Build: NetBeans IDE 6.8 (Build 200912041610)
VM: Java HotSpot(TM) Client VM, 14.2-b01, Java(TM) SE Runtime Environment, 1.6.0_16-b01
Maximum slowness yet reported was 37982 ms, average is 8456
Created attachment 95005 [details]
Seems like a JDK problem. AWT thread is blocked inside javax.swing.JComponent.scrollRectToVisible(...) call.
See this very old JDK bug which seems to be still valid regardless all comments about some fix in jdk6.
Please evaluate if HTMLDocView could be changed to workaround the JDK bug. See the Evaluation part of the JDK bug report for possible help.
The evaluation part of the above mentioned JDK bug suggest to switch the
views used to display a wrapped JTextArea to ZoneView and ParagraphView.
I'm afraid that we don't want to write our own HTML renderer (since code completion uses standard HTML rendering mechanism from JDK - HTMLDocView is just a JEditorPane with HTMLEditorKit installed).
Created attachment 161543 [details]
IDE log - NB DEV 201607230002 JDK 8 u74 x64