add function to delete user

src/ui/user.py

@@ -29,6 +29,8 @@ class UserUI(QtWidgets.QMainWindow, Ui_MainWindow):
         self.btn_userChange_save.clicked.connect(self.saveChanges)
         self.btn_userchange_cancel.clicked.connect(self.discardChanges)
         self.btn_extendSelectedMedia.clicked.connect(self.extendLoan)
+        self.deleteUser.clicked.connect(self.userDelete)
+        self.deleteUser.setIcon(Icon("delete").overwriteColor("red"))
 
         # radioButtons
         self.radio_allLoanedMedia.clicked.connect(self.loadMedia)
@@ -54,6 +56,16 @@ class UserUI(QtWidgets.QMainWindow, Ui_MainWindow):
 
         self.show()
 
+    def userDelete(self):
+        self.db.deleteUser(self.userno)
+        dialog = QtWidgets.QMessageBox()
+        dialog.setIcon(QtWidgets.QMessageBox.Icon.Information)
+        dialog.setWindowIcon(Icon("delete").icon)
+        dialog.setText("Nutzer wurde gelöscht")
+        dialog.setWindowTitle("Nutzer gelöscht")
+        dialog.exec()
+        self.close()
+
     def extendLoan(self):
         extend = ExtendLoan(self.username, self.userMedia)
         extend.exec()