Add validation to keypressScene() for non-callable arguments

Added PyCallable_Check validation to ensure keypressScene() only
accepts callable objects. Now properly raises TypeError with a
clear error message when passed non-callable arguments like
strings, numbers, None, or dicts.

src/McRFPy_API.cpp

@@ -603,6 +603,13 @@ PyObject* McRFPy_API::_createScene(PyObject* self, PyObject* args) {
 PyObject* McRFPy_API::_keypressScene(PyObject* self, PyObject* args) {
     PyObject* callable;
 	if (!PyArg_ParseTuple(args, "O", &callable)) return NULL;
+    
+    // Validate that the argument is callable
+    if (!PyCallable_Check(callable)) {
+        PyErr_SetString(PyExc_TypeError, "keypressScene() argument must be callable");
+        return NULL;
+    }
+    
     /*
     if (game->currentScene()->key_callable != NULL and game->currentScene()->key_callable != Py_None)
     {
@@ -613,6 +620,7 @@ PyObject* McRFPy_API::_keypressScene(PyObject* self, PyObject* args) {
     Py_INCREF(Py_None);
     */
     game->currentScene()->key_callable = std::make_unique<PyKeyCallable>(callable);
+    Py_INCREF(Py_None);
     return Py_None;		
 }
 

tests/keypress_scene_validation_test.py

@@ -0,0 +1,93 @@
+#!/usr/bin/env python3
+"""
+Test for keypressScene() validation - should reject non-callable arguments
+"""
+
+def test_keypress_validation(timer_name):
+    """Test that keypressScene validates its argument is callable"""
+    import mcrfpy
+    import sys
+    
+    print("Testing keypressScene() validation...")
+    
+    # Create test scene
+    mcrfpy.createScene("test")
+    mcrfpy.setScene("test")
+    
+    # Test 1: Valid callable (function)
+    def key_handler(key, action):
+        print(f"Key pressed: {key}, action: {action}")
+    
+    try:
+        mcrfpy.keypressScene(key_handler)
+        print("✓ Accepted valid function as key handler")
+    except Exception as e:
+        print(f"✗ Rejected valid function: {e}")
+        raise
+    
+    # Test 2: Valid callable (lambda)
+    try:
+        mcrfpy.keypressScene(lambda k, a: None)
+        print("✓ Accepted valid lambda as key handler")
+    except Exception as e:
+        print(f"✗ Rejected valid lambda: {e}")
+        raise
+    
+    # Test 3: Invalid - string
+    try:
+        mcrfpy.keypressScene("not callable")
+        print("✗ Should have rejected string as key handler")
+    except TypeError as e:
+        print(f"✓ Correctly rejected string: {e}")
+    except Exception as e:
+        print(f"✗ Wrong exception type for string: {e}")
+        raise
+    
+    # Test 4: Invalid - number
+    try:
+        mcrfpy.keypressScene(42)
+        print("✗ Should have rejected number as key handler")
+    except TypeError as e:
+        print(f"✓ Correctly rejected number: {e}")
+    except Exception as e:
+        print(f"✗ Wrong exception type for number: {e}")
+        raise
+    
+    # Test 5: Invalid - None
+    try:
+        mcrfpy.keypressScene(None)
+        print("✗ Should have rejected None as key handler")
+    except TypeError as e:
+        print(f"✓ Correctly rejected None: {e}")
+    except Exception as e:
+        print(f"✗ Wrong exception type for None: {e}")
+        raise
+    
+    # Test 6: Invalid - dict
+    try:
+        mcrfpy.keypressScene({"not": "callable"})
+        print("✗ Should have rejected dict as key handler")
+    except TypeError as e:
+        print(f"✓ Correctly rejected dict: {e}")
+    except Exception as e:
+        print(f"✗ Wrong exception type for dict: {e}")
+        raise
+    
+    # Test 7: Valid callable class instance
+    class KeyHandler:
+        def __call__(self, key, action):
+            print(f"Class handler: {key}, {action}")
+    
+    try:
+        mcrfpy.keypressScene(KeyHandler())
+        print("✓ Accepted valid callable class instance")
+    except Exception as e:
+        print(f"✗ Rejected valid callable class: {e}")
+        raise
+    
+    print("\n✅ keypressScene() validation test PASSED")
+    sys.exit(0)
+
+# Execute the test after a short delay
+import mcrfpy
+mcrfpy.setTimer("test", test_keypress_validation, 100)