Develop Reference

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.

How can I print a QTableWidget by clicking on QPushButton

I have an interface with two tab: in the first one i ask the user to enter parameters and in the second one i want to print the following QTableWidget.
So basically on the first tab i have a QPushButton that i called process and normally, when i push on it , i want to send the information to the second Tab.
Right now i just tried to show a new window with the QTableWidget and the good parameters :
class Parameters(QWidget):
def __init__(self):
super(Parameters, self).__init__()
self.matrixsize = QLineEdit()
bouton = QPushButton("define matrix_size")
bouton.clicked.connect(self.appui_bouton)
self.halfmatrix = QCheckBox()
self.halfmatrix.toggled.connect(self.on_checked)
self.define_matrix_size = QGroupBox('Define Parameters')
layout = QGridLayout()
layout.addWidget(self.matrixsize, 0, 0, 1, 1, )
layout.addWidget(bouton, 0, 1, 1, 1)
layout.addWidget(QLabel('select half size mode'
), 1, 0, 1, 1)
layout.addWidget(self.halfmatrix, 1, 1, 1, 1)
self.define_matrix_size.setLayout(layout)
process = QPushButton('process')
process.clicked.connect(self.process)
self.matrix = QTableWidget()
self.layout = QGridLayout()
self.layout.addWidget(self.define_matrix_size)
self.layout.addWidget(matrix)
self.layout.addWidget(process)
self.setLayout(self.layout)
def matrix_size(self):
if self.matrixsize.text() == "":
return 0
else:
return int(self.matrixsize.text())
def appui_bouton(self):
taille = self.matrixsize()
self.matrix.deleteLater()
if self.halfmatrix.isChecked():
self.on_checked()
else:
self.matrix = QTableWidget()
self.matrix.setColumnCount(taille)
self.matrix.setRowCount(taille)
self.layout.addWidget(self.matrix)
self.update()
self.setLayout(self.layout)
def keyPressEvent(self, qKeyEvent):
print(qKeyEvent.key())
if qKeyEvent.key() == Qt.Key_Return or qKeyEvent.key() == Qt.Key_Enter:
self.appui_bouton()
else:
super().keyPressEvent(qKeyEvent)
def on_checked(self):
taille = self.matrixsize()
if taille == 0:
pass
else:
if self.halfmatrix.isChecked():
size = int(taille / 2)
self.matrix.deleteLater()
self.matrix = QTableWidget()
self.matrix.setColumnCount(size)
self.matrix.setRowCount(size)
self.layout.addWidget(self.matrix, 3, 0, 20, 4)
self.update()
self.setLayout(self.layout)
else:
self.appui_bouton()
def process (self):
layout = QHBoxLayout()
test = self.matrix
test.setLayout(layout)
test.show()
So in order to clarify what i said: i have a Window on which you get some parameters (size,...) , when you select those parameters, let's say you take matrixsize==5, then a 5x5 table is added to the window. This table can be after this fill by others parameters (i cut them on the code) by a system of drag and drop.
So now that i got a built table, i want to be able to open a new window with just the table by clicking on the ''process'' button.
So i don't want a dynamical table, i just want a table that keeps the same property (for instance if the matrix has dragonly enable then the new matrix should have the same) . I want to keep every information containing in the cells
I hope i am enoughly clear that is my first time asking questions (after many times reading some answers of course^^)
thanks for your answer and advice !

You can just create a new QTableWidget with no parent (which makes it a top level window), and then show it:
class Parameters(QWidget):
# ...
def process(self):
rows = self.matrix.rowCount()
columns = self.matrix.columnCount()
self.newTable = QTableWidget(rows, columns)
for row in range(rows):
for column in range(columns):
source = self.matrix.item(row, column)
if source:
self.newTable.setItem(row, column, QTableWidgetItem(source))
self.newTable.show()
Note that I created the new table as an instance attribute. This allows to avoid the garbage collection in case it was a local variable (resulting in the widget showing and disappearing right after), but has the unfortunate effect that if you click on the process button again and a window already exists, it gets deleted and "overwritten" with a new window. If you want to have more process windows at the same time, you could add them to a list:
class Parameters(QWidget):
def __init__(self):
super(Parameters, self).__init__()
# ...
self.processTables = []
def process(self):
rows = self.matrix.rowCount()
columns = self.matrix.columnCount()
# note that now "newTable" is *local*
newTable = QTableWidget(rows, columns)
self.processTables.append(newTable)
# ...
Some suggestions about your code:
there's absolutely no need to create a new table each time you want to change its size; just use setRowCount and setColumnCount on the existing one, and if you don't want to keep previous values, use clear();
don't use two functions that do almost the same things (appui_bouton and on_checked) and call each other, just use one function that checks for both aspects;
don't call update() unnecessarily: when you change the properties of a widget (or add a new widget to a layout) update is called already; while it's not an actual issue (Qt automatically manages when updates actually happen, avoiding repainting if not necessary), calling it just adds unnecessary noise to your code;
be more careful when adding widgets to a grid layout (I'm referring to the code on on_checked): don't use the rowSpan and columnSpan if not required; also, using a value that high is completely useless, as there are no other widgets in that row, and there's actually only one column in that layout; also, don't call setLayout() again;
if you need a numerical value, then use a QSpinBox, not a QLineEdit.
The function to update the existing table can be rewritten more easily, and you should connect both the button and the checkbox to it:
class Parameters(QWidget):
def __init__(self):
super(Parameters, self).__init__()
self.matrixsize = QSpinBox()
bouton = QPushButton("define matrix_size")
bouton.clicked.connect(self.appui_bouton)
self.halfmatrix = QCheckBox()
self.halfmatrix.toggled.connect(self.appui_bouton)
# ...
def appui_bouton(self):
taille = self.matrixsize.value()
if self.halfmatrix.isChecked():
taille //= 2
if not taille:
return
self.matrix.setColumnCount(taille)
self.matrix.setRowCount(taille)

Issue retrieving values from objects created by button function

I'm working on a small project and I'm having issues retrieving the values stored in combo boxes. The program has a "plus" button that creates additional boxes beneath the existing ones. They are created by calling a "create" function that makes a new instance of the ComboBox class, where the box is created and put onto the screen. A separate "submit" function is then supposed to loop through and retrieve all of the box values and store them in a list. My main flaw is that I used data in the variable names, but I have no clue how else to do this in this scenario. Does anyone have an alternative solution?
(there are some off screen variables that are show used here as parameters, but there are definitely not the source of the issue)
class ComboBox:
def __init__(self, master, counter, fields):
self.master = master
self.counter = counter
self.fields = fields
self.field_box = ttk.Combobox(width=20)
self.field_box["values"] = fields
self.field_box.grid(row=counter + 1, column=0, pady=5)
def get_value(self):
value = self.field_box.get()
return value
def create():
global entry_counter
name = "loop"+str(entry_counter-1)
name = ComboBox(window, entry_counter, fields)
values.append(name.get_value())
entry_counter += 1
def submit():
for i in range(1, entry_counter):
name = "loop" + str(entry_counter-1)
values.append(name.get_value())
For example, if I created 2 boxes and selected the options "test1" and "test2" I would want the my values list to contain ["test1, "test2"]

Not sure I understand the question right, but I guess you are asking about how to loop throw all instances of ComboBox. You can just create an global array, append new instance into it in create() method:
comboboxes = []
def create():
...
comboboxes.append(new_instance)
def submit():
for combobox in comboboxes:
...

You're on the right track with .get(). I believe your solution is that your get_value function also needs an event parameter:
def get_value(self, event):
value = self.field_box.get()
return value
See the following:
Getting the selected value from combobox in Tkinter
Retrieving and using a tkinter combobox selection

How to keep selected points on a ColumnDataSource object and deselect them with ResetTool?

I have plotted a circle glyph. When I select some points they are marked as selected. But I lose the selection when I change the tool I am using or when I click on some other place of the figure. Which is the best way to keep the selection on the circle glyph?. I want to deselect all the points when the ResetTool is pressed. I am working with the master (0.12.14+25.g675aacf72) branch of bokeh where the Selection class already exists.
def update_selection(self, attr, old, new):
''' I do this to avoid deselection '''
if new.indices == []:
self.source.selected.indices = self.old_selection
else:
self.old_selection = list(new.indices)
source.on_change(
'selected',
update_selection
)
I use this to call a callback when the Reset tool is pressed:
def deselect_points(self, event):
''' I do this to deselect point on Reset event
But when the indices are updated the update_selection method is called
'''
self.source.selected.indices = []
plot.on_event(Reset, deselect_points)
So is there a way to keep the selection and only deselect point on Reset event?
Update 03/14/2018
This is happening only when the Tap Tool is enabled. So I have written an issue on GitHub to check if this is the expected behaviour

Finally I made a workaround like this:
# [...]
self.reset_selection = False
# [...]
def _reset_lines(self, event):
# hide the glyphs which mark the selected points
self.lr.visible = False
self.lr_circle_selected.visible = False
self.lr.data_source.data = self.empty_source.data
self.lr_circle_selected.view = self.empty_view
self.reset_selection = True
def update_selection(self, attr, old, new):
if new.indices == []:
if not self.reset_selection:
new.indices = list(self.selection) # keep the selection
else:
self.reset_selection = False
self.selection = []
else:
self.selection = list(new.indices)
self.plot.on_event(Reset, self._reset_lines)
So I am going to use this in the mean time I don´t find anything better
Update
It seems that the issue is already closed. So I hope this is solved already

wxPython ListCtrl Column Ignores Specific Fields

I'm rewriting this post to clarify some things and provide a full class definition for the Virtual List I'm having trouble with. The class is defined like so:
from wx import ListCtrl, LC_REPORT, LC_VIRTUAL, LC_HRULES, LC_VRULES, \
EVT_LIST_COL_CLICK, EVT_LIST_CACHE_HINT, EVT_LIST_COL_RIGHT_CLICK, \
ImageList, IMAGE_LIST_SMALL, Menu, MenuItem, NewId, ITEM_CHECK, Frame, \
EVT_MENU
class VirtualList(ListCtrl):
def __init__(self, parent, datasource = None,
style = LC_REPORT | LC_VIRTUAL | LC_HRULES | LC_VRULES):
ListCtrl.__init__(self, parent, style = style)
self.columns = []
self.il = ImageList(16, 16)
self.Bind(EVT_LIST_CACHE_HINT, self.CheckCache)
self.Bind(EVT_LIST_COL_CLICK, self.OnSort)
if datasource is not None:
self.datasource = datasource
self.Bind(EVT_LIST_COL_RIGHT_CLICK, self.ShowAvailableColumns)
self.datasource.list = self
self.Populate()
def SetDatasource(self, datasource):
self.datasource = datasource
def CheckCache(self, event):
self.datasource.UpdateCache(event.GetCacheFrom(), event.GetCacheTo())
def OnGetItemText(self, item, col):
return self.datasource.GetItem(item, self.columns[col])
def OnGetItemImage(self, item):
return self.datasource.GetImg(item)
def OnSort(self, event):
self.datasource.SortByColumn(self.columns[event.Column])
self.Refresh()
def UpdateCount(self):
self.SetItemCount(self.datasource.GetCount())
def Populate(self):
self.UpdateCount()
self.datasource.MakeImgList(self.il)
self.SetImageList(self.il, IMAGE_LIST_SMALL)
self.ShowColumns()
def ShowColumns(self):
for col, (text, visible) in enumerate(self.datasource.GetColumnHeaders()):
if visible:
self.columns.append(text)
self.InsertColumn(col, text, width = -2)
def Filter(self, filter):
self.datasource.Filter(filter)
self.UpdateCount()
self.Refresh()
def ShowAvailableColumns(self, evt):
colMenu = Menu()
self.id2item = {}
for idx, (text, visible) in enumerate(self.datasource.columns):
id = NewId()
self.id2item[id] = (idx, visible, text)
item = MenuItem(colMenu, id, text, kind = ITEM_CHECK)
colMenu.AppendItem(item)
EVT_MENU(colMenu, id, self.ColumnToggle)
item.Check(visible)
Frame(self, -1).PopupMenu(colMenu)
colMenu.Destroy()
def ColumnToggle(self, evt):
toggled = self.id2item[evt.GetId()]
if toggled[1]:
idx = self.columns.index(toggled[2])
self.datasource.columns[toggled[0]] = (self.datasource.columns[toggled[0]][0], False)
self.DeleteColumn(idx)
self.columns.pop(idx)
else:
self.datasource.columns[toggled[0]] = (self.datasource.columns[toggled[0]][0], True)
idx = self.datasource.GetColumnHeaders().index((toggled[2], True))
self.columns.insert(idx, toggled[2])
self.InsertColumn(idx, toggled[2], width = -2)
self.datasource.SaveColumns()
I've added functions that allow for Column Toggling which facilitate my description of the issue I'm encountering. On the 3rd instance of this class in my application the Column at Index 1 will not display String values. Integer values are displayed properly. If I add print statements to my OnGetItemText method the values show up in my console properly. This behavior is not present in the first two instances of this class, and my class does not contain any type checking code with respect to value display.
It was suggested by someone on the wxPython users' group that I create a standalone sample that demonstrates this issue if I can. I'm working on that, but have not yet had time to create a sample that does not rely on database access. Any suggestions or advice would be most appreciated. I'm tearing my hair out on this one.

Are you building on the wxPython demo code for virtual list controls? There are a couple of bookkeeping things you need to do, like set the ItemCount property.
One comment about your OnGetItemText method: Since there's no other return statement, it will return None if data is None, so your test has no effect.
How about return data or "" instead?

There's a problem with the native object in Windows. If GetImg returns None instead of -1 the list has a problem with column 1 for some reason. That from Robin over on the Google Group post for this issue.