polybar: add clickable calendar widget with PWA support

desktop-environment/polybar/shades/modules.ini

@@ -581,7 +581,9 @@ interval = 10.0
 ;;date = %Y-%m-%d%
 
 ; Optional time format
-time = "  %a, %d %b %Y"
+; Wrapped in a click action (%% escapes % for strftime): left click opens
+; the Google Calendar PWA (or the site, if none is installed).
+time = "%%{A1:~/.config/polybar/shades/scripts/calendar.sh &:}  %a, %d %b %Y%%{A}"
 
 ; Available tags:
 ;   <label> (default)

desktop-environment/polybar/shades/scripts/calendar.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+# Open the Google Calendar PWA if one is installed, otherwise fall back to
+# calendar.google.com in the default browser.
+#
+# Browsers install PWAs as desktop entries named
+# <browser>-<app-id>-<profile>.desktop, so the filename can't be pinned;
+# match on the entry's Name= instead, which is the site's app name.
+
+apps_dir="${XDG_DATA_HOME:-$HOME/.local/share}/applications"
+
+desktop_file=$(grep -lis '^Name=Google Calendar' "$apps_dir"/*.desktop 2>/dev/null | head -n 1)
+
+if [[ -n "$desktop_file" ]]; then
+    if command -v gtk-launch >/dev/null; then
+        exec gtk-launch "$(basename "$desktop_file" .desktop)"
+    elif command -v gio >/dev/null; then
+        exec gio launch "$desktop_file"
+    fi
+fi
+
+exec xdg-open "https://calendar.google.com/"