How to insert a button inside a QLineEdit

I need help inserting a button inside in a QLineEdit that can call a function.

For example, like this google image:

Below is a nearly direct translation of the Qt code from here.

Differences:

• button is always visible
• clicking on the button emits buttonClicked(bool) signal

Code:

from PyQt4 import QtGui, QtCore

class ButtonLineEdit(QtGui.QLineEdit):
    buttonClicked = QtCore.pyqtSignal(bool)

    def __init__(self, icon_file, parent=None):
        super(ButtonLineEdit, self).__init__(parent)

        self.button = QtGui.QToolButton(self)
        self.button.setIcon(QtGui.QIcon(icon_file))
        self.button.setStyleSheet('border: 0px; padding: 0px;')
        self.button.setCursor(QtCore.Qt.ArrowCursor)
        self.button.clicked.connect(self.buttonClicked.emit)

        frameWidth = self.style().pixelMetric(QtGui.QStyle.PM_DefaultFrameWidth)
        buttonSize = self.button.sizeHint()

        self.setStyleSheet('QLineEdit {padding-right: %dpx; }' % (buttonSize.width() + frameWidth + 1))
        self.setMinimumSize(max(self.minimumSizeHint().width(), buttonSize.width() + frameWidth*2 + 2),
                            max(self.minimumSizeHint().height(), buttonSize.height() + frameWidth*2 + 2))

    def resizeEvent(self, event):
        buttonSize = self.button.sizeHint()
        frameWidth = self.style().pixelMetric(QtGui.QStyle.PM_DefaultFrameWidth)
        self.button.move(self.rect().right() - frameWidth - buttonSize.width(),
                         (self.rect().bottom() - buttonSize.height() + 1)/2)
        super(ButtonLineEdit, self).resizeEvent(event)

Usage:

import sys
from PyQt4 import QtGui

def buttonClicked():
    print 'You clicked the button!'

if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)

    main = ButtonLineEdit('/path/to/my_fancy_icon.png')
    main.buttonClicked.connect(buttonClicked)
    main.show()

    sys.exit(app.exec_())