Draggable Frameless PyQt4 Window With A Custom Titlebar

Question

I've managed to make my application draggable using mouseclickevent and mousemoveevent . Here is the current code:

class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.initUI()

    def initUI(self):
        self.CentralWidget = QtGui.QStackedWidget()
        self.CentralWidget.setFixedHeight(600)
        self.setCentralWidget(self.CentralWidget)
        self.Main = Main(self)
        self.CentralWidget.addWidget(self.Main)
        #Set Current Widgets
        self.CentralWidget.setCurrentWidget(self.Main)
        #Set Background
        self.show()

        self.setWindowFlags(QtCore.Qt.FramelessWindowHint)
        self.setStyleSheet("QMainWindow { background-color: \
        rgb(0, 0, 0); }")
        self.setGeometry(0, 0, 850, 600)
        self.setWindowTitle("Folder Locker")
        self.Center()

        Font = QtGui.QFont()
        Font.setPointSize(12)

        TitleBar = QtGui.QDockWidget()

        Actions = QtGui.QGroupBox()

        Title = QtGui.QLabel("Folder Locker")
        Title.setFont(Font)
        Title.setStyleSheet('color: white')
        Title.setAlignment(QtCore.Qt.AlignCenter)

        Fake = QtGui.QPushButton()
        Fake.setFixedWidth(25)
        Fake.setFixedHeight(25)
        Fake.setStyleSheet("QPushButton { background-color: \
        rgb(0, 0, 0); }")
        Fake1 = QtGui.QPushButton()
        Fake1.setFixedWidth(25)
        Fake1.setFixedHeight(25)
        Fake1.setStyleSheet("QPushButton { background-color: \
        rgb(0, 0, 0); }")

        Font = QtGui.QFont()
        Font.setPointSize(12)

        Font2 = QtGui.QFont()
        Font2.setPointSize(18)

        Exit = QtGui.QPushButton("X")
        Exit.setFixedWidth(35)
        Exit.setFixedHeight(25)
        Exit.clicked.connect(self.ExitM)
        Exit.setStyleSheet('QPushButton {background-color: \
        rgb(0, 0, 0); color: grey;}')
        Exit.setFont(Font)

        Minimize = QtGui.QPushButton("-")
        Minimize.setFixedWidth(25)
        Minimize.setFixedHeight(25)
        Minimize.clicked.connect(self.MinimizeM)
        Minimize.setStyleSheet('QPushButton {background-color: \
        rgb(0, 0, 0); color: grey;}')
        Minimize.setFont(Font2)

        Grid = QtGui.QGridLayout()

        Grid.addWidget(Fake, 1, 1)
        Grid.addWidget(Fake1, 1, 2)
        Grid.addWidget(Title, 1, 3)
        Grid.addWidget(Exit, 1, 5)
        Grid.addWidget(Minimize, 1, 4)

        Actions.setLayout(Grid)

        TitleBar.setWidget(Actions)
        TitleBar.setFixedHeight(40)
        TitleBar.setFloating(False)
        TitleBar.setTitleBarWidget(QtGui.QWidget(None))
        TitleBar.setStyleSheet("QGroupBox { background-color: \
        rgb(0, 0, 0); border: 0px solid rgb(0, 0, 0); }")

        self.addDockWidget(QtCore.Qt.TopDockWidgetArea, TitleBar)
        self.oldPos = self.pos()

    def Center(self):
        self.Resolution = QtGui.QDesktopWidget().screenGeometry()
        self.move((self.Resolution.width() / 2) - (self.frameSize().width() / 2),
                  (self.Resolution.height() / 2) - (self.frameSize().height() / 2))

    def MinimizeM(self):
        self.showNormal()
        self.showMinimized()

    def ExitM(self):
        sys.exit(0)

    def mousePressEvent(self, event):
        self.oldPos = event.globalPos()

    def mouseMoveEvent(self, event):
        delta = QtCore.QPoint (event.globalPos() - self.oldPos)
        #print(delta)
        self.move(self.x() + delta.x(), self.y() + delta.y())
        self.oldPos = event.globalPos()

Unfortunately, the window is only draggable by clicking slightly underneath my custom titlebar , I'd like to be able to click the titlebar which is a QDockWidget and for it to cause the window to follow the mouse movement.

Any help would be appreciated, Thank you.

Answer 1

For the problem you describe there are several solutions, one of them might be to activate the Qt::WA_TransparentForMouseEvents attribute of the QDockWidget making the mouse events transparent to pass to the widget below, ie the QMainWindow , but this generates an undesired behavior on the buttons Close and minimize.

So a more elegant solution is to use the eventFilter method and filter the events QEvent::MouseButtonPress and QEvent::MouseMove, but before they must enable the ability to transmit events of the other widget to QMainWindow, in this case we are going to do With TitleBar , Title and self . With this method it is no longer necessary to overwrite the mousePressEvent and mouseMoveEvent methods.

class MainWindow(QtGui.QMainWindow):
    def __init__(self, parent=None):
        QtGui.QMainWindow.__init__(self, parent)
        self.initUI()

    def initUI(self):
        ...
        TitleBar.installEventFilter(self)
        self.installEventFilter(self)
        Title.installEventFilter(self)

    def eventFilter(self, obj, event):
        if event.type() == QtCore.QEvent.MouseButtonPress:
            self.oldPos = event.globalPos()
        elif event.type() == QtCore.QEvent.MouseMove:
            delta = QtCore.QPoint(event.globalPos() - self.oldPos)
            self.move(self.x() + delta.x(), self.y() + delta.y())
            self.oldPos = event.globalPos()
        return QtGui.QMainWindow.eventFilter(self, obj, event)