Tkinter

Learned tkinter so I could make a lattice design GUI for Gang Lab.

Notes taken from article: (Link)

Basics

Windows

Window - The container for all other GUI elements

• tk.Tk() - Creates an instance of Tk class, which is the window for all gui to go on top of

import tkinter as tk
root = tk.Tk() # Conventionally called 'root'

Widgets

Widgets - All other GUI elements like text boxes. labels, buttons

• Widgets must be added onto the window before they can be seen

Adding widgets

1. widget.pack - Sizes the window as small as it can be while still fully encompassing the widget
2. widget.grid - Creates grid structure
3. widget.place

greeting = tk.Label(text="Hello!!!")
greeting.pack() 

mainloop()

The root.mainloop() function listens for events (button clicks, keypresses), and blocks any code coming after it until the window is closed.

root.mainloop() # Listens for events 

The 🍞🧈 of Widgets

Label()

tk.Label

• text - the text to be displayed
• foreground (fg) - text color
• background (bg) - bg color
• width/height - size, measured in text units (determined by the width and height of the char 0 in the default system font)

label = tk.Label(text = "Hello!!!",
                foreground='white', 
                background='black')

moreLabel = tk.Label(text="Hello, Tkinter",
                    fg="white",
                    bg="000000",
                    width=10,
                    height=10)

Button()

tk.Button

• text - text on button
• width/height - same as above
• fg/bg - text/bg colors

![[Screenshot 2024-05-23 at 12.30.27 PM.png

200]]

button = tk.Button(
    text="Click me!",
    width=25,
    height=5,
    bg="blue",
    fg="yellow",
)

Entry()

tk.Entry(fg=’yellow’, bg=’blue’, width=50)

Supports the following methods

• .get() - Retrieves user text inside
• .delete() - Deletes user text inside
  • String inside the entry is indexed starting from 0

entry = tk.Entry(text='Name')
entry.pack()

entry.delete(0) # Deletes first letter in entry
entry.delete(2, 4) # Deletes from index 2 to 4 in entry
entry.delete(0, tk.END) # tk.END specifies end of entry

• .insert() - Inserts user text inside

Creating widgets without variable assignment

tk.Label(text="Hello, Tkinter").pack()

Frames

Assign widgets to frames with master=frame argument

frame = tk.Frame()
label = tk.Label(master=frame)

Reliefs: Frame appearances

Relief attribute customizes border around frame, and can be the following:

• tk.FLAT - No border effect (default)
• tk.SUNKEN - Sunken effect
• tk.RAISED - raised effect
• tk.GROOVED - grooved border effect
• tk.RIDGE - ridged effect

![[Screenshot 2024-05-23 at 12.30.02 PM.png

300]]

import tkinter as tk

border_effects = {
    "flat": tk.FLAT,
    "sunken": tk.SUNKEN,
    "raised": tk.RAISED,
    "groove": tk.GROOVE,
    "ridge": tk.RIDGE,
}

window = tk.Tk()

for relief_name, relief in border_effects.items():
    frame = tk.Frame(master=window, relief=relief, borderwidth=5)
    frame.pack(side=tk.LEFT)
    label = tk.Label(master=frame, text=relief_name)
    label.pack()

window.mainloop()

Geometry Managers

.grid()

• Allows row/column based indexing
• sticky=’nsew’ (north-south-east-west ‘sticky’ meaning it expands as the window is resized in all directions)

![[Screenshot 2024-05-23 at 12.29.04 PM.png

200]]

import tkinter as tk

window = tk.Tk()

for i in range(3):
    for j in range(3):
        frame = tk.Frame(
            master=window,
            relief=tk.RAISED,
            borderwidth=1
        )
        frame.grid(row=i, column=j)
        label = tk.Label(master=frame, text=f"Row {i}\\nColumn {j}")
        label.pack()

window.mainloop()