Content description:
In the current post, I create a GUI .
I define the main program window along with the menu bar, toolbar and search box.
I create methods to display all vehicles using a Treeview element, to remove a vehicle and to mark a car as sold.
The car_manager.py file contains the CarManager class. This is a class that inherits from the Frame class from the Tkinter library
When you create an instance of the CarManager class, an instance of the Helper class is created. Then the window name and application icon are set. A shortcut key for exiting the application has been set (Ctrl+x triggers the close_app() method).
def close_app(self, event):
result = tk.messagebox.askyesno('Exit', 'Close application?')
if result:
self.root.destroy()
The last two lines of the init() method run the methods for creating all widgets in the main window and displaying car data from the database
import tkinter as tk
from tkinter import messagebox, ttk
from sql_helper import Helper
from car import Car
from new_car import NewCarWindow
from repairs import RepairsWindow
from date_picker import DatePicker
class CarManager(tk.Frame):
def __init__(self, root):
super().__init__(root)
self.helper = Helper()
self.root = root
root.attributes('-zoomed', True)
root.title('Car manager')
root.iconphoto(True, tk.PhotoImage(file='Resources/car_logo.png'))
root.bind('<Control-x>', self.close_app)
root.columnconfigure(1, weight=1)
root.rowconfigure(2, weight=1)
self.create_widgets()
self.show_cars()
In the create widget() method, I made the menu bar with File option. I set up a toolbar with buttons for adding & removing a car, adding repair notes, and set-sold-car button.
Then I set up a search box that allows you to search for a car by registration number. The search box responds to gain/loss of focus and data commit events by pressing the ENTER key on the numeric or main keyboard.
I configure the TreeView with a scrollbar where the vehicle data will be displayed.
def create_widgets(self):
# create menu
menubar = tk.Menu(self.root)
self.root.config(menu=menubar)
file_menu = tk.Menu(menubar, tearoff=0)
file_menu.add_command(label='Exit', command=exit, accelerator="Ctrl+x")
menubar.add_cascade(label="File", menu=file_menu)
# create toolbar
tbar_frame = tk.Frame(root, height=10)
tbar_frame.grid(row=0, column=0)
self.add_car_img = tk.PhotoImage(file='Resources/add_car.gif')
self.remove_car_img = tk.PhotoImage(file='Resources/remove_car.gif')
self.repairs_img = tk.PhotoImage(file='Resources/repairs.gif')
self.sold_img = tk.PhotoImage(file='Resources/sold.gif')
add_car_button = tk.Button(tbar_frame, image=self.add_car_img,
command=self.add_car).grid(row=0, column=0, sticky='W')
del_car_button = tk.Button(tbar_frame, image=self.remove_car_img,
command=self.del_car).grid(row=0, column=0, sticky='W', padx=30)
repairs_button = tk.Button(tbar_frame, image=self.repairs_img,
command=self.show_repairs).grid(row=0, column=0, sticky='W', padx=60)
sold_button = tk.Button(tbar_frame, image=self.sold_img,
command=self.sell_car).grid(row=0, column=0, sticky='W', padx=90)
# create search entry
self.search_variable = tk.StringVar()
self.search_entry = tk.Entry(
root, textvariable=self.search_variable)
self.search_entry.config(fg='grey')
# search_variable.trace("w", callback)
self.search_variable.set("Search car by VRN")
self.search_entry.bind('<FocusIn>', self.on_entry_in)
self.search_entry.bind('<FocusOut>', self.on_entry_out)
self.search_entry.bind('<Return>', self.on_entry_return)
self.search_entry.bind('<KP_Enter>', self.on_entry_return)
self.search_entry.grid(row=0, column=1, sticky='E', ipadx=20)
# create TreeView with Scrollbar
col_headers = ('No', 'Make', 'Model', 'Year', 'VRN', 'VIN', 'Sold')
self.car_tview = ttk.Treeview(self.root, columns=col_headers,
show='headings', selectmode='browse')
self.car_tview.columnconfigure(0, weight=1)
self.car_tview.rowconfigure(0, weight=1)
# set column headers
for i, col in enumerate(col_headers):
self.car_tview.heading(col, text=col)
self.car_tview.column(col, anchor='center')
if i == 0:
self.car_tview.column(col, width=50, stretch='NO')
self.car_tview.grid(row=2, column=0, columnspan=2, sticky='NSWE')
scrollbar = tk.Scrollbar(self.root, command=self.car_tview.yview)
scrollbar.grid(column=3, row=2, sticky='NS')
Methods that handle events initiated by interface elements:
First, I will describe a method that displays all saved vehicles.
First, the TreeView is stripped of all previous entries and then repopulated with all entries. To make it easier to distinguish the lines, they are colored differently.
def show_cars(self):
all_cars = self.helper.show_all_cars()
self.car_tview.delete(*self.car_tview.get_children())
for i, car in enumerate(all_cars, start=1):
car = list(car)
car.insert(0, i)
if i % 2:
self.car_tview.insert('', 'end', values=car, tag='c2')
else:
self.car_tview.insert('', 'end', values=car, tag='c1')
self.car_tview.tag_configure('c1', background='ivory3')
self.car_tview.tag_configure('c2', background='ivory2')
I extract a private method: __get_car_from_selection() which returns an instance of the Car class based on the selected row:
def __get_car_from_selection(self):
selected_item = self.car_tview.focus()
if selected_item == '':
messagebox.showinfo('Information', 'No item selected')
else:
selection_dict = self.car_tview.item(selected_item)
selection = selection_dict.get('values')
i, *args = selection
car = Car.from_list(args)
return car
The del_car() method removes an existing vehicle from the database if the user confirms the deletion in the dialog box.
def del_car(self):
car = self.__get_car_from_selection()
if car and messagebox.askyesno('Delete', 'Delete selected car?'):
self.helper.del_car(car)
self.show_cars()
The sell_car() method marks an existing vehicle as sold. If the car has already been marked as sold, a message will be displayed. Otherwise, a sales confirmation window will appear. Once the user accepts the selection, the vehicle will be marked as sold and the list of all vehicles will be updated.
def sell_car(self):
car = self.__get_car_from_selection()
if car and car.sold:
messagebox.showinfo('Information', 'Already marked as sold')
elif car and messagebox.askyesno('Sell', 'Mark car as sold?'):
self.helper.set_sold(car)
self.show_cars()
In the next post, I'll add the remaining CRUD methods and describe how to create child windows.