How to detect the child widget destroy?

GOAL

To do some functions when the child widget is deleted.

Environment

Windows 10
Python 3.8.7
PySide2 5.15.2

Method

Connect the function to child’s signal “destroyed” as below.

import sys
from PySide2.QtWidgets import *

class ItemWidget(QWidget):
    def __init__(self, id_str="", parent=None):
        super(ItemWidget, self).__init__(parent)
        self._generateUI()
    def _generateUI(self):
        main_layout = QGridLayout()
        self.setLayout(main_layout)
        title = QLabel("title")
        main_layout.addWidget(title, 0, 0, 1, 3)
        close_button = QPushButton("×")
        close_button.setFixedWidth(30)
        close_button.clicked.connect(self._close_widget)
        main_layout.addWidget(close_button, 0, 3, 1, 1)
    def _close_widget(self):
        self.deleteLater()

class MyMainWindow(QMainWindow):
    def __init__(self, parent=None):
        super(MyMainWindow, self).__init__(parent)
        self._generateUI()
    def _generateUI(self):
        main_widget = QWidget()
        self.main_layout = QVBoxLayout()
        main_widget.setLayout(self.main_layout)
        self.setCentralWidget(main_widget)
        item = ItemWidget(str(self.id_num))
        item.destroyed.connect(self._deletedItemFunc) # connect the function to execute
        self.main_layout.addWidget(item)
    def _deletedItemFunc(self):
        print("deleted") # when the item deleted, the message "deleted" is displayed

def launch():
    app = QApplication.instance()
    if not app:
        app = QApplication(sys.argv)
    widget = MyMainWindow()
    widget.show()
    app.exec_()

launch()

When click × button, the child widget deleted and the message “deleted” is displayed.

Appendix

If the child is removed from the parent layout. You can add function at the same time.

self.main_layout.removeWIdget(item)
self._deletedItemFunc()

How To Insert Widget To The Layout Counting From The End

GOAL

To insert widget to the layout counting from the end. For example, I’d like to create the add button to add widget at the second position from the end as below.