Select all items in QListView and deselect all when directory is changed

I created a window like this The link! and when I select a directory I would like to select all items in the right Qlist, and when I change to a different directory, I would deselect the items in the previous directory and select all items in my current directory.

How can I approach this?

To select and deselect all items you must use selectAll() and clearSelection(), respectively. But the selection must be after the view that is updated and for this the layoutChanged signal is used, also the selection mode must be set to QAbstractItemView::MultiSelection.

import sys
from PyQt5 import QtCore, QtWidgets

class Widget(QtWidgets.QWidget):
    def __init__(self, *args, **kwargs):
        super(Widget, self).__init__(*args, **kwargs)
        hlay = QtWidgets.QHBoxLayout(self)
        self.treeview = QtWidgets.QTreeView()
        self.listview = QtWidgets.QListView()
        hlay.addWidget(self.treeview)
        hlay.addWidget(self.listview)

        path = QtCore.QDir.rootPath()

        self.dirModel = QtWidgets.QFileSystemModel(self)
        self.dirModel.setRootPath(QtCore.QDir.rootPath())
        self.dirModel.setFilter(QtCore.QDir.NoDotAndDotDot | QtCore.QDir.AllDirs)

        self.fileModel = QtWidgets.QFileSystemModel(self)
        self.fileModel.setFilter(QtCore.QDir.NoDotAndDotDot |  QtCore.QDir.Files)

        self.treeview.setModel(self.dirModel)
        self.listview.setModel(self.fileModel)

        self.treeview.setRootIndex(self.dirModel.index(path))
        self.listview.setRootIndex(self.fileModel.index(path))

        self.listview.setSelectionMode(QtWidgets.QAbstractItemView.MultiSelection)

        self.treeview.clicked.connect(self.on_clicked)
        self.fileModel.layoutChanged.connect(self.on_layoutChanged)

    @QtCore.pyqtSlot(QtCore.QModelIndex)
    def on_clicked(self, index):
        self.listview.clearSelection()
        path = self.dirModel.fileInfo(index).absoluteFilePath()
        self.listview.setRootIndex(self.fileModel.setRootPath(path))

    @QtCore.pyqtSlot()
    def on_layoutChanged(self):
        self.listview.selectAll()

if __name__ == '__main__':
    app = QtWidgets.QApplication(sys.argv)
    w = Widget()
    w.show()
    sys.exit(app.exec_())