--- a/ThumbWheel.st	Sat Nov 10 00:28:03 2018 +0100
+++ b/ThumbWheel.st	Sat Nov 10 00:28:26 2018 +0100
@@ -751,23 +751,20 @@
 
 !ThumbWheel methodsFor:'queries'!
 
-preferredExtent
+computePreferredExtent
     "return a useful default extent"
 
     |ppmm|
 
-    preferredExtent isNil ifTrue:[
-        ppmm := device pixelPerMillimeter.
-        orientation == #vertical ifTrue:[
-            preferredExtent := (ppmm * (5 @ 30)) rounded
-        ] ifFalse:[
-            preferredExtent := (ppmm * (30 @ 5)) rounded
-        ].
+    ppmm := device pixelPerMillimeter.
+    orientation == #vertical ifTrue:[
+        preferredExtent := (ppmm * (5 @ 30)) rounded
+    ] ifFalse:[
+        preferredExtent := (ppmm * (30 @ 5)) rounded
     ].
-
     ^ preferredExtent
 
-    "Modified: 28.5.1997 / 16:03:55 / cg"
+    "Created: / 09-11-2018 / 20:02:47 / Claus Gittinger"
 !
 
 verticalScrollStep