QtForum.org

I have an app.
Multiple tabs.. quite a large number of widgets on each. labels/buttons ect.
Most of these labels is getting updated information multiple times per second.

On ons of these tabs I have a potentially opengl qGraphicsView scene.
Which is quite intensive on the cpu/hardware.

What I found out is that if any single widget redraws it seems the whole gui redraws itself.
This includes widgets on other tabs.

The result is a rather ineffecient application that basicly makes the cpu die.
This is mostly problematic with the opengl widget when its in non-gl/software mode.

I could find no way to force it down to a fix frame rate.

I tried everything I can find or think of all ready.


setViewportUpdateMode(QGraphicsView::NoViewportUpdate); - no effect


I played with: setUpdatesEnabled(false);
but mostly the result is times when the widget is not drawn.


If I click on a button next to the widget then somehow the paint event transfers over to all other widgets.
Its as if when a widget redraws is forces its parent to redraw which then in turn forces all its children to redraw and this then runs recursively through the complete application

Please is there anyway to make Qt behave itself?

I should perhaps mention that:
1. I don't use fixed sized widgets - I use Qts layouts to position things mostly.
2. I have a rather large style sheet loaded over everything.

What really freaks me is that stupid Qt will redraw the non-visible tabs.. this is fail.

hi

THANKS ALOT FOR YOUR RESPONSE!!

I compiled for release.. this helped a little bit.. at least the file size is smaller.
I noticed that the amount of redraws between opengl mode and software mode differ slightly but thats ok.

However I noticed that the stylesheet is the problem.
If the stylesheet is on the QGraphicsView seems to redraw consistantly as other widgets on the screen around it updates.
When I removed the stylesheet this behaviour ends.

I've attached my stylesheet.. I'm not an expert in stylesheets.. so please point out what I screwed up

Here is my code that loads the stylesheet:
void MainWindow::loadStyle(QString filename)

{

QFile sfile(filename);

if (sfile.open(QIODevice::ReadOnly | QIODevice::Text))

{

QTextStream in(&sfile);

QString styleString = in.readAll();

if (!styleString.isEmpty())

{

this->setStyleSheet(styleString);

}

else

{

qCritical() << "Style file is empty!";

}

}

else

{

qCritical() << "Failed to open Style file: " << filename;

}

}


This function is the last thing called in main window constructor after all gui widgets and other things have been setup.