# tkinter ## Tkinter helloworld The absolute most basic way to have a *hello world* GUI program up and running with Tkinter is the following. ```python from tkinter import * root = Tk() MyLabel = Label(root,text="hello world") MyLabel.pack() root.mainloop() ``` Tkinter have two popular architectures, the Tcl and Tk. This two architectures are different, they have their own functionality and their own official documentation. We are gonna use the Tk architecture. The Tk architecture is used to create a GUI widget. He adds a lot of custom commands, so the widget is very customizable. In the previous code,the `mainloop()` instruction allows us to open the main window and to not close immediately the window. And then, the `Label()` method creates label in a layout. This method has many parameters to customize a label. The instruction `pack()` will be always call , this instruction can add and adjust a widget. While it works we know better by now. We should include the `if __name__ == "__main__"` statement. ```python from tkinter import * if __name__ == "__main__": root = Tk() MyLabel = Label(root,text="hello world") MyLabel.pack() root.mainloop() ``` The instance of `Tk()` is what will actually process our event loop and the `root` is the content of our window. We can customize `root` with instruction like geometry, title,etc. In the latter we will create our button and labels so should create our own class and inherit from it. ```python from tkinter import * class MainWindow(Frame): def __init__(self): Label.__init__(self, text="hello world") self.pack() if __name__ == "__main__": root = Tk() root.title("title of the window") root.geometry("500x300") MainWindow() root.mainloop() ``` We can add content to the *frame*, such as labels, input boxes and buttons as follows. ```python from tkinter import * class MainWindow(Frame): def __init__(self): Label.__init__(self, text="hello world") #Label MyLabel = Label(self, text="This is a label") MyLabel.pack() self.config(bg="yellow") self.pack() if __name__ == "__main__": root = Tk() root.title("title of the window") root.geometry("500x300") MainWindow() root.mainloop() ``` Let's try to put multiple visual object into the same frame. ```python3 from tkinter import * class MainWindow(Frame): def __init__(self): Label.__init__(self, text="hello world") #Label MyLabel = Label(self, text="This is a label") MyLabel.pack() #Button MyButton = Button(self, text="I'm clickable!") MyButton.pack() self.config(bg="yellow") self.pack() if __name__ == "__main__": root = Tk() root.title("title of the window") root.geometry("500x300") MainWindow() root.mainloop() ``` You see how they are *stacked* one on top of the other? We can overcome this problem with parameters of [pack()](https://wxpython.org/Phoenix/docs/html/sizers_overview.html). We can also use other geometry managers like [grid()](https://www.pythontutorial.net/tkinter/tkinter-grid/) and [place()](https://www.pythontutorial.net/tkinter/tkinter-place/). ```python from tkinter import * class MainWindow(Frame): def __init__(self): Frame.__init__(self, master=None) MyPanel = PanedWindow.__init__(self, bg="Blue") #Label MyLabel = Label(MyPanel, text="this is a label", bg= "yellow") MyLabel.pack(fill="x") #Bouton MyButton = Button(MyPanel, text="I'm clickable!") MyButton.place(x=10, y=50) self.pack(fill=BOTH,expand=True) if __name__ == "__main__": root = Tk() root.title("this is the title of the window") root.geometry("500x300") win = MainWindow() root.mainloop() ``` This is looking better! But it requires some explanation though. Let's break it down. The `Frame.__init__` is your **window** in which you create a `PanedWindow.__init__` which is used to draw thing to. To this panel you're adding two different *objects* (`Label()` and `Button()`) each with or without their own settings (such as a label or not). It probably looks a bit convoluted but this is how most GUI libraries work internally. 1. You create a frame 2. Within this frame you create a *drawing area* and set some form of automatic layout to it. 3. You create the visual elements you want and add them one by one to the drawing area. 4. Success Now how do we link **user input** to **code actions**? This is a complicated way of saying *actually do something when I click the damn button*! For this we'll need to create a function, or better yet a method to the `Frame.__init__` objects. Each time we click the button, that method will be called. Because it is a *method* it has access to *self* so it can modify *anything* within the scope of the instance. ```python from tkinter import * class MainWindow(Frame): def __init__(self): Frame.__init__(self, master=None) MyPanel = PanedWindow.__init__(self, bg="Blue") #Label MyLabel = Label(MyPanel, text="this is a label", bg= "yellow") MyLabel.pack(fill="x") #Bouton MyButton = Button(MyPanel, text="I'm clickable!", command=lambda : self.ButtonEnable(MyLabel)) MyButton.place(x=10, y=50) self.pack(fill=BOTH,expand=True) def ButtonEnable(self, Label): global number number += 1 counter = "You have press the button {} time".format(number) Label.config(text=counter) number=0 if __name__ == "__main__": root = Tk() root.title("this is the title of the window") root.geometry("500x300") win = MainWindow() root.mainloop() ``` We can use the same *idea* to grab input from the textbox. ```python from tkinter import * class MainWindow(Frame): def __init__(self): Frame.__init__(self, master=None) MyPanel = PanedWindow.__init__(self, bg="Blue") #Label MyLabel = Label(MyPanel, text="this is a label", bg= "yellow") MyLabel.pack(fill="x") #TextBox MyEntry = Entry(MyPanel) MyEntry.place(x=200,y=50) #Bouton MyButton = Button(MyPanel, text="I'm clickable!", command=lambda : self.ButtonEnable(MyLabel,MyEntry)) MyButton.place(x=10, y=50) self.pack(fill=BOTH,expand=True) def ButtonEnable(self, MyLabel, MyEntry): MyText = MyEntry.get() MyLabel.config(text=MyText) if __name__ == "__main__": root = Tk() root.title("this is the title of the window") root.geometry("500x300") win = MainWindow() root.mainloop() ``` ## Tkinter guess the number ```python import time from tkinter import * import random class MainWindow(Frame): def __init__(self): Frame.__init__(self, master=None, bg="white") MyPanel = PanedWindow.__init__(self) MyNumber = random.randint(0, 100) #Label self.MyLabel = Label(MyPanel, text="I have a number in mind...", bg= "blue") self.MyLabel.pack(fill="x", ipadx=25, ipady=20) #TextBox MyEntry = Entry(MyPanel) MyEntry.place(x=200,y=90) #Bouton MyButton = Button(MyPanel, text="I'm clickable!", command=lambda : self.ButtonEnable(MyEntry, MyNumber)) MyButton.place(x=10, y=90) self.pack(fill=BOTH,expand=True) def ButtonEnable(self, MyEntry, MyNumber): if self.IsCorrect(MyEntry.get()): number = int(MyEntry.get()) if number != MyNumber: self.GameOver(number, MyNumber) else: self.Win() else: self.MyLabel.config(text="I need numbers!") def GameOver(self, number, MyNumber): if number > MyNumber: self.MyLabel.config(text="My number is smaller") else: self.MyLabel.config(text="My number is bigger") def Win(self): self.MyLabel.config(text="You WIN!") def IsCorrect(self, MyEntry): x = str(MyEntry) if x.isdigit() == True: return True else: return False if __name__ == "__main__": root = Tk() root.title("Guess the number") root.geometry("500x300") win = MainWindow() root.mainloop() ``` ## MVC design pattern A simple console only MVC. We'll add the GUI view in a bit. ```python from tkinter import * class ConsoleView(object): """A view for console.""" def select_task(self): """Asks which index to look up.""" idx = input("which task do you want to see? ") return idx def show(self, task): """Displays the task to the console. This method is called from the controller.""" print("your task: {}".format(task)) def error(self, msg): """Prints error messages coming from the controller.""" print("error: {}".format(msg)) class Model(object): """The model houses add data and should implement all methods related to adding, modifying and deleting tasks.""" db = ["go to the shops", "dryhop beer", "drop of motorbike"] def get_task(self, idx): """Performs a task lookun into the database and returns it when found. If no task is found, it returns an error message that will be displayed in the view (via the controller).""" try: task = Model.db[idx] except IndexError: task = "task with {} not found!".format(idx) return task class Controller(object): """Binds the model and the view together.""" def __init__(self, view): self.model = Model() self.view = view def run(self): """The controller's main function. Depending on what type of view is selected, a different event loop is setup. Do note that the ConsoleView is not a real event loop, just a basic flow of action.""" if self.view is ConsoleView: self.view = self.view() self._run_console_view() elif self.view is TkinterView: root = Tk() root.title("Task Manager") root.geometry("500x300") self.view = self.view() self.view._set_controller(self) root.mainloop() def get_task_from_model(self, idx): """Needed for the TkinterView to communicate with the controller.""" task = self.model.get_task(idx) self.view.show_task(task) def _run_console_view(self): """Super simple event loop.""" while True: try: idx = self.view.select_task() idx = int(idx) except Exception as e: self.view.error(e) continue task = self.model.get_task(idx) self.view.show(task) if __name__ == "__main__": view = ConsoleView app = Controller(view) app.run() ``` And now with the implemented `TkinterView` class. ```python from tkinter import * class ConsoleView(object): """A view for console.""" def select_task(self): """Asks which index to look up.""" idx = input("which task do you want to see? ") return idx def show(self, task): """Displays the task to the console. This method is called from the controller.""" print("your task: {}".format(task)) def error(self, msg): """Prints error messages coming from the controller.""" print("error: {}".format(msg)) class TkinterView(Frame): """A view using a wx.Dialog window""" def __init__(self): Frame.__init__(self, master=None) #Panel self.panel = PanedWindow(self, bg="green") self.panel.pack(fill=BOTH, expand=True) #Task Label self.task = Label(self.panel, text="your task") self.task.pack(expand=True) #SpinBox self.idx = Spinbox(self.panel, from_=0, to=2, wrap=True ) self.idx.pack(side= TOP) #Button self.button = Button(self.panel, text="submit", command=lambda : self.select_task()) self.button.pack(ipadx=60, ipady=30) self.pack(fill=BOTH, expand=True) def _set_controller(self, controller): """Set the controller so the view can communicate it's requests to it and update it's values too.""" self.controller = controller def select_task(self): """Gets the index to look up in the model and submits the request to the controller.""" idx = self.idx.get() self.controller.get_task_from_model(idx) def show_task(self, task): """Updates the visual label in the view with the task. This method is called from the controller.""" self.task.config(text=task) class Model(object): """The model houses add data and should implement all methods related to adding, modifying and deleting tasks.""" db = ["go to the shops", "dryhop beer", "drop of motorbike"] def get_task(self, idx): """Performs a task lookun into the database and returns it when found. If no task is found, it returns an error message that will be displayed in the view (via the controller).""" try: task = Model.db[int(idx)] except IndexError: task = "task with {} not found!".format(idx) return task class Controller(object): """Binds the model and the view together.""" def __init__(self, view): self.model = Model() self.view = view def run(self): """The controller's main function. Depending on what type of view is selected, a different event loop is setup. Do note that the ConsoleView is not a real event loop, just a basic flow of action.""" if self.view is ConsoleView: self.view = self.view() self._run_console_view() elif self.view is TkinterView: root = Tk() root.title("Task Manager") root.geometry("500x300") self.view = self.view() self.view._set_controller(self) root.mainloop() def get_task_from_model(self, idx): """Needed for the TkinterView to communicate with the controller.""" task = self.model.get_task(idx) self.view.show_task(task) def _run_console_view(self): """Super simple event loop.""" while True: try: idx = self.view.select_task() idx = int(idx) except Exception as e: self.view.error(e) continue task = self.model.get_task(idx) self.view.show(task) if __name__ == "__main__": view = TkinterView app = Controller(view) app.run() ``` For a GUI only login generator an implementation without MVC could look a bit like this. Note that the actual calculation is done inside the window itself. This is not a good idea because we should separate responsibilities into classes! ```python from tkinter import * from tkinter import ttk import login_generator class MainWindow(Frame): def __init__(self): Frame.__init__(self) self.full_window = PanedWindow(self,orient=VERTICAL) self.full_window.pack(fill=BOTH,expand=True) self.create_top_panel() self.create_bottom_panel() self.pack(fill=BOTH, expand=True) def create_bottom_panel(self): bottom_panel = PanedWindow(self.full_window, bg="green") bottom_panel.pack(fill=BOTH, side=BOTTOM) #List self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6) self.login_list.pack() self.login_list.heading("username", text="Username") self.login_list.heading("password", text="Password") self.login_list.bind("", lambda e: self.show_popup()) def create_top_panel(self): top_panel = PanedWindow(self.full_window, bg="red") self.login_amount = Text(top_panel, height=5, width=52) self.login_amount.place(x=10,y=10) self.complex = BooleanVar() self.complex.set(False) self.login_complex = Checkbutton(top_panel, text="complex",var=self.complex) self.login_complex.place(x=10,y=100) self.login_create = Button(top_panel, text="Create", command=lambda: self.add_login()) self.login_create.place(x=100,y=100) top_panel.pack(expand=True, fill=BOTH) def show_popup(self): global root menu = Menu() menu.add_command(label="Copy selected items", command=lambda : self.copy_items()) root.config(menu=menu) def copy_items(self): global root try: Item = self.login_list.item(self.login_list.focus()) FunctionValue = Item.values() Array = list(FunctionValue) Login = Array[2] self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0],Login[1])) except: Msg = Toplevel(root) l1 = Label(Msg, text="You have to take something") l1.pack(fill=BOTH, expand=True) def add_login(self): self.username = login_generator.generate_username() self.password = login_generator.generate_password(12,self.complex.get()) self.login_list.insert('', END,values=[self.username, self.password]) if __name__ == "__main__": root = Tk() root.title("Login Generator") root.geometry("500x300") win = MainWindow() root.mainloop() ``` Now let's assume the generate username and password function take some calculation time. We'll add in a fake `time.sleep` to simulate. ```python from tkinter import * from tkinter import ttk import login_generator import time class MainWindow(Frame): def __init__(self): Frame.__init__(self) self.full_window = PanedWindow(self,orient=VERTICAL) self.full_window.pack(fill=BOTH,expand=True) self.create_top_panel() self.create_bottom_panel() self.pack(fill=BOTH, expand=True) def create_bottom_panel(self): bottom_panel = PanedWindow(self.full_window, bg="green") bottom_panel.pack(fill=BOTH, side=BOTTOM) #List self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6) self.login_list.pack() self.login_list.heading("username", text="Username") self.login_list.heading("password", text="Password") self.login_list.bind("", lambda e: self.show_popup()) def create_top_panel(self): top_panel = PanedWindow(self.full_window, bg="red") self.login_amount = Text(top_panel, height=5, width=52) self.login_amount.place(x=10,y=10) self.complex = BooleanVar() self.complex.set(False) self.login_complex = Checkbutton(top_panel, text="complex",var=self.complex) self.login_complex.place(x=10,y=100) self.login_create = Button(top_panel, text="Create", command=lambda: self.add_login()) self.login_create.place(x=100,y=100) top_panel.pack(expand=True, fill=BOTH) def show_popup(self): global root menu = Menu() menu.add_command(label="Copy selected items", command=lambda : self.copy_items()) root.config(menu=menu) def copy_items(self): global root try: Item = self.login_list.item(self.login_list.focus()) FunctionValue = Item.values() Array = list(FunctionValue) Login = Array[2] self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0],Login[1])) time.sleep(1) except: Msg = Toplevel(root) l1 = Label(Msg, text="You have to take something") l1.pack(fill=BOTH, expand=True) def add_login(self): self.username = login_generator.generate_username() self.password = login_generator.generate_password(12,self.complex.get()) self.login_list.insert('', END,values=[self.username, self.password]) if __name__ == "__main__": root = Tk() root.title("Login Generator") root.geometry("500x300") win = MainWindow() root.mainloop() ``` A clear separation of responsabilities can be acchieved via an MVC pattern and a login *library*. The library code is quite straightforward and goes as follows. It's basically the same code we did before but with added `try except` blocks. Can you tell me why I added those? ```python import random import string def load_file(filename): """ We load a file and make a list out of it. Note that the same function is used for both files (both adjectives and subjects). Functions should be made as generic as possible. There IS a problem you can fix, some logins will have spaces in them. Try to remove them in this function! """ words = [] with open(filename, "r") as fp: lines = fp.readlines() for line in lines: words.append(line.strip()) # what does strip() do, what does append() do? remember CTRL+Q! return words def generate_username(): """ We'll generate a random pair of adjectives and subjects from two wordlists. You NEED to have both files in you python project for this to work! Note the capitalize method call to make it all prettier... """ try: adjectives = load_file("./adjectives.txt") except: adjectives = ["big", "funny", "normal", "red"] try: subjects = load_file("./subjects.txt") except: subjects = ["giraffe", "elephant", "cougar", "tiger"] adjective = random.choice(adjectives) subject = random.choice(subjects) username = adjective.capitalize() + subject.capitalize() return username def generate_password(length=10, complictated=True): """ We generate a password with default settings. You can overide these by changing the arguments in the function call. """ password = "" if complictated: chars = string.ascii_letters + string.digits + string.punctuation else: chars = string.ascii_letters for i in range(0, length): password += random.choice(chars) return password if __name__ == "__main__": # let's do some testing! username_test = generate_username() print(username_test) password_test = generate_password() print(password_test) ``` And now the GUI code nicely split up in a **model**, **controller** and a **view**. The overhead is quite large but it makes the code a lot more scalable. ```python from tkinter import * from tkinter import ttk import login_generator import time import threading import queue class View(Frame): def __init__(self, controller): Frame.__init__(self) self.controller = controller self.full_window = PanedWindow(self, orient=VERTICAL) self.full_window.pack(fill=BOTH, expand=True) self.create_top_panel() self.create_bottom_panel() self.pack(fill=BOTH, expand=True) def create_bottom_panel(self): bottom_panel = PanedWindow(self.full_window, bg="green") bottom_panel.pack(fill=BOTH, side=BOTTOM) # List self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6) self.login_list.pack() self.login_list.heading("username", text="Username") self.login_list.heading("password", text="Password") self.login_list.bind("", lambda e: self.show_popup()) def create_top_panel(self): top_panel = PanedWindow(self.full_window, bg="red") self.login_amount = Text(top_panel, height=5, width=52) self.login_amount.place(x=10, y=10) self.complex = BooleanVar() self.complex.set(False) self.login_complex = Checkbutton(top_panel, text="complex", var=self.complex) self.login_complex.place(x=10, y=100) self.login_create = Button(top_panel, text="Create", command=lambda: self.submit_request()) self.login_create.place(x=100, y=100) top_panel.pack(expand=True, fill=BOTH) def show_popup(self): global app menu = Menu() menu.add_command(label="Copy selected items", command=lambda : self.copy_items()) app.config(menu=menu) def copy_items(self): try: Item = self.login_list.item(self.login_list.focus()) FunctionValue = Item.values() Array = list(FunctionValue) Login = Array[2] self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0], Login[1])) time.sleep(1) except: Msg = Toplevel(root) l1 = Label(Msg, text="You have to take something") l1.pack(fill=BOTH, expand=True) def submit_request(self): amount = self.login_amount.get("1.0", END) complex_bool = self.complex.get() try: amount = int(amount) except: amount = 1 self.controller.get_new_logins(amount, complex_bool) def update_logins(self, login): username, password = login self.login_list.insert('', END, values=[username, password]) class Controller(object): def __init__(self): global app app.title("Login Generator") app.geometry("450x300") self.view = View(self) self.model = Model(self) def get_new_logins(self, amount, complex_bool): self.model.generate_login(amount, complex_bool) def set_new_logins(self, logins): self.view.update_logins(logins) class Model(threading.Thread): def __init__(self, controller): threading.Thread.__init__(self, target=self.main) self.controller = controller self.queue = queue.Queue() self.start() def main(self): while True: amount, complex_bool = self.queue.get() username = login_generator.generate_username() password = login_generator.generate_password(12, complex_bool) logins = (username, password) self.controller.set_new_logins(logins) time.sleep(1) def generate_login(self, amount, complex_bool): for i in range(0, amount): self.queue.put((amount, complex_bool)) if __name__ == "__main__": app = Tk() mvc = Controller() app.mainloop() ``` If you want to add a scrollbar in the project. ````python from tkinter import * from tkinter import ttk import login_generator import time import threading import queue class View(Frame): def __init__(self, controller): Frame.__init__(self) self.controller = controller self.full_window = PanedWindow(self, orient=VERTICAL) self.full_window.pack(fill=BOTH, expand=True) self.create_top_panel() self.create_bottom_panel() self.pack(fill=BOTH, expand=True) def create_bottom_panel(self): bottom_panel = PanedWindow(self.full_window, bg="green") bottom_panel.pack(fill=BOTH, side=BOTTOM) ##Scrollbar self.Scrollbar = Scrollbar(bottom_panel ) self.Scrollbar.pack(side=RIGHT, fill= Y) # List self.login_list = ttk.Treeview(bottom_panel, columns=["username", "password"], show="headings", height=6, yscrollcommand= self.Scrollbar.set) self.login_list.pack() self.login_list.heading("username", text="Username") self.login_list.heading("password", text="Password") self.login_list.bind("", lambda e: self.show_popup()) self.Scrollbar.config(command= self.login_list.yview) def create_top_panel(self): top_panel = PanedWindow(self.full_window, bg="red") self.login_amount = Text(top_panel, height=5, width=52) self.login_amount.place(x=10, y=10) self.complex = BooleanVar() self.complex.set(False) self.login_complex = Checkbutton(top_panel, text="complex", var=self.complex) self.login_complex.place(x=10, y=100) self.login_create = Button(top_panel, text="Create", command=lambda: self.submit_request()) self.login_create.place(x=100, y=100) top_panel.pack(expand=True, fill=BOTH) def show_popup(self): global app menu = Menu() menu.add_command(label="Copy selected items", command=lambda : self.copy_items()) app.config(menu=menu) def copy_items(self): try: Item = self.login_list.item(self.login_list.focus()) FunctionValue = Item.values() Array = list(FunctionValue) Login = Array[2] self.login_amount.insert(END, "Username : {} \nPassword : {} \n".format(Login[0], Login[1])) time.sleep(1) except: Msg = Toplevel(root) l1 = Label(Msg, text="You have to take something") l1.pack(fill=BOTH, expand=True) def submit_request(self): amount = self.login_amount.get("1.0", END) complex_bool = self.complex.get() try: amount = int(amount) except: amount = 1 self.controller.get_new_logins(amount, complex_bool) def update_logins(self, login): username, password = login self.login_list.insert('', END, values=[username, password]) class Controller(object): def __init__(self): global app app.title("Login Generator") app.geometry("450x300") self.view = View(self) self.model = Model(self) def get_new_logins(self, amount, complex_bool): self.model.generate_login(amount, complex_bool) def set_new_logins(self, logins): self.view.update_logins(logins) class Model(threading.Thread): def __init__(self, controller): threading.Thread.__init__(self, target=self.main) self.controller = controller self.queue = queue.Queue() self.start() def main(self): while True: amount, complex_bool = self.queue.get() username = login_generator.generate_username() password = login_generator.generate_password(12, complex_bool) logins = (username, password) self.controller.set_new_logins(logins) time.sleep(1) def generate_login(self, amount, complex_bool): for i in range(0, amount): self.queue.put((amount, complex_bool)) if __name__ == "__main__": app = Tk() mvc = Controller() app.mainloop() ```` ## Coding challenge - Login generator with GUI ## Coding challenge - Trivial pursuit with GUI # WXpython ## wxpython helloworld The absolute most basic way to have a *hello world* GUI program up and running with wxpython is the following. ```python import wx app = wx.App() frame = wx.Frame(None, title="hello world") frame.Show() app.MainLoop() ``` While it works we know better by now. We should include the `if __name__ == "__main__"` statement. ```python import wx if __name__ == "__main__": app = wx.App() frame = wx.Frame(None, title="hello world") frame.Show() app.MainLoop() ``` The instance of `wx.App` is what will actually process our event loop and the `wx.Frame` is the content of our window. In the latter we will create our button and labels so should create our own class and inherit from it. ```python import wx class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title="hello world") self.Show() if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` We can add content to the *frame*, such as labels, input boxes and buttons as follows. Note the first argument to the `wx.StaticText` creation. This is *where* we put the label *into*. It kind of works but we'll encounter a **problem** when we pack more visual **objects** into the same frame. ```python import wx class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title="hello world") self.label = wx.StaticText(self, label="this is a label") self.Show() if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` Let's try to put multiple visual object into the same frame. ```python import wx class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title="hello world") self.label = wx.StaticText(self, label="this is a label") self.input = wx.TextCtrl(self) self.button = wx.Button(self) self.Show() if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` You see how they are *stacked* one on top of the other? We can overcome this problem with [sizers](https://wxpython.org/Phoenix/docs/html/sizers_overview.html). There are multiple ones we can use but let's dive into a first one called a **box sizer**. ```python import wx class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title="hello world") self.panel = wx.Panel(self) self.box = wx.BoxSizer() self.label = wx.StaticText(self.panel, label="this is a label") self.input = wx.TextCtrl(self.panel) self.button = wx.Button(self.panel, label="I'm clickable!") self.box.Add(self.label) self.box.Add(self.input) self.box.Add(self.button) self.panel.SetSizer(self.box) self.Show() if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` This is looking better! But it requires some explanation though. Let's break it down. The `wx.Frame` is your **window** in which you create a `wx.Panel` which is used to draw thing to. To this panel you're adding three different *objects* (`wx.StaticText`, `wx.TextCtrl` and `wx.Button`) each with or without their own settings (such as a label or not). Next you add these three objects to the `wx.BoxSizer` and you tell the panel to use this box as sizer. It probably looks a bit convoluted but this is how most GUI libraries work internally. 1. You create a frame 2. Within this frame you create a *drawing area* and set some form of automatic layout to it (the `wx.BoxSizer`). 3. You create the visual elements you want and add them one by one to the drawing area. 4. Success Now how do we link **user input** to **code actions**? This is a complicated way of saying *actually do something when I click the damn button*! For this we'll need to create a function, or better yet a method to the `wx.Frame` objects. Each time we click the button, that method will be called. Because it is a *method* it has access to *self* so it can modify *anything* within the scope of the instance. ```python import wx import random class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title="hello world") self.panel = wx.Panel(self) self.box = wx.BoxSizer() self.label = wx.StaticText(self.panel, label="this is a label") self.input = wx.TextCtrl(self.panel) self.button = wx.Button(self.panel, label="I'm clickable!") self.button.Bind(wx.EVT_BUTTON, self.set_label_value) self.box.Add(self.label) self.box.Add(self.input) self.box.Add(self.button) self.panel.SetSizer(self.box) self.Show() def set_label_value(self, event): number = random.randint(0, 100) self.label.SetLabel("{}".format(number)) if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` We can use the same *idea* to grab input from the textbox. ```python import wx class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title="hello world") self.panel = wx.Panel(self) self.box = wx.BoxSizer() self.label = wx.StaticText(self.panel, label="this is a label") self.input = wx.TextCtrl(self.panel) self.button = wx.Button(self.panel, label="I'm clickable!") self.button.Bind(wx.EVT_BUTTON, self.set_label_value) self.box.Add(self.label) self.box.Add(self.input) self.box.Add(self.button) self.panel.SetSizer(self.box) self.Show() def set_label_value(self, event): msg = self.input.GetValue() self.label.SetLabel("{}".format(msg)) if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` ## wxpython guess the number ```python import wx import random class MainWindow(wx.Frame): def __init__(self): wx.Frame.__init__(self, None, title="Guess the number") self.number = random.randint(0, 100) self.panel = wx.Panel(self) self.box = wx.BoxSizer(wx.VERTICAL) self.label = wx.StaticText(self.panel, label="I have a number in mind...") self.input = wx.TextCtrl(self.panel) self.button = wx.Button(self.panel, label="I'm clickable!") self.button.Bind(wx.EVT_BUTTON, self.set_label_value) self.box.Add(self.label) self.box.Add(self.input) self.box.Add(self.button) self.panel.SetSizer(self.box) self.Show() def set_label_value(self, event): result = self.input.GetValue() if result.isdigit(): status, context = self.evaluate_user_number(int(result)) self.label.SetLabel(context) else: self.label.SetLabel("I need numbers!") def evaluate_user_number(self, number): if number > self.number: return False, "my number is smaller" elif number < self.number: return False, "my number is bigger" elif number == self.number: return True, "You win!" if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` ## MVC design pattern A simple console only MVC. We'll add the GUI view in a bit. ```python import wx class ConsoleView(object): """A view for console.""" def select_task(self): """Asks which index to look up.""" idx = input("which task do you want to see? ") return idx def show(self, task): """Displays the task to the console. This method is called from the controller.""" print("your task: {}".format(task)) def error(self, msg): """Prints error messages coming from the controller.""" print("error: {}".format(msg)) class WxView(wx.Dialog): pass class Model(object): """The model houses add data and should implement all methods related to adding, modifying and deleting tasks.""" db = ["go to the shops", "dryhop beer", "drop of motorbike"] def get_task(self, idx): """Performs a task lookun into the database and returns it when found. If no task is found, it returns an error message that will be displayed in the view (via the controller).""" try: task = Model.db[idx] except IndexError: task = "task with {} not found!".format(idx) return task class Controller(object): """Binds the model and the view together.""" def __init__(self, view): self.model = Model() self.view = view def run(self): """The controller's main function. Depending on what type of view is selected, a different event loop is setup. Do note that the ConsoleView is not a real event loop, just a basic flow of action.""" if self.view is ConsoleView: self.view = self.view() self._run_console_view() elif self.view is WxView: app = wx.App() self.view = self.view() self.view._set_controller(self) app.MainLoop() def get_task_from_model(self, idx): """Needed for the WxView to communicate with the controller.""" task = self.model.get_task(idx) self.view.show_task(task) def _run_console_view(self): """Super simple event loop.""" while True: try: idx = self.view.select_task() idx = int(idx) except Exception as e: self.view.error(e) continue task = self.model.get_task(idx) self.view.show(task) if __name__ == "__main__": view = ConsoleView # view = WxView app = Controller(view) app.run() ``` And now with the implemented `WxView` class. ```python import wx class ConsoleView(object): """A view for console.""" def select_task(self): """Asks which index to look up.""" idx = input("which task do you want to see? ") return idx def show(self, task): """Displays the task to the console. This method is called from the controller.""" print("your task: {}".format(task)) def error(self, msg): """Prints error messages coming from the controller.""" print("error: {}".format(msg)) class WxView(wx.Dialog): """A view using a wx.Dialog window""" def __init__(self): wx.Dialog.__init__(self, None, title="Task Manager") self.panel = wx.Panel(self) self.box = wx.BoxSizer(wx.VERTICAL) self.task = wx.StaticText(self.panel, label="your task") self.idx = wx.SpinCtrl(self.panel) self.button = wx.Button(self.panel, label="submit") self.button.Bind(wx.EVT_BUTTON, self.select_task) self.box.Add(self.task, 0, wx.EXPAND, 1) self.box.Add(self.idx, 0, wx.EXPAND, 1) self.box.Add(self.button, 0, wx.EXPAND, 1) self.panel.SetSizer(self.box) self.Show() def _set_controller(self, controller): """Set the controller so the view can communicate it's requests to it and update it's values too.""" self.controller = controller def select_task(self, event): """Gets the index to look up in the model and submits the request to the controller.""" idx = self.idx.GetValue() self.controller.get_task_from_model(idx) def show_task(self, task): """Updates the visual label in the view with the task. This method is called from the controller.""" self.task.SetLabel(task) class Model(object): """The model houses add data and should implement all methods related to adding, modifying and deleting tasks.""" db = ["go to the shops", "dryhop beer", "drop of motorbike"] def get_task(self, idx): """Performs a task lookun into the database and returns it when found. If no task is found, it returns an error message that will be displayed in the view (via the controller).""" try: task = Model.db[idx] except IndexError: task = "task with {} not found!".format(idx) return task class Controller(object): """Binds the model and the view together.""" def __init__(self, view): self.model = Model() self.view = view def run(self): """The controller's main function. Depending on what type of view is selected, a different event loop is setup. Do note that the ConsoleView is not a real event loop, just a basic flow of action.""" if self.view is ConsoleView: self.view = self.view() self._run_console_view() elif self.view is WxView: app = wx.App() self.view = self.view() self.view._set_controller(self) app.MainLoop() def get_task_from_model(self, idx): """Needed for the WxView to communicate with the controller.""" task = self.model.get_task(idx) self.view.show_task(task) def _run_console_view(self): """Super simple event loop.""" while True: try: idx = self.view.select_task() idx = int(idx) except Exception as e: self.view.error(e) continue task = self.model.get_task(idx) self.view.show(task) if __name__ == "__main__": view = WxView app = Controller(view) app.run() ``` For a GUI only login generator an implementation without MVC could look a bit like this. Note that the actual calculation is done inside the window itself. This is not a good idea because we should separate responsibilities into classes! ```python import wx import login_generator class MainWindow(wx.Dialog): def __init__(self): wx.Dialog.__init__(self, None, title="Login Generator") self.full_window = wx.Panel(self) self.full_window_sizer = wx.BoxSizer(wx.VERTICAL) self.full_window_sizer.Add(self.create_top_panel(), 0, wx.EXPAND | wx.ALL, 20) self.full_window_sizer.Add(self.create_bottom_panel(), 0, wx.EXPAND, 0) self.full_window.SetSizer(self.full_window_sizer) self.Show() def create_bottom_panel(self): bottom_panel = wx.Panel(self.full_window) bottom_panel_sizer = wx.BoxSizer(wx.HORIZONTAL) self.login_list = wx.ListCtrl(bottom_panel, style=wx.LC_REPORT) self.login_list.Bind(wx.EVT_RIGHT_UP, self.show_popup) self.login_list.InsertColumn(0, 'username', width=200) self.login_list.InsertColumn(1, 'password', width=200) bottom_panel_sizer.Add(self.login_list, 0, wx.EXPAND | wx.ALL, 200) return bottom_panel def create_top_panel(self): top_panel = wx.Panel(self.full_window) top_panel_sizer = wx.BoxSizer(wx.HORIZONTAL) self.login_amount = wx.TextCtrl(top_panel) self.login_complex = wx.CheckBox(top_panel, label="complex") self.login_create = wx.Button(top_panel, label="Create") self.login_create.Bind(wx.EVT_BUTTON, self.add_login) top_panel_sizer.Add(self.login_amount, 1, wx.EXPAND|wx.ALL,0) top_panel_sizer.Add(self.login_complex, 1, wx.EXPAND|wx.ALL,0) top_panel_sizer.Add(self.login_create, 1, wx.EXPAND|wx.ALL,0) top_panel.SetSizer(top_panel_sizer) return top_panel def show_popup(self, event): menu = wx.Menu() menu.Append(1, "Copy selected items") menu.Bind(wx.EVT_MENU, self.copy_items, id=1) self.PopupMenu(menu) def copy_items(self, event): selected_items = [] for i in range(self.login_list.GetItemCount()): if self.login_list.IsSelected(i): username = selected_items.append( self.login_list.GetItem(i, 0).GetText() ) password = selected_items.append( self.login_list.GetItem(i, 1).GetText() ) clipdata = wx.TextDataObject() clipdata.SetText("\n".join(selected_items)) wx.TheClipboard.Open() wx.TheClipboard.SetData(clipdata) wx.TheClipboard.Close() def add_login(self, event): amount = self.login_amount.GetValue() complex = self.login_complex.GetValue() try: amount = int(amount) except: amount = 1 for i in range(0, amount): username = login_generator.generate_username() password = login_generator.generate_password(12, complex) index = self.login_list.InsertItem(0, username) self.login_list.SetItem(index, 1, password) if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` Now let's assume the generate username and password function take some calculation time. We'll add in a fake `time.sleep` to simulate. ```python import wx import login_generator import time class MainWindow(wx.Dialog): def __init__(self): wx.Dialog.__init__(self, None, title="Login Generator") self.full_window = wx.Panel(self) self.full_window_sizer = wx.BoxSizer(wx.VERTICAL) self.full_window_sizer.Add(self.create_top_panel(), 0, wx.EXPAND | wx.ALL, 20) self.full_window_sizer.Add(self.create_bottom_panel(), 0, wx.EXPAND, 0) self.full_window.SetSizer(self.full_window_sizer) self.Show() def create_bottom_panel(self): bottom_panel = wx.Panel(self.full_window) bottom_panel_sizer = wx.BoxSizer(wx.HORIZONTAL) self.login_list = wx.ListCtrl(bottom_panel, style=wx.LC_REPORT) self.login_list.Bind(wx.EVT_RIGHT_UP, self.show_popup) self.login_list.InsertColumn(0, 'username', width=200) self.login_list.InsertColumn(1, 'password', width=200) bottom_panel_sizer.Add(self.login_list, 0, wx.EXPAND | wx.ALL, 200) return bottom_panel def create_top_panel(self): top_panel = wx.Panel(self.full_window) top_panel_sizer = wx.BoxSizer(wx.HORIZONTAL) self.login_amount = wx.TextCtrl(top_panel) self.login_complex = wx.CheckBox(top_panel, label="complex") self.login_create = wx.Button(top_panel, label="Create") self.login_create.Bind(wx.EVT_BUTTON, self.add_login) top_panel_sizer.Add(self.login_amount, 1, wx.EXPAND|wx.ALL,0) top_panel_sizer.Add(self.login_complex, 1, wx.EXPAND|wx.ALL,0) top_panel_sizer.Add(self.login_create, 1, wx.EXPAND|wx.ALL,0) top_panel.SetSizer(top_panel_sizer) return top_panel def show_popup(self, event): menu = wx.Menu() menu.Append(1, "Copy selected items") menu.Bind(wx.EVT_MENU, self.copy_items, id=1) self.PopupMenu(menu) def copy_items(self, event): selected_items = [] for i in range(self.login_list.GetItemCount()): if self.login_list.IsSelected(i): username = selected_items.append( self.login_list.GetItem(i, 0).GetText() ) password = selected_items.append( self.login_list.GetItem(i, 1).GetText() ) clipdata = wx.TextDataObject() clipdata.SetText("\n".join(selected_items)) wx.TheClipboard.Open() wx.TheClipboard.SetData(clipdata) wx.TheClipboard.Close() def add_login(self, event): amount = self.login_amount.GetValue() complex_bool = self.login_complex.GetValue() try: amount = int(amount) except: amount = 1 for i in range(0, amount): username = login_generator.generate_username() password = login_generator.generate_password(12, complex_bool) time.sleep(1) index = self.login_list.InsertItem(0, username) self.login_list.SetItem(index, 1, password) if __name__ == "__main__": app = wx.App() win = MainWindow() app.MainLoop() ``` A clear separation of responsabilities can be acchieved via an MVC pattern and a login *library*. The library code is quite straightforward and goes as follows. It's basically the same code we did before but with added `try except` blocks. Can you tell me why I added those? ```python import random import string def load_file(filename): """ We load a file and make a list out of it. Note that the same function is used for both files (both adjectives and subjects). Functions should be made as generic as possible. There IS a problem you can fix, some logins will have spaces in them. Try to remove them in this function! """ words = [] with open(filename, "r") as fp: lines = fp.readlines() for line in lines: words.append(line.strip()) # what does strip() do, what does append() do? remember CTRL+Q! return words def generate_username(): """ We'll generate a random pair of adjectives and subjects from two wordlists. You NEED to have both files in you python project for this to work! Note the capitalize method call to make it all prettier... """ try: adjectives = load_file("./adjectives.txt") except: adjectives = ["big", "funny", "normal", "red"] try: subjects = load_file("./subjects.txt") except: subjects = ["giraffe", "elephant", "cougar", "tiger"] adjective = random.choice(adjectives) subject = random.choice(subjects) username = adjective.capitalize() + subject.capitalize() return username def generate_password(length=10, complictated=True): """ We generate a password with default settings. You can overide these by changing the arguments in the function call. """ password = "" if complictated: chars = string.ascii_letters + string.digits + string.punctuation else: chars = string.ascii_letters for i in range(0, length): password += random.choice(chars) return password if __name__ == "__main__": # let's do some testing! username_test = generate_username() print(username_test) password_test = generate_password() print(password_test) ``` And now the GUI code nicely split up in a **model**, **controller** and a **view**. The overhead is quite large but it makes the code a lot more scalable. ```python import wx import login_generator import time import threading import queue class View(wx.Dialog): def __init__(self, controller): wx.Dialog.__init__(self, None, title="Login Generator") self.controller = controller self.full_window = wx.Panel(self) self.full_window_sizer = wx.BoxSizer(wx.VERTICAL) self.full_window_sizer.Add(self.create_top_panel(), 0, wx.EXPAND | wx.ALL, 20) self.full_window_sizer.Add(self.create_bottom_panel(), 0, wx.EXPAND, 0) self.full_window.SetSizer(self.full_window_sizer) self.Show() def create_bottom_panel(self): bottom_panel = wx.Panel(self.full_window) bottom_panel_sizer = wx.BoxSizer(wx.HORIZONTAL) self.login_list = wx.ListCtrl(bottom_panel, style=wx.LC_REPORT) self.login_list.Bind(wx.EVT_RIGHT_UP, self.show_popup) self.login_list.InsertColumn(0, 'username', width=200) self.login_list.InsertColumn(1, 'password', width=200) bottom_panel_sizer.Add(self.login_list, 0, wx.EXPAND | wx.ALL, 200) return bottom_panel def create_top_panel(self): top_panel = wx.Panel(self.full_window) top_panel_sizer = wx.BoxSizer(wx.HORIZONTAL) self.login_amount = wx.TextCtrl(top_panel) self.login_complex = wx.CheckBox(top_panel, label="complex") self.login_create = wx.Button(top_panel, label="Create") self.login_create.Bind(wx.EVT_BUTTON, self.submit_request) top_panel_sizer.Add(self.login_amount, 1, wx.EXPAND|wx.ALL,0) top_panel_sizer.Add(self.login_complex, 1, wx.EXPAND|wx.ALL,0) top_panel_sizer.Add(self.login_create, 1, wx.EXPAND|wx.ALL,0) top_panel.SetSizer(top_panel_sizer) return top_panel def show_popup(self, event): menu = wx.Menu() menu.Append(1, "Copy selected items") menu.Bind(wx.EVT_MENU, self.copy_items, id=1) self.PopupMenu(menu) def copy_items(self, event): selected_items = [] for i in range(self.login_list.GetItemCount()): if self.login_list.IsSelected(i): username = selected_items.append( self.login_list.GetItem(i, 0).GetText() ) password = selected_items.append( self.login_list.GetItem(i, 1).GetText() ) clipdata = wx.TextDataObject() clipdata.SetText("\n".join(selected_items)) wx.TheClipboard.Open() wx.TheClipboard.SetData(clipdata) wx.TheClipboard.Close() def submit_request(self, event): amount = self.login_amount.GetValue() complex_bool = self.login_complex.GetValue() try: amount = int(amount) except: amount = 1 self.controller.get_new_logins(amount, complex_bool) def update_logins(self, login): username, password = login index = self.login_list.InsertItem(0, username) self.login_list.SetItem(index, 1, password) class Controller(object): def __init__(self): self.app = wx.App() self.view = View(self) self.model = Model(self) def get_new_logins(self, amount, complex_bool): self.model.generate_login(amount, complex_bool) def set_new_logins(self, logins): self.view.update_logins(logins) class Model(threading.Thread): def __init__(self, controller): threading.Thread.__init__(self, target=self.main) self.controller = controller self.queue = queue.Queue() self.start() def main(self): while True: amount, complex_bool = self.queue.get() username = login_generator.generate_username() password = login_generator.generate_password(12, complex_bool) logins = (username, password) self.controller.set_new_logins(logins) time.sleep(1) def generate_login(self, amount, complex_bool): for i in range(0, amount): self.queue.put((amount, complex_bool)) if __name__ == "__main__": mvc = Controller() mvc.app.MainLoop() ``` ## Coding challenge - Login generator with GUI ## Coding challenge - Trivial pursuit with GUI