Make QLabel clickable

Question

I have a Qlabel filled with QPixmap and I want to start a process/function once this label clicked. I had extended QLabel class as follows:

from PyQt5.QtCore import *
from PyQt5.QtWidgets import *
from PyQt5.QtGui import *

class QLabel_alterada(QLabel):
  clicked=pyqtSignal()
  def __init(self, parent):
    QLabel.__init__(self, QMouseEvent)

  def mousePressEvent(self, ev):
    self.clicked.emit()

Then, in my pyuic5-based .py file (I used QtDesigner to do the layout) after importing the module where I save the extended QLabel class, inside the automatically generated setupui, function I changed my Label from

self.label1=QtWidgets.QLabel(self.centralwidget)

to

self.label1 = QLABEL2.QLabel_alterada(self.centralwidget)

Finally, in the core app Python file where I put all the procedures/classes whetever needed to the application functionality I added

self.ui.label1.clicked.connect(self.dosomestuff) 

The application does not crashes but the labels still not clickable. Can someone give me some help on this?

Answer 1

I do not understand why you pass QMouseEvent to the parent constructor, you must pass the parent attribute as shown below:

class QLabel_alterada(QLabel):
    clicked=pyqtSignal()

    def mousePressEvent(self, ev):
        self.clicked.emit()

To avoid having problems with imports we can directly promote the widget as shown below:

We place a QLabel and right click and choose Promote to ...:

We get the following dialog and place the QLABEL2.h in header file and QLabel_changed in Promoted class Name, then press Add and Promote

Then we generate the .ui file with the help of pyuic. Obtaining the following structure:

├── main.py
├── QLABEL2.py
└── Ui_main.ui

Obtaining the following structure:

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        QtWidgets.QMainWindow.__init__(self, parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.ui.label.clicked.connect(self.dosomestuff) 

    def dosomestuff(self):
        print("click")


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

Answer 2

Since Python can pass function as object, I think make a class inherit QLabel only to make it clickable is overkill. Instead I do like this:

import sys

from PyQt5 import QtWidgets
from PyQt5.QtWidgets import QFrame, QLabel


def foo(*arg, **kwargs):
   print("Bar")


if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    Frame = QFrame()
    label = QLabel(Frame)
    label.mousePressEvent = foo
    label.setText("Label")
    Frame.show()
    sys.exit(app.exec_())