feat(icons): read the icon theme from gsettings

The icon theme name was hardcoded in three places (bin/wb-icon,
modules/extras/taskbar.jsonc and install.sh), so switching themes in the
appearance drawer was silently reverted as far as this bar was concerned.

wb-icon now reads org.gnome.desktop.interface icon-theme and gains two modes
for install.sh: --path NAME prints one icon's absolute path, --theme prints
the resolved theme name.

Icons are resolved per name rather than by substituting a directory prefix,
because themes disagree about both subdirectory and file extension: the Suru
themes keep web-browser at categories/22/*.svg, elementary-xfce at
apps/22/*.png. Only a real GTK lookup knows the path.

styles/modules.css therefore carries @ICON:name@ placeholders and
modules/extras/taskbar.jsonc carries @ICON_THEME@, both filled at install
time. taskbar.jsonc is generated rather than symlinked for that reason, and
install.sh removes the old symlink first so the redirect cannot overwrite the
committed source.

A theme missing one of the twenty names fails the install at the --selftest
step rather than drawing empty pills.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/styles/modules.css b/styles/modules.css
index ee5c4b2..b6fd38d 100644
--- a/styles/modules.css
+++ b/styles/modules.css
@@ -2,8 +2,10 @@
  *
  * The icons for the workspaces, the clock pair, the launcher and the language
  * live here rather than in the config, because waybar's format-icons takes
- * text and not paths. @ICONS@ is substituted by install.sh with the icon
- * theme's absolute path, so the theme can move without editing this file.
+ * text and not paths. Each icon placeholder below is substituted by install.sh
+ * with the absolute path `wb-icon --path <name>` resolves, so this file names
+ * icons and never a directory: themes disagree about both subdirectory and
+ * file extension, and only a real icon lookup knows which.
  */
 
 /* ------------------------------------------------------------------ *
@@ -59,11 +61,11 @@
 }
 
 #clock.date {
-	background-image: url("@ICONS@/mimetypes/22/x-office-calendar.svg");
+	background-image: url("@ICON:x-office-calendar@");
 }
 
 #clock.time {
-	background-image: url("@ICONS@/categories/22/clock.svg");
+	background-image: url("@ICON:clock@");
 }
 
 /* ------------------------------------------------------------- *
@@ -104,14 +106,14 @@
 
 /* The eight. Generic names, so the bar does not lie when the application on a
  * workspace changes. */
-#workspaces button:nth-child(1) { background-image: url("@ICONS@/categories/22/web-browser.svg"); }
-#workspaces button:nth-child(2) { background-image: url("@ICONS@/categories/22/text-editor.svg"); }
-#workspaces button:nth-child(3) { background-image: url("@ICONS@/categories/22/utilities-terminal.svg"); }
-#workspaces button:nth-child(4) { background-image: url("@ICONS@/devices/22/network-server.svg"); }
-#workspaces button:nth-child(5) { background-image: url("@ICONS@/actions/22/document-edit.svg"); }
-#workspaces button:nth-child(6) { background-image: url("@ICONS@/categories/22/applications-graphics.svg"); }
-#workspaces button:nth-child(7) { background-image: url("@ICONS@/actions/22/dialog-messages.svg"); }
-#workspaces button:nth-child(8) { background-image: url("@ICONS@/devices/22/input-gaming.svg"); }
+#workspaces button:nth-child(1) { background-image: url("@ICON:web-browser@"); }
+#workspaces button:nth-child(2) { background-image: url("@ICON:text-editor@"); }
+#workspaces button:nth-child(3) { background-image: url("@ICON:utilities-terminal@"); }
+#workspaces button:nth-child(4) { background-image: url("@ICON:network-server@"); }
+#workspaces button:nth-child(5) { background-image: url("@ICON:document-edit@"); }
+#workspaces button:nth-child(6) { background-image: url("@ICON:applications-graphics@"); }
+#workspaces button:nth-child(7) { background-image: url("@ICON:dialog-messages@"); }
+#workspaces button:nth-child(8) { background-image: url("@ICON:input-gaming@"); }
 
 /* ------------------------------------------------ *
  * Language: a flag, shipped by this repo.           *
@@ -135,7 +137,7 @@
  * ------------------------------------------------------ */
 
 #custom-mail {
-	background-image: url("@ICONS@/actions/22/mail-unread.svg");
+	background-image: url("@ICON:mail-unread@");
 	background-repeat: no-repeat;
 	background-position: 10px center;
 	background-size: 16px 16px;
@@ -240,13 +242,13 @@
 }
 
 #custom-presentation.deactivated {
-	background-image: url("@ICONS@/categories/22/preferences-desktop-screensaver.svg");
+	background-image: url("@ICON:preferences-desktop-screensaver@");
 }
 
 #custom-presentation.activated {
-	background-image: url("@ICONS@/mimetypes/22/x-office-presentation.svg");
+	background-image: url("@ICON:x-office-presentation@");
 }
 
 #custom-presentation.down {
-	background-image: url("@ICONS@/status/22/dialog-warning.svg");
+	background-image: url("@ICON:dialog-warning@");
 }