How show progress of slow a operation?

[shud]

I need to show the progress of a slow operation , but I doesn´t have a loop to set the values for a qprogressdialog.
I have only a call to a method compute(); but I don´t have get access to his internal code.

[schnitzel]

I believe threading is your only option then:
http://doc.qt.nokia.com/4.6/threads.html

[squidge]

throw compute() into a seperate thread, and then do some animation until the thread returns.

[shud]

but , the thread can pass or set the value of the q?progressdialog?

[squidge]

No, you set the volume of the progress dialog in your main gui loop using a timer.

[shud]

Ok, but my problem is that the operation sometimes is fast (depending of his entries) and other times is very slow , so predefined a time is very difficult.

[schnitzel]

QProgressDialog supports marquee style which just moves the progess back and forth to show that something is happening but it is unknown how long it will take.

[squidge]

The thread will send you a signal when it is completed, so you can remove the progress bar. Therefore it doesn't matter if the task takes long time or short time.

[schnitzel]

The thread will send you a signal when it is completed, so you can remove the progress bar. Therefore it doesn't matter if the task takes long time or short time.

If I understand shud correctly, then the 'volume' is unknown, so in that case it is better to make the progressbar go back and forth - imho.

[squidge]

If I understand shud correctly, then the 'volume' is unknown, so in that case it is better to make the progressbar go back and forth - imho.

Yes, and I completely agree with you, but you still need to remove that progress bar when the task is finished, hence why I mentioned using the signal that the thread object will send when the thread completes execution.