53438: support for changing terminal cursor shape and colour

2025-12-05 01:10:17 +00:00 · 2025-11-10 21:02:34 +01:00
parent 6a691a3487
commit ba008572e8
9 changed files with 320 additions and 25 deletions
--- a/4
+++ b/4
@@ -1,5 +1,9 @@
 2025-11-10  Oliver Kiddle  <opk@zsh.org>

+	* 53438: Doc/Zsh/params.yo, Doc/Zsh/zle.yo, Src/Zle/termquery.c,
+	Src/Zle/zle.h, Src/Zle/zle_refresh.c, Src/Zle/zle_vi.c, Src/init.c,
+	Src/zsh.h: support for changing terminal cursor shape and colour
+
 	* 53404: Doc/Zsh/params.yo, Src/Zle/termquery.c, Src/Zle/zle_main.c,
 	Src/builtin.c, Src/init.c, Src/input.c, Src/loop.c, Src/prompt.c,
 	Src/subst.c, Src/utils.c, Src/zsh.h, Test/X04zlehighlight.ztst,
--- a/Doc/Zsh/params.yo
+++ b/Doc/Zsh/params.yo
@@ -1749,6 +1749,12 @@ inserted instead of invoking editor commands. Furthermore, pasted text forms a
 single undo event and if the region is active, pasted text will replace the
 region.
 )
+item(tt(cursor-color) <E>)(
+Support for changing the color of the cursor.
+)
+item(tt(cursor-shape) <E>)(
+Support for changing the shape of the cursor.
+)
 item(tt(integration-output) <E>)(
 This provides the terminal with semantic information regarding where the output
 from commands start and finish. Some terminals use this information to make it
@@ -1769,6 +1775,11 @@ item(tt(query-bg) <E>)(
 Query the terminal background color which is used for tt(.term.bg) and
 tt(.term.mode).
 )
+item(tt(query-cursor) <E>)(
+Query the cursor color. This facilitates restoring the cursor to its original
+color if it has been configured via tt(zle_cursorform). The color is also
+assigned to tt(.term.cursor).
+)
 item(tt(query-fg) <E>)(
 Query the terminal foreground color which is used for tt(.term.fg).
 )
@@ -1900,6 +1911,13 @@ parameter has the effect of ensuring that bracketed paste remains disabled.
 However, see also the tt(.term.extensions) parameter which provides a single
 place to enable or disable terminal features.
 )
+vindex(zle_cursorform)
+item(tt(zle_cursorform))(
+An array describing contexts in which ZLE should change the shape and color
+of the cursor.
+See ifzman(em(Cursor Form) in zmanref(zshzle))\
+ifnzman(noderef(Cursor Form)).
+)
 vindex(zle_highlight)
 item(tt(zle_highlight))(
 An array describing contexts in which ZLE should highlight the input text.
--- a/Doc/Zsh/zle.yo
+++ b/Doc/Zsh/zle.yo
@@ -2855,3 +2855,64 @@ special array parameter tt(region_highlight); see
 ifnzman(noderef(Zle Widgets))\
 ifzman(above).

+texinode(Cursor Form)()()(Character Highlighting)
+subsect(Cursor Form)
+cindex(cursor form)
+
+vindex(zle_cursorform, setting)
+Some terminals support the ability to change the shape and color of the cursor.
+On such terminals, the line editor will use cursor styles appropriate to
+different contexts. This is controlled via the array parameter
+tt(zle_cursorform). To disable all cursor changes, see the tt(.term.extensions)
+parameter.
+
+Each element of the array should consist of a word indicating a context
+followed by a colon, then a comma-separated list of properties describing the
+shape and color to apply to the cursor.
+
+The available contexts follow with the default cursor form shown in
+parentheses. Where no default is given, the terminal's default is applied:
+
+startitem()
+item(tt(command))(
+Used for vi normal mode.
+)
+item(tt(edit))(
+The default form used in the line editor and for editing text in emacs
+mode.
+)
+item(tt(insert) (tt(bar)))(
+Used for vi editing mode.
+)
+item(tt(overwrite) (tt(underline)))(
+Used when editing text in overwrite mode or with the vi replace command.
+)
+item(tt(pending) (tt(underline)))(
+Used where the line editor is waiting for a single key press such as the vi
+operator pending mode widget.
+)
+item(tt(region))(
+Applied for both tt(regionstart) and tt(regionend) contexts.
+)
+item(tt(regionstart))(
+Used when the region is active and the cursor is positioned at the start of the
+region. The region includes the text under the cursor when it is positioned at
+the start so it is best to choose a cursor form that does not obscure this fact.
+)
+item(tt(regionend))(
+Used when the region is active and the cursor is positioned at the end of the
+region. Note that when this is the case, the region does not include the cursor
+position.
+)
+item(tt(visual))(
+Used when vi visual mode is active. The visual selection always includes the
+cursor position so the same advice as for tt(regionstart) applies.
+)
+enditem()
+
+The available cursor forms are tt(none), tt(bar), tt(block), tt(underline) and
+tt(hidden). Additionally, you can specify either tt(blink) or tt(steady) to
+indicate whether the cursor should flash and specify a color as an RGB triplet
+in hexadecimal format with with tt(color=)var(#xxxxxx). The value tt(none)
+applies the terminal's default cursor form. Note that on many terminals, this
+may be different to the initial cursor state from when the shell started.
--- a/Src/Zle/termquery.c
+++ b/Src/Zle/termquery.c
@@ -132,8 +132,7 @@ typedef const unsigned char seqstate_t;
 static char *EXTVAR  = ".term.extensions";
 static char *IDVAR   = ".term.id";
 static char *VERVAR  = ".term.version";
-static char *BGVAR   = ".term.bg";
-static char *FGVAR   = ".term.fg";
+static char *COLORVAR[]  = { ".term.fg", ".term.bg", ".term.cursor" };
 static char *MODEVAR = ".term.mode";

 /* Query sequences
@@ -144,6 +143,7 @@ static char *MODEVAR = ".term.mode";
 * because tmux will need to pass these on. */
 #define TQ_BGCOLOR "\033]11;?\033\\"
 #define TQ_FGCOLOR "\033]10;?\033\\"
+#define TQ_CURSOR  "\033]12;?\033\\"

 /* Kitty / fixterms keyboard protocol which allows wider support for keys
 * and modifiers. This clears the screen in terminology. */
@@ -420,32 +420,33 @@ probe_terminal(const char *tquery, seqstate_t *states,
    settyinfo(&torig);
 }

+static unsigned memo_cursor;
+
 static void
 handle_color(int bg, int red, int green, int blue)
 {
    char *colour;

-    switch (bg) {
-	case 1: /* background color */
-	    /* scale by Rec.709 coefficients for lightness */
-	    setsparam(MODEVAR, ztrdup(
-		    0.2126f * red + 0.7152f * green + 0.0722f * blue <= 127 ?
-		    "dark" : "light"));
-	  /* fall-through */
-	case 0:
-	    colour = zalloc(8);
-	    sprintf(colour, "#%02x%02x%02x", red, green, blue);
-	    setsparam(bg ? BGVAR : FGVAR, colour);
-	    break;
-	default: break;
+    if (bg == 1) {  /* background color */
+	/* scale by Rec.709 coefficients for lightness */
+	setsparam(MODEVAR, ztrdup(
+		0.2126f * red + 0.7152f * green + 0.0722f * blue <= 127 ?
+		"dark" : "light"));
    }
+
+    if (bg == 2)  /* cursor color */
+	memo_cursor = (red << 24) | (green << 16) | (blue << 8);
+
+    colour = zalloc(8);
+    sprintf(colour, "#%02x%02x%02x", red, green, blue);
+    setsparam(COLORVAR[bg], colour);
 }

 /* roughly corresponding feature names */
 static const char *features[] =
-	{ "bg", "fg", "modkeys-kitty", "truecolor", "id" };
+	{ "bg", "fg", "cursor", "modkeys-kitty", "truecolor", "id" };
 static const char *queries[] =
-	{ TQ_BGCOLOR, TQ_FGCOLOR, TQ_KITTYKB, TQ_RGB, TQ_XTVERSION, TQ_DA };
+	{ TQ_BGCOLOR, TQ_FGCOLOR, TQ_CURSOR, TQ_KITTYKB, TQ_RGB, TQ_XTVERSION, TQ_DA };

 static void
 handle_query(int sequence, int *numbers, int len, char *capture, int clen,
@@ -460,12 +461,12 @@ handle_query(int sequence, int *numbers, int len, char *capture, int clen,
 	    break;
 	case 2: /* kitty keyboard */
 	    feat = zshcalloc(2 * sizeof(char *));
-	    *feat = ztrdup(features[2]);
+	    *feat = ztrdup(features[3]);
 	    assignaparam(EXTVAR, feat, ASSPM_WARN|ASSPM_AUGMENT);
 	    break;
 	case 3: /* truecolor */
 	    feat = zshcalloc(2 * sizeof(char *));
-	    *feat = ztrdup(features[3]);
+	    *feat = ztrdup(features[4]);
 	    assignaparam(EXTVAR, feat, ASSPM_WARN|ASSPM_AUGMENT);
 	    break;
 	case 4: /* id */
@@ -480,7 +481,7 @@ handle_query(int sequence, int *numbers, int len, char *capture, int clen,
 /**/
 void
 query_terminal(void) {
-    char tquery[sizeof(TQ_BGCOLOR TQ_FGCOLOR TQ_KITTYKB TQ_RGB TQ_XTVERSION TQ_DA)];
+    char tquery[sizeof(TQ_BGCOLOR TQ_FGCOLOR TQ_CURSOR TQ_KITTYKB TQ_RGB TQ_XTVERSION TQ_DA)];
    char *tqend = tquery;
    static seqstate_t states[] = QUERY_STATES;
    char **f, **flist = getaparam(EXTVAR);
@@ -504,7 +505,7 @@ query_terminal(void) {
 	/* if termcap indicates 24-bit color, assume support - even
 	 * though this is only based on the initial $TERM
 	 * failing that, check $COLORTERM */
-	if (i == 3 && (tccolours == 1 << 24 ||
+	if (i == 4 && (tccolours == 1 << 24 ||
 		((cterm = getsparam("COLORTERM")) &&
 		    (!strcmp(cterm, "truecolor") ||
 			!strcmp(cterm, "24bit")))))
@@ -624,7 +625,7 @@ extension_enabled(const char *class, const char *ext, unsigned clen, int def)
 	if (strncmp(*e + negate, class, clen))
 	    continue;

-	if (!*(*e + negate + clen) || !strcmp(*e + negate + clen, ext))
+	if (!*(*e + negate + clen) || !strcmp(*e + negate + clen + 1, ext))
 	    return !negate;
    }
    return def;
@@ -703,7 +704,7 @@ end_edit(void)
 const char **
 prompt_markers(void)
 {
-    static unsigned aid = 0;
+    static unsigned int aid = 0;
    static char pre[] = "\033]133;A;cl=m;aid=zZZZZZZ\033\\"; /* before the prompt */
    static const char *const PR = "\033]133;P;k=i\033\\";   /* primary (PS1) */
    static const char *const SE = "\033]133;P;k=s\033\\";   /* secondary (PS2) */
@@ -754,3 +755,180 @@ notify_pwd(void)
    write_loop(SHTTY, url, ulen);
    write_loop(SHTTY, "\033\\", 2);
 }
+
+static unsigned int *cursor_forms;
+static unsigned int cursor_enabled_mask;
+
+static void
+match_cursorform(const char *teststr, unsigned int *cursor_form)
+{
+    static const struct {
+	const char *name;
+	unsigned char value, mask;
+    } shapes[] = {
+	{ "none", 0, 0xff },
+	{ "underline", CURF_UNDERLINE, CURF_SHAPE_MASK },
+	{ "bar", CURF_BAR, CURF_SHAPE_MASK },
+	{ "block", CURF_BLOCK, CURF_SHAPE_MASK },
+	{ "blink",  CURF_BLINK, CURF_STEADY },
+	{ "steady",  CURF_STEADY, CURF_BLINK },
+	{ "hidden", CURF_HIDDEN, 0 }
+    };
+
+    *cursor_form = 0;
+    while (*teststr) {
+	size_t s;
+	int found = 0;
+
+	if (strpfx("color=#", teststr)) {
+	    char *end;
+	    teststr += 7;
+	    zlong col = zstrtol(teststr, &end, 16);
+            if (end - teststr == 4) {
+		unsigned int red = col >> 8;
+		unsigned int green = (col & 0xf0) >> 4;
+		unsigned int blue = (col & 0xf);
+		*cursor_form &= 0xff; /* clear color */
+		*cursor_form |= CURF_COLOR |
+		    ((red << 4 | red) << CURF_RED_SHIFT) |
+		    ((green << 4 | green) << CURF_GREEN_SHIFT) |
+		    ((blue << 4 | blue) << CURF_BLUE_SHIFT);
+		found = 1;
+	    } else if (end - teststr == 6) {
+		*cursor_form |= (col << 8) | CURF_COLOR;
+		found = 1;
+	    }
+	    teststr = end;
+	}
+	for (s = 0; !found && s < sizeof(shapes) / sizeof(*shapes); s++) {
+	    if (strpfx(shapes[s].name, teststr)) {
+		teststr += strlen(shapes[s].name);
+		*cursor_form &= ~shapes[s].mask;
+		*cursor_form |= shapes[s].value;
+		found = 1;
+	    }
+	}
+	if (!found) /* skip an unknown component */
+	    teststr = strchr(teststr, ',');
+	if (!teststr || *teststr != ',')
+	    break;
+	teststr++;
+    }
+}
+
+/**/
+void
+zle_set_cursorform(void)
+{
+    char **atrs = getaparam("zle_cursorform");
+    static int setup = 0;
+    size_t i;
+    static const char *contexts[] = {
+	"edit:",
+	"command:",
+	"insert:",
+	"overwrite:",
+	"pending:",
+	"regionstart:",
+	"regionend:",
+        "visual:"
+    };
+
+    if (!cursor_forms)
+	cursor_forms = zalloc(CURC_DEFAULT * sizeof(*cursor_forms));
+    memset(cursor_forms, 0, CURC_DEFAULT * sizeof(*cursor_forms));
+    cursor_forms[CURC_INSERT] = CURF_BAR;
+    cursor_forms[CURC_OVERWRITE] = CURF_UNDERLINE;
+    cursor_forms[CURC_PENDING] = CURF_UNDERLINE;
+
+    for (; atrs && *atrs; atrs++) {
+	if (strpfx("region:", *atrs)) {
+	    match_cursorform(*atrs + 7, &cursor_forms[CURC_REGION_END]);
+	    cursor_forms[CURC_REGION_START] = cursor_forms[CURC_REGION_END];
+	    continue;
+	}
+	for (i = 0; i < sizeof(contexts) / sizeof(*contexts); i++) {
+	    if (strpfx(contexts[i], *atrs)) {
+		match_cursorform(*atrs + strlen(contexts[i]), &cursor_forms[i]);
+		break;
+	    }
+	}
+    }
+
+    if (!setup || trashedzle) {
+	cursor_enabled_mask = 0;
+	setup = 1;
+	if (!extension_enabled("cursor", "shape", 6, 1))
+	    cursor_enabled_mask |= CURF_SHAPE_MASK | CURF_BLINK | CURF_STEADY;
+	if (!extension_enabled("cursor", "color", 6, 1))
+	    cursor_enabled_mask |= CURF_COLOR_MASK;
+    }
+}
+
+/**/
+void
+free_cursor_forms(void)
+{
+    if (cursor_forms)
+	zfree(cursor_forms, CURC_DEFAULT * sizeof(*cursor_form));
+    cursor_forms = 0;
+}
+
+/**/
+void
+cursor_form(void)
+{
+    char seq[31];
+    char *s = seq;
+    unsigned int want, changed;
+    static unsigned int state = CURF_DEFAULT;
+    enum cursorcontext context = CURC_DEFAULT;
+
+    if (!cursor_forms)
+	return;
+
+    if (trashedzle) {
+	;
+    } else if (!insmode) {
+	context = CURC_OVERWRITE;
+    } else if (vichgflag == 2) {
+	context = CURC_PENDING;
+    } else if (region_active) {
+        if (invicmdmode()) {
+	    context = CURC_VISUAL;
+	} else {
+	    context = mark > zlecs ? CURC_REGION_START : CURC_REGION_END;
+	}
+    } else
+	context = invicmdmode() ? CURC_COMMAND : (vichgflag ? CURC_INSERT : CURC_EDIT);
+    want = (context == CURC_DEFAULT) ? CURF_DEFAULT : cursor_forms[context];
+    if (!(changed = (want ^ state) & ~cursor_enabled_mask))
+	return;
+
+    if (changed & CURF_HIDDEN)
+	 tcout(want & CURF_HIDDEN ? TCCURINV : TCCURVIS);
+    if (changed & CURF_SHAPE_MASK) {
+	char c = '0';
+	switch (want & CURF_SHAPE_MASK) {
+	    case CURF_BAR: c += 2;
+	    case CURF_UNDERLINE: c += 2;
+	    case CURF_BLOCK:
+		c += 2 - !!(want & CURF_BLINK);
+		changed &= ~(CURF_BLINK | CURF_STEADY);
+	}
+	s += sprintf(s, "\033[%c q", c);
+    }
+    if (changed & (CURF_BLINK | CURF_STEADY)) {
+	s += sprintf(s, "\033[?12%c", (want & CURF_BLINK) ? 'h' : 'l');
+    }
+    if (changed & CURF_COLOR_MASK) {
+	if (!(want & CURF_COLOR_MASK))
+	    want = memo_cursor | (want & 0xff);
+	s += sprintf(s, "\033]12;rgb:%02x00/%02x00/%02x00\033\\",
+		want >> CURF_RED_SHIFT, (want >> CURF_GREEN_SHIFT) & 0xff,
+		(want >> CURF_BLUE_SHIFT) & 0xff);
+    }
+    if (s - seq)
+	write_loop(SHTTY, seq, s - seq);
+    state = want;
+}
--- a/Src/Zle/zle.h
+++ b/Src/Zle/zle.h
@@ -470,6 +470,32 @@ struct region_highlight {
 * interaction in Doc/Zsh/zle.yo. */
 #define N_SPECIAL_HIGHLIGHTS	(4)

+/* Terminal cursor contexts */
+enum cursorcontext {
+    CURC_EDIT,
+    CURC_COMMAND,
+    CURC_INSERT,
+    CURC_OVERWRITE,
+    CURC_PENDING,
+    CURC_REGION_START,
+    CURC_REGION_END,
+    CURC_VISUAL,
+    CURC_DEFAULT
+};
+
+#define CURF_DEFAULT 0
+#define CURF_UNDERLINE 1
+#define CURF_BAR 2
+#define CURF_BLOCK 3
+#define CURF_SHAPE_MASK 3
+#define CURF_BLINK (1 << 2)
+#define CURF_STEADY (1 << 3)
+#define CURF_HIDDEN (1 << 4)
+#define CURF_COLOR (1 << 5)
+#define CURF_COLOR_MASK ((0xffffffu << 8) | CURF_COLOR)
+#define CURF_RED_SHIFT   24
+#define CURF_GREEN_SHIFT 16
+#define CURF_BLUE_SHIFT  8

 #ifdef MULTIBYTE_SUPPORT
 /*
--- a/Src/Zle/zle_refresh.c
+++ b/Src/Zle/zle_refresh.c
@@ -1024,6 +1024,8 @@ zrefresh(void)
 	tmpalloced = 0;
    }

+    zle_set_cursorform();
+
    /* this will create region_highlights if it's still NULL */
    zle_set_highlight();

@@ -1666,6 +1668,7 @@ individually */

 /* move to the new cursor position */
    moveto(rpms.nvln, rpms.nvcs);
+    cursor_form();

 /* swap old and new buffers - better than freeing/allocating every time */
    bufswap();
@@ -2706,4 +2709,6 @@ zle_refresh_finish(void)
 	region_highlights = NULL;
 	n_region_highlights = 0;
    }
+
+    free_cursor_forms();
 }
--- a/Src/Zle/zle_vi.c
+++ b/Src/Zle/zle_vi.c
@@ -186,6 +186,7 @@ getvirange(int wf)
 	virangeflag = 1;
 	wordflag = wf;
 	mark = -1;
+	cursor_form();
 	/* use operator-pending keymap if one exists */
 	Keymap km = openkeymap("viopp");
 	if (km)
--- a/Src/init.c
+++ b/Src/init.c
@@ -754,7 +754,7 @@ static char *tccapnams[TC_COUNT] = {
    "cl", "le", "LE", "nd", "RI", "up", "UP", "do",
    "DO", "dc", "DC", "ic", "IC", "cd", "ce", "al", "dl", "ta",
    "md", "mh", "so", "us", "ZH", "me", "se", "ue", "ZR", "ch",
-    "ku", "kd", "kl", "kr", "sc", "rc", "bc", "AF", "AB"
+    "ku", "kd", "kl", "kr", "sc", "rc", "bc", "AF", "AB", "vi", "ve"
 };

 /**/
--- a/Src/zsh.h
+++ b/Src/zsh.h
@@ -2674,7 +2674,9 @@ struct ttyinfo {
 #define TCBACKSPACE    34
 #define TCFGCOLOUR     35
 #define TCBGCOLOUR     36
-#define TC_COUNT       37
+#define TCCURINV       37
+#define TCCURVIS       38
+#define TC_COUNT       39

 #define tccan(X) (tclen[X])