config: add url.style=none|single|double|curly|dotted|dashed

This option allows you to configure which underline style to use with
URLs.

The default is dotted. Since before this patch, URL underlines were
always plain underlines, this means the default URL underline style
has changed, from single to dotted.

Closes #2302

CHANGELOG.md

@@ -71,7 +71,20 @@
 
 ## Unreleased
 ### Added
+
+* `url.style=none|single|double|curly|dotted|dashed` option added,
+  allowing you to configure how URL underlines are drawn. The default
+  is `dotted` ([#2302][2302]).
+
+[2302]: https://codeberg.org/dnkl/foot/issues/2302
+
+
 ### Changed
+
+* URL underlines are now dotted by default, instead of plain
+  underlines. This can be changed with the new `url.style` option.
+
+
 ### Deprecated
 ### Removed
 ### Fixed

config.c

@@ -1304,6 +1304,14 @@ parse_section_url(struct context *ctx)
     else if (streq(key, "label-letters"))
         return value_to_wchars(ctx, &conf->url.label_letters);
 
+    else if (streq(key, "style")) {
+        _Static_assert(sizeof(conf->url.style) == sizeof(int),
+                       "enum is not 32-bit");
+        return value_to_enum(
+            ctx, (const char *[]){"none", "single", "double", "curly", "dotted", "dashed", NULL},
+            (int *)&conf->url.style);
+    }
+
     else if (streq(key, "osc8-underline")) {
         _Static_assert(sizeof(conf->url.osc8_underline) == sizeof(int),
                        "enum is not 32-bit");
@@ -3518,6 +3526,7 @@ config_load(struct config *conf, const char *conf_path,
         .url = {
             .label_letters = xc32dup(U"sadfjklewcmpgh"),
             .osc8_underline = OSC8_UNDERLINE_URL_MODE,
+            .style = UNDERLINE_DOTTED,
         },
         .custom_regexes = tll_init(),
         .can_shape_grapheme = fcft_caps & FCFT_CAPABILITY_GRAPHEME_SHAPING,

config.h

@@ -218,6 +218,15 @@ enum center_when {
     CENTER_ALWAYS,
 };
 
+enum underline_style {
+    UNDERLINE_NONE,
+    UNDERLINE_SINGLE,  /* Legacy underline */
+    UNDERLINE_DOUBLE,
+    UNDERLINE_CURLY,
+    UNDERLINE_DOTTED,
+    UNDERLINE_DASHED,
+};
+
 struct config {
     char *conf_path;
     char *term;
@@ -327,6 +336,7 @@ struct config {
             OSC8_UNDERLINE_URL_MODE,
             OSC8_UNDERLINE_ALWAYS,
         } osc8_underline;
+        enum underline_style style;
 
         char *regex;
         regex_t preg;

doc/foot.ini.5.scd

@@ -867,6 +867,14 @@ section.
 	
 	Default: _url-mode_
 
+*style*
+	The underline style to use when rendering URL underlines. This
+	applies to both OSC-8 underlines when *osc8-underline=always*, and
+	all detected URLs in URL mode. One of *none*, *single*, *double*,
+	*curly*, *dotted* or *dashed*.
+	
+	Default: _dotted_
+
 *label-letters*
 	String of characters to use when generating key sequences for URL
 	jump labels.

foot.ini

@@ -72,6 +72,7 @@
 [url]
 # launch=xdg-open ${url}
 # label-letters=sadfjklewcmpgh
+# style=dotted  (none|single|double|curly|dotted|dashed)
 # osc8-underline=url-mode
 # regex=(((https?://|mailto:|ftp://|file:|ssh:|ssh://|git://|tel:|magnet:|ipfs://|ipns://|gemini://|gopher://|news:)|www\.)([0-9a-zA-Z:/?#@!$&*+,;=.~_%^\-]+|\([]\["0-9a-zA-Z:/?#@!$&'*+,;=.~_%^\-]*\)|\[[\(\)"0-9a-zA-Z:/?#@!$&'*+,;=.~_%^\-]*\]|"[]\[\(\)0-9a-zA-Z:/?#@!$&'*+,;=.~_%^\-]*"|'[]\[\(\)0-9a-zA-Z:/?#@!$&*+,;=.~_%^\-]*')+([0-9a-zA-Z/#@$&*+=~_%^\-]|\([]\["0-9a-zA-Z:/?#@!$&'*+,;=.~_%^\-]*\)|\[[\(\)"0-9a-zA-Z:/?#@!$&'*+,;=.~_%^\-]*\]|"[]\[\(\)0-9a-zA-Z:/?#@!$&'*+,;=.~_%^\-]*"|'[]\[\(\)0-9a-zA-Z:/?#@!$&*+,;=.~_%^\-]*'))
 

render.c

@@ -1171,13 +1171,16 @@ render_cell(struct terminal *term, pixman_image_t *pix,
     if (cell->attrs.strikethrough)
         draw_strikeout(term, pix, font, &fg, x, y, cell_cols);
 
-    if (unlikely(cell->attrs.url)) {
+    if (unlikely(cell->attrs.url && term->conf->url.style != UNDERLINE_NONE)) {
         pixman_color_t url_color = color_hex_to_pixman(
             term->conf->colors_dark.use_custom.url
             ? term->conf->colors_dark.url
             : term->colors.table[3],
             gamma_correct);
-        draw_underline(term, pix, font, &url_color, x, y, cell_cols);
+
+        draw_styled_underline(
+            term, pix, font, &url_color, term->conf->url.style,
+            x, y, cell_cols);
     }
 
 draw_cursor:

terminal.h

@@ -105,15 +105,6 @@ struct uri_range_data {
     char *uri;
 };
 
-enum underline_style {
-    UNDERLINE_NONE,
-    UNDERLINE_SINGLE,  /* Legacy underline */
-    UNDERLINE_DOUBLE,
-    UNDERLINE_CURLY,
-    UNDERLINE_DOTTED,
-    UNDERLINE_DASHED,
-};
-
 struct underline_range_data {
     enum underline_style style;
     enum color_source color_src;

tests/test-config.c

@@ -632,6 +632,10 @@ test_section_url(void)
               (const char *[]){"url-mode", "always"},
               (int []){OSC8_UNDERLINE_URL_MODE, OSC8_UNDERLINE_ALWAYS},
               (int *)&conf.url.osc8_underline);
+    test_enum(&ctx, &parse_section_url, "style",
+              6, (const char *[]){"none", "single", "double", "curly", "dotted", "dashed"},
+              (int []){UNDERLINE_NONE, UNDERLINE_SINGLE, UNDERLINE_DOUBLE, UNDERLINE_CURLY, UNDERLINE_DOTTED, UNDERLINE_DASHED},
+              (int *)&conf.url.style);
     test_c32string(&ctx, &parse_section_url, "label-letters", &conf.url.label_letters);
 
     config_free(&conf);