From 7a7f8441eba396faeeef579b01f7200722188310 Mon Sep 17 00:00:00 2001
From: Martin Putzlocher <m.putzlocher@stiftland-gymnasium.de>
Date: Tue, 2 Nov 2021 12:35:51 +0100
Subject: [PATCH] Feet to Meters example

---
 tk_first_steps/feet.py | 62 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 tk_first_steps/feet.py

diff --git a/tk_first_steps/feet.py b/tk_first_steps/feet.py
new file mode 100644
index 0000000..08fe1a4
--- /dev/null
+++ b/tk_first_steps/feet.py
@@ -0,0 +1,62 @@
+from tkinter import *
+from tkinter import ttk
+
+def calculate(*args):
+    try:
+        stringvalue = feet.get()
+        stringvalue = stringvalue.replace(",",".")
+        value = float(stringvalue)
+        m_value = 0.3048 * value
+        m_value = round(m_value, 2)
+        meters.set(m_value)
+    except ValueError:
+        pass
+    return True
+
+# Hauptfenster
+root = Tk()
+root.title("Feet to Meters")
+
+# Rahmen im Hauptfenster (aus ttk für Farbanpassung)
+mainframe = ttk.Frame(root, padding = "3 3 12 12")
+
+mainframe.grid(column = 0, row = 0, sticky = (N,W,E,S))
+root.columnconfigure(0, weight = 1)
+root.rowconfigure(0, weight = 1)
+
+# Eingabefeld für Länge in feet
+feet = StringVar()
+feet_entry = ttk.Entry(mainframe, width = 7, textvariable = feet)
+feet_entry.grid(column = 2, row = 1, sticky = (W, E))
+
+# Einheit-Label für Eingabefeld der Länge in feet
+ttk.Label(mainframe, text = "feet").grid(column = 3, row = 1, sticky = W)
+
+# Label für Ausgabefeld der Länge in Metern
+ttk.Label(mainframe, text = "ist äquivalent zu").grid(column = 1, row = 2, sticky = E)
+
+# Einheit-Label für Ausgabefeld der Länge in Metern
+ttk.Label(mainframe, text = "Meter").grid(column = 3, row = 2, sticky = W)
+
+# Ausgabefeld für Länge in Metern
+meters = StringVar()
+meters_entry = ttk.Entry(mainframe, width = 7, textvariable = meters)
+meters_entry.grid(column = 2, row = 2, sticky = (W,E))
+meters_entry.configure(state = 'disabled') # keine Eingabe, aber selektierbar
+
+# Button für Berechnung
+
+button_calc = ttk.Button(mainframe, text = "Berechne", command = calculate)
+button_calc.grid(column = 3, row = 3, sticky = W)
+
+# schönere Abstände
+for child in mainframe.winfo_children():
+    child.grid_configure(padx = 5, pady = 5)
+
+# Setze Fokus in Eingabefeld
+feet_entry.focus()
+
+root.bind("<Return>", calculate)
+root.bind("<KP_Enter>", calculate)
+
+root.mainloop()