@Gojir4 said in Styling the QMdiArea using the the fusion style and QPalette (dark theme): darkPalette.setColor(QPalette::Disabled, QPalette::Shadow, QColor(r, g, b)); (Edited) tried, but it didn't work. I suspect that underneath it's a QLabel with a raised text but I don't know how to set the color of those using QPalette

That geometryRectangle is irrelevant, as it is used only for the widget with 2 large, red close buttons which is positioned correctly. What I observed via debugging/logging is that code part: if (isMinimized()) { //emit minimizeAddNewEquipmentDialog(); addEquipmentDialog->showMinimized();//that's 2nd widget } somehow spoils behavior of the widget, if I recall correctly after manual, separate minimizing call showNormal() simultaneously worked fine for both widgets. Need to confirm that after work, though.

That's usually applied to dialogs. Is that what you were using ?

@SGaist exactly, thanks!

I finally use event filter to filter the "user click on tab" event to achieved my goal.

I got it working! You were right, after some more testing, it turned out, that my class was deleted after QApplication was already deleted. That's what I'm using now: // shared_window.h #ifndef SHARED_WINDOW_H #define SHARED_WINDOW_H #include <QObject> #include <QMdiArea> #include <QMdiSubWindow> #include <QMainWindow> class ROBOTCORE_EXPORT SharedWindow : public QObject { Q_OBJECT // Singleton Q_DISABLE_COPY(SharedWindow) public: ~SharedWindow(); static SharedWindow *instance(void); private: QMdiArea *mdi; static SharedWindow *inst; QMainWindow *wnd; // Singleton SharedWindow(); private slots: void cleanup(void); }; #endif // SHARED_WINDOW_H // shared_window.cpp #include "shared_window.h" SharedWindow *SharedWindow::inst = nullptr; SharedWindow::SharedWindow() { this->wnd = new QMainWindow(); this->mdi = new QMdiArea(); this->wnd->setCentralWidget(this->mdi); this->mdi->addSubWindow(new QSlider()); this->wnd->show(); } void SharedWindow::cleanup() { delete this->wnd; } SharedWindow::~SharedWindow() { } SharedWindow *SharedWindow::instance() { if(SharedWindow::inst == nullptr) { SharedWindow::inst = new SharedWindow(); // Setting qApp as the parent won't do it, don't know why connect(QApplication::instance(), &QApplication::aboutToQuit, SharedWindow::inst, &SharedWindow::cleanup); } return SharedWindow::inst; } I couldn't delete it from the main application, because I have no control over the main application. Also, my shared window is only used by some specific plugins and isn't part of the main project. The main application has a window of it's own. Thanks!

Thanks for the info. Well i have tried to port the programm to use regular QMainWindows. But then i have issues to handle the maximum, minimum controls and to constrain the maximized window to my own mdiarea. Any advice?

Yes of course