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Python pyqt (gui) example 'part3'
part3
Python pyqt example: part3
#!/usr/bin/env python
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
##
## "Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are
## met:
## * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## * Redistributions in binary form must reproduce the above copyright
## notice, this list of conditions and the following disclaimer in
## the documentation and/or other materials provided with the
## distribution.
## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
## the names of its contributors may be used to endorse or promote
## products derived from this software without specific prior written
## permission.
##
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
## $QT_END_LICENSE$
##
#############################################################################
from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import (QGridLayout, QHBoxLayout, QLabel, QLineEdit,
QMessageBox, QPushButton, QTextEdit, QVBoxLayout, QWidget)
class SortedDict(dict):
class Iterator(object):
def __init__(self, sorted_dict):
self._dict = sorted_dict
self._keys = sorted(self._dict.keys())
self._nr_items = len(self._keys)
self._idx = 0
def __iter__(self):
return self
def next(self):
if self._idx >= self._nr_items:
raise StopIteration
key = self._keys[self._idx]
value = self._dict[key]
self._idx += 1
return key, value
__next__ = next
def __iter__(self):
return SortedDict.Iterator(self)
iterkeys = __iter__
class AddressBook(QWidget):
def __init__(self, parent=None):
super(AddressBook, self).__init__(parent)
self.contacts = SortedDict()
self.oldName = ''
self.oldAddress = ''
nameLabel = QLabel("Name:")
self.nameLine = QLineEdit()
self.nameLine.setReadOnly(True)
addressLabel = QLabel("Address:")
self.addressText = QTextEdit()
self.addressText.setReadOnly(True)
self.addButton = QPushButton("&Add")
self.addButton.show()
self.submitButton = QPushButton("&Submit")
self.submitButton.hide()
self.cancelButton = QPushButton("&Cancel")
self.cancelButton.hide()
self.nextButton = QPushButton("&Next")
self.nextButton.setEnabled(False)
self.previousButton = QPushButton("&Previous")
self.previousButton.setEnabled(False)
self.addButton.clicked.connect(self.addContact)
self.submitButton.clicked.connect(self.submitContact)
self.cancelButton.clicked.connect(self.cancel)
self.nextButton.clicked.connect(self.next)
self.previousButton.clicked.connect(self.previous)
buttonLayout1 = QVBoxLayout()
buttonLayout1.addWidget(self.addButton, Qt.AlignTop)
buttonLayout1.addWidget(self.submitButton)
buttonLayout1.addWidget(self.cancelButton)
buttonLayout1.addStretch()
buttonLayout2 = QHBoxLayout()
buttonLayout2.addWidget(self.previousButton)
buttonLayout2.addWidget(self.nextButton)
mainLayout = QGridLayout()
mainLayout.addWidget(nameLabel, 0, 0)
mainLayout.addWidget(self.nameLine, 0, 1)
mainLayout.addWidget(addressLabel, 1, 0, Qt.AlignTop)
mainLayout.addWidget(self.addressText, 1, 1)
mainLayout.addLayout(buttonLayout1, 1, 2)
mainLayout.addLayout(buttonLayout2, 3, 1)
self.setLayout(mainLayout)
self.setWindowTitle("Simple Address Book")
def addContact(self):
self.oldName = self.nameLine.text()
self.oldAddress = self.addressText.toPlainText()
self.nameLine.clear()
self.addressText.clear()
self.nameLine.setReadOnly(False)
self.nameLine.setFocus(Qt.OtherFocusReason)
self.addressText.setReadOnly(False)
self.addButton.setEnabled(False)
self.nextButton.setEnabled(False)
self.previousButton.setEnabled(False)
self.submitButton.show()
self.cancelButton.show()
def submitContact(self):
name = self.nameLine.text()
address = self.addressText.toPlainText()
if name == "" or address == "":
QMessageBox.information(self, "Empty Field",
"Please enter a name and address.")
return
if name not in self.contacts:
self.contacts[name] = address
QMessageBox.information(self, "Add Successful",
"\"%s\" has been added to your address book." % name)
else:
QMessageBox.information(self, "Add Unsuccessful",
"Sorry, \"%s\" is already in your address book." % name)
return
if not self.contacts:
self.nameLine.clear()
self.addressText.clear()
self.nameLine.setReadOnly(True)
self.addressText.setReadOnly(True)
self.addButton.setEnabled(True)
number = len(self.contacts)
self.nextButton.setEnabled(number > 1)
self.previousButton.setEnabled(number > 1)
self.submitButton.hide()
self.cancelButton.hide()
def cancel(self):
self.nameLine.setText(self.oldName)
self.addressText.setText(self.oldAddress)
if not self.contacts:
self.nameLine.clear()
self.addressText.clear()
self.nameLine.setReadOnly(True)
self.addressText.setReadOnly(True)
self.addButton.setEnabled(True)
number = len(self.contacts)
self.nextButton.setEnabled(number > 1)
self.previousButton.setEnabled(number > 1)
self.submitButton.hide()
self.cancelButton.hide()
def next(self):
name = self.nameLine.text()
it = iter(self.contacts)
try:
while True:
this_name, _ = it.next()
if this_name == name:
next_name, next_address = it.next()
break
except StopIteration:
next_name, next_address = iter(self.contacts).next()
self.nameLine.setText(next_name)
self.addressText.setText(next_address)
def previous(self):
name = self.nameLine.text()
prev_name = prev_address = None
for this_name, this_address in self.contacts:
if this_name == name:
break
prev_name = this_name
prev_address = this_address
else:
self.nameLine.clear()
self.addressText.clear()
return
if prev_name is None:
for prev_name, prev_address in self.contacts:
pass
self.nameLine.setText(prev_name)
self.addressText.setText(prev_address)
if __name__ == '__main__':
import sys
from PyQt5.QtWidgets import QApplication
app = QApplication(sys.argv)
addressBook = AddressBook()
addressBook.show()
sys.exit(app.exec_())
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/