September 2017 Update

Task/GUI-enabling-disabling-of-controls/Python/gui-enabling-disabling-of-controls.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+
+import tkinter as tk
+
+class MyForm(tk.Frame):
+
+    def __init__(self, master=None):
+        tk.Frame.__init__(self, master)
+        self.pack(expand=True, fill="both", padx=10, pady=10)
+        self.master.title("Controls")
+        self.setupUI()
+
+    def setupUI(self):
+        self.value_entry = tk.Entry(self, justify=tk.CENTER)
+        self.value_entry.grid(row=0, column=0, columnspan=2,
+                              padx=5, pady=5, sticky="nesw")
+        self.value_entry.insert('end', '0')
+        self.value_entry.bind("<KeyPress-Return>", self.eventHandler)
+
+        self.decre_btn = tk.Button(self, text="Decrement", state=tk.DISABLED)
+        self.decre_btn.grid(row=1, column=0, padx=5, pady=5)
+        self.decre_btn.bind("<Button-1>", self.eventHandler)
+
+        self.incre_btn = tk.Button(self, text="Increment")
+        self.incre_btn.grid(row=1, column=1, padx=5, pady=5)
+        self.incre_btn.bind("<Button-1>", self.eventHandler)
+
+    def eventHandler(self, event):
+        value = int(self.value_entry.get())
+        if event.widget == self.value_entry:
+            if value > 10:
+                self.value_entry.delete("0", "end")
+                self.value_entry.insert("end", "0")
+            elif value == 10:
+                self.value_entry.config(state=tk.DISABLED)
+                self.incre_btn.config(state=tk.DISABLED)
+                self.decre_btn.config(state=tk.NORMAL)
+            elif value == 0:
+                self.value_entry.config(state=tk.NORMAL)
+                self.incre_btn.config(state=tk.NORMAL)
+                self.decre_btn.config(state=tk.DISABLED)
+            elif (value > 0) and (value < 10):
+                self.value_entry.config(state=tk.DISABLED)
+                self.incre_btn.config(state=tk.NORMAL)
+                self.decre_btn.config(state=tk.NORMAL)
+        else:
+            if event.widget == self.incre_btn:
+                if (value >= 0) and (value < 10):
+                    value += 1
+                    self.value_entry.config(state=tk.NORMAL)
+                    self.value_entry.delete("0", "end")
+                    self.value_entry.insert("end", str(value))
+                if value > 0:
+                    self.decre_btn.config(state=tk.NORMAL)
+                    self.value_entry.config(state=tk.DISABLED)
+                if value == 10:
+                    self.incre_btn.config(state=tk.DISABLED)
+            elif event.widget == self.decre_btn:
+                if (value > 0) and (value <= 10):
+                    value -= 1
+                    self.value_entry.config(state=tk.NORMAL)
+                    self.value_entry.delete("0", "end")
+                    self.value_entry.insert("end", str(value))
+                    self.value_entry.config(state=tk.DISABLED)
+                if (value) < 10:
+                    self.incre_btn.config(state=tk.NORMAL)
+                if (value) == 0:
+                    self.decre_btn.config(state=tk.DISABLED)
+                    self.value_entry.config(state=tk.NORMAL)
+
+def main():
+    app = MyForm()
+    app.mainloop()
+
+if __name__ == "__main__":
+    main()