Lost My Qt Widgets StyleSheets

Ketan__Patel__0011

Hello friends and Qt expert

i am facing some varied
i Create a qt widget Application project and i used Multiple controls like PushButton
Groupboxes and many more.
And For Make Attractive GUI i Apply some stylesheet on controls

now when i run my application some times i lost my all controls stylesheet and display default stylesheet

for example :
i was set Background-color property for Pushbutton but when i run application Pushbutton Background-color is lost and display default color

i was search about this problem but i did't get any things about this problem

please help me for solve this problem and if you have any idea or any Suggestion
please drop here

Thanks you so much

Ketan__Patel__0011

@Hardy91

Thanks for reply
but i was figured out problem and solve it.
Problem was what that i was updating my UI control in thread which is wrong.

Christian Ehrlicher

Please provide a minimal, compilable example of your problem.

Ketan__Patel__0011

@Christian-Ehrlicher

My PushButton StyleSheets before the start My Application

My PushButton StyleSheets after the run My Application

you can see when i run my application that time pushbutton stylesheets are lost

and this is not only in Pushbutton problem whatever controls i was used in my application every controls lost it's Stylesheet

Christian Ehrlicher

Then you don't load them correct. But since you don't provide some source code to reproduce your problem we can't help.

Ketan__Patel__0011

@Christian-Ehrlicher

it is simple Stylesheet Like:

QPushButton
{
background-color:rgb(241,92,34);
}

i am not used any other functionality to design any control, i just apply some Stylesheet on my qt application

but whenever i run my application my application stylesheet are gone...

Christian Ehrlicher

This is still no reproducible example. Create one which is compilable or we can't help - how should we know what else you're doing somewhere?

Ketan__Patel__0011

@Christian-Ehrlicher

when i start My QFuture<void> thread And run Any function parallelly
that time this problem is raised

Christian Ehrlicher

I'm giving up... provide code where we can reproduce the problem!

and btw: you must not do any gui oeration outside the main thread.

Ketan__Patel__0011

@Christian-Ehrlicher

but way i can't use Any GUI controls in QFuture Thread ?

jsulm

@Ketan__Patel__0011 said in Lost My Qt Widgets StyleSheets:

but way i can't use Any GUI controls in QFuture Thread ?

Because it's not supported. UI may only be accessed from UI thread.
This is mentioned in the documentation: https://doc.qt.io/qt-5/thread-basics.html

Ketan__Patel__0011

@jsulm

is it possible to run one or more function parallel in GUI thread ?

JonB

@Ketan__Patel__0011
No: how would it be possible to "run something in parallel" within the one GUI thread? Not to mention: why would you need to/bother anyway?

This is quite separate from running any non-GUI threads in parallel with the GUI thread.

jsulm

@Ketan__Patel__0011 said in Lost My Qt Widgets StyleSheets:

is it possible to run one or more function parallel in GUI thread ?

Of course not. But why do you want to do this? Simply do your heavy stuff in parallel threads and emit signals there if UI needs to do something. And in the UI thread you connect to these signal and do what needs to be done. This is how this is done properly...

Ketan__Patel__0011

@jsulm

Hiii

As you say i was change my code
i have stop updating my GUI controls in Thread.
And Updating my GUI Controls using emit signals

But still i am facing this problem..

jsulm

@Ketan__Patel__0011 Can you explain exact problem you have now? The thread is a bit old already.

Ketan__Patel__0011

@jsulm

my exact problem is some time i am lost my widgets stylesheets.
this problem is not continuously generating and i can't find exact sequence for it.

jsulm

@Ketan__Patel__0011 Then you will need to show what you are doing with stylesheets

Ketan__Patel__0011

@jsulm

I am just changing my buttons or other controls stylesheet based of some condition..
like

if(IS_ Button_1_Clicked == true)
{
       ui->pushbutton_1->setStyleSheet(MY_FIRST_STYLE);
}
else
{
       ui->pushbutton_1->setStyleSheet(MY_SECOND_STYLE);
}

Ketan__Patel__0011

@jsulm

Here i am using

   QApplication::processEvents();
   QApplication::sendPostedEvents();
   this->update();
   this->show();

is it right ?

mrjj

@Ketan__Patel__0011

Hi
Are you trying to update the stylesheets?

Normally for dynamic properties in stylesheet one can do

widget->style()->unpolish(widget);
widget->style()->polish(widget);
QEvent event(QEvent::StyleChange);
QApplication::sendEvent(widget, &event);
widget->update();
widget->updateGeometry();

Im not sure its what's wrong in your case.
Is the stylesheet inline strings or do you load them from file?