Simple support for newlines

gaart.scm

@@ -65,19 +65,26 @@
      (blit! rpos cpos grapheme)
      #f)))
 
-(define (text str)
-  (gaart
-   (string-width str) 1
-   (λ (okay? blit! rpos cpos)
-     ;; Go through each grapheme, print it and advance the position
-     ;; depending on the width
-     (fold
-      (λ (gr c)
-        (blit! rpos c gr)
-        (+ c (grapheme-width gr)))
-      cpos
-      (string->grapheme-list str))
-     #f)))
+;; TODO: detect non-printable characters other than newline
+;; We need to discard them and also handle escape codes/printing those, etc.
+(define* (text str #:key (halign #f))
+  (define contains-newline? (string-index str #\newline))
+  (if contains-newline?
+      (if halign
+          (vappend* (map text (string-split str #\newline)) #:halign halign)
+          (scm-error 'keyword-argument-error "text" "String contained newlines but no halign argument was set" '() (list halign)))
+      (gaart
+       (string-width str) 1
+       (λ (okay? blit! rpos cpos)
+         ;; Go through each grapheme, print it and advance the position
+         ;; depending on the width
+         (fold
+          (λ (gr c)
+            (blit! rpos c gr)
+            (+ c (grapheme-width gr)))
+          cpos
+          (string->grapheme-list str))
+         #f))))
 
 (define (place-at back row-offset col-offset front)
   (match-let ((($ <gaart> bw bh draw-b) back)