config: make selection foreground/background colors configurable

The default is still to inverse the regular foreground/background
colors.

If the user sets *both* of the new options, selection-foreground and
selection-background, those colors will *always* be used for selected
cells, instead of inverting the regular foreground/background colors.

CHANGELOG.md

@@ -28,6 +28,8 @@
 * **mouse.hide-when-typing** option to `footrc`.
 * **scrollback.multiplier** option to `footrc`
   (https://codeberg.org/dnkl/foot/issues/54).
+* **colors.selection-foreground** and **colors.selection-background**
+  options to `footrc`.
 
 
 ### Deprecated

config.c

@@ -474,6 +474,8 @@ parse_section_colors(const char *key, const char *value, struct config *conf,
     else if (strcmp(key, "bright5") == 0)    color = &conf->colors.bright[5];
     else if (strcmp(key, "bright6") == 0)    color = &conf->colors.bright[6];
     else if (strcmp(key, "bright7") == 0)    color = &conf->colors.bright[7];
+    else if (strcmp(key, "selection-foreground") == 0) color = &conf->colors.selection_fg;
+    else if (strcmp(key, "selection-background") == 0) color = &conf->colors.selection_bg;
     else if (strcmp(key, "alpha") == 0) {
         double alpha;
         if (!str_to_double(value, &alpha) || alpha < 0. || alpha > 1.) {
@@ -1257,6 +1259,9 @@ config_load(struct config *conf, const char *conf_path, bool errors_are_fatal)
                 default_bright[7],
             },
             .alpha = 0xffff,
+            .selection_fg = 0x80000000,  /* Use default bg */
+            .selection_bg = 0x80000000,  /* Use default fg */
+            .selection_uses_custom_colors = false,
         },
 
         .cursor = {
@@ -1373,6 +1378,10 @@ config_load(struct config *conf, const char *conf_path, bool errors_are_fatal)
     ret = parse_config_file(f, conf, conf_path, errors_are_fatal);
     fclose(f);
 
+    conf->colors.selection_uses_custom_colors =
+        conf->colors.selection_fg >> 24 == 0 &&
+        conf->colors.selection_bg >> 24 == 0;
+
 out:
     if (ret && tll_length(conf->fonts) == 0)
         tll_push_back(conf->fonts, config_font_parse("monospace"));

config.h

@@ -70,6 +70,9 @@ struct config {
         uint32_t regular[8];
         uint32_t bright[8];
         uint16_t alpha;
+        uint32_t selection_fg;
+        uint32_t selection_bg;
+        bool selection_uses_custom_colors;
     } colors;
 
     struct {

doc/footrc.5.scd

@@ -156,6 +156,11 @@ _alpha_ option.
 	Background translucency. A value in the range 0.0-1.0, where 0.0
 	means completely transparent, and 1.0 is opaque. Default: _1.0_.
 
+*selection-foreground*, *selection-background*
+	Foreground (text) and background color to use in selected
+	text. Note that *both* options must be set, or the default will be
+	used. Default: _inverse foreground/background_.
+
 
 # SECTION: csd
 

footrc

@@ -43,6 +43,8 @@
 # bright5=fcace3   # bright magenta
 # bright6=b3ffff   # bright cyan
 # bright7=ffffff   # bright white
+# selection-foreground=<inverse foreground/background>
+# selection-background=<inverse foreground/background>
 
 [csd]
 # preferred=server

render.c

@@ -384,15 +384,19 @@ render_cell(struct terminal *term, pixman_image_t *pix,
     uint32_t _fg = 0;
     uint32_t _bg = 0;
 
-    /* Use cell specific color, if set, otherwise the default colors (possible reversed) */
+    if (is_selected && term->conf->colors.selection_uses_custom_colors) {
-    _fg = cell->attrs.have_fg ? cell->attrs.fg : term->colors.fg;
+        _fg = term->conf->colors.selection_fg;
-    _bg = cell->attrs.have_bg ? cell->attrs.bg : term->colors.bg;
+        _bg = term->conf->colors.selection_bg;
+    } else {
+        /* Use cell specific color, if set, otherwise the default colors (possible reversed) */
+        _fg = cell->attrs.have_fg ? cell->attrs.fg : term->colors.fg;
+        _bg = cell->attrs.have_bg ? cell->attrs.bg : term->colors.bg;
 
-    /* If *one* is set, we reverse */
+        if (term->reverse ^ cell->attrs.reverse ^ is_selected) {
-    if (term->reverse ^ cell->attrs.reverse ^ is_selected) {
+            uint32_t swap = _fg;
-        uint32_t swap = _fg;
+            _fg = _bg;
-        _fg = _bg;
+            _bg = swap;
-        _bg = swap;
+        }
     }
 
     if (cell->attrs.blink && term->blink.state == BLINK_OFF)