import tkinter
import numpy as np
# from .resolution import Instrument, load


from tkinter import *
from tkinter import ttk

def main():
    def calculate(*args):
        try:
            value = float(feet.get())
            meters.set((0.3048 * value * 10000.0 + 0.5)/10000.0)
        except ValueError:
            pass

    root = Tk()
    root.title("Feet to Meters")
    
    mainframe = ttk.Frame(root, padding="3 3 12 12")
    mainframe.grid(column=0, row=0, sticky=(N, W, E, S))
    mainframe.columnconfigure(0, weight=1)
    mainframe.rowconfigure(0, weight=1)
    
    feet = StringVar()
    meters = StringVar()
    
    feet_entry = ttk.Entry(mainframe, width=7, textvariable=feet)
    feet_entry.grid(column=2, row=1, sticky=(W, E))
    
    ttk.Label(mainframe, textvariable=meters).grid(column=2, row=2, sticky=(W, E))
    ttk.Button(mainframe, text="Calculate", command=calculate).grid(column=3, row=3, sticky=W)
    
    ttk.Label(mainframe, text="feet").grid(column=3, row=1, sticky=W)
    ttk.Label(mainframe, text="is equivalent to").grid(column=1, row=2, sticky=E)
    ttk.Label(mainframe, text="meters").grid(column=3, row=2, sticky=W)
    
    for child in mainframe.winfo_children():
        child.grid_configure(padx=5, pady=5)
    
    feet_entry.focus()
    root.bind('<Return>', calculate)
    
    root.mainloop()

if __name__ == "__main__":
    main()
