--- a/VDBThreadGroupPresenter.st	Mon Jan 08 19:48:11 2018 +0000
+++ b/VDBThreadGroupPresenter.st	Mon Jan 15 09:57:48 2018 +0000
@@ -102,6 +102,24 @@
     "Created: / 21-09-2014 / 23:41:57 / Jan Vrany <jan.vrany@fit.cvut.cz>"
 ! !
 
+!VDBThreadGroupPresenter methodsFor:'protocol-displaying'!
+
+heightOn:aGC
+
+    "/ Following is a performance optimization. We know
+    "/ that label will be a string, so passing any string
+    "/ would do (this in the end asks a font metrics).
+    "/ 
+    "/ This saves us a lot of time when system generates
+    "/ a lot of events since #label sends ask GDB dof details
+    height isNil ifTrue:[
+        height := self heightOf:'%1 [%2%3]' on:aGC
+    ].
+    ^ height
+
+    "Created: / 15-01-2018 / 09:54:22 / jv"
+! !
+
 !VDBThreadGroupPresenter methodsFor:'testing'!
 
 isThreadGroupPresenter