[FIXED] Change text when button is clicked

Issue

I want to change the text on a button ( Start optimization ) to ( Cancel optimization ) when the text was clicked. So far I got:

class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
                
        layout = QGridLayout()
        layout.addLayout(self.optimize_button(), 1, 3, 1, 1)            
        
        widget = QWidget()
        widget.setLayout(layout)     
        self.setCentralWidget(widget)        


    # method for widgets
    def optimize_button(self):
        
        hbox = QHBoxLayout()  
        button = QPushButton("", self)
        button.setText("Start optimization")      
        button.setGeometry(200, 150, 100, 30)
        button.clicked.connect(self.clickme)    
        #self.push.clicked.connect(self.clickme)   
        hbox.addWidget(button)        
        self.show()        
        return hbox
  
    
    def clickme(self):
  
        print("pressed")
        self.button.setText("Cancel optimization")
        

I tried to make use out of https://www.geeksforgeeks.org/pyqt5-how-to-change-the-text-of-existing-push-button/ but it doesn't work. I guess the issue lays somewhere that clicking the button is calling clickme() which doesn't know anything about that button. But I don't know how to refer accordingly.

edit:

def clickme(self):

    print("pressed")
    self.button = QPushButton("", self)
    self.button.setText("Cancel optimization")  

is not working?

Solution

Option 1: Store it as a class member

A solution is to:

• Store the button as a class member during construction
• Change the button that is stored as class member.

So, your simplified example would become:

class MainWindow(QMainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
               
        hbox = QHBoxLayout()  
        self.button = QPushButton("", self) // (1) store the button as a class member
        button.setText("Start optimization")
        button.clicked.connect(self.clickme)    
        hbox.addWidget(button)        

        widget = QWidget()
        widget.setLayout(hbox)     
        self.setCentralWidget(widget)        

        self.show()        
    
    def clickme(self):
  
        print("pressed")
        self.button.setText("Cancel optimization") // (2) self.button is the button stored in (1)

Option 2: QObject::sender

As mentioned in the comments, using QObject::sender may be an alternative to obtain the clicked button inside clickme.

Answered By - m7913d