Big number of pushbuttons and smart checking which is checked - python

I have dialog:
It contains many flat QPushButtons, QTextEdit and another QPushButton. After click on 'Get list' we can see list of checked buttons in QTextEdit.
My question is how to get this functionality in some smart way. Right now I'm checking every button:
if self.ui.bq6o.isChecked():
cards.append("Q6o")
if self.ui.bk2o.isChecked():
cards.append("K2o")
if self.ui.bq3o.isChecked():
cards.append("Q3o")
if self.ui.bt7s.isChecked():
cards.append("T7s")
if self.ui.bq4o.isChecked():
cards.append("Q4o")
if self.ui.bt4s.isChecked():
cards.append("T4s")
if self.ui.b98o.isChecked():
cards.append("98o")
if self.ui.bjto.isChecked():
cards.append("JTo")
if self.ui.btt.isChecked():
cards.append("TT")
if self.ui.bq7o.isChecked():
cards.append("Q7o")
[...]
Obviously I can't like code like that. I was looking for some widget "button matrix" like, but without luck. I will be grateful for advises.

All the buttons should be children of the same widget, probably the dialog itself. Just get a handle to that widget to get all the child buttons, then loop through them and if they're checked, included their text.
parent = dialog # or whatever
cards = [widget.text() for widget in parent.children() if isinstance(widget, QPushButton) and widget.isChecked()]
You may need to include some code in the if statement to exclude the "Get List" button, or any other pushbuttons in your dialog that could be set to "checked" but shouldn't be included in cards list.

As #Brendan suggested in the other question, you could loop through them in a single list comprehension. But one other approach is to connect each buttons toggled signal to a slot that allows them to register when they are checked.
# somewhere in your class
self.checkedList = set()
def buttonChecked(self, checked):
button = self.sender()
if checked:
self.checkedList.add(button)
else:
if button in self.checkedList:
self.checkedList.remove(button)
# when you create a new button
button.toggled.connect(self.buttonChecked)
This would let you always have a set of just the checked buttons, which are self reporting. Otherwise, you would have to track them under their parent and loop to find out which are checked each time.
Update
Here is a another version that combines #Brendans loop and my signal suggestion. This might help in a situation where your buttons are a bit more spread out across your UI as opposed to be all under a single parent... but first assuming them all under a parent...
parent = dialog
for widget in parent.children():
if isinstance(widget, QPushButton):
widget.toggled.connect(self.buttonChecked)
You could repeat this in your __init__() for all the locations of your buttons and get them all registered to the slot.

Related

Can I get a signal from a QGroupbox when one of the radiobuttons in it is changed?

I'm making a user-interface in PYQT 5. It includes a QGroupBox containing several QRadioButton. When there is a toggled event I check the buttons and do some stuff. The problem is that there are two toggled events because one button is toggled on and one off so my code is always running twice.
I have been looking for an event from the QGroupBox instead. That should only happen once instead of twice when i toggle a radiobutton.
def __init__(self):
self.radioButton1.toggled.connect(self.update_stimulus)
self.radioButton2.toggled.connect(self.update_stimulus)
self.radioButton3.toggled.connect(self.update_stimulus)
def update_stimulus(self):
if self.radioButton1.isChecked():
print('1')
if self.radioButton2.isChecked():
print('2')
if self.radioButton3.isChecked():
print('3')
# Do stuff based on button positions
I tried using
self.groupBox.toggled.connect(self.update_stimulus)
But that only works if the groupbox itself is toggled. Is there any way to get a signal from the groupbox when one of the radiobuttons changes or do I have to find some way of doing it with the indivdual signals from the radiobuttons?
As #ekhumoro explains, you can add the checked parameter to the function and do your processing only if it's True:
def update_stimulus(self, checked):
if not checked:
return
if self.radioButton1.isChecked():
print('1')
if self.radioButton2.isChecked():
print('2')
if self.radioButton3.isChecked():
print('3')
Keep in mind, though, that if you want to have different radio button "groups" within the same groupbox, none of this will work properly as they will all be considered as part of the same single group: all Qt buttons (widgets that inherit QAbstractButton: QPushButton, QToolButton, QCheckBox and QRadioButton) have an autoExclusive property which is off by default except from radio buttons. This property makes all button that belong to the same parent widget automatically exclusive.
If you need different groups within the same parent, the solution is to use a QButtonGroup, which extends the exclusive functionality by limiting the membership of each button to a specific group.
def __init__(self):
# ...
self.buttonGroupA = QtWidgets.QButtonGroup()
self.buttonGroupA.addButton(self.radioButton1)
self.buttonGroupA.addButton(self.radioButton2)
self.buttonGroupA.addButton(self.radioButton3)
self.buttonGroupA.buttonToggled[QtWidgets.QAbstractButton, bool].connect(self.update_stimulusA)
self.buttonGroupB = QtWidgets.QButtonGroup()
self.buttonGroupB.addButton(self.radioButton4)
self.buttonGroupB.addButton(self.radioButton5)
self.buttonGroupB.addButton(self.radioButton6)
self.buttonGroupB.buttonToggled[QtWidgets.QAbstractButton, bool].connect(self.update_stimulusB)
def update_stimulusA(self, btn, checked):
if not checked:
return
# do something with group A
def update_stimulusB(self, btn, checked):
if not checked:
return
# do something with group B
Creation of a button group is also possible from Designer: just select at least two buttons that will be members of the same group, right click on one of them, go to the "Assign to button group" sub menu and select "New button group". To add a button to an existing group, just use the same context menu and choose the group you want to add that button to.

PyQt - trigger an event when nothing is selected in a QListWidget?

I have an object of type QListWidget where the user can select 0 or more items.
If nothing is selected, how can i trigger an event that would call a function?
I know that you can detect clicking on a specific item by using:
QListWidget.itemClicked.connect(self.item_click)
Is there something similar for when nothing is selected at all? (or in other words, the QListWidget is clear)
Thanks!
Generally, you would connect to the itemSelectionChanged signal and then check whether anything is selected.
self.listwidget.itemSelectionChanged.connect(self.on_selection_changed)
def on_selection_changed(self):
if not self.listwidget.selectedItems():
# Do Stuff Here
self.nothing_selected_function()
But that will only catch events where something was selected and then the user deselected everything. If nothing was ever selected, it's not going to trigger this signal (like the first time you build the list, and nothing is selected). You'd have to call the slot manually in that case.
self.listwidget = ... # Code that builds and populates list widget
# Call this manually the first time.
self.on_selection_changed()
But part of your question is ambiguous. Why do you want to know when something is "not selected"? What about when a new item is added to the list? Should it trigger your "not selected" function since the list has changed, but there still isn't anything selected?

get widgets by name from layout

How should I proceed if I want to get an especific widget from a layout in python Qt?
What I have done so far:
for i in range(self.ui.horizontalLayout_14.count()):
#here it does fail
name = self.ui.horizontalLayout_14.itemAt(i).objectName()
#if the above would had worked, then I could do something like this for example
if "button" in name:
self.ui.horizontalLayout_14.itemAt(i).widget().close()
Note that, for the example, I am using button but It might be whatever widget inside the layout, lineEdit, or comboBox, labels, etc etc, but not all of them though.
The problem is that itemAt() function returns the QLayoutItem and not a widget. So you have to call the QLayoutItem::widget() function to get the containing widget, i.e.:
name = self.ui.horizontalLayout_14.itemAt(i).widget().objectName()
UPDATE
However, you can do the same much easier with using the QObject::findChild() function. I.e.:
widget = self.ui.findChild(QPushButton, "button")
# Check whether the returned widget is null...

Trying to make a collapsible widget: How to hide/unhide all child widgets?

Im making a simplish widget that can act as a container for other widgets. One of the features of the widget is that you can expand/collapse it by clicking on it. My current method is basically looking up all child widgets of the layout and hiding them. I'm looking for any help on how to handle this properly - my current implementation has at least one serious caveat: that you can't add widgets while it's collapsed (they're added in an 'unhidden' state)
heres the setCollapsed method that is run when the widget is clicked
def collapsed(self):
return self._isCollapsed
def setCollapsed(self, collapseBool):
self._isCollapsed = collapseBool
if self.layout()!=None:
childWidgets = [self.layout().itemAt(i).widget() for i in range(self.layout().count())]
for w in childWidgets:
if isinstance(w,QtGui.QWidget):
w.setHidden(collapseBool)
if collapseBool:
self._cachedMargin = self.layout().margin()
self.layout().setMargin(0)
else:
self.layout().setMargin(self._cachedMargin)
Rather than hiding all child widgets individually, I would just hide a single parent item.

How to get (childless) “tabs” in a pygtk application

I am facing the problem to need tabs in a pygtk app. Pretty much just like gedit has, but without any per-child widget content.
I’ve come across gtk.Notebook, but that requires me to put a widget for each tab, which I don't want.
The reason is, that I have one widget, but would only like to updates its content based on which tab is selected.
Any hints on how to do that?
My idea so far would be to just add some invisible widget for each tab and then connect to the select-page signal. Which widget could I use as invisible widget, or is there a better/alternative way of achieving my goal?
The invisble widget idea works. But not with gtk.Invisible (this just crashes), but with gtk.HBox() or any other thing that seems empty.
self.notebook.append_page(gtk.HBox(), gtk.Label("title"))
Now if I want to display stuff inside the tab actually, I can use reparent to move the widget to the current tab like this.
class Tab(gtk.HBox):
def __init__(self, child):
self.child = child
self.notebook.append_page(Tab(myWidget), gtk.Label("title"))
def pageSelected(self, notebook, page, pagenum):
box = notebook.get_nth_page(pagenum)
box.child.reparent(box)
You can have global widgets, one per tab as you want, in order to access them easily when the tab is selected.
self.notebook.append_page(self.rightBox, gtk.Label("Orders"))
Then connect to the "switch page" signal
self.notebook.connect("switch-page", self.pageSelected)
and :
def pageSelected(self, notebook, page, pagenum):
name = notebook.get_tab_label(notebook.get_nth_page(pagenum))
Now you have "name" with the label of the currently selected page. Just test it (if name == "Orders" ...) to interact.
Hope this was of some help !

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