From bb45edc83d12396ff754d4687904c65bf93ec3f0 Mon Sep 17 00:00:00 2001
From: Raheman Vaiya <r.vaiya@gmail.com>
Date: Sun, 26 Dec 2021 18:57:04 +0100
Subject: Add support for OSC color sequences

---
 config.def.h | 49 ++++++++++++++++++++-----------------
 st.c         | 80 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 st.h         |  3 +++
 x.c          | 13 ++++++++++
 4 files changed, 121 insertions(+), 24 deletions(-)

diff --git a/config.def.h b/config.def.h
index be1b2e3..7c68baa 100644
--- a/config.def.h
+++ b/config.def.h
@@ -105,29 +105,32 @@ float alpha = 0.8;
 /* Terminal colors (16 first used in escape sequence) */
 static const char *colorname[] = {
 
-  /* 8 normal colors */
-  [0] = "#22212f", /* black   */
-  [1] = "#ff5555", /* red     */
-  [2] = "#50fa7b", /* green   */
-  [3] = "#f1fa8c", /* yellow  */
-  [4] = "#6071a9", /* blue    */
-  [5] = "#ff79c6", /* magenta */
-  [6] = "#8cd5df", /* cyan    */
-  [7] = "#ced3e2", /* white   */
-
-  /* 8 bright colors */
-  [8]  = "#6071a9", /* black   */
-  [9]  = "#ff5555", /* red     */
-  [10] = "#50fa7b", /* green   */
-  [11] = "#f1fa8c", /* yellow  */
-  [12] = "#6071a9", /* blue    */
-  [13] = "#ff79c6", /* magenta */
-  [14] = "#8cd5df", /* cyan    */
-  [15] = "#ced3e2", /* white   */
-
-  /* special colors */
-  [256] = "#22212f", /* background */
-  [257] = "#ced3e2", /* foreground */
+        /* 8 normal colors */
+        [0] = "#22212f", /* black   */
+        [1] = "#ff5555", /* red     */
+        [2] = "#50fa7b", /* green   */
+        [3] = "#f1fa8c", /* yellow  */
+        [4] = "#6071a9", /* blue    */
+        [5] = "#ff79c6", /* magenta */
+        [6] = "#8cd5df", /* cyan    */
+        [7] = "#ced3e2", /* white   */
+
+        /* 8 bright colors */
+        [8]  = "#6071a9", /* black   */
+        [9]  = "#ff5555", /* red     */
+        [10] = "#50fa7b", /* green   */
+        [11] = "#f1fa8c", /* yellow  */
+        [12] = "#6071a9", /* blue    */
+        [13] = "#ff79c6", /* magenta */
+        [14] = "#8cd5df", /* cyan    */
+        [15] = "#ced3e2", /* white   */
+
+        /* more colors can be added after 255 to use with DefaultXX */
+        /* special colors */
+        [256] = "#22212f", /* background */
+        [257] = "#ced3e2", /* foreground */
+        "gray90", /* default foreground colour */
+        "black", /* default background colour */
 };
 
 /*
diff --git a/st.c b/st.c
index 1934bcf..3346543 100644
--- a/st.c
+++ b/st.c
@@ -1904,6 +1904,42 @@ csireset(void)
 	memset(&csiescseq, 0, sizeof(csiescseq));
 }
 
+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)
 {
@@ -1942,6 +1978,45 @@ 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;
@@ -1949,7 +2024,10 @@ 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 99c14f2..2feb8c3 100644
--- a/st.h
+++ b/st.h
@@ -113,6 +113,8 @@ 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;
@@ -126,3 +128,4 @@ extern unsigned int tabspaces;
 extern unsigned int defaultfg;
 extern unsigned int defaultbg;
 extern float alpha;
+extern unsigned int defaultcs;
diff --git a/x.c b/x.c
index a0552bf..23d85b7 100644
--- a/x.c
+++ b/x.c
@@ -829,6 +829,19 @@ xloadcols(void)
 	loaded = 1;
 }
 
+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)
 {
-- 
cgit v1.2.3