login_frame.py

# TODO: complete it!

'''
Contains login-promt frame tkinter widget
'''

import tkinter as tk
from tkinter.ttk import Combobox


class LoginFrame(tk.Frame):
    '''
    A login-promt frame tkinter widget
    '''
    __strings = {'login':       'Login:',
                 'password':    'Password:',
                 'ok':          'OK',
                 'cancel':      'Cancel'
                 }
    
    __styles = {'login_label':      {'font': 'helvetica 11'},
                'login_combo':      {'font': 'helvetica 11'},
                'password_label':   {'font': 'helvetica 11'},
                'password_entry':   {'highlightthickness': 0,
                                     'font': 'helvetica 11'},
                'ok_button':        {'font': 'helvetica 11'},
                'cancel_button':    {'font': 'helvetica 11'}
                }
    
    def __init__(self, *args, users, hidden_users=None, hashfunc=None, command=None,
                 cancel_command=None, error_command=None, text=None, **kwargs):
        self.users = users
        self.hidden_users = hidden_users or []
        self.hashfunc = hashfunc or (lambda passw: passw)
        self.command = command or (lambda user: None)
        self.cancel_command = cancel_command or (lambda: None)
        self.error_command = error_command or (lambda user: None)
        if text is not None:
            self.__strings = dict(text)
        super().__init__(*args, **kwargs)
        self.__make_widgets()

    def __make_widgets(self):
        # create subframes
        login_frame = tk.Frame(self)
        login_frame.columnconfigure(1, weight=100)  # to make column expandable
        login_frame.rowconfigure(0, weight=100)
        login_frame.rowconfigure(1, weight=100)
        login_frame.pack(expand=True, fill='both')
        buttons_frame = tk.Frame(self)
        buttons_frame.pack(expand=True, fill='both', anchor='e')
        # login field
        login_label = tk.Label(login_frame, text=self.__strings['login'],
                               **self.__styles['login_label'])
        login_label.grid(row=0, column=0, sticky='W')
        displayed_users = sorted(set(self.users) - set(self.hidden_users))
        login_combo = Combobox(login_frame, values=displayed_users,
                               **self.__styles['login_combo'])
        login_combo.bind('<<ComboboxSelected>>',
                         lambda event: login_combo.selection_clear())
        login_combo.grid(row=0, column=1, columnspan=5, sticky='EW')
        self.get_login = login_combo.get
        # password field
        password_label = tk.Label(login_frame, text=self.__strings['password'],
                                  **self.__styles['password_label'])
        password_label.grid(row=1, column=0, sticky='W')
        password_entry = tk.Entry(login_frame, show='*',
                                  **self.__styles['password_entry'])
        password_entry.bind('<Return>', lambda event: self._ok_callback())
        password_entry.grid(row=1, column=1, columnspan=5, sticky='EW')
        self.get_password = password_entry.get
        # buttons
        ok_button = tk.Button(buttons_frame, text=self.__strings['ok'],
                              command=self._ok_callback,
                              **self.__styles['ok_button'])
        ok_button.pack(side='left', expand=True, anchor='w')
        cancel_button = tk.Button(buttons_frame, text=self.__strings['cancel'],
                              command=self._cancel_callback,
                              **self.__styles['cancel_button'])
        cancel_button.pack(side='right', expand=True, anchor='e')
        # add password field to self
        self.password_entry = password_entry

    def _ok_callback(self):
        login = self.get_login()
        passw = self.get_password()
        hashed = self.hashfunc(passw)
        if login in self.users and hashed==self.users[login]:
            self.command(login)
        else:
            self._login_error(login)

    def _cancel_callback(self):
        return self.cancel_command()

    def _login_error(self, login):
        self.password_entry.delete(0, 'end')
        return self.error_command(login)
        
        
        
        
if __name__ == '__main__':
    users = dict(Baboon='greatbaboon', Monkey='iammonkey', StupidMonkey='A-A-A',
                 thd='name')
    root = tk.Tk()
    fr = LoginFrame(root, users=users, hidden_users=['Monkey'],
                    command=lambda usr:print('User', usr, 'logged in ...'),
                    error_command=lambda usr:print('Error:', usr, '...'),
                    cancel_command=lambda: print('Exit requested ...') or fr.quit())
    fr.pack(side='bottom', expand=True, fill='both')
    tk.Label(root, text='ANOTHER LABEL', font='12').pack(side='top', anchor='w')
    root.mainloop()