Update X desktop info handling

- Update initial value for `xdistate`
- Function for current window name

nbcl/panel/panel_section_center.nbcl

@@ -17,9 +17,7 @@ fn panel_center() {
 			truncate = true 
 			truncate_left = false
 			limit_width = config.panel_windowtitle_maxchars
-			text = global("xdistate").mutate(|val|{
-				json.parse(val).active_window.name
-			})
+			text = xdi.windowname()
 		}
 	}
 }

nbcl/vars/vars.nbcl

@@ -1,4 +1,4 @@
-import "nbcl/vars/xdi.nbcl" as xdi
+import "nbcl/vars/xdi.nbcl" as xdi { * }
 
 Poll "time_hhmm" {
 	initial = "00:00"

nbcl/vars/xdi.nbcl

@@ -1,9 +1,13 @@
 import core.json
 
 Listen "xdistate" {
-	initial = "{}"
-	cmd = "xdi -f"
+	initial = "{\"active_window\":{\"id\":0,\"name\":\"\",\"class\":\"\"},\"workspaces\":[{\"id\":0,\"current\":true,\"windows\":[]}]}"
+	cmd = "/usr/local/bin/xdi -f"
 }
 
-
-#let wmstate = 
+# Usage: xdi.windowname()
+fn windowname() {
+	global("xdistate").mutate(|val|{
+		json.parse(val).active_window.name
+	})
+}