Custom DelayButton background not changing

MiklYarochkin

Hello,

I need to make a PushButton with delayed activation: press during 1 sec-> checked.

To indicate activation progress to the user, I am trying to use QProxyStyle: for example, change color from lighter to darker every 100ms.

But it is not working even in a simple form:

...
ui.DelayButtonDemo->setStyle(new DelayButtonStyle);
...

class DelayButtonStyle : public QProxyStyle
{
 void drawControl(ControlElement element, const QStyleOption* option, QPainter* painter, const QWidget* widget) const
 {
     QPushButton* currentDelayButton = (QPushButton*)widget;

     if (currentDelayButton->isDown() == true)
     {
         QStyleOptionButton buttonOption(*qstyleoption_cast<const QStyleOptionButton*>(option));

         buttonOption.palette.setColor(QPalette::Button,
             QColor(Qt::red));

         QProxyStyle::drawControl(element, &buttonOption, painter, widget);

         return;
     }

     QProxyStyle::drawControl(element, option, painter, widget);
 }
}

Can you help me please to find mistake?

J.Hilk

@MiklYarochkin in such cases, it's most likely a blocked event loop

how do you call this function?

can you show that?

MiklYarochkin

Hello,

Thank you for your fast reaction.

I updated my code snippet.

Don't think the loop is blocked.
This function is called correctly.
As an experiment, I was trying to play with text color, and I see a change of color:
QPalette::Button -> QPalette::ButtonText

...
buttonOption.palette.setColor(QPalette::ButtonText,
            QColor(Qt::red));
...

I found this:
https://doc.qt.io/qt-5/stylesheet-reference.html
Warning: If you only set a background-color on a QPushButton, the background may not appear unless you set the border property to some value. This is because, by default, the QPushButton draws a native border which completely overlaps the background-color. For example,

Could it be a reason?

But I don't know how to set it in drawControl
If I set border using setStyleSheet, it stops working completely.

J.Hilk

@MiklYarochkin I see, this, is sadly out of my scope of experience 😔
Hopefully someone else can help you here!

Could it be a reason?

Sounds like it could very well be the reason!

mrjj

@MiklYarochkin said in Custom DelayButton background not changing:

QStyleOptionButton

Hi
You can see here what drawControl really does

https://code.woboq.org/qt5/qtbase/src/widgets/styles/qcommonstyle.cpp.html#1321
(and in fusion style/for your platform)

I did try to copy the code and add brushes etc in my delegate but i was not able to change the background but
you might have better luck :)

MiklYarochkin

I finally made it:
in order to operate color, I have to overrule standard behavior

set full set of styles using setStyleSheet
handle events
manage flow

And I gave up to use it at the end:

a lot of custom code with a doubtful outcome
ugly design
not clear flow

Solution:
I use the standard functionality of the standard button. Better explain to the user what "it works and feels the same as all other buttons in Windows"