[FIXED] Group buttons to do the same thing when pressed

Issue

I have several plots that I want the user to evaluate with OK/NOK. How do I group all the OKs and NOKs such that when any of the OKs is pressed, the button turns green (or red when NOK is pressed). At the moment I have it for one button only.

 x_mean_ok = QPushButton("OK")
 x_mean_ok.setCheckable(True)
 x_mean_ok.setStyleSheet(":checked{ background-color: #6cdb53;}")

Also, when the user clicks OK and then NOK in the same plot then the OK button should "get" unselected again, so another grouping is needed. I assume I need QGroupBox for the latter but not quite sure how to put it all together. Here is a visual to get a better idea: Buttons:

I'm new to pyqt so the question probably has a trivial answer, I just don't seem to find it.

Solution

QGroupBox is only a visual container, it has nothing to do with the relation between buttons.

Well, almost: when adding radio buttons to the same parent (no matter if it's a QGroupBox, a QFrame, a plain QWidget, etc), they become automatically exclusive, since their autoExclusive property is enabled for QRadioButton, but that's not your case: even if you were setting the property for those buttons, you seem to need a state for which also no button could be checked, and exclusiveness doesn't allow that.

The simplest solution would be to create a function that returns the widgets grouped by a parent, with all the parameters and basic functions set:

def createButtons(self):
    def check_ok(state):
        if state:
            x_mean_ok.setChecked(False)
    x_mean_ok = QPushButton("OK")
    x_mean_ok.setCheckable(True)
    x_mean_ok.setStyleSheet(":checked{ background-color: #6cdb53;}")
    x_mean_nok = QPushButton("NOK")
    x_mean_nok.setCheckable(True)
    x_mean_nok.setStyleSheet(":checked{ background-color: red;}")
    x_mean_nok.toggled.connect(check_ok)

    layout = QtWidgets.QVBoxLayout()
    layout.addWidget(x_mean_ok)
    layout.addWidget(x_mean_nok)
    return layout, x_mean_ok, x_mean_nok

# ...
def somefunction(self):
    # create the plot...
    button_layout, x_mean_ok, x_mean_nok = self.createButtons()
    layout.addLayout(button_layout)
    # ...

Some considerations:

• To logically group buttons, you can use the QButtonGroup class.

• If you're adding many objects and plots, I'd suggest you to use a subclass for each group, and add a new instances everytime; this will make your code more cleaner and better organized.

• stylesheets support the property selector to differentiate widgets. You can set a property for those buttons and set a single stylesheet for the parent (or even the whole QApplication):

      def createButtons(self):
          x_mean_ok.setProperty("OK", True)
          x_mean_nok.setProperty("NOK", True)
          # ...
  
  app = QApplication(sys.argv)
  app.setStyleSheet('''
      QPushButton[OK="true"]:checked {
          background-color: #6cdb53;
      }
      QPushButton[NOK="true"]:checked {
         background-color: red;
      }
  ''')
  

Answered By - musicamante