config+render: allow cursor.style=hollow

Closes #1965

CHANGELOG.md

@@ -68,9 +68,11 @@
 * Support for custom regex matching ([#1386][1386],
   [#1872][1872])
 * Support for kitty's text-sizing protocol (`w`, width, only), OSC-66.
+* `cursor.style` can now be set to `hollow` ([#1965][1965]).
 
 [1386]: https://codeberg.org/dnkl/foot/issues/1386
 [1872]: https://codeberg.org/dnkl/foot/issues/1872
+[1965]: https://codeberg.org/dnkl/foot/issues/1965
 
 
 ### Changed

config.c

@@ -1517,7 +1517,7 @@ parse_section_cursor(struct context *ctx)
 
         return value_to_enum(
             ctx,
-            (const char *[]){"block", "underline", "beam", NULL},
+            (const char *[]){"block", "underline", "beam", "hollow", NULL},
             (int *)&conf->cursor.style);
     }
 

config.h

@@ -28,7 +28,7 @@ struct font_size_adjustment {
     float percent;
 };
 
-enum cursor_style { CURSOR_BLOCK, CURSOR_UNDERLINE, CURSOR_BEAM };
+enum cursor_style { CURSOR_BLOCK, CURSOR_UNDERLINE, CURSOR_BEAM, CURSOR_HOLLOW };
 enum cursor_unfocused_style {
     CURSOR_UNFOCUSED_UNCHANGED,
     CURSOR_UNFOCUSED_HOLLOW,

doc/foot.ini.5.scd

@@ -842,8 +842,8 @@ applications can change these at runtime.
 
 *style*
 	Configures the default cursor style, and is one of: *block*,
-	*beam* or *underline*. Note that this can be overridden by
-	applications. Default: _block_.
+	*beam*, *underline* or *hollow*. Note that this can be overridden
+	by applications. Default: _block_.
 
 *unfocused-style*
 	Configures how the cursor is rendered when the terminal window is

render.c

@@ -647,6 +647,11 @@ draw_cursor(const struct terminal *term, const struct cell *cell,
             draw_underline_cursor(term, pix, font, &cursor_color, x, y, cols);
         }
         break;
+
+    case CURSOR_HOLLOW:
+        if (likely(term->cursor_blink.state == CURSOR_BLINK_ON))
+            draw_hollow_block(term, pix, &cursor_color, x, y, cols);
+        break;
     }
 }