Add standalone Tkinter calculator app with optional headless screenshot

calculator.py

@@ -0,0 +1,121 @@
+#!/usr/bin/env python3
+import os
+import sys
+import tkinter as tk
+from tkinter import ttk
+
+# Attempt optional screenshot capability without adding hard dependencies
+# Tries pyscreenshot first (works on many Linux environments), then PIL.ImageGrab
+
+def try_save_screenshot(root, path="calculator_screenshot.png"):
+    try:
+        # Ensure window is up to date and visible
+        root.update_idletasks()
+        root.update()
+
+        x = root.winfo_rootx()
+        y = root.winfo_rooty()
+        w = root.winfo_width()
+        h = root.winfo_height()
+        bbox = (x, y, x + w, y + h)
+
+        try:
+            import pyscreenshot as ImageGrab  # type: ignore
+            img = ImageGrab.grab(bbox=bbox)
+            img.save(path)
+            print(f"Saved screenshot to {path}")
+            return True
+        except Exception:
+            pass
+
+        try:
+            from PIL import ImageGrab  # type: ignore
+            img = ImageGrab.grab(bbox=bbox)
+            img.save(path)
+            print(f"Saved screenshot to {path}")
+            return True
+        except Exception:
+            pass
+    except Exception:
+        pass
+
+    print("Unable to capture screenshot (optional).")
+    return False
+
+
+class Calculator(tk.Tk):
+    def __init__(self):
+        super().__init__()
+        self.title("Calculator")
+        self.resizable(False, False)
+
+        # Display
+        self.display_var = tk.StringVar()
+        self.entry = ttk.Entry(self, textvariable=self.display_var, justify="right", font=("Arial", 18))
+        self.entry.grid(row=0, column=0, columnspan=4, sticky="nsew", padx=8, pady=(8, 4))
+        self.entry.focus_set()
+
+        # Buttons layout
+        buttons = [
+            ["7", "8", "9", "÷"],
+            ["4", "5", "6", "×"],
+            ["1", "2", "3", "-"],
+            ["C", "0", "=", "+"],
+        ]
+
+        for r, row in enumerate(buttons, start=1):
+            for c, char in enumerate(row):
+                btn = ttk.Button(self, text=char, command=lambda ch=char: self.on_button(ch))
+                btn.grid(row=r, column=c, sticky="nsew", padx=4, pady=4, ipadx=4, ipady=6)
+
+        for i in range(4):
+            self.grid_columnconfigure(i, weight=1)
+        for i in range(5):
+            self.grid_rowconfigure(i, weight=1)
+
+        # Key bindings
+        self.bind("<Return>", lambda e: self.on_button("="))
+        self.bind("<KP_Enter>", lambda e: self.on_button("="))
+        for key in "0123456789+-*/":
+            self.bind(key, self._key_insert)
+        self.bind("c", lambda e: self.on_button("C"))
+        self.bind("C", lambda e: self.on_button("C"))
+
+    def _key_insert(self, event):
+        mapping = {"*": "×", "/": "÷"}
+        ch = mapping.get(event.char, event.char)
+        self.display_var.set(self.display_var.get() + ch)
+
+    def on_button(self, ch: str):
+        if ch == "C":
+            self.display_var.set("")
+            return
+        if ch == "=":
+            expr = self.display_var.get().replace("×", "*").replace("÷", "/")
+            try:
+                # Evaluate using Python's eval with restricted globals and locals
+                result = eval(expr, {"__builtins__": {}}, {})
+                self.display_var.set(str(result))
+            except Exception:
+                self.display_var.set("Error")
+            return
+        self.display_var.set(self.display_var.get() + ch)
+
+
+def main(argv=None):
+    argv = argv or sys.argv[1:]
+    app = Calculator()
+
+    if "--screenshot" in argv or os.environ.get("CALC_SCREENSHOT"):
+        # Place window then try to capture
+        app.update()
+        try_save_screenshot(app)
+        app.destroy()
+        return 0
+
+    app.mainloop()
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

readme.md

@@ -1 +1,8 @@
 intended to test the copilot
+
+
+Usage:
+- Run `python3 calculator.py` to open the calculator window.
+- Use `python3 calculator.py --screenshot` to generate a screenshot without opening an interactive window (useful in CI).
+
+The calculator supports digits (0–9), basic operations (+, -, ×, ÷), clear (C), and equals (=).