How to insert a button inside a QLineEdit

Question

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

For example, like this google image:

Answer 1

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_())

Answer 2

Here is the runnable code:

from PyQt4.QtGui import *
from PyQt4.QtCore import *
from sys import argv, exit

class ButtonInLineEdit(QLineEdit):
    def __init__(self,parent=None):
        QLineEdit.__init__(self,parent)

        self.ButtonShowKeyboard = QToolButton(self)
        self.ButtonShowKeyboard.setCursor(Qt.PointingHandCursor)

        self.ButtonShowKeyboard.setFocusPolicy(Qt.NoFocus)
        self.ButtonShowKeyboard.setIcon(QIcon("icons/myIcon.png"))
        self.ButtonShowKeyboard.setStyleSheet("background: transparent; border: none;")

        layout = QHBoxLayout(self)
        layout.addWidget(self.ButtonShowKeyboard,0,Qt.AlignRight)

        layout.setSpacing(0)
        layout.setMargin(5)

        self.ButtonShowKeyboard.setToolTip(QApplication.translate("None", "Show virtual keyboard", None, QApplication.UnicodeUTF8))

def MyFunction(arg=None):
    print "MyFunction() called: arg = %s"%arg

a=QApplication(argv)
LineEdit = ButtonInLineEdit()
LineEdit.connect(LineEdit.ButtonShowKeyboard, SIGNAL("clicked()"), MyFunction)
LineEdit.show()
exit(a.exec_())