Switch object style Sheet

[Loc888]

Hi, i am trying to switch styles when i click the button.

So i use this code:

ui->Red_To_Black->QLineEdit::styleSheet() = ui->Black_To_Red->QLineEdit::styleSheet();

But it doesn't work....
Any help?

[Jorgen]

you try to assign and return value to an return value.

try the setter method instead:

ui->Red_To_Black->setStyleSheet(ui->Black_To_Red->styleSheet());

[Loc888]

It doesn't help me... I need to pick it from the object number 2..

[mrjj]

@Loc888
What is object number 2 ?
@Jorgen shows how to set stylesheet from Black_To_Red to the
Red_To_Black button.
If that is not what you try, can you tell what it is you want to archive ?

[Loc888]

I wanna create a loop. Something like:

text_edit_black = text_edit_red

text_edit_red = text_edit_green;

text_edit_green = text_edit_blue; Etc.

Don't ask me why anyone can need something like that. I need to do it in this way.

[mrjj]

@Loc888
Hi
But if you override one buttons stylesheet with other,
the first style is lost so u can not reuse or switch back.

What about having the stylesheet as variables ?

auto st_red
  = R"(
    background-color: rgb(255, 0, 0);
    )";

auto st_blue
  = R"(
    background-color: rgb(0, 0, 255);
    )";

void MainWindow::on_SomeButton_released() {
ui->SomeButton->setStyleSheet(st_red);
}

[Loc888]

We dont understand.. I know how to set the style.

The problem is how to do a loop of styles...Again dont ask me why i need it..

I need to find any way to switch the styles from mulitple objects. And the object type is line edit.
That's it, just setStyle doesn't help.

[Loc888]

I dont know if variables can help. I need 3 styles, and multiple objects.

I need to get the style from object b, set it to object a. Then;

Get the style from b, set to c;

c to d;

d to f; Etc. That's my problem.

[mrjj]

@Loc888
But if you let the buttons keep the stylesheet then
in your example
Get the style from b, set to c;
c to d;
d to f;

then all get stylesheet from B
just like
QString bstylesheet=ui->b->stylehseet();
ui->c-setStylesheet(bstylesheet);
ui->d-setStylesheet(bstylesheet);
ui->f-setStylesheet(bstylesheet);

Do you need to sort of rotate the style sheets ?

QString Bst=ui->b->stylehseet();
QString Cst=ui->C->stylehseet();
QString Dst=ui->D->stylehseet();

ui->c-setStylesheet(Bst);
ui->d-setStylesheet(Cst);
ui->f-setStylesheet( Dst);

kinda ?

[J.Hilk]

Hi,
setting stylesheets is actually a rather "heavy" operation so using setStylesheet in a loop with small intervalls is something you should not do.

I would suggest, Create your own LineEdit, dervied from QLineEdit. Give it a custom property and simply extend original stylesheet to handle the new property

Link Dynamic Properties and Stylesheets

[Loc888]

@mrjj Something like that, but not exacly.

The best way, is if i could

a = b;

b = c;

c=d; Etc. This is mutch more easy. Is it possible in any way??

[Loc888]

@J.Hilk Ye, i would know how to do that.. I am not so good in that Qt and programming.
If i dont find any way to do that simply, i go probably to do that.

[mrjj]

@Loc888

you could create function

void setSS(QWidget *w1, QWidget *w2) {
 w1->setStyleSheet(w2->styleSheet());
}

and call it like
setSS( ui->Red_To_Black, ui->Black_To_Red );

You cannot use = as it will assign the object variable.

[Jorgen]

maybe you can try the QStateMachine if you want to toggle through defined styles and order:

Code not tested - just as idea...

auto leToggleStatesStyleSheet = R"(
      QLineEdit[state1=true] {
        background: red;
      }
      QLineEdit[state2=true] {
        background: yellow;
      }
      QLineEdit[state3=true] {
        background: green;
      }
    )";

ui->le1->setStyleSheet(leToggleStatesStyleSheet);
ui->le2->setStyleSheet(leToggleStatesStyleSheet);
ui->le3->setStyleSheet(leToggleStatesStyleSheet);

QStateMachine *machine = new QStateMachine(this);
QState *state1 = new QState();
state1->assignProperty(ui->le1, "state1", true);
state1->assignProperty(ui->le2, "state2", true);
state1->assignProperty(ui->le3, "state3", true);
QState *state2 = new QState();
state2->assignProperty(ui->le1, "state2", true);
state2->assignProperty(ui->le2, "state3", true);
state2->assignProperty(ui->le3, "state1", true);
// if you using timer you can automatically go to next state
// state1->addTransition(state1, SIGNAL(finished()), state2);
QState *state3 = new QState();
state3->assignProperty(ui->le1, "state3", true);
state3->assignProperty(ui->le2, "state1", true);
state3->assignProperty(ui->le3, "state2", true);
// if you using timer you can automatically go to next state
// state2->addTransition(state2, SIGNAL(finished()), state3);
// state3->addTransition(state3, SIGNAL(finished()), state1);

machine->addState(state1);
machine->addState(state2);
machine->addState(state3);
machine->setInitialState(state1);
machine->start();

[Loc888]

@mrjj The problem is, i have around 30 objects, and to achieve what i want, they need to switch 30 styles at the same moment.. I dont know if that can work.
Can i do something like that?

w1->setStyleSheet(w2->styleSheet());

w2->setStyleSheet(w3->styleSheet());

w3->setStyleSheet(w4->styleSheet());

And progress?

[mrjj]

@Loc888
Well yes that could work 1 time. then some of the stylesheets will be overwritten.

You could also use
QList<QPushButton*> buttonList = parent->findChilden<QPushButton*>();
To get a list of all pushbuttons and then loop over and rotate the stylesheets or
what you are trying to really do.

If you dream of it becoming some sort of animation effect, it wont happen.
you will only see the last setting of stylesheet.

I think i would keep the stylesheets in a list and the assign to the buttons.

[Loc888]

@mrjj I have a timer, and he is re-calling that function. So, the stylesheet switch by one textlinedit for one cycle.

This can work?

w1->setStyleSheet(w2->styleSheet());

w2->setStyleSheet(w3->styleSheet());

w3->setStyleSheet(w4->styleSheet());

w4->setStyleSheet(w5->styleSheet());

w5->setStyleSheet(w6->styleSheet());

w6->setStyleSheet(w1->styleSheet());

[mrjj]

@Loc888

Hi
Timer is a good idea.
Yes that should be fine but im not sure what effect you are after.
But it will rotate the style sheets for a while.

[JonB]

@Loc888
Your code:

w1->setStyleSheet(w2->styleSheet());
...
w6->setStyleSheet(w1->styleSheet());

Do you understand that this way of writing code will always "get it wrong" when you try to set the last to the first one?

[Loc888]

@JonB I have one editline to avoid this error. Yes, i see that, because at the same time when i am rotating the styles, i am rotating the text too, so i fix that error just by adding one "empty" edit line, and then hiding it. Ye, maybe this is not the best way of creating tools, but in future i am gonna fix that, at this point it's fine, hopefull it's gonna work for the style sheets too. When i learn a little bit more, then i come back and maybe change it.