Get current application QStyle

Sixshaman

Suppose I have a custom application style:

class MyStyle: public QProxyStyle
{
public:
    MyStyle(QStyle* style);
   ~MyStyle();

    void drawPrimitive(PrimitiveElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget) const Q_DECL_OVERRIDE;
}

Now I set the style for the whole application:

qApp->setStyle(new MyStyle());

I need a way to get it back. Unfortunately, QApplication::style() doesn't return the style I created, meaning the returned copy is not an instance of MyStyle:

const QStyle* style = qApp->style();
const MyStyle* myStyle = dynamic_cast<const MyStyle*>(style); //Returns nullptr

I've tried using QStyle::proxy, but it didn't work either. It seems the only way to get current application QStyle is storing a pointer somewhere. But probably I'm missing something. Is there a way to do it without dirty hacks?

JonB

@Sixshaman
Not sure, but do you have to use the static method and not the instance (qApp->style()) one?

http://doc.qt.io/qt-5/qapplication.html#style
QStyle *QApplication::style() [static]

Sixshaman

@JonB
The method is static anyway, but I use the qApp->style() form.

JonB

@Sixshaman
OK, I'm not a C++-er. Can't do that in "nice" languages :) OOI, what does qDebug() << QApplication::style()->metaObject()->className(); give you?

Sixshaman

@JonB
Oh. It outputs QStyleSheetStyle.

You see, we use both stylesheets and QStyle's. Stylesheets are nessessary if you need a bigger palette for elements, but it's impossible to change the entire appearance of complex controls using stylesheets.

It seems that QStyleSheetStyle always overrides QProxyStyle and it doesn't matter if I call qApp->setStyleSheet(styleSheet); before or after qApp->setStyle(myStyle);.

So probably the only way to solve my case is storing the pointer.

mrjj

@Sixshaman said in Get current application QStyle:

const MyStyle* myStyle = dynamic_cast<const MyStyle*>(style); //Returns nullptr

Does

MyStyle* myStyle = qobject_cast<MyStyle*>(style);
also return null ?

Sixshaman

@mrjj
Yes.

mrjj

@Sixshaman
Thats odd as if i modify the
NorwegianWoodStyle example like

void WidgetGallery::changeStyle(const QString &styleName)
//! [5] //! [6]
{
    if (styleName == "NorwegianWood") {
        QApplication::setStyle(new NorwegianWoodStyle);
        NorwegianWoodStyle *mine = qobject_cast<NorwegianWoodStyle *>(QApplication::style());        

    } else {
        QApplication::setStyle(QStyleFactory::create(styleName));
    }
    changePalette();
}

It does report the expected type and cast do not fail.