node: Noop when detaching a node without a parent.

In practice, throwing an error was real annoying.

1 files changed, 8 insertions, 9 deletions

diff --git a/starling/node.scm b/starling/node.scm
index 920a9bd..a0141c1 100644
--- a/starling/node.scm
+++ b/starling/node.scm
@@ -247,15 +247,14 @@ represented as a ratio in the range [0, 1]."
 (define-method (detach (node <node>))
   "Detach NODE from its parent."
   (let ((p (parent node)))
-    (unless p
-      (error "node has no parent" node))
-    (set! (children p) (delq node (children p)))
-    (hashq-remove! (children-map p) (name node))
-    ;; Detaching deactives the node and all of its children.
-    (when (active? node)
-      (deactivate node))
-    (set! (parent node) #f)
-    (on-detach p node)))
+    (when p
+      (set! (children p) (delq node (children p)))
+      (hashq-remove! (children-map p) (name node))
+      ;; Detaching deactives the node and all of its children.
+      (when (active? node)
+        (deactivate node))
+      (set! (parent node) #f)
+      (on-detach p node))))
 
 (define-method (detach . nodes)
   "Detach all NODES from their respective parents."