class EmbeddedTerminal(QWidget):
    finished = pyqtSignal()

    def __init__(self, parent=None):
        super(EmbeddedTerminal, self).__init__(parent)
        self.process = QProcess(self)
        self.process.finished.connect(self.term_finished)
        self.terminal = QWidget(self)
        layout = QVBoxLayout(self)
        layout.addWidget(self.terminal)
        self.process.start('alacritty', ['--embed', str(int(self.winId()))])

    @pyqtSlot()
    def term_finished(self):
        self.finished.emit()

When I start this widget, the terminal is always 640x480 pixels, but I want it do take as much space as possible. As far as I can tell there should be two ways
First, the Layout should tell the Process to take the space (preferred way, but I don't know how).
Second, I need the width and height in pixels of the available space, to calculate the dimensions of the terminal by hand and give it as a parameter in process.start().

I really don't want to have to resort to the second option. Any suggestions on how to solve the issue? Maybe something completely different I did not think of?

Thanks in advance!