How to use the leo.core.leoQt.QtWidgets function in leo

try:
                    thread.stop(0.1)
                except Exception:
                    pass
                    
        t5 = time.process_time()

        if 1: # EKR
            g.pr('\nMainWindowShim.closeEvent 2')
            g.pr('stage 1:          %5.2f' % (t2-t1))
            g.pr('stage 2: shells:  %5.2f' % (t3-t2))
            g.pr('stage 3: tools:   %5.2f' % (t4-t3))
            g.pr('stage 4: threads: %5.2f' % (t5-t4))

        # Proceed as normal
        QtWidgets.QMainWindow.closeEvent(self, event)

        # Harder exit to prevent segfault. Not really a solution,
        # but it does the job until Pyside gets fixed.
        if sys.version_info >= (3,3,0): # and not restarting:
            if hasattr(os, '_exit'):
                os._exit(0)
    #@+node:ekr.20190402101635.1: *3* MainWindowShim.monkey_patch_leo

def create_input_area(self, layout):
            
            # Create the Label
            label = QtWidgets.QLabel()
            label.setText('Debugger command:')
            # Create the editor.
            self.line_edit = w = QtWidgets.QLineEdit()
            w.setStyleSheet('background: white; color: black;')
            w.returnPressed.connect(self.debug_input)
            # Add the widgets to a new layout.
            layout2 = QtWidgets.QVBoxLayout()
            layout2.addWidget(label)
            layout2.addWidget(w)
            layout.addLayout(layout2)
        #@+node:ekr.20181006154605.1: *4* create_output_area

def print_doc(self, doc):
        dialog = QtWidgets.QPrintDialog()
        if dialog.exec_() == QtWidgets.QDialog.Accepted:
            doc.print_(dialog.printer())
    #@+node:peckj.20130513115943.22662: *4* print preview dialog

pen = QtGui.QPen()

        self.line.setZValue(0)
        if not hierarchyLink:
            self.setZValue(1)
            pen.setWidth(2)
        else:
            self.setZValue(0)
            pen.setColor(QtGui.QColor(240,240,240))
            pen.setWidth(2) # (0.5)

        self.line.setPen(pen)
        self.addToGroup(self.line)

        self.head = QtWidgets.QGraphicsPolygonItem()

        if hierarchyLink:
            self.head.setBrush(QtGui.QBrush(QtGui.QColor(180,180,180)))
        else:
            self.head.setBrush(QtGui.QBrush(QtGui.QColor(0,0,0)))

        self.head.setPen(QtGui.QPen(QtConst.NoPen))
        self.addToGroup(self.head)
    #@+node:bob.20110119123023.7406: *3* mousePressEvent

def __init__(self, c, parent, root):
        QtWidgets.QScrollArea.__init__(self, parent)
        self.qtree = QtWidgets.QTreeWidget()
        self.root = root
        self.busy = False
        #self.root_pos = leoNodes.Position(root.children[0], 0)
        self.gnx_decluttered = {} # keeps cache of decluttering nodes
        self.declutter_patterns = None
        self.c = c

        # the following two ivars allows to skip expensive operation
        # drawing_items(self.root)
        # for tree redraw after scrolling there is no need to recompute
        # list of visible items.
        # Only on expand, contract and other commands that change the outline
        # we have to recalculate this list
        self._visibles_version = 0
        self._last_visibles_version = -1

def construct_complex_document(self, nodes, heads=False):
        doc = QtWidgets.QTextDocument()
        doc.setDefaultStyleSheet(self.stylesheet)
        contents = ''
        for n in nodes:
            if heads:
                contents += '<h1>%s</h1>\n' % (self.sanitize_html(n.h))
            contents += '<pre>%s</pre>\n' % (self.sanitize_html(n.b))
        doc.setHtml(contents)
        return doc
    #@+node:peckj.20130513115943.22661: *4* print dialog

def _build_gui(self):
        self.w = w = QtWidgets.QWidget()

        w.setObjectName('show_livecode')
        w.setLayout(QtWidgets.QVBoxLayout())
        self.status = QtWidgets.QLabel()
        w.layout().addWidget(self.status)
        self.text = QtWidgets.QTextBrowser()
        w.layout().addWidget(self.text)
        h = QtWidgets.QHBoxLayout()
        w.layout().addLayout(h)
        self.activate = QtWidgets.QPushButton("Stop")
        self.activate.setToolTip("Start / stop live code display")
        h.addWidget(self.activate)
        self.activate.clicked.connect(lambda checked: self.toggle_active())
        b = QtWidgets.QPushButton("Run here")
        b.setToolTip("Show live code for this node")
        h.addWidget(b)

def __init__(self, parent=None, n=3, columns=3):
        """set up

        :Parameters:
        - `self`: the widget
        - `n`: number of months to display
        - `columns`: months to display before start a new row
        """

        QtWidgets.QDateEdit.__init__(self, parent)
        self.setCalendarPopup(True)
        self.cw = QNCalendarWidget(n=n, columns=columns)
        self.setCalendarWidget(self.cw)

def __init__(self, parent, title, text, entries):

        self.entries = entries
        QtWidgets.QDialog.__init__(self, parent)
        vbox = QtWidgets.QVBoxLayout()
        sa = QtWidgets.QScrollArea()
        salo = QtWidgets.QVBoxLayout()
        frame = QtWidgets.QFrame()
        frame.setLayout(salo)
        self.buttons = []
        for entry in entries:
            hbox = QtWidgets.QHBoxLayout()
            cb = QtWidgets.QCheckBox(entry[0])
            self.buttons.append(cb)
            if entry[1]:
                cb.setCheckState(QtCore.Qt.Checked)
            hbox.addWidget(cb)
            salo.addLayout(hbox)
        sa.setWidget(frame)
        vbox.addWidget(sa)
        hbox = QtWidgets.QHBoxLayout()
        ok = QtWidgets.QPushButton("Ok")
        cancel = QtWidgets.QPushButton("Cancel")

def __init__(self, owner):
            '''Ctor for backlinkQtUI class.'''
            self.owner = owner
            QtWidgets.QWidget.__init__(self)
            uiPath = g.os_path_join(g.app.leoDir, 'plugins', 'Backlink.ui')
            form_class, base_class = uic.loadUiType(uiPath)
            self.owner.c.frame.log.createTab('Links', widget = self)
            self.UI = form_class()
            self.UI.setupUi(self)
            u = self.UI
            o = self.owner
            # Compatible with PyQt5
            u.markBtn.clicked.connect(o.mark)
            u.swapBtn.clicked.connect(o.swap)
            u.linkBtn.clicked.connect(self.linkClicked)
            u.rescanBtn.clicked.connect(o.loadLinksInt)
            u.dirLeftBtn.clicked.connect(self.dirClicked)
            u.dirRightBtn.clicked.connect( self.dirClicked)
            u.linkList.itemClicked.connect(self.listClicked)
            u.deleteBtn.stateChanged.connect(o.deleteSet)