How to use the taurus.external.qt.Qt.QVBoxLayout function in taurus

def demo():
    "QGroup Widget"
    w = Qt.QWidget()
    l = Qt.QVBoxLayout()
    w.setLayout(l)

    panel = QGroupWidget()
    panel.title = "Database"
    contentLayout = Qt.QFormLayout()
    panel.content().setLayout(contentLayout)
    contentLayout.addRow("&Host", Qt.QLineEdit())
    contentLayout.addRow("&Port", Qt.QLineEdit())
    l.addWidget(panel, 0)

    panel = QGroupWidget()
    panel.title = "Hello world"
    panel.titleIcon = Qt.QIcon.fromTheme("video-x-generic")
    panel.setTitleStyle({
        'start_color': 'rgb(255, 60, 60)',
        'stop_color': 'rgb(200, 0, 0)',

Qt.QSplitter.__init__(self, parent)

        self.editorstacks = []
        self.editorwindows = []

        self.menu_actions, self.io_actions = self.createMenuActions()

        self.find_widget = FindReplace(self, enable_replace=True)
        self.outlineexplorer = OutlineExplorerWidget(self, show_fullpath=False,
                                                     show_all_files=False)
        self.outlineexplorer.edit_goto.connect(self.go_to_file)
        self.editor_splitter = EditorSplitter(self, self, self.menu_actions,
                                              first=True)

        editor_widgets = Qt.QWidget(self)
        editor_layout = Qt.QVBoxLayout()
        editor_layout.setContentsMargins(0, 0, 0, 0)
        editor_widgets.setLayout(editor_layout)
        editor_layout.addWidget(self.editor_splitter)
        editor_layout.addWidget(self.find_widget)

        self.setContentsMargins(0, 0, 0, 0)
        self.addWidget(editor_widgets)
        self.addWidget(self.outlineexplorer)

        self.setStretchFactor(0, 5)
        self.setStretchFactor(1, 1)

        self.toolbar_list = None
        self.menu_list = None
        self.setup_window([], [])

def createActionBar(self):
        layout = Qt.QVBoxLayout()
        layout.setContentsMargins(0, 0, 0, 0)
        deleteButton = Qt.QToolButton()
        deleteButton.setDefaultAction(self.list.removeAction)
        layout.addWidget(deleteButton)
        deleteAllButton = Qt.QToolButton()
        deleteAllButton.setDefaultAction(self.list.removeAllAction)
        layout.addWidget(deleteAllButton)
        moveUpButton = Qt.QToolButton()
        moveUpButton.setDefaultAction(self.list.moveUpAction)
        layout.addWidget(moveUpButton)
        moveDownButton = Qt.QToolButton()
        moveDownButton.setDefaultAction(self.list.moveDownAction)
        layout.addWidget(moveDownButton)
        spacerItem = Qt.QSpacerItem(0, 0, Qt.QSizePolicy.Fixed, Qt.QSizePolicy.Expanding)
        layout.addItem(spacerItem)
        return layout

def __init__(self, input_data=None, parent=None,
                 input_panel_klass=None, designMode=False):
        if input_panel_klass is None:
            from taurus.qt.qtgui.panel import TaurusInputPanel
            input_panel_klass = TaurusInputPanel
        self.input_data = input_data
        self.input_panel_klass = input_panel_klass
        Qt.QDialog.__init__(self, parent)
        if input_data and 'title' in input_data:
            self.setWindowTitle(input_data['title'])
        layout = Qt.QVBoxLayout()
        self.setLayout(layout)
        self._panel = panel = input_panel_klass(input_data, self)
        layout.setContentsMargins(0, 0, 0, 0)
        layout.addWidget(self._panel)
        self.connect(panel.buttonBox(), Qt.SIGNAL("accepted()"), self.accept)
        self.connect(panel.buttonBox(), Qt.SIGNAL("rejected()"), self.reject)
        self._panel.setInputFocus()

def __init__(self, parent=None):
            Qt.QWidget.__init__(self, parent)
            panel_l = Qt.QVBoxLayout()
            self.setLayout(panel_l)
            panel_l.setContentsMargins(M, M, M, M)
            panel_l.setSpacing(M)

            w = TaurusLabel()
            display_panel = Qt.QGroupBox("Taurus Label Display")
            display_l = Qt.QHBoxLayout()
            display_l.setContentsMargins(M, M, M, M)
            display_l.setSpacing(M)
            display_panel.setLayout(display_l)
            # display_l.addStretch(1)
            display_l.addWidget(w)

            control_panel = Qt.QGroupBox("Control Panel")
            control_l = Qt.QFormLayout()
            control_l.setContentsMargins(M, M, M, M)

def initComponents(self):
        self.setLayout(Qt.QHBoxLayout())
        self.layout().setContentsMargins(0, 0, 0, 0)

        self.tree = MacroParametersTree(self)
        self.delegate = ParamEditorDelegate(self.tree)
        self.tree.setItemDelegate(self.delegate)
        self.tree.setSizePolicy(Qt.QSizePolicy.Expanding, Qt.QSizePolicy.Expanding)
        self.layout().addWidget(self.tree)

        actionLayout = Qt.QVBoxLayout()
        actionLayout.setContentsMargins(0, 0, 0, 0)
        addButton = Qt.QToolButton()
        addButton.setDefaultAction(self.tree.addAction)
        actionLayout.addWidget(addButton)
        deleteButton = Qt.QToolButton()
        deleteButton.setDefaultAction(self.tree.deleteAction)
        actionLayout.addWidget(deleteButton)
        moveUpButton = Qt.QToolButton()
        moveUpButton.setDefaultAction(self.tree.moveUpAction)
        actionLayout.addWidget(moveUpButton)
        moveDownButton = Qt.QToolButton()
        moveDownButton.setDefaultAction(self.tree.moveDownAction)
        actionLayout.addWidget(moveDownButton)
        spacerItem = Qt.QSpacerItem(0, 0, Qt.QSizePolicy.Fixed, Qt.QSizePolicy.Expanding)
        actionLayout.addItem(spacerItem)

def build_gui():
    mw = Qt.QMainWindow()
    mw.setObjectName("main window")
    w = Qt.QWidget()
    w.setObjectName("central widget")
    mw.setCentralWidget(w)
    l = Qt.QVBoxLayout()
    w.setLayout(l)
    l1 = Qt.QLabel("H1")
    l1.setObjectName("label 1")
    l.addWidget(l1)
    l2 = Qt.QLabel("H2")
    l2.setObjectName("label 2")
    l.addWidget(l2)
    mw.show()
    return mw

detailed description of this QMimeData object.
        :param singleModel: (bool) If True, the selection will be of just one
                            model. Otherwise (default) a list of models can be selected
        :param windowTitle: (str) Title of the dialog (default="Model Chooser")
        :param listedModels: (list) List of model names for initializing the 
                             model list

        :return: (list,bool or QMimeData,bool) Returns a models,ok tuple. models can be
                 either a list of models or a QMimeData object, depending on
                 `asMimeData`. ok is True if the dialog was accepted (by
                 clicking on the "update" button) and False otherwise
        '''
        dlg = Qt.QDialog(parent)
        dlg.setWindowTitle(windowTitle)
        dlg.setWindowIcon(Qt.QIcon("logos:taurus.png"))
        layout = Qt.QVBoxLayout()
        w = TaurusModelChooser(
            parent=parent, selectables=selectables, host=host, singleModel=singleModel)
        if listedModels is not None:
            w.setListedModels(listedModels)
        layout.addWidget(w)
        dlg.setLayout(layout)
        w.updateModels.connect(dlg.accept)
        dlg.exec_()
        return w.getListedModels(asMimeData=asMimeData), (dlg.result() == dlg.Accepted)

def __init__(self, err_type=None, err_value=None, err_traceback=None,
                 parent=None, designMode=False):
        Qt.QDialog.__init__(self, parent)
        layout = Qt.QVBoxLayout()
        self.setLayout(layout)
        import taurus.qt.qtgui.panel
        MsgPanel = taurus.qt.qtgui.panel.TaurusMessagePanel
        self._panel = MsgPanel(err_type, err_value, err_traceback,
                               self, designMode)
        layout.setContentsMargins(0, 0, 0, 0)
        layout.addWidget(self._panel)
        self.connect(self.panel().buttonBox(), Qt.SIGNAL("accepted()"),
                     self.accept)
        self.connect(self._panel, Qt.SIGNAL("toggledDetails(bool)"),
                     self._onShowDetails)

def setButtonsPos(self, buttonsPos):
        # we must delete the previous layout before we can set a new one
        currlayout = self.layout()
        if currlayout is not None:
            currlayout.deleteLater()
            Qt.QCoreApplication.sendPostedEvents(
                currlayout, Qt.QEvent.DeferredDelete)
        # add to layout
        if buttonsPos is None:
            self.setLayout(Qt.QVBoxLayout())
            self.layout().addWidget(self._deviceTree)
        elif buttonsPos == Qt.Qt.BottomToolBarArea:
            self._toolbar.setOrientation(Qt.Qt.Horizontal)
            self.setLayout(Qt.QVBoxLayout())
            self.layout().addWidget(self._deviceTree)
            self.layout().addWidget(self._toolbar)
        elif buttonsPos == Qt.Qt.TopToolBarArea:
            self._toolbar.setOrientation(Qt.Qt.Horizontal)
            self.setLayout(Qt.QVBoxLayout())
            self.layout().addWidget(self._toolbar)
            self.layout().addWidget(self._deviceTree)
        elif buttonsPos == Qt.Qt.LeftToolBarArea:
            self._toolbar.setOrientation(Qt.Qt.Vertical)
            self.setLayout(Qt.QHBoxLayout())
            self.layout().addWidget(self._toolbar)
            self.layout().addWidget(self._deviceTree)
        elif buttonsPos == Qt.Qt.RightToolBarArea:
            self._toolbar.setOrientation(Qt.Qt.Vertical)
            self.setLayout(Qt.QHBoxLayout())
            self.layout().addWidget(self._deviceTree)