Add support for OSC color sequences

4 files changed, 100 insertions, 4 deletions

diff --git a/config.def.h b/config.def.h
index 6f05dce..91ab8ca 100644
--- a/config.def.h
+++ b/config.def.h
@@ -120,6 +120,8 @@ static const char *colorname[] = {
         /* more colors can be added after 255 to use with DefaultXX */
         "#cccccc",
         "#555555",
+        "gray90", /* default foreground colour */
+        "black", /* default background colour */
 };
 
 
@@ -127,9 +129,9 @@ static const char *colorname[] = {
  * Default colors (colorname index)
  * foreground, background, cursor, reverse cursor
  */
-unsigned int defaultfg = 7;
-unsigned int defaultbg = 0;
-static unsigned int defaultcs = 256;
+unsigned int defaultfg = 258;
+unsigned int defaultbg = 259;
+unsigned int defaultcs = 256;
 static unsigned int defaultrcs = 257;
 
 /*
diff --git a/st.c b/st.c
index a9338e1..781dbf2 100644
--- a/st.c
+++ b/st.c
@@ -1843,6 +1843,42 @@ csireset(void)
 }
 
 void
+osc4_color_response(int num)
+{
+        int n;
+        char buf[32];
+        unsigned char r, g, b;
+
+        if (xgetcolor(num, &r, &g, &b)) {
+                fprintf(stderr, "erresc: failed to fetch osc4 color %d\n", num);
+                return;
+        }
+
+        n = snprintf(buf, sizeof buf, "\033]4;%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
+                     num, r, r, g, g, b, b);
+
+        ttywrite(buf, n, 1);
+}
+
+void
+osc_color_response(int index, int num)
+{
+        int n;
+        char buf[32];
+        unsigned char r, g, b;
+
+        if (xgetcolor(index, &r, &g, &b)) {
+                fprintf(stderr, "erresc: failed to fetch osc color %d\n", index);
+                return;
+        }
+
+        n = snprintf(buf, sizeof buf, "\033]%d;rgb:%02x%02x/%02x%02x/%02x%02x\007",
+                     num, r, r, g, g, b, b);
+
+        ttywrite(buf, n, 1);
+}
+
+void
 strhandle(void)
 {
         char *p = NULL, *dec;
@@ -1880,6 +1916,45 @@ strhandle(void)
                                 }
                         }
                         return;
+                case 10:
+                        if (narg < 2)
+                                break;
+
+                        p = strescseq.args[1];
+
+                        if (!strcmp(p, "?"))
+                                osc_color_response(defaultfg, 10);
+                        else if (xsetcolorname(defaultfg, p))
+                                fprintf(stderr, "erresc: invalid foreground color: %s\n", p);
+                        else
+                                redraw();
+                        break;
+                case 11:
+                        if (narg < 2)
+                                break;
+
+                        p = strescseq.args[1];
+
+                        if (!strcmp(p, "?"))
+                                osc_color_response(defaultbg, 11);
+                        else if (xsetcolorname(defaultbg, p))
+                                fprintf(stderr, "erresc: invalid background color: %s\n", p);
+                        else
+                                redraw();
+                        break;
+                case 12:
+                        if (narg < 2)
+                                break;
+
+                        p = strescseq.args[1];
+
+                        if (!strcmp(p, "?"))
+                                osc_color_response(defaultcs, 12);
+                        else if (xsetcolorname(defaultcs, p))
+                                fprintf(stderr, "erresc: invalid cursor color: %s\n", p);
+                        else
+                                redraw();
+                        break;
                 case 4: /* color set */
                         if (narg < 3)
                                 break;
@@ -1887,7 +1962,10 @@ strhandle(void)
                         /* FALLTHROUGH */
                 case 104: /* color reset, here p = NULL */
                         j = (narg > 1) ? atoi(strescseq.args[1]) : -1;
-                        if (xsetcolorname(j, p)) {
+
+                        if (!strcmp(p, "?"))
+                                osc4_color_response(j);
+                        else if (xsetcolorname(j, p)) {
                                 if (par == 104 && narg <= 1)
                                         return; /* color reset without parameter */
                                 fprintf(stderr, "erresc: invalid color j=%d, p=%s\n",
diff --git a/st.h b/st.h
index fa2eddf..519b9bd 100644
--- a/st.h
+++ b/st.h
@@ -111,6 +111,8 @@ void *xmalloc(size_t);
 void *xrealloc(void *, size_t);
 char *xstrdup(const char *);
 
+int xgetcolor(int x, unsigned char *r, unsigned char *g, unsigned char *b);
+
 /* config.h globals */
 extern char *utmp;
 extern char *scroll;
@@ -123,3 +125,4 @@ extern char *termname;
 extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
+extern unsigned int defaultcs;
diff --git a/x.c b/x.c
index 89786b8..8a16faa 100644
--- a/x.c
+++ b/x.c
@@ -800,6 +800,19 @@ xloadcols(void)
 }
 
 int
+xgetcolor(int x, unsigned char *r, unsigned char *g, unsigned char *b)
+{
+        if (!BETWEEN(x, 0, dc.collen))
+                return 1;
+
+        *r = dc.col[x].color.red >> 8;
+        *g = dc.col[x].color.green >> 8;
+        *b = dc.col[x].color.blue >> 8;
+
+        return 0;
+}
+
+int
 xsetcolorname(int x, const char *name)
 {
         Color ncolor;