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Python pyqt (gui) example 'recent'
recent
Python pyqt example: recent
#!/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 QFile, QFileInfo, QSettings, Qt, QTextStream
from PyQt5.QtGui import QKeySequence
from PyQt5.QtWidgets import (QAction, QApplication, QFileDialog, QMainWindow,
QMessageBox, QTextEdit)
class MainWindow(QMainWindow):
MaxRecentFiles = 5
windowList = []
def __init__(self):
super(MainWindow, self).__init__()
self.recentFileActs = []
self.setAttribute(Qt.WA_DeleteOnClose)
self.textEdit = QTextEdit()
self.setCentralWidget(self.textEdit)
self.createActions()
self.createMenus()
self.statusBar()
self.setWindowTitle("Recent Files")
self.resize(400, 300)
def newFile(self):
other = MainWindow()
MainWindow.windowList.append(other)
other.show()
def open(self):
fileName, _ = QFileDialog.getOpenFileName(self)
if fileName:
self.loadFile(fileName)
def save(self):
if self.curFile:
self.saveFile(self.curFile)
else:
self.saveAs()
def saveAs(self):
fileName, _ = QFileDialog.getSaveFileName(self)
if fileName:
self.saveFile(fileName)
def openRecentFile(self):
action = self.sender()
if action:
self.loadFile(action.data())
def about(self):
QMessageBox.about(self, "About Recent Files",
"The <b>Recent Files</b> example demonstrates how to provide "
"a recently used file menu in a Qt application.")
def createActions(self):
self.newAct = QAction("&New", self, shortcut=QKeySequence.New,
statusTip="Create a new file", triggered=self.newFile)
self.openAct = QAction("&Open...", self, shortcut=QKeySequence.Open,
statusTip="Open an existing file", triggered=self.open)
self.saveAct = QAction("&Save", self, shortcut=QKeySequence.Save,
statusTip="Save the document to disk", triggered=self.save)
self.saveAsAct = QAction("Save &As...", self,
shortcut=QKeySequence.SaveAs,
statusTip="Save the document under a new name",
triggered=self.saveAs)
for i in range(MainWindow.MaxRecentFiles):
self.recentFileActs.append(
QAction(self, visible=False,
triggered=self.openRecentFile))
self.exitAct = QAction("E&xit", self, shortcut="Ctrl+Q",
statusTip="Exit the application",
triggered=QApplication.instance().closeAllWindows)
self.aboutAct = QAction("&About", self,
statusTip="Show the application's About box",
triggered=self.about)
self.aboutQtAct = QAction("About &Qt", self,
statusTip="Show the Qt library's About box",
triggered=QApplication.instance().aboutQt)
def createMenus(self):
self.fileMenu = self.menuBar().addMenu("&File")
self.fileMenu.addAction(self.newAct)
self.fileMenu.addAction(self.openAct)
self.fileMenu.addAction(self.saveAct)
self.fileMenu.addAction(self.saveAsAct)
self.separatorAct = self.fileMenu.addSeparator()
for i in range(MainWindow.MaxRecentFiles):
self.fileMenu.addAction(self.recentFileActs[i])
self.fileMenu.addSeparator()
self.fileMenu.addAction(self.exitAct)
self.updateRecentFileActions()
self.menuBar().addSeparator()
self.helpMenu = self.menuBar().addMenu("&Help")
self.helpMenu.addAction(self.aboutAct)
self.helpMenu.addAction(self.aboutQtAct)
def loadFile(self, fileName):
file = QFile(fileName)
if not file.open( QFile.ReadOnly | QFile.Text):
QMessageBox.warning(self, "Recent Files",
"Cannot read file %s:\n%s." % (fileName, file.errorString()))
return
instr = QTextStream(file)
QApplication.setOverrideCursor(Qt.WaitCursor)
self.textEdit.setPlainText(instr.readAll())
QApplication.restoreOverrideCursor()
self.setCurrentFile(fileName)
self.statusBar().showMessage("File loaded", 2000)
def saveFile(self, fileName):
file = QFile(fileName)
if not file.open( QFile.WriteOnly | QFile.Text):
QMessageBox.warning(self, "Recent Files",
"Cannot write file %s:\n%s." % (fileName, file.errorString()))
return
outstr = QTextStream(file)
QApplication.setOverrideCursor(Qt.WaitCursor)
outstr << self.textEdit.toPlainText()
QApplication.restoreOverrideCursor()
self.setCurrentFile(fileName)
self.statusBar().showMessage("File saved", 2000)
def setCurrentFile(self, fileName):
self.curFile = fileName
if self.curFile:
self.setWindowTitle("%s - Recent Files" % self.strippedName(self.curFile))
else:
self.setWindowTitle("Recent Files")
settings = QSettings('Trolltech', 'Recent Files Example')
files = settings.value('recentFileList', [])
try:
files.remove(fileName)
except ValueError:
pass
files.insert(0, fileName)
del files[MainWindow.MaxRecentFiles:]
settings.setValue('recentFileList', files)
for widget in QApplication.topLevelWidgets():
if isinstance(widget, MainWindow):
widget.updateRecentFileActions()
def updateRecentFileActions(self):
settings = QSettings('Trolltech', 'Recent Files Example')
files = settings.value('recentFileList', [])
numRecentFiles = min(len(files), MainWindow.MaxRecentFiles)
for i in range(numRecentFiles):
text = "&%d %s" % (i + 1, self.strippedName(files[i]))
self.recentFileActs[i].setText(text)
self.recentFileActs[i].setData(files[i])
self.recentFileActs[i].setVisible(True)
for j in range(numRecentFiles, MainWindow.MaxRecentFiles):
self.recentFileActs[j].setVisible(False)
self.separatorAct.setVisible((numRecentFiles > 0))
def strippedName(self, fullFileName):
return QFileInfo(fullFileName).fileName()
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
mainWin = MainWindow()
mainWin.show()
sys.exit(app.exec_())
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/