Getting Started with Tkinter

Events: Making Your App Interactive

Your app isn't just a static mess; it's a dynamic piece of art that responds to user actions. Events are the commands that the user sends to your app, like clicking a left mouse button or pressing a key. Tkinter keeps an ear out for these events and lets you decide how your app should react.

Button Clicks: These happen when the user clicks a button to trigger an action. For example, clicking the “Submit” button to send your data or the “Play” button to start your music or a video.

Text Input: These occur when the user inputs (types) text into a widget. For example, typing your name into a text box or your password into a password field.

Mouse Movements: These are when the user moves the mouse over a widget. For example, changing the color of a button when the mouse hovers over it or displaying a tooltip when the mouse lingers on it.

By defining event handlers, you make your app more user-friendly and interactive.

Bindings: Linking Events to Actions

So, how do you get these events to trigger actions in your code? That's right, you use bindings! Bindings are the glue that connects events to the code that handles them. It's not as hard as it might sound, you simply define a function and set it up where you need it.

Binding Functions to Events: This is like instructing your app on what to do when an event occurs. For example, binding a function to a button click event, so the function executes when the button is clicked.

Customizing Event Responses: This is like giving your app different responses for different event types on the same widget, making it more flexible and fun. Did the user press the button labeled 1, 2, or 3? Make sure to choose the correct response for that. Nobody wants the app to close when they press the combination of keys and expect to save their current work.

Bindings allow you to create astonishing features based on user interactions, making your app a powerful tool. And remember, this might sound intimidating, but it's not harder than any other non GUI app you have written. Just a different API with unique abilities! Don't sweat it!

Let's take a look at the example:

import tkinter as tk
from tkinter import font




def on_button_click():
   button.config(text=entry.get())




def on_enter(event):
   button.config(bg='light green')




def on_leave(event):
   button.config(bg='SystemButtonFace')




app = tk.Tk()
default_font = font.nametofont('TkDefaultFont')
default_font.configure(size=16)


entry = tk.Entry(app, font=default_font)
entry.pack(pady=10)
entry.insert(0, 'Rename the button...')


button = tk.Button(app, text='Rename me!', command=on_button_click, font=default_font)
button.pack(pady=10)


button.bind('<Enter>', on_enter)
button.bind('<Leave>', on_leave)


app.mainloop()

We use the bind method to bind something. The name of the event (e.g., '<Enter>') and then binding it to a function that we made for this event. We also provide our “command” for a button.

It's not difficult to understand that all these actions happen by altering the internal config of the object.

Here is the result:

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This is just a taste of the vast possibilities that Tkinter's core concepts can offer. With a bit of practice and curiosity, you'll be a master of these tools in a reasonable amount of time! Crafting beautiful and useful desktop apps that bring joy not only to your users but to you as well.

Pick at properties

Let's make a little exception and describe a few properties, so we have a better picture of that stuff we did before.

One of the key features of Tkinter is its ability to customize widgets to suit your needs. This part will talk through the process of customizing widget appearance and behavior in Tkinter. So, let's take a look at the possibilities that Tkinter can offer.

‍Colors and Fonts

You can change the color of a widget by using the bg (background) and fg (foreground) options. Here's an example:

button = tkinter.Button(app, text='Click Me', bg='red', fg='white')

In this example, the button's background color is red, and the text color is white.

You can also customize the font of the label widget text using the font option:

label = tkinter.Label(app, text='Hello there!', font=('Helvetica', 16))

In this example, the label's font is set to Helvetica and the font size to 16.

Size and Position

The size of a widget can be controlled using the width and height options. The position of a widget can be controlled using the grid system or pack method.

State

You can enable or disable a widget using the state option. A disabled widget will not respond to user interactions:

button = tkinter.Button(app, text='Click Me', state=tkinter.DISABLED)

In this example, the button is disabled and will not respond to click events.

Customizing the appearance and behavior of widgets in Tkinter allows you to create a unique and interactive user interface for your Python applications. With the options provided by Tkinter, you can control every aspect of your widgets, from their color and minimum size to their behavior and response to user interactions.

Advanced topics

Let's take a brief look at some advanced topics.

‍Canvas: Beside our poetic and artful thinking before, tkinter provides us with the Canvas widget. The Canvas widget is one of the most powerful and flexible widgets in Tkinter. It allows you to create complex GUIs and is used to draw shapes, such as lines, ovals, polygons, and rectangles, in your application. You can also use it to display images or text.

Let's draw some shapes:

import tkinter as tk


app = tk.Tk()


canvas = tk.Canvas(app, width=400, height=400)
canvas.pack()


canvas.create_line(50, 50, 200, 200)
canvas.create_rectangle(50, 50, 200, 200)
canvas.create_oval(50, 50, 200, 200)


app.mainloop()

Here is how it looks like:

Menus: Menus are an integral part of any robust GUI application window. They provide a way to organize commands and features in a hierarchical manner, making it easier for users to navigate through the application.

Here's a basic example of how to create a menu:

bar = tk.Menu(app)


menu = tk.Menu(bar, tearoff=0)
menu.add_command(label='Open', command=None)
menu.add_command(label='About', command=None)
menu.add_separator()
menu.add_command(label='Exit', command=app.quit)


bar.add_cascade(label='File', menu=menu)

Here is how it looks like:

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Dialog boxes: the thing that most users hate because in practice it means that something bad happened.

from tkinter import messagebox


messagebox.showinfo('Information', 'This is an info message box')
messagebox.showwarning('Warning', 'This is a warning message box')
messagebox.showerror('Error', 'This is an error message box')

Here is how they look like:

The 'question' type dialog also exists and is not that annoying. It may be useful, if you want to make sure the user agrees to something.

response = messagebox.askokcancel('Confirmation', 'Are you sure you want to start over?')

In addition to advanced features, one may find it useful with the combination of other libraries.

PIL: It's all about Images, and you know what? Tkinter can handle them. How about combining this and making your own app?

Matplotlib: Are you into stats and want to visualize your insights? Don't be shy, you can embed Matplotlib plots in your Tkinter applications.

‍NumPy and SciPy: How about making your static jupyter notebooks more interactive and push them into masses. Tkinter will help you to organize your scientific presentation.

‍SQLite: Fear not, by combining tkinter and SQLite, you will make the database reader you always wanted.

Remember, one of the strengths of Python is its rich ecosystem of libraries. Don't be afraid to explore these libraries and see how they can enhance your Tkinter applications.

Conclusion

Let’s wrap up. We've covered the basics of Tkinter, a powerful Python code library for creating real-world applications. We've explored its fundamental concepts, including widgets, geometry managers, and event handling. We've also delved into more advanced topics such as widgets behavior. At the end, we took a little peek at the widget appearance.

If you're interested in learning more about tkinter, here are some recommendations:

— Official Tkinter Documentation: This is the most authoritative source of information on Tkinter for Python. It provides a comprehensive overview of the cide library's classes, methods, and options. It’s not a beginner-friendly reading.

— Online Tutorials: Some websites have good tutorials on Tkinter. These tutorials provide step-by-step instructions and examples, making it easy for beginners to learn at their pace.

— Books: Python GUI programming with Tkinter by Alan D. Moore is the book I can recommend. It offers a deep dive into Tkinter, with practical examples and best practices.

— Courses: How about a good video course on YouTube? https://www.youtube.com/watch?v=mop6g-c5HEY This course has 18.5 hours worth of content. Step by step implementation and numerous projects. Well-designed code and intuitive approach for problem-solving.

As you might have noticed, this course is 18.5 hours long, the book is 700 pages long. That's a lot of time to master this craft. This makes the final and the most crucial idea of the best way to learn — do stuff. I encourage you to experiment with Tkinter, try out different widgets and options, and create your own applications. Remember, the key to mastering any programming library is consistent practice and curiosity