[Qt-interest] Faster logfile viewer

[Christoph Bartoschek]

Thomas Dähling wrote:

> Try using a QPlainTextEdit instead of a QTextEdit. Not sure how much
> performance improvement it will bring (no Qt installed on this machine
> so cannot test it) but it is supposed to be a lot faster since it's
> position calculations are a lot simpler than those in QTextEdit.

QPlainTextEdit reduces the runtime down to 22 seconds. However this is still
way slower than the old code.

By commenting out the repaint() call the runtime is 1.7 seconds. This would
be acceptable but we cannot get rid of the view updates.

Christoph