how to immediately show / update a window without returning to event loop?

[davecotter]

on windows, the moment i call this:

i_qWindP->show();

the window shows. on mac it doesn't show. is there some "idle" call i can make to allow the OS some CPU time to get the window on screen?

then, say i update a control in that window (like, a progress bar), how do i get that to flush immediately? this is during startup so we're not at the event loop just yet...

[davecotter]

Okay it seems the secret was calling QApplication::processEvents();

[mpergand]

To update a widget immediately, call repaint() on that widget.

[davecotter]

okay i'm calling repaint() on the QWindow widget but it doesn't actually draw when i step over that call, do i need to somehow yield some time to the event handler for that to actually be serviced?

[davecotter]

also, on the mac, the window isn't even being shown. i call show and i get nothing.

[Kent-Dorfman]

This post is deleted!

[SGaist]

Hi,

What do you do in that QWindow ?

Since it's a QWindow, you are likely doing OpenGL therefore, did you initialise everything properly ?

[davecotter]

Okay it seems the secret was calling QApplication::processEvents();

[davecotter]

@SGaist no it's just a regular dialog window

[SGaist]

@davecotter said in how to immediately show / update a window without returning to event loop?:

okay i'm calling repaint() on the QWindow widget but it doesn't actually draw when i step over that call, do i need to somehow yield some time to the event handler for that to actually be serviced?

That QWindow was then misleading ;-)

As for your solution, you are in fact forcing a round of the event loop.