main.py

import tkinter as tk
from functools import partial
from tkinter import ttk

from module_loader import names
from secure_eval import eval_expr

# NOTE: LSP code rules:
# - ty LSP can perform type checking if you use hinting.
#       Always use hinting on variables.
#   For completions sake, use `typing.Any` if you ever need not to have
#       strict typing.
# - Ruff LSP doesn't support star imports. Don't use star imports.
# INFO: Curricular competencies met:
# - Nothing yet!

# ------- Functions

# ----- Event functions


# Enters a string into the expression box; used for buttons.
def enterText(char: str) -> None:
    print(f"Pressed '{char}' button.")
    oldExpression: str = expression.get()
    expression.set(oldExpression + char)


# Calculates the result and packs it into the output label.
def calculate() -> None:
    expression_str: str = expression.get()
    print(f"Calculating '{expression_str}'")
    try:
        result: str = eval_expr(expression_str, module_loader.names)
        output.set(result)
        print(f"Answer is '{result}'.")
    except ValueError as e:
        # Show error in GUI
        output.set(f"ERROR: {e}")
        # Show error in console
        print(f"Caught an error: {e}")


# ------- Initialization

# ----- Initialize Tk and window
# Initialize Tk instance and window
root: tk.Tk = tk.Tk()
root.title("Calculator")

# Initialize themed frame
main_frame: ttk.Frame = ttk.Frame(root, padding=(12, 12, 12, 12))
main_frame.grid(sticky="nsew")

# Ensure main_frame expands to window size
root.columnconfigure(0, weight=1)
root.rowconfigure(0, weight=1)

# ----- Define layout and widgets
# --- Expression view/entry
expression: tk.StringVar = tk.StringVar()
expression_entry: ttk.Entry = ttk.Entry(main_frame, textvariable=expression)
expression_entry.grid(sticky="new")

# --- Output pane
output: tk.StringVar = tk.StringVar(value="= ?")
output_label: ttk.Label = ttk.Label(
    main_frame, anchor="e", textvariable=output
)
output_label.grid(row=1, sticky="ew")

# --- Buttons panes
# Create buttons notebook (creates tabs for switching between button sets)
buttons_notebook: ttk.Notebook = ttk.Notebook(main_frame)
buttons_notebook.grid(row=2, sticky="nsew")

# Let buttons notebook take additional space
main_frame.rowconfigure(2, weight=1)
main_frame.columnconfigure(0, weight=1)

# Add arithmetic buttons frame
arithmetic_frame: ttk.Frame = ttk.Frame()
buttons_notebook.add(arithmetic_frame, text="Common")

# --- Buttons

# -- Arithmetic frame

# - Buttons definitions

button_1: ttk.Button = ttk.Button(
    arithmetic_frame, text="1", command=partial(enterText, "1")
)
button_2: ttk.Button = ttk.Button(
    arithmetic_frame, text="2", command=partial(enterText, "2")
)
button_3: ttk.Button = ttk.Button(
    arithmetic_frame, text="3", command=partial(enterText, "3")
)
button_4: ttk.Button = ttk.Button(
    arithmetic_frame, text="4", command=partial(enterText, "4")
)
button_5: ttk.Button = ttk.Button(
    arithmetic_frame, text="5", command=partial(enterText, "5")
)
button_6: ttk.Button = ttk.Button(
    arithmetic_frame, text="6", command=partial(enterText, "6")
)
button_7: ttk.Button = ttk.Button(
    arithmetic_frame, text="7", command=partial(enterText, "7")
)
button_8: ttk.Button = ttk.Button(
    arithmetic_frame, text="8", command=partial(enterText, "8")
)
button_9: ttk.Button = ttk.Button(
    arithmetic_frame, text="9", command=partial(enterText, "9")
)
button_0: ttk.Button = ttk.Button(
    arithmetic_frame, text="0", command=partial(enterText, "0")
)

button_decimal: ttk.Button = ttk.Button(
    arithmetic_frame, text=".", command=partial(enterText, ".")
)

button_divide: ttk.Button = ttk.Button(
    arithmetic_frame, text="/", command=partial(enterText, "/")
)
button_multiply: ttk.Button = ttk.Button(
    arithmetic_frame, text="*", command=partial(enterText, "*")
)
button_subtract: ttk.Button = ttk.Button(
    arithmetic_frame, text="-", command=partial(enterText, "-")
)
button_add: ttk.Button = ttk.Button(
    arithmetic_frame, text="+", command=partial(enterText, "+")
)

button_equals: ttk.Button = ttk.Button(
    arithmetic_frame, text="=", command=calculate
)

# - Button layout

button_7.grid(row=1, column=1, sticky="nsew")
button_8.grid(row=1, column=2, sticky="nsew")
button_9.grid(row=1, column=3, sticky="nsew")
button_divide.grid(row=1, column=4, sticky="nsew")
button_4.grid(row=2, column=1, sticky="nsew")
button_5.grid(row=2, column=2, sticky="nsew")
button_6.grid(row=2, column=3, sticky="nsew")
button_multiply.grid(row=2, column=4, sticky="nsew")
button_1.grid(row=3, column=1, sticky="nsew")
button_2.grid(row=3, column=2, sticky="nsew")
button_3.grid(row=3, column=3, sticky="nsew")
button_subtract.grid(row=3, column=4, sticky="nsew")
button_0.grid(row=4, column=1, sticky="nsew")
button_decimal.grid(row=4, column=2, sticky="nsew")
button_equals.grid(row=4, column=3, sticky="nsew")
button_add.grid(row=4, column=4, sticky="nsew")

arithmetic_frame.columnconfigure(0, weight=1)
arithmetic_frame.rowconfigure(0, weight=1)

# --- Finalizing
# Bind return key to calculate function
expression_entry.bind("<Return>", calculate)  # ty:ignore[no-matching-overload]

# --- Start main loop
root.mainloop()