def _session_preview_update(self):
        self.ui.plainTextEditNotes.setPlainText(self.session.preview_notes)

        for pv_client in self.session.preview_client_list:
            client_slot = self.ui.listWidgetPreview.create_client_widget(
                pv_client)
            client_slot.set_launched(
                pv_client.client_id in self.session.preview_started_clients)

        self.main_snap_group.snapshots.clear()
        self._add_snapshots(self.session.preview_snapshots)

        locale = QLocale()
        self.ui.labelSessionSize.setText(
            locale.formattedDataSize(self.session.preview_size))

        # store size in item
        item = self.ui.sessionList.currentItem()
        if item is not None:
            item.setData(COLUMN_NAME, DATA_SIZE, self.session.preview_size)
            self._set_preview_scripted(bool(item.text(COLUMN_SCRIPTS)))
        else:
            self._set_preview_scripted(False)

        self._update_session_menu()