Want to refresh window without processEvents()

**jnk5y** · 30th March 2006, 04:04

Whenever I use QApplication::processEvents() it allows the user to still do things in my application that I would rather them wait for the process to finish.

Is there a way to refresh the window so it doesn't look like it's frozen without having to call QApplication::processEvents() ?

If I have to use QApplication::processEvents() how can I deactivate everything until the process is done?

**jpn** · 30th March 2006, 07:51

Maybe you could show a modal progress dialog during the process?
A modal dialog would block the user in a sophisticated way from clicking elsewhere in the application.
Sounds a bit harsh, but another option could be to disable the whole window during the process..

**Kapil** · 30th March 2006, 07:59

Hi jpn..

Refreshing of a window or a page or else is a very fast executing operation...
Modal Dialogs are used when the process takes some time and the progress of the operation is shown...

Can this be a sol??? - > Capturing the snapshot of the entire window and then repainting the contents...
This is just a suggestion.. It can be a wrong idea also...

Kapil

**jpn** · 30th March 2006, 08:56

Originally Posted by Kapil

Refreshing of a window or a page or else is a very fast executing operation...

Refreshing of a window is not the lengthy process we are talking here..

jnk5y: if you want your application to be responsive, you will have to let it to process it's events once in a while.
So don't prevent your application from receiving it's events, rather block the user interaction somehow (modality, disabling..).

**Kapil** · 30th March 2006, 09:15

Originally Posted by jpn

Refreshing of a window is not the lengthy process we are talking here..

Did i get the question wrong???

Aahhh... what exactly it is??? Can u plz tel me...

Kapil

**wysota** · 30th March 2006, 09:21

QApplication::processEvents() taken an argument which can tell it not to process user input.

If you want to refresh a window without refering to the event queue, call repaint().

But you should really use a modal dialog here instead of doing any hacks. It can be as simple as:

Qt Code:

Switch view

QDialog dlg(this);
QLabel *l = new QLabel("Please wait", &dlg);
dlg.exec();

QDialog dlg(this);
QLabel *l = new QLabel("Please wait", &dlg);
dlg.exec();

To copy to clipboard, switch view to plain text mode

**jnk5y** · 31st March 2006, 00:32

I didn't realize that processEvents() took arguments.

QEventLoop::AllEvents - is the default
QEventLoop::ExcludeUserInputEvents - will allow the user to move the window and redraw it but will not let them press any buttons. I think this is what I will probably use unless there is a reason not to.

Thanks for your help.