How to use the ginga.qtw.QtHelp.QtCore function in ginga

combobox = QtHelp.ComboBox()
        options = []
        index = 0
        for name in self.cmap_names:
            options.append(name)
            combobox.addItem(name)
            index += 1
        cmap_name = self.magcmap
        try:
            index = self.cmap_names.index(cmap_name)
        except Exception:
            index = self.cmap_names.index('gray')
        combobox.setCurrentIndex(index)
        combobox.activated.connect(self.set_cmap_cb)
        self.btn['cmap'] = combobox
        btns.addWidget(combobox, stretch=0, alignment=QtCore.Qt.AlignRight)

        combobox = QtHelp.ComboBox()
        options = []
        index = 0
        for name in self.imap_names:
            options.append(name)
            combobox.addItem(name)
            index += 1
        imap_name = self.magimap
        try:
            index = self.imap_names.index(imap_name)
        except Exception:
            index = self.imap_names.index('ramp')
        combobox.setCurrentIndex(index)
        combobox.activated.connect(self.set_imap_cb)
        self.btn['imap'] = combobox

wopen.clicked.connect(self.open_file)
        wquit = QtGui.QPushButton("Quit")
        wquit.clicked.connect(self.quit)

        hbox.addStretch(1)
        for w in (wopen, wdrawtype, wdrawcolor, wfill,
                  QtGui.QLabel('Alpha:'), walpha, wclear, wquit):
            hbox.addWidget(w, stretch=0)

        hw = QtGui.QWidget()
        hw.setLayout(hbox)
        vbox.addWidget(hw, stretch=0)

        mode = self.canvas.get_draw_mode()
        hbox = QtGui.QHBoxLayout()
        hbox.setContentsMargins(QtCore.QMargins(4, 2, 4, 2))

        btn1 = QtGui.QRadioButton("Draw")
        btn1.setChecked(mode == 'draw')
        btn1.toggled.connect(lambda val: self.set_mode_cb('draw', val))
        btn1.setToolTip("Choose this to draw on the canvas")
        hbox.addWidget(btn1)

        btn2 = QtGui.QRadioButton("Edit")
        btn2.setChecked(mode == 'edit')
        btn2.toggled.connect(lambda val: self.set_mode_cb('edit', val))
        btn2.setToolTip("Choose this to edit things on the canvas")
        hbox.addWidget(btn2)

        btn3 = QtGui.QRadioButton("Pick")
        btn3.setChecked(mode == 'pick')
        btn3.toggled.connect(lambda val: self.set_mode_cb('pick', val))

fi.add_callback('focus', self.focus_cb, name)
        vbox.addWidget(iw, stretch=1)
        fi.set_name(name)

        if use_readout:
            readout = self.build_readout()
            # TEMP: hack
            readout.fitsimage = fi
            fi.add_callback('image-set', self.readout_config, readout)
            self.add_callback('field-info', self.readout_cb, readout, name)
            rw = readout.get_widget()
            # one level deeper to the native widget in gw.Readout
            rw = rw.get_widget()
            rw.setSizePolicy(QtGui.QSizePolicy(QtGui.QSizePolicy.Fixed,
                                               QtGui.QSizePolicy.Fixed))
            vbox.addWidget(rw, stretch=0, alignment=QtCore.Qt.AlignLeft)
        else:
            readout = None

        # Add a page to the specified notebook
        if not workspace:
            workspace = 'channels'
        self.ds.add_tab(workspace, vwidget, 1, name)

        self.update_pending()
        bnch = Bunch.Bunch(fitsimage=fi, view=iw, container=vwidget,
                           readout=readout, workspace=workspace)
        return bnch

#fi.show_focus_indicator(True)

        # add little mode indicator that shows keyboard modal states
        fi.show_mode_indicator(True, corner='ur')

        w = fi.get_widget()
        w.resize(512, 512)

        vbox = QtGui.QVBoxLayout()
        vbox.setContentsMargins(QtCore.QMargins(2, 2, 2, 2))
        vbox.setSpacing(1)
        vbox.addWidget(w, stretch=1)

        self.readout = QtGui.QLabel("")
        vbox.addWidget(self.readout, stretch=0,
                       alignment=QtCore.Qt.AlignCenter)

        hbox = QtGui.QHBoxLayout()
        hbox.setContentsMargins(QtCore.QMargins(4, 2, 4, 2))

        wdrawtype = QtGui.QComboBox()
        for name in self.drawtypes:
            wdrawtype.addItem(name)
        index = self.drawtypes.index('rectangle')
        wdrawtype.setCurrentIndex(index)
        wdrawtype.activated.connect(self.set_drawparams)
        self.wdrawtype = wdrawtype

        wdrawcolor = QtGui.QComboBox()
        for name in self.drawcolors:
            wdrawcolor.addItem(name)
        index = self.drawcolors.index('lightblue')

def draw_polygon(self, cpoints):
        ## cpoints = trcalc.strip_z(cpoints)
        qpoints = [QtCore.QPoint(p[0], p[1]) for p in cpoints]
        p = cpoints[0]
        qpoints.append(QtCore.QPoint(p[0], p[1]))
        qpoly = QPolygon(qpoints)

        self.cr.drawPolygon(qpoly)

btn = QtGui.QRadioButton("IRAF")
        btn.toggled.connect(lambda w: self.switchMode('iraf'))
        self.w.mode_d['iraf'] = btn
        self.w.control.layout().addWidget(btn, stretch=0,
                                          alignment=QtCore.Qt.AlignLeft)

        fr.layout().addWidget(w, stretch=1, alignment=QtCore.Qt.AlignLeft)
        vbox.addWidget(fr, stretch=0, alignment=QtCore.Qt.AlignTop)

        fr = QtHelp.Frame("Frame/Channel")

        lbl = QtGui.QLabel("")
        self.w.frch = lbl

        fr.layout().addWidget(lbl, stretch=1, alignment=QtCore.Qt.AlignLeft)
        vbox.addWidget(fr, stretch=0, alignment=QtCore.Qt.AlignTop)

        cw = container.get_widget()
        cw.addWidget(vbox, stretch=0, alignment=QtCore.Qt.AlignTop)

def build_gui(self, container):
        assert iqcalc.have_scipy == True, \
               Exception("Please install python-scipy to use this plugin")

        self.pickcenter = None

        # Splitter is just to provide a way to size the graph
        # to a reasonable size
        vpaned = QtGui.QSplitter()
        vpaned.setOrientation(QtCore.Qt.Vertical)
        
        nb = QtHelp.TabWidget()
        nb.setTabPosition(QtGui.QTabWidget.East)
        nb.setUsesScrollButtons(True)
        self.w.nb1 = nb
        vpaned.addWidget(nb)
        
        cm, im = self.fv.cm, self.fv.im

        di = ImageViewCanvasQt.ImageViewCanvas(logger=self.logger)
        di.set_desired_size(200, 200)
        di.enable_autozoom('off')
        di.enable_autocuts('off')
        di.zoom_to(3, redraw=False)
        settings = di.get_settings()
        settings.getSetting('zoomlevel').add_callback('set',

def center_cursor(self):
        if self.imgwin is None:
            return
        win_x, win_y = self.get_center()
        w_pt = QtCore.QPoint(win_x, win_y)
        s_pt = self.imgwin.mapToGlobal(w_pt)

        # set the cursor position
        cursor = self.imgwin.cursor()
        cursor.setPos(s_pt)

_resizeEvent = widget.resizeEvent

    def resizeEvent(*args):
        rect = widget.geometry()
        x1, y1, x2, y2 = rect.getCoords()
        width = x2 - x1
        height = y2 - y1

        if viewer is not None:
            viewer.configure_window(width, height)

        _resizeEvent(*args)

    widget.setFocusPolicy(QtCore.Qt.FocusPolicy(
        QtCore.Qt.TabFocus |
        QtCore.Qt.ClickFocus |
        QtCore.Qt.StrongFocus |
        QtCore.Qt.WheelFocus))
    widget.setMouseTracking(True)
    widget.setAcceptDrops(True)

    # Matplotlib has a bug where resize events are not reported
    widget.resizeEvent = resizeEvent

def build_gui(self, container):
        # Splitter is just to provide a way to size the graph
        # to a reasonable size
        vpaned = QtGui.QSplitter()
        vpaned.setOrientation(QtCore.Qt.Vertical)
        
        # Make the cuts plot
        twidget = QtHelp.VBox()
        vbox1 = twidget.layout()
        vbox1.setContentsMargins(4, 4, 4, 4)
        vbox1.setSpacing(2)

        msgFont = self.fv.getFont("sansFont", 14)
        tw = QtGui.QLabel()
        tw.setFont(msgFont)
        tw.setWordWrap(True)
        self.tw = tw

        fr = QtHelp.Frame("Instructions")
        fr.layout().addWidget(tw, stretch=1, alignment=QtCore.Qt.AlignTop)
        vbox1.addWidget(fr, stretch=0, alignment=QtCore.Qt.AlignTop)