gui.py

"""
Contains all the GUI-related code.

The resulting GUI is very simple (or ugly, depending on your tastes). It might
be improved in the future.
"""
import threading
import tkinter as tk

from utils import Mfloat


class GUI:
    def __init__(self, quit_event: threading.Event, frequency: Mfloat):
        self.quit_event = quit_event
        self.frequency = frequency

    def gui_loop(self):
        """
        Runs the main GUI execution loop.
        """

        window = tk.Tk()
        window.geometry("300x200")
        window.title("PyFM")
        frame = tk.Frame(window)
        frame.pack()

        self.info_text = tk.Label(
            window, text="Select the frequency you want to listen to:"
        )
        self.info_text.pack()
        self.info_text.pack(pady=30)

        self.spinner_value = tk.StringVar(window)
        self.spinner_value.set(self.frequency.str_value)
        freq_selector = tk.Spinbox(
            from_=80, to=108, increment=0.01, textvariable=self.spinner_value, width=30
        )
        freq_selector.pack(fill="y")
        self.spinner_value.trace_add("write", self.on_frequency_update)

        window.protocol("WM_DELETE_WINDOW", lambda arg=window: self.on_closing(arg))
        window.mainloop()

    def on_frequency_update(self, a, b, c):
        """
        Called when the user updates the frequency value in the spinner widget.
        """
        # We multiply the input value by 1M to convert from MHz (as displayed)
        # into Hz
        self.frequency.value = float(self.spinner_value.get()) * 1000000

    def on_closing(self, window):
        """
        Called upon closing the main window.
        """
        # Stopping the radio reception thread
        self.quit_event.set()
        window.destroy()