Graphicsview drawing

from PySide import QtCore, QtGui
import sys

class Ui_fi(object):
    '''
    UI, auto-generated by using QtDesigner, do not change anything here,
    but only in the .ui file with QtDesigner.
    '''

    def setupUi(self, fi):
        fi.setObjectName("fi")
        fi.resize(603, 361)
        self.zoneDessin = QtGui.QGraphicsView(fi)
        self.zoneDessin.setGeometry(QtCore.QRect(80, 80, 421, 231))
        self.zoneDessin.setObjectName("zoneDessin")

        self.retranslateUi(fi)
        QtCore.QMetaObject.connectSlotsByName(fi)

    def retranslateUi(self, fi):
        fi.setWindowTitle(QtGui.QApplication.translate("fi", "Essai de dessin", None, QtGui.QApplication.UnicodeUTF8))


class Gui(QtGui.QMainWindow, Ui_fi):
    '''Graphical user interface, without any logic'''

    def __init__(self):
        super(Gui, self).__init__()
        self.setupUi(self)

    def customPaint(self):
        '''Example to draw some text and lines in the graphicsview'''

        scene = QtGui.QGraphicsScene(0, 0, 200, 200)
        scene.addText("Hello Georges!")

        # Draw a box around the text
        width = 110
        height = 40
        downX = width / 2
        downY = height + 20
        scene.addLine(0, 0, 0, height)
        scene.addLine(width, height, downX, downY)
        scene.addLine(0, height, downX, downY)
        scene.addLine(width, 0, width, height)
        scene.addLine(0, 0, width, 0)

        self.zoneDessin.setScene(scene)


class Controller(object):
    '''Controls interaction between view and logic'''

    def __init__(self):
        self.view = Gui()

    def start(self):
        '''Start the application'''

        self.view.customPaint()
        self.view.show()



if __name__== "__main__":
    app = QtGui.QApplication(sys.argv)
    controller = Controller()
    controller.start()
    sys.exit(app.exec_())