Another weird backtrace related to cover drawing

[Ian Monroe]

On Tue, Jul 22, 2008 at 12:06 PM, Daniel Winter <dw at danielwinter.de> wrote:>
[snip]
> If the BQ could not be fixed (do not know enough about the workings of the Qt
> event system),  I would propose a workaround by changing the QueryMaker Api.
>
> a new method
> void QueryMaker::blocking( bool )  (witout calling it, it is non blocking,
> with true the QueryMaker itself will block).
>
> and
> DataList QueryMaker::results( void )  to get the result in that case.
>
> Sure that would mean to change all QueryMakers, but in terms of code reuse and
> also just to have that feature it would be a better solution in the longterm.
> (if bq can not get fixed)

After talking to Daniel in the channel, I think is a good idea.

I do think that using QueryMaker in a synchronous manner from the GUI
thread should be discouraged.  Using QueryMaker's asynchronous methods
is more difficult, but its how your supposed to do heavy tasks in GUI
programs. BlockingQueries use of processEvents tried to get the best
of both worlds (doing work in a thread, but the design simplicity of a
sync function call) and failed. But there was a good reason to have
these queries done in a thread to begin with that we shouldn't forget.

Ian