问Python/PyQT:如何截断QLineEdit中的文本

EN

import sys
from PyQt4.QtCore import Qt
from PyQt4.QtGui import QApplication,\
                        QLineEdit,\
                        QLabel,\
                        QFontMetrics,\
                        QHBoxLayout,\
                        QVBoxLayout,\
                        QWidget,\
                        QIcon,\
                        QPushButton,\
                        QToolTip,\
                        QBrush,\
                        QColor,\
                        QFont,\
                        QPalette,\
                        QPainter

qt_app = QApplication(sys.argv)

class Example(QWidget):
    def __init__(self):
        QWidget.__init__(self)
        self.setMinimumWidth(100)

        self.init_ui()


    def init_ui(self):
        v_layout = QVBoxLayout()
        v_layout.addStretch(1)

        lbl = ExtendedTruncateTextLabel("This is a really, long and poorly formatted runon sentence used to illustrate a point", self)
        #lbl.setText("This is a really, long and poorly formatted runon sentence used to illustrate a point")

        lbl_1 = ExtendedTruncateTextLabel(self)
        lbl_1.setText("Dies ist ein normaler Text")

        l_text = ExtendedTruncateTextLineEdit()
        l_text.setText("In the widget namend QLineEdit is also a very long text")


        v_layout.addWidget(lbl)
        v_layout.addWidget(lbl_1)
        v_layout.addWidget(l_text)

        self.setLayout(v_layout)

    def run(self):
        self.show()
        qt_app.exec_()

class ExtendedTruncateTextLineEdit(QLineEdit):   
    def __init(self, parent):
        QLineEdit.__init__(self, parent)

    def paintEvent(self, event):

        """ Handle the paint event for the title bar.

        This paint handler draws the title bar text and title buttons.

        """
        super(ExtendedTruncateTextLineEdit, self).paintEvent(event)
        painter = QPainter(self)

        metrics = QFontMetrics(self.font())
        elided  = metrics.elidedText(self.text(), Qt.ElideMiddle, self.width())

        painter.drawText(self.rect(), self.alignment(), elided)

if __name__ == '__main__':
    app = Example()
    app.run()