[Interest] QTextEdit is too slow - hints needed

[JM]

Hi all,

I am using QTextEdit to display log text files, just like the Unix command tail -f. 
My current implementation just displays the last 5 lines and then follows the growing
log file, displaying lines as they come.
Now, I am asked to make QTextEdit display the whole file when the user opens a file.
A log file can be very large. I tested it with a 2mbyte file, and inserting data to QTextEdit
caused the GUI to freeze for almost 1 minute.
This is not acceptable, and I am looking for a solution. I have the following questions:

-) what is the fastest way to insert lots of text into QTextEdit?
-) should I go to the route of implementing my own QTextDisplay? If so, 
should I use QAbstractScrollArea as class base? Any pointer to how to use it?

Thanks in advance,
JM