[Kstars-devel] A strange problem with qApp->processEvents()

[James Bowlin]

The QT docs described this as:

  Processes all pending events according to the specified flags
  until there are no more events to process.  

  You can call this function occasionally when your program is
  busy performing a long operation (e.g. copying a file).

http://doc.trolltech.com/4.3/qcoreapplication.html#processEvents

This is exactly what I'm doing from within KSFileReader. For the
star data, I call qApp->processEvents() every time 1% of the file
has been read.  This has always worked fine during start up when
the only window we have open is the splash window.

If the user increase the faint magnitude limit of the stars, we
read in the fainter stars from disk.  Unfortunately, calling
processEvents() causes the skymap in the main kstars window to
turn entirely light gray (the default background color).
It gets repainted during the next draw cycle but this is still
very disruptive.  If I don't call qApp->processEvents() then
the splash screen can sometimes stay blank and the progress
messages mostly don't show up.  I had added qApp->processEvents()
calls to our code to fix these same problems in the original
splash screen.

I've narrowed the problem down to that call.  I don't even need
a KStarsSplash window in order for it to happen.


-- 
Peace, James