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Crashes when moving cellWidgets around in a TableWidget - python

I am writing a tool that allows me to track some tasks along a path of predifined stages, from something on a backlog, to ToDo, through WIP, Review and finally to done.
I created a custom widget, that will eventually be yellow, not unlike a postit note and perhaps with a bit of formatting it to give it a nice frame, etc... but stopped before getting far enough to make it look right because of this issue.
The idea is that each of these yellow Task widgets will have a stage they are at, and that I can select them in a Table Widget, and move them onto the next or previous stage, which will update taht objects stage, then refresh the TableWidget, read all the widget and where thay should be and set them in their new place.
So I have it kind of working to some degree (below), where I can move the tasks forward and they update location, but I noticed when I click the cells that the widget was previously in, print statement still says that the cell still has a widget there (which kind of makes sense, as code below isn't removing the previous one, but I'd expect to visually still see it). And I can move them forward and backwards, and the information on the tasks does update correctly, but the table won't refresh unless the task moves to a cell that never had a cellWidget in it. Test this by moving it backwards. It works, movnig forward visually does nothing, but moving again, does show up.
I tried clearing the TableWidget and rebuilding from scratch and that crashes. The main issue I am having is that with all these crashes, which is an issue in itself as it makes debugging very tough... When I try and clear the TableWidget (with .clear()) before repopulating, I get this.
Process finished with exit code -1073741819 (0xC0000005)
Same error code if I try removing the old cells by setting the Table Widget to 0 rows before adding the correct number of rows.
A known issue that is less important is when I select a cell without a widget and try and move it, gies me this, but don't worry too much about that fix, as it's known issue.
Process finished with exit code -1073740791 (0xC0000409)
Also tried cleaning up by iterating every cell and if it has a cell widget, remove cell widget before re-setting them to correct place and it still crashes. I'm out of ideas.
Task Widget
import sys
from PyQt5.QtWidgets import (QApplication, QTableWidget, QWidget, QFrame, QHBoxLayout, QLabel,
QPushButton,QVBoxLayout)
class Task(QWidget):
def __init__(self, ID, name, est):
super(Task, self).__init__()
# Creates a small widget that will be added to a table widget
self.ID = ID
self.name = name
self.est = est
# These cell widgets represent tasks. So each task has a particular 'stage' it is at
self.stage = 'ToDo'
self.stages = ['Backlog', 'ToDo', 'WIP', 'Review', 'Done']
self.objects_labels = {}
self.initUI()
def initUI(self):
# adds a bunch of labels to the widget
layout = QVBoxLayout()
frame = QFrame()
frame.setFrameShape(QFrame.StyledPanel)
frame.setStyleSheet('background-color: red')
frame.setLineWidth(2)
layout.addWidget(frame)
info = [self.ID, self.name, self.est]
for section in info:
self.objects_labels[section] = QLabel(str(section))
layout.addWidget(self.objects_labels[section])
self.setLayout(layout)
self.setStyleSheet('background-color: yellow')
def task_move(self, forward = True):
# The main widget will allow me to change the stage of a particular Task
# The idea is that I update the Table widget to show everything in the right place
# This function finds out what stage it is at and increments/decrements by one
index = self.stages.index(self.stage)
print(self.stages)
print(index)
if forward:
print('--->')
if self.stage == self.stages[-1]:
print('Already at the end of process')
return
self.stage = self.stages[index + 1]
else:
print('<---')
if self.stage == self.stages[0]:
print('Already at the start of process')
return
self.stage = self.stages[index - 1]
MainWidget
class MainWidget(QWidget):
def __init__(self):
super().__init__()
self.tasks = self.make_tasks()
self.init_ui()
self.update_tw()
def make_tasks(self):
# Create a few tasks
a = Task(0, 'Name_A', 44)
b = Task(0, 'Name_B', 22)
c = Task(0, 'Name_C', 66)
d = Task(0, 'Name_D', 90)
return [a, b, c, d]
def init_ui(self):
layout_main = QVBoxLayout()
self.tw = QTableWidget()
self.tw.cellClicked.connect(self.cell_clicked)
self.tw.horizontalHeader().setDefaultSectionSize(120)
self.tw.verticalHeader().setDefaultSectionSize(120)
layout_main.addWidget(self.tw)
layout_bottom_button_bar = QHBoxLayout()
self.btn_task_backward = QPushButton('<--- Task')
self.btn_task_backward.clicked.connect(lambda: self.move_task(forward=False))
self.btn_task_forward = QPushButton('Task --->')
self.btn_task_forward.clicked.connect(lambda: self.move_task())
for widget in [self.btn_task_backward, self.btn_task_forward]:
layout_bottom_button_bar.addWidget(widget)
layout_main.addLayout(layout_bottom_button_bar)
self.setLayout(layout_main)
self.setGeometry(300, 300, 800, 600)
self.setWindowTitle('MainWidget')
self.show()
#property
def tw_header(self):
return {'Backlog': 0, 'ToDo': 1, 'WIP': 2, 'Review': 3, 'Done': 4}
#property
def selected_indices(self):
return [(x.row(), x.column()) for x in self.tw.selectedIndexes()]
#property
def selected_widgets(self):
selected_widgets = [self.tw.cellWidget(x[0], x[1]) for x in self.selected_indices]
print(selected_widgets)
return selected_widgets
def move_task(self, forward=True):
# Crashes if you select a non-widget cell, but thats a known issue
# Moves the task forward or backward and then prompts to update the TableWidget
for object in self.selected_widgets:
object.task_move(forward=forward)
self.tw.clearSelection()
self.update_tw()
def cell_clicked(self, row, column):
if self.tw.cellWidget(row, column):
print(self.selected_indices)
print(self.selected_widgets)
else:
print('No Cell Widget here')
def update_tw(self):
#I wanted to clear the Table widget and rebuild, but this crashes
# self.tw.clear()
self.tw.setHorizontalHeaderLabels(self.tw_header.keys())
rows = len(self.tasks)
columns = len(self.tw_header)
self.tw.setRowCount(rows)
self.tw.setColumnCount(columns)
# Looks through each task, and then gets it's stage, and then adds the widget to the correct column
for index, object in enumerate(self.tasks):
column = self.tw_header[object.stage]
print('Setting stage {} for {}\n...to r={}, c={}\n***'.format(object.stage, object, index, column))
self.tw.setCellWidget(index, column, object)
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = MainWidget()
sys.exit(app.exec_())

From my previous experience, I always found using setCellWidget clunky, underperforming and buggy.
Most of the times my Widgets were lost or misplaced, while refreshing the table similarly to the way you are doing it.
In addition, I guess you would want to use this "Task Mover" on a larger scale, and from what I could see, setting separate Widgets inside QWidgetItems becomes quite slow when done on loads of items.
My suggestion would be to use style delegates, so that you can customize the look of your items to your liking, without having to deal with the setCellWidget stuff which is giving you problem.
Once you have your own delegate, and paint the items the way you want, you can just keep updating that item data and moving the items around the table by using "take" and "set".
I am not sure if this would be the best way of executing this specific task, but moving towards this direction would probably give you greater flexibility and customisation power in the long run.
import sys
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
class TaskProperty():
properties = ["ID", "name", "est", "stage"]
count = 4
ID, Name, Est, Stage = [Qt.UserRole + x for x in range(count)]
STAGES = ['Backlog', 'ToDo', 'WIP', 'Review', 'Done']
class MainWidget(QWidget):
def __init__(self):
super(MainWidget, self).__init__()
self.tasks = self.make_tasks()
self.init_ui()
self.update_tw()
def make_tasks(self):
# Create a few tasks
a = Task(0, 'Name_A', 44)
b = Task(0, 'Name_B', 22)
c = Task(0, 'Name_C', 66)
d = Task(0, 'Name_D', 90)
return [a, b, c, d]
def init_ui(self):
layout_main = QVBoxLayout()
self.tw = QTableWidget()
# create and set the delegate to the TableWidget
self.delegate = TaskDelegate(self.tw )
self.tw.setItemDelegate(self.delegate)
self.tw.cellClicked.connect(self.cell_clicked)
self.tw.horizontalHeader().setDefaultSectionSize(120)
self.tw.verticalHeader().setDefaultSectionSize(120)
layout_main.addWidget(self.tw)
layout_bottom_button_bar = QHBoxLayout()
self.btn_task_backward = QPushButton('<--- Task')
self.btn_task_backward.clicked.connect(lambda: self.move_task(forward=False))
self.btn_task_forward = QPushButton('Task --->')
self.btn_task_forward.clicked.connect(lambda: self.move_task())
for widget in [self.btn_task_backward, self.btn_task_forward]:
layout_bottom_button_bar.addWidget(widget)
layout_main.addLayout(layout_bottom_button_bar)
self.setLayout(layout_main)
self.setGeometry(300, 300, 800, 600)
self.setWindowTitle('MainWidget')
self.show()
#property
def tw_header(self):
return {'Backlog': 0, 'ToDo': 1, 'WIP': 2, 'Review': 3, 'Done': 4}
#property
def selected_indices(self):
return [(x.row(), x.column()) for x in self.tw.selectedIndexes()]
def move_task(self, forward=True):
'''
To move the task to the next step, we iterate all the items selected.
If the task can be moved, we take the corresponding item from its current cell and move it to the destination.
:param forward:
:return:
'''
selected =self.tw.selectedItems()
for item in selected:
item.setSelected(False)
result = item.task_move(forward=forward)
if result:
next = 1 if forward else -1
row = item.row()
column = item.column()
moveItem = self.tw.takeItem(row, column)
self.tw.setItem(row, column + next, moveItem)
moveItem.setSelected(True)
def cell_clicked(self, row, column):
item = self.tw.item(row, column)
if not isinstance(item, TaskItem):
print "No Task Item Here"
def update_tw(self):
# I wanted to clear the Table widget and rebuild, but this crashes
# self.tw.clear()
self.tw.clear()
self.tw.setHorizontalHeaderLabels(self.tw_header.keys())
rows = len(self.tasks)
columns = len(self.tw_header)
self.tw.setRowCount(rows)
self.tw.setColumnCount(columns)
# Looks through each task, and then gets it's stage, and then adds the widget to the correct column
for row, object in enumerate(self.tasks):
# create items of our custom type only for the column that need to be filled.
# the other cells will be filled with null items.
column = STAGES.index(object.stage)
print('Setting stage {} for {}\n...to r={}, c={}\n***'.format(object.stage, object, row, column))
item = TaskItem(object)
self.tw.setItem(row, column, item)
class TaskDelegate(QStyledItemDelegate):
'''
This delegate take care of Drawing our cells the way we want it to be.
'''
def paint(self, painter, option, index):
'''
Override the Paint function to draw our own cell.
If the QTableWidgetItem does not have our Data stored in it, we do a default paint
:param painter:
:param option:
:param index:
:return:
'''
painter.save()
rect = option.rect
status = index.data(TaskProperty.Stage)
if status is None:
return super(TaskDelegate, self).paint(painter, option, index)
else:
id = STAGES.index(status)
pen = painter.pen()
pen.setBrush(Qt.black)
painter.setPen(pen)
if id == index.column():
rect.translate(3, 3)
newRect = QRect(rect.x(), rect.y(), rect.width() - 6, 20)
infos = [index.data(TaskProperty.ID), index.data(TaskProperty.Name), index.data(TaskProperty.Est)]
painter.setBrush(Qt.red)
painter.drawRect(newRect)
painter.setBrush(Qt.yellow)
for info in infos:
newRect.translate(0, 25)
painter.drawRect(newRect)
painter.drawText(newRect, Qt.AlignHCenter | Qt.AlignVCenter,
str(info))
class TaskItem(QTableWidgetItem):
'''
Subclass QTableWidgetItem.
Probably not needed, since we can set the property when we create the item instead of in the init,
and keep track of which item is attached to which task object using the Column Index of the table.
However, this can be useful if you want to attach more specific procedures to your items
'''
def __init__(self, task):
super(TaskItem, self).__init__()
self._task = task
self.setData(TaskProperty.ID, task.ID)
self.setData(TaskProperty.Name, task.name)
self.setData(TaskProperty.Est, task.est)
self.setData(TaskProperty.Stage, task.stage)
self.objects_labels = {}
def task_move(self, forward=True):
result = self._task.task_move(forward=forward)
self.setData(TaskProperty.Stage, self._task.stage)
return result
class Task(object):
'''
The Task class is now just an object, not a widget.
'''
def __init__(self, ID, name, est):
# Creates a small widget that will be added to a table widget
self.ID = ID
self.name = name
self.est = est
# These cell widgets represent tasks. So each task has a particular 'stage' it is at
self.stage = 'ToDo'
self.stages = ['Backlog', 'ToDo', 'WIP', 'Review', 'Done']
self.objects_labels = {}
def task_move(self, forward=True):
# The main widget will allow me to change the stage of a particular Task
# The idea is that I update the Table widget to show everything in the right place
# This function finds out what stage it is at and increments/decrements by one
index = self.stages.index(self.stage)
if forward:
print('--->')
if self.stage == self.stages[-1]:
#print('Already at the end of process')
return False
self.stage = self.stages[index + 1]
else:
print('<---')
if self.stage == self.stages[0]:
#print('Already at the start of process')
return False
self.stage = self.stages[index - 1]
return True
if __name__ == '__main__':
app = QApplication(sys.argv)
ex = MainWidget()
sys.exit(app.exec_())

It is not necessary to clean and create everything again, instead just move the widget for it we must know if it can be moved or not and for that task_move must indicate if the movement is valid or not. Considering the above, the solution is:
def task_move(self, forward=True):
# The main widget will allow me to change the stage of a particular Task
# The idea is that I update the Table widget to show everything in the right place
# This function finds out what stage it is at and increments/decrements by one
index = self.stages.index(self.stage)
print(self.stages)
print(index)
if forward:
print("---&gt")
if self.stage == self.stages[-1]:
print("Already at the end of process")
return False
self.stage = self.stages[index + 1]
else:
print("&lt---")
if self.stage == self.stages[0]:
print("Already at the start of process")
return False
self.stage = self.stages[index - 1]
return True
def move_task(self, forward=True):
for row, column in self.selected_indices:
widget = self.tw.cellWidget(row, column)
if isinstance(widget, Task) and widget.task_move(forward):
next_column = column + (1 if forward else -1)
# create new task widget
task = Task(widget.ID, widget.name, widget.est)
# remove all task widget
self.tw.removeCellWidget(row, column)
# move task widget
self.tw.setCellWidget(row, next_column, task)
self.tw.clearSelection()
The crashed is because when using clear you are also removing the Task widget so "self.tasks" has objects deleted from C++ that you should not use.

Related

Is is a piece of my code . I have two classes CheckerScene and Checkers . CHesckers - is my main window . I can't realize EndGameSignal defined in CheckerScene class . When it emits , pySlot can't catch it in class Checkers , as i want . When my EndGameSignal emmits - i want to see a dialog message on my main screen (pyQtSlots functions realized in my code), not on the scene . How can i correct my program to do it .
class CheckerScene(QtWidgets.QGraphicsScene):
EndGameSignal=QtCore.pyqtSignal('QString')
def init(self):
QtWidgets.QGraphicsScene.init(self)
# scene congifuratios
self.setSceneRect(margin, margin, gridCount * gridSlotSize, gridCount * gridSlotSize)
self.addRect(self.sceneRect())
# create signal . It will be emit() from blackboard.crash()
self.signaldel.connect(self.del_item)
#choosing the visual checker and its coordinates
self.current = None
#list of grids and checkers
self.grid = []
self.white_checkers = []
self.black_checkers = []
for row in range(8):
for column in range(8):
# this is a "trick" to make the grid creation easier: it creates
# a grid square only if the row is odd and the column is even,
# and viceversa.
if (not row & 1 and column & 1) or (row & 1 and not column & 1):
# create a gridItem with a rectangle that uses 0-based
# coordinates, *then* we set its position
gridItem = self.addRect(0, 0, gridSlotSize, gridSlotSize)
gridItem.setPos(margin + column * gridSlotSize, margin + row * gridSlotSize)
gridItem.setBrush(QtGui.QColor(QtCore.Qt.lightGray))
self.grid.append(gridItem)
if 3 <= row <= 4:
# don't add checkers in the middle
continue
# create checkers being careful to assign them the gridItem
# as a *parent*; their coordinate will *always* be relative
# to the parent, so that if we change it, they will always
# be centered
if row < 3:
self.black_checkers.append(CheckerItem(0, gridItem))#!
else:
self.white_checkers.append(CheckerItem(1, gridItem))#!
self.additionsl__init__()
self.EndGameSignal.connect(Checkers.handler_EndGameSignal)
self.EndGameSignal.emit('=NAME')
class Checkers(QtWidgets.QWidget):
def __init__(self):
QtWidgets.QWidget.__init__(self)
self.Initialization()
def Initialization(self):
layout = QtWidgets.QGridLayout()
self.setLayout(layout)
self.player2Label = QtWidgets.QLabel('Player 2')
layout.addWidget(self.player2Label)
self.player2Label.setAlignment(QtCore.Qt.AlignCenter)
self.checkerView = QtWidgets.QGraphicsView()
layout.addWidget(self.checkerView)
self.checkerScene = CheckerScene()
self.checkerView.setScene(self.checkerScene)
self.checkerView.setFixedSize(gridSize, gridSize)
# set the Antialiasing render hints to paint "smoother" shapes
self.checkerView.setRenderHints(QtGui.QPainter.Antialiasing)
self.player1Label = QtWidgets.QLabel('Player 1')
layout.addWidget(self.player1Label)
self.player1Label.setAlignment(QtCore.Qt.AlignCenter)
#QtCore.pyqtSlot(str)
def handler_EndGameSignal(self, result):
result=QtWidgets.QMessageBox.question(self,f"Выиграл {result}","Сиграть еще раз ?",QtWidgets.QMessageBox.Yes |
QtWidgets.QMessageBox.No,QtWidgets.QMessageBox.No)
if result == QtWidgets.QMessageBox.Yes :
self.close()
else :
pass
print(f"WINNER {result}")
#QtCore.pyqtSlot(bool)
def handler_EndGameSignal(self, result):
result = QtWidgets.QMessageBox.question(self, f"НИЧЬЯ !", "Сиграть еще раз ?",
QtWidgets.QMessageBox.Yes |
QtWidgets.QMessageBox.No, QtWidgets.QMessageBox.No)
if result == QtWidgets.QMessageBox.Yes:
self.close()
else:
pass
print("DRAW")
if __name__ == '__main__':
import sys
app = QtWidgets.QApplication(sys.argv)
checkers = Checkers()
checkers.show()
sys.exit(app.exec_())

As with your previous question, you're still confusing classes and instancies. In your code you connect the signal to the class, while you have to connect it to the instance.
Since you have no reference with the receiver (the Checker instance) from the sender (the scene), you'll have to connect it from the former:
class Checkers(QtWidgets.QWidget):
def Initialization(self):
# ...
self.checkerScene.EndGameSignal.connect(self.handler_EndGameSignal)

Updated Question
I think my original quandary might be a result of the structure of my PyQt app. The way I've approached creating a GUI is to divide the larger widget into smaller pieces, each given their own class until the parts are simple enough. Because of this, I end up with a ton of nesting, as a large widget holds instances of smaller widgets, and those hold their own even smaller widgets. It makes it hard to navigate data around the app.
How should a PyQt app be structured so that it is simple to understand in code and yet has a structure containing very little nesting? I haven't found many examples of this around, so I'm sort of stuck. The code example in my original question shows a pretty good example of the structure I'm currently using, which has a large amount of nesting.
Info on program
The GUI is used to create a set of parameters for running a test. The options in each setting should correspond to a binary number, and all of the binary numbers indicated by each set of options are collected, formed into a single sequence of binary numbers, and passed on. Changes to settings do not have to be carried over between sessions, as each new session will most likely correspond to a new test (and thus a new set of choices for settings).
The basic flow of the app should be that upon opening it, all available settings (about 20 total) are set to their default values. A user can go through and change whatever settings they would like, and once they're done they can press a "Generate" button to gather all of the binary numbers corresponding to the settings and create the command. It would be very helpful to have a live preview of individual bits that updates as settings are changed, which is why updates must be immediate.
Some settings are dependent on other; for instance, Setting A has 4 options, and if option 3 is selected, Setting B should be made visible, otherwise it is invisible.
Original Question
I'm definitely a beginner to PyQt, so I don't quite know if I've worded my question correctly, but here goes. I've got a GUI wherein I'm attempting to take a bunch of different settings, keep track of what number was selected from each setting, and then pass the number up to an object that keeps track of all of the numbers from all of the settings. The trouble is that I don't know the best way to get all the individual settings values up my tree of classes, so to speak. Here's the structure of my GUI so far:
Bottom: individual custom QWidgets, each responsible for a single setting. Each has a signal that fires whenever the value it returns changes.
Middle: a QWidget containing ~7-10 individual settings each. These collect settings into related groups.
Top: a QTabWidget that places each instance of a setting group into an individual tab. This widget also contains an object that should ideally collect all of the settings from individual groups into it.
My question is how do I get the values from the bottom layer signals to the top layer widget? My only idea is to connect all of the signals from those small setting widgets to a signal in the middle layer, and connect the middle layer signal to something in the top layer. This sort of chaining seems crazy, though.
I'm running PyQt5 and Python 3.7.
Here's some stripped down code which hopefully shows what I want to do.
class TabWindow(QTabWidget):
def __init__(self):
super().__init__()
self.tabs = [SettingsGroup1, SettingsGroup2, SettingsGroup3]
self.setting_storage = { # dictionary is where I'd like to store all settings values
# 'setting name': setting value
}
for tab in self.tabs:
self.addTab(tab, 'Example')
class SettingsGroup(QWidget):
def __init__(self):
super().__init__()
# not shown: layout created for widget
self.settings = []
def add_to_group(self, new_setting):
self.settings.append(new_setting)
# not shown: add setting to the layout
class SettingsGroup1(SettingsGroup):
def __init__(self):
super().__init__()
self.add_to_group([Setting1, Setting2, Setting3])
class SettingsGroup2(SettingsGroup):...
class SettingsGroup3(SettingsGroup):...
class Setting(QWidget):
val_signal = pyqtSignal([int], name='valChanged')
def __init__(self, name):
self.val = None
self.name = name
def set_val(self, new_val):
self.val = new_val
self.val_signal.emit(self.val) # <-- the signal I want to pass up
class Setting1(Setting):
def __init__(self, name):
super().__init__(name)
# not shown: create custom setting layout/interface
class Setting2(Setting):...
class Setting3(Setting):...
I use a lot of inheritance (SettingsGroup -> SettingsGroup1, 2, 3) because each subclass will have its own functions and internal dependencies that are unique to it. For each Setting subclass, for instance, there is a different user interface.
Thanks for any help provided!

EDIT: The question has been updated in the meantime, I've added a solution that's more specific at the bottom of this answer.
I feel like this question is slightly "opinion based", but since I've had my share of similar situations I'd like to propose my suggestions. In these situations it's important to understand that there's not one good way to do things, but many ways to do it wrong.
Original answer
An idea could be to create a common signal interface for every "level", which will get that signal and send it back to its parent by adding its own name to keep track of the setting "path"; the topmost widget will then evaluate the changes accordingly.
In this example every tab "group" has its own valueChanged signal, which includes the group name, setting name and value; the source signal is fired from the "source" (a spinbox, in this case), then it follows its parents which, in turn "add" their name in turn.
Keep in mind that you can also just use a generalized pyqtSignal(object) for every parent and connect it with widget.valueChanged.connect(self.valueChanged), and then track its group and setting by walking by self.sender() parents backwards.
As a final notice, if you are using these values for application settings, remember that Qt already provides the QSettings API, which can be used as a common and OS-transparent interface for every configuration you need to set (and remember between sessions) in your application. I implemented it in the example, but I suggest you to read its documentation to better understand how it works.
import sys
from PyQt5 import QtCore, QtWidgets
class SettingWidget(QtWidgets.QWidget):
valueChanged = QtCore.pyqtSignal(int)
def __init__(self, name):
super().__init__()
self.settings = QtCore.QSettings()
self.val = 0
self.name = name
layout = QtWidgets.QVBoxLayout()
self.setLayout(layout)
layout.addWidget(QtWidgets.QLabel(self.name))
self.spinBox = QtWidgets.QSpinBox()
layout.addWidget(self.spinBox)
self.spinBox.valueChanged.connect(self.set_val)
def set_val(self, new_val):
if self.val != new_val:
self.val = new_val
self.valueChanged.emit(self.val)
# enter a setting group, ensuring that same name settings won't
# be mismatched; this allows a single sub level setting only
self.settings.beginGroup(self.parent().name)
self.settings.setValue(self.name, new_val)
# leave the setting group. THIS IS IMPORTANT!!!
self.settings.endGroup()
class SettingWidget1(SettingWidget):
def __init__(self):
super().__init__('Setting1')
class SettingWidget2(SettingWidget):
def __init__(self):
super().__init__('Setting2')
class SettingWidget3(SettingWidget):
def __init__(self):
super().__init__('Setting3')
class SettingsGroup(QtWidgets.QWidget):
# create two signal signatures, the first sends the full "path",
# while the last will just send the value
valueChanged = QtCore.pyqtSignal([str, str, int], [int])
def __init__(self, name):
super().__init__()
self.name = name
layout = QtWidgets.QHBoxLayout()
self.setLayout(layout)
def add_to_group(self, new_setting):
widget = new_setting()
# emit both signal signatures
widget.valueChanged.connect(
lambda value, name=widget.name: self.valueChanged.emit(
self.name, name, value))
widget.valueChanged.connect(self.valueChanged[int])
self.layout().addWidget(widget)
class SettingsGroup1(SettingsGroup):
def __init__(self):
super().__init__('Group1')
self.add_to_group(SettingWidget1)
self.add_to_group(SettingWidget2)
class SettingsGroup2(SettingsGroup):
def __init__(self):
super().__init__('Group2')
self.add_to_group(SettingWidget3)
class TabWidget(QtWidgets.QTabWidget):
def __init__(self):
QtWidgets.QTabWidget.__init__(self)
self.settings = QtCore.QSettings()
self.tabs = [SettingsGroup1, SettingsGroup2]
self.settingsDict = {}
for tab in self.tabs:
widget = tab()
self.addTab(widget, widget.__class__.__name__)
widget.valueChanged[str, str, int].connect(self.valueChangedFullPath)
widget.valueChanged[int].connect(self.valueChangedOnly)
def valueChangedFullPath(self, group, setting, value):
# update the settings dict; if the group key doesn't exist, create it
try:
self.settingsDict[group][setting] = value
except:
self.settingsDict[group] = {setting: value}
settingsData = [group, setting, value]
print('Full path result: {}'.format(settingsData))
# Apply setting from here, instead of using the SettingWidget
# settings.setValue() option; this allows a single sub level only
# self.applySetting(data)
def valueChangedOnly(self, value):
parent = sender = self.sender()
# sender() returns the last signal sender, so we need to track down its
# source; keep in mind that this is *not* a suggested approach, as
# tracking the source might result in recursion if the sender's sender
# is not one of its children; this system also has issues if you're
# using a Qt.DirectConnection from a thread different from the one that
# emitted it
while parent.sender() in sender.children():
parent = sender.sender()
widgetPath = []
while parent not in self.children():
widgetPath.insert(0, parent)
parent = parent.parent()
settingsData = [w.name for w in widgetPath] + [value]
print('Single value result: {}'.format(settingsData))
# similar to valueChangedFullPath(), but with this implementation more
# nested "levels" can be used instead
# self.applySetting(settingsData)
def applySetting(self, settingsData):
# walk up to the next to last of settingsData levels, assuming they are
# all parent group section names
for count, group in enumerate(settingsData[:-2], 1):
self.settings.beginGroup(group)
# set the setting name settingsData[-2] to its value settingsData[-1]
self.settings.setValue(*settingsData[-2:])
for g in range(count):
self.settings.endGroup()
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
# set both Organization and Application name to make settings persistent
app.setOrganizationName('StackOverflow')
app.setApplicationName('Example')
w = TabWidget()
w.show()
sys.exit(app.exec_())
Alternate solution, based on updated answer
Since the answer has become more specific in its update, I'm adding another suggestion.
As far as we can understand now, you don't need that level of "nested" classes, but more specifically designed code that can be reused according to your purposes. Also, since you're using binary based data, it makes things a bit (pun intended) easier, as long as you know how bit operation works (which I assume you do) and the setting "widgets" don't require specific GUI customization.
In this example I created just one "setting" class and one "group" class, and their instancies are created only according to their names and default values.
import sys
from PyQt5 import QtCore, QtWidgets
defaultValues = '0010101', '1001010', '000111'
# set bit lengths for each setting; be careful in ensuring that each
# setting group has the full default value bit length!
groups = [
['Group 1', [1, 3, 2, 1]],
['Group 2', [1, 2, 2, 1, 1]],
['Group 1', [2, 1, 2, 1]],
]
class BinaryWidget(QtWidgets.QFrame):
changed = QtCore.pyqtSignal()
def __init__(self, name, index, defaults='0'):
QtWidgets.QFrame.__init__(self)
self.setFrameShape(self.StyledPanel|self.Sunken)
layout = QtWidgets.QGridLayout()
self.setLayout(layout)
self.index = index
self.defaults = defaults
self.buttons = []
# use the "defaults" length to create buttons
for i in range(len(defaults)):
value = int(defaults[i], 2) & 1
# I used QToolButtons as they're usually smaller than QPushButtons
btn = QtWidgets.QToolButton()
btn.setText(str(value))
layout.addWidget(btn, 1, i)
btn.setCheckable(True)
btn.setChecked(value)
btn.toggled.connect(self.changed)
# show the binary value on change, just for conveniency
btn.toggled.connect(lambda v, btn=btn: btn.setText(str(int(v))))
self.buttons.append(btn)
layout.addWidget(QtWidgets.QLabel(name), 0, 0, 1, layout.columnCount())
def value(self):
# return the correct value of all widget's buttons; they're reversed
# because of how bit shifting works
v = 0
for i, btn in enumerate(reversed(self.buttons)):
v += btn.isChecked() << i
# bit shift again, according to the actual "setting" bit index
return v << self.index
def resetValues(self):
oldValue = self.value()
self.blockSignals(True)
for i, value in enumerate(self.defaults):
self.buttons[i].setChecked(int(self.defaults[i], 2) & 1)
self.blockSignals(False)
newValue = self.value()
# emit the changed signal only once, and only if values actually changed
if oldValue != newValue:
self.changed.emit()
class Group(QtWidgets.QWidget):
changed = QtCore.pyqtSignal()
def __init__(self, name, defaults=None, lenghts=None):
QtWidgets.QWidget.__init__(self)
layout = QtWidgets.QHBoxLayout()
self.setLayout(layout)
self.name = name
self.bitLength = 0
self.widgets = []
if defaults is not None:
self.addOptions(defaults, lenghts)
def value(self):
v = 0
for widget in self.widgets:
v += widget.value()
return v
def addOption(self, name, index, default='0'):
widget = BinaryWidget(name, index, default)
self.layout().addWidget(widget)
self.widgets.append(widget)
widget.changed.connect(self.changed)
self.bitLength += len(default)
def addOptions(self, defaults, lenghts = None):
if lenghts is None:
lenghts = [1] * len(defaults)
# reverse bit order for per-setting indexing
defaultsIndex = 0
bitIndex = len(defaults)
for i, l in enumerate(lenghts):
self.addOption(
'Setting {}'.format(i + 1),
bitIndex - l,
defaults[defaultsIndex:defaultsIndex + l])
bitIndex -= l
defaultsIndex += l
def resetValues(self):
for widget in self.widgets:
widget.resetValues()
class Tester(QtWidgets.QWidget):
def __init__(self):
QtWidgets.QWidget.__init__(self)
layout = QtWidgets.QGridLayout()
self.setLayout(layout)
self.tabWidget = QtWidgets.QTabWidget()
layout.addWidget(self.tabWidget)
resultLayout = QtWidgets.QHBoxLayout()
layout.addLayout(resultLayout, layout.rowCount(), 0, 1, layout.columnCount())
self.tabs = []
self.labels = []
for (group, lenghts), defaults in zip(groups, defaultValues):
tab = Group(group, defaults, lenghts)
self.tabWidget.addTab(tab, group)
tab.changed.connect(self.updateResults)
self.tabs.append(tab)
tabLabel = QtWidgets.QLabel()
self.labels.append(tabLabel)
resultLayout.addWidget(tabLabel)
self.resetButton = QtWidgets.QPushButton('Reset values')
layout.addWidget(self.resetButton)
self.resetButton.clicked.connect(lambda: [tab.resetValues() for tab in self.tabs])
self.updateResults()
def values(self):
return [tab.value() for tab in self.tabs]
def updateResults(self):
for value, tab, label in zip(self.values(), self.tabs, self.labels):
label.setText('''
{0}: <span style="font-family:monospace;">{1} <b>{1:0{2}b}</b></span>
'''.format(tab.name, value, tab.bitLength))
if __name__ == '__main__':
app = QtWidgets.QApplication(sys.argv)
w = Tester()
w.show()
sys.exit(app.exec_())

If a list selection does not exist for filtered results then I would like to automatically highlight the first item. I created the method force_selection() that highlight's the first item if nothing is selected. I am using the QListView.selectionModel() to determine the selection index. I have tried connecting force_selection() to the QLineEdit slots: textEdited(QString) and textChanged(QString). However, it appears that there is a timing issue between textChanged and the proxy refreshing the QListView. Sometimes the selection is made while other times it disappears.
So how would I go about forcing a selection (blue highlight) during a proxy filter if the user has not made a selection yet? The idea behind my code is that the user searches for an item, the top item is the best result so it is selected (unless they manually select another item in the filter view).
You can find an image of the problem here.
Recreate issue:
Execute sample script with Python 2.7
Do not select anything in the list (QLineEdit should have focus)
Search for 'Red2', slowly type 'R', 'e', 'd' --> Red1 and Red2 are visible and Red1 is highlighted
Finish the search by typing the number '2' --> Red2 is no longer highlighted/selected
Final solution:
from PySide import QtCore
from PySide import QtGui
class SimpleListModel(QtCore.QAbstractListModel):
def __init__(self, contents):
super(SimpleListModel, self).__init__()
self.contents = contents
def rowCount(self, parent):
return len(self.contents)
def data(self, index, role):
if role == QtCore.Qt.DisplayRole:
return str(self.contents[index.row()])
class Window(QtGui.QWidget):
def __init__(self, parent=None):
super(Window, self).__init__(parent)
data = ['Red1', 'Red2', 'Blue', 'Yellow']
self.model = SimpleListModel(data)
self.view = QtGui.QListView(self)
self.proxy = QtGui.QSortFilterProxyModel(self)
self.proxy.setSourceModel(self.model)
self.proxy.setDynamicSortFilter(True)
self.proxy.setFilterCaseSensitivity(QtCore.Qt.CaseInsensitive)
self.view.setModel(self.proxy)
self.search = QtGui.QLineEdit(self)
self.search.setFocus()
layout = QtGui.QGridLayout()
layout.addWidget(self.search, 0, 0)
layout.addWidget(self.view, 1, 0)
self.setLayout(layout)
# Connect search to proxy model
self.connect(self.search, QtCore.SIGNAL('textChanged(QString)'),
self.proxy.setFilterFixedString)
# Moved after connect for self.proxy.setFilterFixedString
self.connect(self.search, QtCore.SIGNAL('textChanged(QString)'),
self.force_selection)
self.connect(self.search, QtCore.SIGNAL('returnPressed()'),
self.output_index)
# #QtCore.Slot(QtCore.QModelIndex)
#QtCore.Slot(str)
def force_selection(self, ignore):
""" If user has not made a selection, then automatically select top item.
"""
selection_model = self.view.selectionModel()
indexes = selection_model.selectedIndexes()
if not indexes:
index = self.proxy.index(0, 0)
selection_model.select(index, QtGui.QItemSelectionModel.Select)
def output_index(self):
print 'View Index:',self.view.currentIndex().row()
print 'Selected Model Current Index:',self.view.selectionModel().currentIndex()
print 'Selected Model Selected Index:',self.view.selectionModel().selectedIndexes()
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
window = Window()
window.show()
sys.exit(app.exec_())

The problem is the order of connect calls. You connect textChanged to force_selection first, so it's called first. But at that time, filter is not processed and proxy is not updated. So you select an item that might soon be removed by filtering.
Just switch the order of connect calls.
By the way, you might want to reconsider your logic in force_selection. currentIndex doesn't necessarily correspond to selected indexes. You can observe that by typing red2 and deleting 2. You'll get both Red1 and Red2 selected. If you want to deal with currentIndex use setCurrentIndex instead of select. If you want to deal with selected indexes, then your condition should be based on selectedRows or selectedIndexes.

I am creating a small app in python using PySide. I read lines from a text file and display each line in a separate QLineEdit Widget. Each "entry" has 2 line edits and 2 QPushButtons. For every line I add those widgets. My problem is that I set a signal-slot for the QPushButtons, but when all the "entries" are generated, only the last entries QPushButtons connects to the slot. May someone please help me.
Here is my code
class ItemLogger(QtGui.QMainWindow, Ui.Ui_MainWindow):
def __init__(self, parent = None):
super(ItemLogger, self).__init__(parent)
self.setupUi(self)
self.parseBossItem()
self.comboBox.currentIndexChanged.connect(self.parseBossItem)
self.increase.clicked.connect(self.add_subtract)
def add_subtract(self):
initial = 1
print "kajskasdjflsdkjflk"
def addRow(self, item):
self.frame = QtGui.QFrame()
self.layout = QtGui.QHBoxLayout()
self.itemName = QtGui.QLineEdit(item)
self.itemName.setReadOnly(True)
self.itemCount = QtGui.QLineEdit()
self.itemCount.setText("0")
self.itemCount.setMaximumWidth(40)
self.decrease = QtGui.QPushButton("-")
self.increase = QtGui.QPushButton("+")
self.layout.addWidget(self.itemName)
self.layout.addWidget(self.itemCount)
self.layout.addWidget(self.decrease)
self.layout.addWidget(self.increase)
self.frame.setLayout(self.layout)
self.verticalLayout_3.addWidget(self.frame)
def parseBossItem(self):
if self.comboBox.currentText() == "Item_1":
item_list = open("BossItems/Random_Item")
for line in item_list.readlines():
self.addRow(line)
if self.comboBox.currentText() == "Item_2":
item_list = open("BossItems/Random_Item_2")
for line in item_list.readlines():
self.addRow(line)

This is because you only connected the last entry.
Here is what you are actually doing:
You add row for item 1, and assign button widgets to self.decrease, self.increase.
You add row for item 2, replacing values of self.decrease, self.increase by newly created widgets.
You connect self.increase, which is now the last added widget.
If you don't need access to you widgets after their creation, you should consider using local variables (e.g. without self) and connecting the signal inside the addRow function.
If you need to keep track of widget references, then you could add them to an array:
# Somewhere in __init__ or in parseBossItem
self.increase = []
# in addRow
self.increase.append(QtGui.QPushButton("+"))
self.layout.addWidget(self.increase[-1])
self.increase[-1].clicked.connect(self.add_subtract)
# and so on...
To use the same slot form different senders, you need to identify who sent the signal. You could do something like this:
def onIncrease(self):
button = self.sender()
if isinstance(button, QtGui.QPushButton):
buttonName = button.text()
if buttonName == 'name of button 1':
self.itemCount[0].setText(str(int(self.itemCount[0])+1))
elif buttonName == 'name of button 2':
...
Off course, this is assuming you put each QLineEdit in the array self.itemCount.
Since all your buttons have the same name, we need to use another approach.
# in addRow
self.increase.clicked.connect(lambda: self.onIncrease(itemCount))
def onIncrease(self, edit):
edit.setText(str(int(edit.text()+1))

I wrote a simple program to print out all non-hidden files and subdirectories in a given directory.
I am now trying to migrate my code into a clist widget example I found on Google. Other than ripping out some unneeded buttons, all I changed was the top portion to integrate my code, and it partially works except that it only returns the first character of each file and subdirectory. So I expected this:
Desktop
Downloads
Scripts
textfile.txt
pron.avi
But instead got this:
D
D
S
t
p
Here is the example with the code I changed (really just the first def)
import gtk, os
class CListExample:
# this is the part Thraspic changed (other than safe deletions)
# User clicked the "Add List" button.
def button_add_clicked(self, data):
dirList=os.listdir("/usr/bin")
for item in dirList:
if item[0] != '.':
data.append(item)
data.sort()
return
def __init__(self):
self.flag = 0
window = gtk.Window(gtk.WINDOW_TOPLEVEL)
window.set_size_request(250,150)
window.set_title("GtkCList Example")
window.connect("destroy", gtk.mainquit)
vbox = gtk.VBox(gtk.FALSE, 5)
vbox.set_border_width(0)
window.add(vbox)
vbox.show()
scrolled_window = gtk.ScrolledWindow()
scrolled_window.set_policy(gtk.POLICY_AUTOMATIC, gtk.POLICY_ALWAYS)
vbox.pack_start(scrolled_window, gtk.TRUE, gtk.TRUE, 0)
scrolled_window.show()
clist = gtk.CList(1)
# What however is important, is that we set the column widths as
# they will never be right otherwise. Note that the columns are
# numbered from 0 and up (to an anynumber of columns).
clist.set_column_width(0, 150)
# Add the CList widget to the vertical box and show it.
scrolled_window.add(clist)
clist.show()
hbox = gtk.HBox(gtk.FALSE, 0)
vbox.pack_start(hbox, gtk.FALSE, gtk.TRUE, 0)
hbox.show()
button_add = gtk.Button("Add List")
hbox.pack_start(button_add, gtk.TRUE, gtk.TRUE, 0)
# Connect our callbacks to the three buttons
button_add.connect_object("clicked", self.button_add_clicked,
clist)
button_add.show()
# The interface is completely set up so we show the window and
# enter the gtk_main loop.
window.show()
def main():
gtk.mainloop()
return 0
if __name__ == "__main__":
CListExample()
main()

When you adding data to CList through append method, you must pass a sequence. Rewrite your code:
def button_add_clicked(self, data):
dirList = os.listdir("/usr/bin")
for item in dirList:
if not item.startswith('.'):
data.append([item])
data.sort()
When you creating CList instance you passes to the constructor number of collumns. In your example you created CList with one collumn, that's why you can see only first element (first character) of passed sequence in the append method.