n)
 
         lim = &s[n];
         for (t = s; t < lim; t += len) {
- if (IS_SET(MODE_UTF8)) {
+ if (IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
                         len = utf8decode(t, &u, n);
                 } else {
                         u = *t & 0xFF;
_AT_@ -2548,6 +2550,7 @@ strhandle(void)
                 xsettitle(strescseq.args[0]);
                 return;
         case 'P': /* DCS -- Device Control String */
+ term.mode |= ESC_DCS;
         case '_': /* APC -- Application Program Command */
         case '^': /* PM -- Privacy Message */
                 return;
_AT_@ -2754,9 +2757,12 @@ tdectest(char c)
 void
 tstrsequence(uchar c)
 {
+ strreset();
+
         switch (c) {
         case 0x90: /* DCS -- Device Control String */
                 c = 'P';
+ term.esc |= ESC_DCS;
                 break;
         case 0x9f: /* APC -- Application Program Command */
                 c = '_';
_AT_@ -2768,7 +2774,6 @@ tstrsequence(uchar c)
                 c = ']';
                 break;
         }
- strreset();
         strescseq.type = c;
         term.esc |= ESC_STR;
 }
_AT_@ -2968,7 +2973,7 @@ tputc(Rune u)
         Glyph *gp;
 
         control = ISCONTROL(u);
- if (!IS_SET(MODE_UTF8)) {
+ if (!IS_SET(MODE_UTF8) && !IS_SET(MODE_SIXEL)) {
                 c[0] = u;
                 width = len = 1;
         } else {
_AT_@ -2991,30 +2996,47 @@ tputc(Rune u)
         if (term.esc & ESC_STR) {
                 if (u == '\a' || u == 030 || u == 032 || u == 033 ||
                    ISCONTROLC1(u)) {
- term.esc &= ~(ESC_START|ESC_STR);
+ term.esc &= ~(ESC_START|ESC_STR|ESC_DCS);
+ if (IS_SET(MODE_SIXEL)) {
+ /* TODO: render sixel */;
+ term.mode &= ~MODE_SIXEL;
+ return;
+ }
                         term.esc |= ESC_STR_END;
- } else if (strescseq.len + len < sizeof(strescseq.buf) - 1) {
- memmove(&strescseq.buf[strescseq.len], c, len);
- strescseq.len += len;
+ goto check_control_code;
+ }
+
+
+ if (IS_SET(MODE_SIXEL)) {
+ /* TODO: implement sixel mode */
                         return;
- } else {
- /*
- * Here is a bug in terminals. If the user never sends
- * some code to stop the str or esc command, then st
- * will stop responding. But this is better than
- * silently failing with unknown characters. At least
- * then users will report back.
- *
- * In the case users ever get fixed, here is the code:
- */
- /*
- * term.esc = 0;
- * strhandle();
- */
+ }
+ if (term.esc&ESC_DCS && strescseq.len == 0 && u == 'q')
+ term.mode |= MODE_SIXEL;
+
+ if (strescseq.len+len >= sizeof(strescseq.buf)-1) {
+ /*
+ * Here is a bug in terminals. If the user never sends
+ * some code to stop the str or esc command, then st
+ * will stop responding. But this is better than
+ * silently failing with unknown characters. At least
+ * then users will report back.
+ *
+ * In the case users ever get fixed, here is the code:
+ */
+ /*
+ * term.esc = 0;
+ * strhandle();
+ */
                         return;
                 }
+
+ memmove(&strescseq.buf[strescseq.len], c, len);
+ strescseq.len += len;
+ return;
         }
 
+check_control_code:
         /*
          * Actions of control codes must be performed as soon they arrive
          * because they can be embedded inside a control sequence, and
Received on Wed Sep 14 2016 - 08:37:45 CEST