Here I'll describe few final changes to the text editor. The first one is the usage of
QFileSystemWatcher to watch if the open file didn't changed while open in our editor. Next one is the option to save a new file (when we enter some text without opening any file). So here is the
start.py:
# -*- coding: utf-8 -*-
import sys
from PyQt4 import QtCore, QtGui
from edytor import Ui_notepad
import codecs
import codecs
from os.path import isfile
class StartQT4(QtGui.QMainWindow):
def __init__(self, parent=None):
QtGui.QWidget.__init__(self, parent)
self.ui = Ui_notepad()
self.ui.setupUi(self)
self.watcher = QtCore.QFileSystemWatcher(self)
QtCore.QObject.connect(self.ui.button_open,QtCore.SIGNAL("clicked()"), self.file_dialog)
QtCore.QObject.connect(self.ui.button_save,QtCore.SIGNAL("clicked()"), self.file_save)
QtCore.QObject.connect(self.ui.editor_window,QtCore.SIGNAL("textChanged()"), self.enable_save)
QtCore.QObject.connect(self.watcher,QtCore.SIGNAL("fileChanged(const QString&)"), self.file_changed)
self.filename = False
def file_dialog(self):
response = False
# buttons texts
SAVE = 'Save'
DISCARD = 'Discard Changes'
CANCEL = 'Cancel'
# if we have changes then ask about them
if self.ui.button_save.isEnabled():
message = QtGui.QMessageBox(self)
message.setText('Changes haven't been saved')
message.setWindowTitle('Notepad')
message.setIcon(QtGui.QMessageBox.Question)
message.addButton(SAVE, QtGui.QMessageBox.AcceptRole)
message.addButton(DISCARD, QtGui.QMessageBox.DestructiveRole)
message.addButton(CANCEL, QtGui.QMessageBox.RejectRole)
message.setDetailedText('Unsaved Changes in: ' + str(self.filename))
message.exec_()
response = message.clickedButton().text()
# save file
if response == SAVE:
self.file_save()
self.ui.button_save.setEnabled(False)
# discard changes
elif response == DISCARD:
self.ui.button_save.setEnabled(False)
# if we didn't canceled show the file dialog
if response != CANCEL:
fd = QtGui.QFileDialog(self)
# remove old file from watcher
if self.filename:
self.watcher.removePath(self.filename)
self.filename = fd.getOpenFileName()
if isfile(self.filename):
s = codecs.open(self.filename,'r','utf-8').read()
self.ui.editor_window.setPlainText(s)
self.ui.button_save.setEnabled(False)
# add file to watcher
self.watcher.addPath(self.filename)
def enable_save(self):
self.ui.button_save.setEnabled(True)
def file_changed(self, path):
response = False
# buttons texts
SAVE = 'Save As'
RELOAD = 'Reload File'
CANCEL = 'Cancel'
message = QtGui.QMessageBox(self)
message.setText('Open file have been changed !')
message.setWindowTitle('Notepad')
message.setIcon(QtGui.QMessageBox.Warning)
message.addButton(SAVE, QtGui.QMessageBox.AcceptRole)
message.addButton(RELOAD, QtGui.QMessageBox.DestructiveRole)
message.addButton(CANCEL, QtGui.QMessageBox.RejectRole)
message.setDetailedText('The file "' + str(path) + '" have been changed or removed by other application. What do you want to do ?')
message.exec_()
response = message.clickedButton().text()
# save current file under a new or old name
if response == SAVE:
fd = QtGui.QFileDialog(self)
newfile = fd.getSaveFileName()
if newfile:
s = codecs.open(newfile,'w','utf-8')
s.write(unicode(self.ui.editor_window.toPlainText()))
s.close()
self.ui.button_save.setEnabled(False)
# new file, remove old and add the new one to the watcher
if self.filename and str(newfile) != str(self.filename):
self.watcher.removePath(self.filename)
self.watcher.addPath(newfile)
self.filename = newfile
# reload the text in the editor
elif response == RELOAD:
s = codecs.open(self.filename,'r','utf-8').read()
self.ui.editor_window.setPlainText(s)
self.ui.button_save.setEnabled(False)
def file_save(self):
# save changes to existing file
if self.filename and isfile(self.filename):
# don't react on our changes
self.watcher.removePath(self.filename)
s = codecs.open(self.filename,'w','utf-8')
s.write(unicode(self.ui.editor_window.toPlainText()))
s.close()
self.ui.button_save.setEnabled(False)
self.watcher.addPath(self.filename)
# save a new file
else:
fd = QtGui.QFileDialog(self)
newfile = fd.getSaveFileName()
if newfile:
s = codecs.open(newfile,'w','utf-8')
s.write(unicode(self.ui.editor_window.toPlainText()))
s.close()
self.ui.button_save.setEnabled(False)
if __name__ == "__main__":
app = QtGui.QApplication(sys.argv)
myapp = StartQT4()
myapp.show()
sys.exit(app.exec_())
A new method
file_changed(self, path) showed up. It is called by signal
fileChanged(const QString&) from
QFileSystemWatcher, which passes as the first argument the path to the file which changed:
def file_changed(self, path):
response = False
# buttons texts
SAVE = 'Save As'
RELOAD = 'Reload File'
CANCEL = 'Cancel'
message = QtGui.QMessageBox(self)
message.setText('Open file have been changed !')
message.setWindowTitle('Notepad')
message.setIcon(QtGui.QMessageBox.Warning)
message.addButton(SAVE, QtGui.QMessageBox.AcceptRole)
message.addButton(RELOAD, QtGui.QMessageBox.DestructiveRole)
message.addButton(CANCEL, QtGui.QMessageBox.RejectRole)
message.setDetailedText('The file "' + str(path) + '" have been changed or removed by other application. What do you want to do ?')
message.exec_()
response = message.clickedButton().text()
# save current file under a new or old name
if response == SAVE:
fd = QtGui.QFileDialog(self)
newfile = fd.getSaveFileName()
if newfile:
s = codecs.open(newfile,'w','utf-8')
s.write(unicode(self.ui.editor_window.toPlainText()))
s.close()
self.ui.button_save.setEnabled(False)
# new file, remove old and add the new one to the watcher
if self.filename and str(newfile) != str(self.filename):
self.watcher.removePath(self.filename)
self.watcher.addPath(newfile)
self.filename = newfile
# reload the text in the editor
elif response == RELOAD:
s = codecs.open(self.filename,'r','utf-8').read()
self.ui.editor_window.setPlainText(s)
self.ui.button_save.setEnabled(False)
We use
QMessageBox to show the message in a window and allow user to save current file under different name or reload the file. To save a file we use
QFileDialog with
getSaveFileName. Using QFileSystemWatcher we have to remember about adding and removing files from the watch list.
Download source
- Added: 14.07.2008 by riklaunim
