A first step towards completion: Add completion for command plugins

scheme/nuit-engine.scm

@@ -288,12 +288,13 @@
      ((= ch key-control-x)
       (loop (wait-for-input) #t))
 
-     ((= ch key-tab)
-      (debug-message "Should do completion now")
+     ((and (focus-on-command-buffer?)
+	   (= ch key-tab))
+      (offer-completions (last (buffer-text command-buffer)))
       (loop (wait-for-input) #f))
 
      ;; F7 toggle scheme-mode / command-mode (FIXME: find a better key)
-     ((= ch key-home)
+     ((= ch key-f7)
       (toggle-command/scheme-mode)
       (loop (wait-for-input) #f))
 
@@ -740,6 +741,22 @@
 	(loop (cdr lst)
 	      (string-append str " " (car lst))))))
 
+(define (completions->select-list completions)
+  (debug-message "possible completions " completions)
+  (make-select-list
+   (map (lambda (s) (make-unmarked-element s #f s))
+	completions)
+   (result-buffer-num-lines result-buffer)))
+
+(define (offer-completions command)
+  (debug-message "offer-completions " command)
+  (let ((select-list
+	 (completions->select-list
+	  (completions-for (command-completions) command))))
+    (wclear (app-window-curses-win result-window))
+    (paint-result-buffer (paint-selection-list select-list))
+    (refresh-result-window)))
+
 (define-record-type standard-result-obj standard-result-obj
   (make-standard-result-obj cursor-pos-y
 			    cursor-pos-x