pyqt-new-window-handler PyQt QObject type class which operates/handles "New Window" feature Requirements PyQt5 >= 5.15 Setup python -m pip install pyqt-new-window-handler Included Packages pyqt-custom-titlebar-setter pyqt-custom-titlebar-window Example Look at the source of darkNotepadApp.py of pyqt-dark-notepad package calculatorApp.py of pyqt-dark-calculator package