Editing behavior of “backspace” key of QDoubleSpinBox - python

I’ve got a problem with QDoubleSpinBox. Editing behavior of “backspace” key somehow depends on the size of the suffix.
If I set “m” as suffix, then set the cursor at the end of the spinbox and press “backspace”, the cursor jumps over the “m” suffix to the value which then can be edited with further “backspaces”.
If I set the suffix to “mm” or any double-lettered word, the cursor remains at the end of the spinbox no matter how many “backspaces” I press.
I tried to debug what comes into “validate” method, and got a peculiar result:
When the “backspace” is pressed while cursor is at the end of "0,00m", validate receives "0,00m".
When the “backspace” is pressed while cursor is at the end of "0,00_m" validate receives "0,00__m"
When the “backspace” is pressed while cursor is at the end of "0,00_mm" validate receives "0,00_m_mm"
What is the cause of such behavior and how can I overcome it?
# coding=utf-8
from PyQt5 import QtWidgets
class SpinBox(QtWidgets.QDoubleSpinBox):
def __init__(self):
super().__init__()
def validate(self, text, index):
res = super().validate(text, index)
print(text, res, self.text())
return res
if __name__ == "__main__":
q_app = QtWidgets.QApplication([])
sb = SpinBox()
sb.setSuffix(" m")
sb.show()
q_app.exec_()

The source code for QDoubleSpinBox/QAbstractSpinBox is extremely convoluted when it comes to key-event handling - I couldn't work out what default behaviour is supposed to be, or even where it might be implemented. There might be a bug somewhere, but I wouldn't want to bet on it.
It looks like the only option is to reimplement keyPressEvent:
class SpinBox(QtWidgets.QDoubleSpinBox):
def keyPressEvent(self, event):
if event.key() == QtCore.Qt.Key_Backspace:
suffix = self.suffix()
if suffix:
edit = self.lineEdit()
text = edit.text()
if (text.endswith(suffix) and
text != self.specialValueText()):
pos = edit.cursorPosition()
end = len(text) - len(suffix)
if pos > end:
edit.setCursorPosition(end)
return
super().keyPressEvent(event)

Related

Dynamically add QTableView to dynamically created tab pages (QTabWidget)

I am trying to have a series of QTableView created at runtime and added to newly created pages of a multipage QTabWidget.
All seems to go fine, but the QTableView don't show up.
The QTabWidget gets zeroed (reset to no pages) and refurbished (...) flawlessly (at least it looks like so) depending on the selection of a combobox (and the dictionaries therein related).
I am also using a delegate callback to include a column of checkboxes to the QTableView (thanks to https://stackoverflow.com/a/50314085/7710452), which works fine stand alone.
Here is the code.
Main Window
EDIT
as recommended by eyllanesc, here is the standalone module (jump to the end of the post for details on the part I think is problematic):
"""
qt5 template
"""
import os
import sys
from PyQt5 import QtWidgets as qtw
from PyQt5 import QtCore as qtc
from PyQt5 import QtGui as qtg
from PyQt5 import uic
from configparser import ConfigParser, ExtendedInterpolation
from lib.SearchControllers import findGuis, get_controller_dict, show_critical, show_exception
import resources.resources
from lib.CheckBoxesDelegate import CheckBoxDelegate
myForm_2, baseClass = uic.loadUiType('./forms/setup.ui')
class MainWindow(baseClass):
def __init__(self, config_obj: ConfigParser,
config_name: str,
proj_name: str,
*args,
**kwargs):
super().__init__(*args, **kwargs)
self.ui = myForm_2()
self.ui.setupUi(self)
# your code begins here
self.setWindowTitle(proj_name + " Setup")
self.ui.logo_lbl.setPixmap(qtg.QPixmap(':/logo_Small.png'))
self.config_obj = config_obj
self.config_name = config_name
self.proj_filename = proj_name
self.proj_config = ConfigParser(interpolation=ExtendedInterpolation())
self.proj_config.read(proj_name)
self.guis_dict = {}
self.components = {}
self.cdp_signals = {}
self.root_path = self.config_obj['active']['controllers']
self.tableViews = []
self.tabs = []
self.iniControllersBox()
self.setActSignals()
self.load_bulk()
self.set_signals_table()
self.update_CurController_lbl()
self.update_ControllersTab() # here is where the action gets hot
# your code ends here
self.show() # here crashes if I passed the new tab to the instance of
# QTabView. otherwise it shows empty tabs
#########################################################
def load_bulk(self):
# get the list of running components into a dictionary
for i in self.list_controllers:
i_path = os.path.join(self.root_path, i)
print(i)
self.components[i] = get_controller_dict(i_path,
self.config_obj,
'Application.xml',
'Subcomponents/Subcomponent',
'Name',
'src')
for j in self.components[i]:
print(j)
signals_key = (i , j)
tgt = os.path.join(self.root_path, self.components[i][j])
self.cdp_signals[signals_key] = get_controller_dict(i_path,
self.config_obj,
self.components[i][j],
'Signals/Signal',
'Name',
'Type',
'Routing')
def set_signals_table(self):
self.ui.MonitoredDevicesTable.setHorizontalHeaderItem(0, qtw.QTableWidgetItem('GUI caption'))
self.ui.MonitoredDevicesTable.setHorizontalHeaderItem(1, qtw.QTableWidgetItem('Monitored Signal'))
def setActSignals(self):
self.ui.controllersBox.currentIndexChanged.connect(self.update_guis_list)
self.ui.controllersBox.currentIndexChanged.connect(self.update_CurController_lbl)
self.ui.controllersBox.currentIndexChanged.connect(self.update_ControllersTab)
def update_ControllersTab(self):
self.ui.componentsTab.clear() # this is the QTabWidget
self.tabs = []
self.tableViews = []
curr_controller = self.ui.controllersBox.currentText()
for i in self.components[curr_controller]:
if len(self.cdp_signals[curr_controller, i]) == 0:
continue
self.tabs.append(qtw.QWidget())
tabs_index = len(self.tabs) - 1
header_labels = ['', 'Signal', 'Type', 'Routing', 'Input']
model = qtg.QStandardItemModel(len(self.cdp_signals[curr_controller, i]), 5)
model.setHorizontalHeaderLabels(header_labels)
# in the next line I try to create a new QTableView passing
# the last tab as parameter, in the attempt to embed the QTableView
# into the QWidget Tab
self.tableViews.append(qtw.QTableView(self.tabs[tabs_index]))
tbw_Index = len(self.tableViews) - 1
self.tableViews[tbw_Index].setModel(model)
delegate = CheckBoxDelegate(None)
self.tableViews[tbw_Index].setItemDelegateForColumn(0, delegate)
rowCount = 0
for row in self.cdp_signals[curr_controller, i]:
for col in range(len(self.cdp_signals[curr_controller, i][row])):
index = model.index(rowCount, col, qtc.QModelIndex())
model.setData(index, self.cdp_signals[curr_controller, i][row][col])
try:
self.ui.componentsTab.addTab(self.tabs[tabs_index], i) # no problems, some controllers ask up to
except Exception as ex:
print(ex)
def update_CurController_lbl(self):
self.ui.active_controller_lbl.setText(self.ui.controllersBox.currentText())
def iniControllersBox(self):
self.list_controllers = [os.path.basename(f.path) for f in os.scandir(self.root_path) if f.is_dir() and str(
f.path).upper().endswith('NC')]
self.ui.controllersBox.addItems(self.list_controllers)
for i in range(self.ui.controllersBox.count()):
self.ui.controllersBox.setCurrentIndex(i)
newKey = self.ui.controllersBox.currentText()
cur_cntrlr = os.path.join(self.config_obj['active']['controllers'], self.ui.controllersBox.currentText())
self.guis_dict[newKey] = findGuis(cur_cntrlr, self.config_obj)
self.ui.controllersBox.setCurrentIndex(0)
self.update_guis_list()
def update_guis_list(self, index=0):
self.ui.GuisListBox.clear()
self.ui.GuisListBox.addItems(self.guis_dict[self.ui.controllersBox.currentText()])
if __name__ == '__main__':
config = ConfigParser()
config.read('./config.ini')
app = qtw.QApplication([sys.argv])
w = MainWindow(config, './config.ini',
'./test_setup_1.proj')
sys.exit(app.exec_())
and here the external to add the checkboxes column:
class CheckBoxDelegate(QtWidgets.QItemDelegate):
"""
A delegate that places a fully functioning QCheckBox cell of the column to which it's applied.
"""
def __init__(self, parent):
QtWidgets.QItemDelegate.__init__(self, parent)
def createEditor(self, parent, option, index):
"""
Important, otherwise an editor is created if the user clicks in this cell.
"""
return None
def paint(self, painter, option, index):
"""
Paint a checkbox without the label.
"""
self.drawCheck(painter, option, option.rect, QtCore.Qt.Unchecked if int(index.data()) == 0 else QtCore.Qt.Checked)
def editorEvent(self, event, model, option, index):
'''
Change the data in the model and the state of the checkbox
if the user presses the left mousebutton and this cell is editable. Otherwise do nothing.
'''
if not int(index.flags() & QtCore.Qt.ItemIsEditable) > 0:
return False
if event.type() == QtCore.QEvent.MouseButtonRelease and event.button() == QtCore.Qt.LeftButton:
# Change the checkbox-state
self.setModelData(None, model, index)
return True
if event.type() == QtCore.QEvent.MouseButtonPress or event.type() == QtCore.QEvent.MouseMove:
return False
return False
def setModelData (self, editor, model, index):
'''
The user wanted to change the old state in the opposite.
'''
model.setData(index, 1 if int(index.data()) == 0 else 0, QtCore.Qt.EditRole)
The 1st picture shows the layout in QTDesigner, the 2nd the result (emtpy tabs) when avoiding the crashing.
the QTabWidget has no problems in zeroing, or scale up, back to as many tab as I need, it's just that I have no clue on how to show the QTabview. My approach was to try to embed the QTabView in the tabpage passing it as parameter to the line creating the new QTabView.
Since I am using rather convoluted dictionaries, calling an XML parser to fill them up, not to mention the config files, I know even this version of my script is hardly reproduceable/runnable.
If someone had the patience of focusing on the update_ControllersTab method though, and tell me what I am doing wrong handling the QWidgets, it'd be great.
Again the basic idea is to clear the QTabWidget any time the user selects a different controller (combo box on the left):
self.ui.componentsTab.clear() # this is the QTabWidget
self.tabs = [] # list to hold QTabView QWidgets (pages) throughout the scope
self.tableViews = [] # list to hold QTabView(s) thorughout the scope
count how many tabs (pages) and hence embedded TabViews I need with the new controllers selected.
and then for each tab needed:
create a new tab (page)
self.tabs.append(qtw.QWidget())
tabs_index = len(self.tabs) - 1
create a new QTabView using a model:
header_labels = ['', 'Signal', 'Type', 'Routing', 'Input']
model = qtg.QStandardItemModel(len(self.cdp_signals[curr_controller, i]), 5)
model.setHorizontalHeaderLabels(header_labels)
self.tableViews.append(qtw.QTableView(self.tabs[tabs_index]))
tbw_Index = len(self.tableViews) - 1
self.tableViews[tbw_Index].setModel(model)
populate the TableView with data, and then finally add the tab widget (with the suppposedly embedded QTableView to the QTabWidget (the i argument is a string from my dbases Names:
self.ui.componentsTab.addTab(self.tabs[tabs_index], i)
This method is called also by the __init__ to initialize and apparently all goes error free, until the last 'init' statement:
`self.show()`
at which point the app crashes with:
Process finished with exit code 1073741845
on the other hand, if here instead of trying to embed the QTableView:
self.tableViews.append(qtw.QTableView(self.tabs[tabs_index]))
I omit the parameter, that is:
self.tableViews.append(qtw.QTableView())
the app doesn't crash anymore, but of course no QtableViews are shown, only empty tabpages:
As stupid as this may sound the problem is in... the delegate class that creates the checkboxes in the first column (see https://stackoverflow.com/a/50314085/7710452)
I commented out those two lines:
delegate = CheckBoxDelegate(None)
self.tableViews[tbw_Index].setItemDelegateForColumn(0, delegate)
and... bingo!
the CheckBoxDelegate works fine in the example shown in the post (a single QTableView form). I also tinkered around adding columns and rows, and moving the checkbox column back and forth with no problems. In that standalone. But as soon as I add the class and set the delegate, i am back at square zero, app crashing with:
Process finished with exit code 1073741845
so I am left with this problem now. Thnx to whomever read this.
Problem solved, see comment to post above.

QLineEdit unexpected behavior using QRegExpValidator

I'm using a QLineEdit widget to enter email addresses and I set up a QRegExpValidor to validate the entry.
The validator is working as far as preventing the input of characters not allowed in the QRegExp, but funny enough, it allows to enter intermediate input, either by pushing the enter key or by firing the "editingfinished" signal.
I verified the return of the validator which is correct (Intermediate or Acceptable).
Checking the PyQt5 documentation it seams that an intermediate state of the validator does not prevent the focus to change to another widget. Furthermore, it stops the firing of the editingFinished and returnedPressed signals so the user may enter wrong address as far as it marches partially the RegExp.
Ref: https://doc.qt.io/qt-5/qlineedit.html#acceptableInput-prop
I was able to solve my needs by removing the validator from the QLineEdit widget, and placing a method "checkValidator" linked to the cursorPositionChanged of the QLineEdit widget discarting the last character entered when nonacceptable, and setting the focus back to the QLineEdit when it validats intermmediate. It works just fine but when the the focus was reset, the others signals on other widgets were fired one at a time. Momentarily, I handle this by checking if the sender has focus at the start of the methods (see lookForFile)
Even though I could handle the issue, I appreciate very much anybody explaining me the proper way to use the RegExpValidator and or why resetting the focus fires the other signals out of the blue.
def setUI(self):
self.setWindowTitle("EMail Settings")
self.setModal(True)
rx = QRegExp(r"[a-z0-9_%]+#[a-z0-9%_]+\.[a-z0-9%_]{3,3}")
lblAddress = QLabel("EMail Address")
self.lineAddress = QLineEdit(self)
self.mailValidator = QRegExpValidator(rx, self.lineAddress)
#self.lineAddress.setValidator(self.mailValidator)
self.lineAddress.cursorPositionChanged.connect(self.checkValidator)
self.lineAddress.returnPressed.connect(self.checkValidator)
lblPassword = QLabel("Password")
self.linePwd = QLineEdit()
self.linePwd.setEchoMode(QLineEdit.PasswordEchoOnEdit)
lblOauth2 = QLabel("Oauth2 Token")
self.lineOauth = QLineEdit()
pushOauth = QPushButton("...")
pushOauth.setObjectName("token")
pushOauth.clicked.connect(self.lookForFile)
pushOauth.setFixedWidth(30)
#pyqtSlot()
def checkValidator(self):
self.lineAddress.blockSignals(True)
v = self.mailValidator.validate(self.lineAddress.text(), len(self.lineAddress.text()))
if v[0] == 0:
self.lineAddress.setText(self.lineAddress.text()[:-1])
elif v[0] == 1:
self.lineAddress.setFocus()
elif v[0] == 2:
pass
print("validates", v)
self.lineAddress.blockSignals(False)
#pyqtSlot()
def lookForFile(self):
try:
if not self.sender().hasFocus():
return
baseDir = "C"
obj = self.sender()
if obj.objectName() == "Draft":
capt = "Email Draft"
baseDir = os.getcwd() + "\\draft"
fileType = "Polo Management Email (*.pad)"
dialog = QFileDialog(self, directory=os.getcwd())
dialog.setFileMode(QFileDialog.Directory)
res = dialog.getExistingDirectory()
elif obj.objectName() == "token":
capt = "Gmail Outh2 token File"
fileType = "Gmail token Files (*.json)"
baseDir = self.lineOauth.text()
res = QFileDialog.getOpenFileName(self, caption=capt, directory=baseDir, filter=fileType)[0]
fileName = res
if obj.objectName() == "Draft":
self.lineDraft.setText(fileName)
elif obj.objectName() == "tokenFile":
self.lineOauth.setText(fileName)
except Exception as err:
print("settings: lookForFile", err.args)
Hope to answer #eyllanesc and Qmusicmante request with this minimal reproducible example. I change the regex for a simple one allowing for a string of lower case a-z follow by a dot and three more lowercase characters.
What I intend is the validator not allowing the user to enter a wrong input. The example allows for "xxxzb.ods" but also allows "xxxzb" or "xxxzb.o" for instance.
In short, not allowing the user to enter a wrong input.
This is my minimal reproducible example:
class CheckValidator(QDialog):
def __init__(self, parent=None):
super().__init__()
self.parent = parent
self.setUI()
def setUI(self):
self.setWindowTitle("EMail Settings")
self.setModal(True)
rx = QRegExp(r"[a-z]+\.[a-z]{3}")
lblAddress = QLabel("Check Line")
self.lineAddress = QLineEdit()
self.mailValidator = QRegExpValidator(rx, self.lineAddress)
self.lineAddress.setValidator(self.mailValidator)
self.lineAddress.cursorPositionChanged[int, int].connect(lambda
oldPos, newPos: self.printValidator(newPos))
lblCheck = QLabel("Check")
lineCheck = QLineEdit()
formLayout = QFormLayout()
formLayout.addRow(lblAddress, self.lineAddress)
formLayout.addRow(lblCheck, lineCheck)
self.setLayout(formLayout)
#pyqtSlot(int)
def printValidator(self, pos):
print(self.mailValidator.validate(self.lineAddress.text(), pos))
if __name__ == '__main__':
app = QApplication(sys.argv)
tst = CheckValidator()
tst.show()
app.exec()
I found a solution and I post it here for such a case it may help somebody else.
First I remove the QRegExpValidator from the QLineEdit widget. The reason being is that QLineEdit only fires editingFinished (and we'll need it ) only when QRegExpValidator returns QValidator.Acceptable while the validator is present.
Then we set a method fired by the 'cursorPositionchanged' signal of QlineEdit widget. On this method, using the QRegExpValidator we determine if the last character entered is a valid one. If not we remove it.
Finally, I set a method fired by the 'editingFinished' signal using the RegEx exactMatch function to determine if the entry is valid. If it is not, we give the user the option to clear the entry or to return to the widget to continue entering data. The regex used is for testing purposes only, for further information about email validation check #Musicamante comments.
This is the code involved:
def setUI(self):
................
................
rx = QRegExp(r"[a-z0-9_%]+#[a-z0-9%_]+\.[a-z0-9%_]{3,3}")
lblAddress = QLabel("EMail Address")
self.lineAddress = QLineEdit(self)
self.mailValidator = QRegExpValidator(rx, self.lineAddress)
self.lineAddress.cursorPositionChanged[int, int].connect(lambda oldPos,
newPos: self.checkValidator(newPos))
self.lineAddress.editingFinished.connect(lambda : self.checkRegExp(rx))
#pyqtSlot(int)
def checkValidator(self, pos):
v = self.mailValidator.validate(self.lineAddress.text(), pos ))
if v[0] == 0:
self.lineAddress.setText(self.lineAddress.text()[:-1])
#pyqtSlot(QRegExp)
def checkRegExp(self, rx):
if not rx.exactMatch(self.lineAddress.text()) and self.lineAddress.text():
if QMessageBox.question(self, "Leave the Address field",
"The string entered is not a valid email address! \n"
"Do you want to clear the field?", QMessageBox.Yes|QMessageBox.No) ==
QMessageBox.Yes:
self.lineAddress.clear()
else:
self.lineAddress.setFocus()

How to format the entries in Gtk.Entry

For example, the telephone format is +999 99 9999-9999. That is, the GtkEntry automatically add the characters (+,[space] and -) as the user types.
1. How to make an entry validator?
In order to do an entry validator in gtk, you need to connect the insert_text signal to a validation method. It goes like so:
class EntryWithValidation(Gtk.Entry):
"""A Gtk.Entry with validation code"""
def __init__(self):
Gtk.Entry.__init__(self)
self.connect("insert_text", self.entryInsert)
def entryInsert(self, entry, text, length, position):
# Called when the user inserts some text, by typing or pasting.
# The `position` argument is not working as expected in Python
pos = entry.get_position()
# Your validation code goes here, outputs are new_text and new_position (cursor)
if new_text:
# Set the new text (and block the handler to avoid recursion).
entry.handler_block_by_func(self.entryInsert)
entry.set_text(new_text)
entry.handler_unblock_by_func(self.entryInsert)
# Can't modify the cursor position from within this handler,
# so we add it to be done at the end of the main loop:
GObject.idle_add(entry.set_position, new_pos)
# We handled the signal so stop it from being processed further.
entry.stop_emission("insert_text")
This code will generate a warning: Warning: g_value_get_int: assertion 'G_VALUE_HOLDS_INT (value)' failed Gtk.main() because of the incapacity of handling return arguments in the Python bindings of Gtk signals. This question gives details about the bug. As suggested in the accepted answer, you can override the default signal handler like so:
class EntryWithValidation(Gtk.Entry, Gtk.Editable):
def __init__(self):
super(MyEntry, self).__init__()
def do_insert_text(self, new_text, length, position):
# Your validation code goes here, outputs are new_text and new_position (cursor)
if new_text:
self.set_text(new_text)
return new_position
else:
return position
2.The validation code
You now need to write the validation code. It is a bit fiddly since we need to place the cursor at the end of the inserted text but we may have added some extra characters while formatting.
import gi
gi.require_version("Gtk", "3.0")
from gi.repository import Gtk, GObject
class TelNumberEntry(Gtk.Entry):
"""A Gtk.Entry field for phone numbers"""
def __init__(self):
Gtk.Entry.__init__(self)
self.connect("insert_text", self.entryInsert)
def entryInsert(self, entry, text, length, position):
pos = entry.get_position()
old_text = entry.get_text()
# Format entry text
# First we filter digits in insertion text
ins_dig = ''.join([c for c in text if c.isdigit()])
# Second we insert digits at pos, truncate extra-digits
new_text = ''.join([old_text[:pos], ins_dig, old_text[pos:]])[:17]
# Third we filter digits in `new_text`, fill the rest with underscores
new_dig = ''.join([c for c in new_text if c.isdigit()]).ljust(13, '_')
# We are ready to format
new_text = '+{0} {1} {2}-{3}'.format(new_dig[:3], new_dig[3:5],
new_dig[5:9], new_dig[9:13]).split('_')[0]
# Find the new cursor position
# We get the number of inserted digits
n_dig_ins = len(ins_dig)
# We get the number of digits before
n_dig_before = len([c for c in old_text[:pos] if c.isdigit()])
# We get the unadjusted cursor position
new_pos = pos + n_dig_ins
# If there was no text in the entry, we added a '+' sign, therefore move cursor
new_pos += 1 if not old_text else 0
# Spacers are before digits 4, 6 and 10
for i in [4, 6, 10]:
# Is there spacers in the inserted text?
if n_dig_before < i <= n_dig_before + n_dig_ins:
# If so move cursor
new_pos += 1
if new_text:
entry.handler_block_by_func(self.entryInsert)
entry.set_text(new_text)
entry.handler_unblock_by_func(self.entryInsert)
GObject.idle_add(entry.set_position, new_pos)
entry.stop_emission("insert_text")
if __name__ == "__main__":
window = Gtk.Window()
window.connect("delete-event", Gtk.main_quit)
entry = TelNumberEntry()
window.add(entry)
window.show_all()
Gtk.main()

Urwid: make cursor invisible

I'm using urwid, which is a Python "framework" for designing terminal user interfaces in ncurses. There's one thing though that I'm not able to do in urwid that was easy in curses - make the cursor invisible. As it is now, the cursor is visible when selecting buttons, and it just looks plain ugly. Is there a way to disable it?
I agree that the flashing cursor on an urwid.Button looks a bit lame, so I've come up with a solution to hide it. In urwid, the Button class is just a subclass of WidgetWrap containing a SelectableIcon and two Text widgets (the enclosing "<" and ">"). It's the SelectableIcon class that sets the cursor position to the first character of the label, by default. By subclassing SelectableIcon, modifying the cursor position and then wrapping it into an urwid.WidgetWrap subclass you can create your own custom button that can do all the tricks a built-in Button, or even more.
Here' what it looks like in my project.
import urwid
class ButtonLabel(urwid.SelectableIcon):
def __init__(self, text):
"""
Here's the trick:
we move the cursor out to the right of the label/text, so it doesn't show
"""
curs_pos = len(text) + 1
urwid.SelectableIcon.__init__(self, text, cursor_position=curs_pos)
Next, you can wrap a ButtonLabel object along with any other objects into a WidgetWrap subclass that will be your custom button class.
class FixedButton(urwid.WidgetWrap):
_selectable = True
signals = ["click"]
def __init__(self, label):
self.label = ButtonLabel(label)
# you could combine the ButtonLabel object with other widgets here
display_widget = self.label
urwid.WidgetWrap.__init__(self, urwid.AttrMap(display_widget, None, focus_map="button_reversed"))
def keypress(self, size, key):
"""
catch all the keys you want to handle here
and emit the click signal along with any data
"""
pass
def set_label(self, new_label):
# we can set the label at run time, if necessary
self.label.set_text(str(new_label))
def mouse_event(self, size, event, button, col, row, focus):
"""
handle any mouse events here
and emit the click signal along with any data
"""
pass
In this code, there is actually not much combination of widgets in the FixedButton WidgetWrap subclass, but you could add a "[" and "]" to the edges of the button, wrap it into a LineBox, etc. If all this is superfluous, you can just move the event handling functions into the ButtonLabel class, and make it emit a signal when it gets clicked.
To make the button reversed when the user moves on it, wrap it into AttrMap and set the focus_map to some palette entry ("button_reversed", in my case).
Building upon Drunken Master's answer, I've cleaned up the solution as much as possible.
The urwid.SelectableIcon is basically an urwid.Text field with this ugly blinking cursor.
So instead of overriding the urwid.SelectableIcon and packing it into an urwid.WidgetWrap, let's take an urwid.Text directly and make it selectable and react to button/mouse activation (inspired from urwid's simple menu tutorial):
import urwid
choices = u'Chapman Cleese Gilliam Idle Jones Palin'.split()
class ListEntry(urwid.Text):
_selectable = True
signals = ["click"]
def keypress(self, size, key):
"""
Send 'click' signal on 'activate' command.
"""
if self._command_map[key] != urwid.ACTIVATE:
return key
self._emit('click')
def mouse_event(self, size, event, button, x, y, focus):
"""
Send 'click' signal on button 1 press.
"""
if button != 1 or not urwid.util.is_mouse_press(event):
return False
self._emit('click')
return True
def menu(title, choices):
body = [urwid.Text(title), urwid.Divider()]
for c in choices:
button = ListEntry(c)
urwid.connect_signal(button, 'click', item_chosen, c)
body.append(urwid.AttrMap(button, None, focus_map='reversed'))
return urwid.ListBox(urwid.SimpleFocusListWalker(body))
def item_chosen(button, choice):
response = urwid.Text([u'You chose ', choice, u'\n'])
done = ListEntry(u'Ok')
urwid.connect_signal(done, 'click', exit_program)
main.original_widget = urwid.Filler(urwid.Pile([response,
urwid.AttrMap(done, None, focus_map='reversed')]))
def exit_program(button):
raise urwid.ExitMainLoop()
main = urwid.Padding(menu(u'Pythons', choices), left=2, right=2)
top = urwid.Overlay(main, urwid.SolidFill(u'\N{MEDIUM SHADE}'),
align='center', width=('relative', 60),
valign='middle', height=('relative', 60),
min_width=20, min_height=9)
urwid.MainLoop(top, palette=[('reversed', 'standout', '')]).run()
Works like a charm:
urwid uses the curs_set function, but does not expose it as a class method anywhere. Someone could modify urwid to allow using this method; otherwise there's no reliable method of doing this.
You might report it as an issue.
Along the lines of Drunken Master's answer, but with "minimally invasive surgery":
class ButtonLabel(urwid.SelectableIcon):
'''
use Drunken Master's trick to move the cursor out of view
'''
def set_text(self, label):
'''
set_text is invoked by Button.set_label
'''
self.__super.set_text(label)
self._cursor_position = len(label) + 1
class MyButton(urwid.Button):
'''
- override __init__ to use our ButtonLabel instead of urwid.SelectableIcon
- make button_left and button_right plain strings and variable width -
any string, including an empty string, can be set and displayed
- otherwise, we leave Button behaviour unchanged
'''
button_left = "["
button_right = "]"
def __init__(self, label, on_press=None, user_data=None):
self._label = ButtonLabel("")
cols = urwid.Columns([
('fixed', len(self.button_left), urwid.Text(self.button_left)),
self._label,
('fixed', len(self.button_right), urwid.Text(self.button_right))],
dividechars=1)
super(urwid.Button, self).__init__(cols)
if on_press:
urwid.connect_signal(self, 'click', on_press, user_data)
self.set_label(label)
Here, we only modify the button's appearance but otherwise leave its behaviour unchanged.

QValidator fixup issue

Following is my code to validate an account code, and add dashes at certain intervals. An example account code is 140-100-1000-6610-543. The code takes the regex: \d{3}-\d{3}-\d{4}-\d{4}-\d{3] and allows the user to type in numbers, and where there is a dash in the regex, it places the dash for the user. Or rather, it should. On our production server (('Qt version:', '4.8.1'), ('SIP version:', '4.13.2'), ('PyQt version:', '4.9.1')) it does work. Our dev server is upgraded to ('Qt version:', '4.8.6'), ('SIP version:', '4.15.5'), ('PyQt version:', '4.10.4') and it doesn't work there.
On each server, I type in 140. On the production (older version), the line edit value changes to 140-. On the newer version development server, it does not add the dash.
Please let me know if you see my issue, and let me know if this is a PyQt issue, or a Qt issue.
import sys
from PyQt4 import QtGui, QtCore
DEBUG = True
class acValidator(QtGui.QRegExpValidator):
def __init__(self, regexp, widget):
QtGui.QRegExpValidator.__init__(self, regexp, widget)
self.widget = widget
def validate(self, text, pos):
'''function to decide if this account code is valid'''
valid, _npos = QtGui.QRegExpValidator.validate(self, text, pos)
if valid != QtGui.QValidator.Acceptable:
self.fixup(text)
print 'acWidget.validate result of fixup', text
# move position to the end, if fixup just added a dash
# to the end
newstr = self.widget.text()
newpos = len(str(newstr))
if pos + 1 == newpos and newstr[pos:newpos] == '-':
pos = newpos
# return the valid variable, and the current position
return (valid, pos)
def fixup(self, text):
'''place dashes, if we can'''
# pylint: disable=no-member
if DEBUG:
print 'acWidget.py fixup'
reParts = self.regExp().pattern().split('-')
if DEBUG:
print list(reParts)
newreg = ''
for i in range(len(reParts)):
newreg += reParts[i]
if DEBUG:
print i, reParts[i]
nr = QtCore.QRegExp(newreg)
# pylint: disable=no-member
if nr.exactMatch(text) and not self.regExp().exactMatch(text):
if DEBUG:
print 'adding dash'
text += '-'
return
newreg += '-'
def isValid(self):
'''return a true or false for the validity based on whether the
widget is a lineEdit or a comboBox (acCB). true only if the
validator returns QtGui.QValidator.Acceptable
'''
valid, _npos = QtGui.QRegExpValidator.validate(self,
self.widget.text(),
self.widget.cursorPosition())
if valid == QtGui.QValidator.Acceptable:
return True
return False
class acWidget(QtGui.QLineEdit):
def __init__(self, parent=None):
QtGui.QLineEdit.__init__(self, parent)
self.regex = r'\d{3}-\d{3}-\d{4}-\d{4}-\d{3}'
self.setMinimumWidth(200)
self.setValidator(acValidator(QtCore.QRegExp(self.regex),
self))
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
form = QtGui.QDialog()
layout = QtGui.QVBoxLayout(form)
a = acWidget(form)
layout.addWidget(a)
form.setLayout(layout)
form.setMinimumWidth(400)
form.setMinimumHeight(200)
form.show()
app.exec_()
The problem is caused by the C++ signatures of fixup and validate requiring that the text argument is modifiable. If you're using Python 2, this distinctly unpythonic way of doing things is honoured by PyQt; whereas with Python 3, the signatures have been changed so that the methods simply return the modified values.
The specific issue in your code can be found here:
def fixup(self, text):
...
text += '-'
It seems that, in earlier versions of PyQt, augmented assignment on a QString did an implicit in-place mutation. But in more recent versions, it works more like normal python augmented assignment and simply re-binds the local variable like this:
text = text + '-'
To work around this, you can do an explict in-place mutation:
text.append('-')

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