Add ctypes implementation (no compilation)

- Only minimally tested

keycode.py

@@ -0,0 +1,99 @@
+#!/usr/bin/env python
+# http://stackoverflow.com/questions/1918841/how-to-convert-ascii-character-to-cgkeycode */
+
+import ctypes
+import ctypes.util
+import CoreFoundation
+import Foundation
+import objc
+
+try:
+    unichr
+except NameError:
+    unichr = chr
+
+carbon_path = ctypes.util.find_library('Carbon')
+carbon = ctypes.cdll.LoadLibrary(carbon_path)
+
+# We could rely on the fact that kTISPropertyUnicodeKeyLayoutData has
+# been the string @"TISPropertyUnicodeKeyLayoutData" since even the
+# Classic Mac days. Or we could load it from the framework. 
+# Unfortunately, the framework doesn't have PyObjC wrappers, and there's
+# no easy way to force PyObjC to wrap a CF/ObjC object that it doesn't
+# know about. So:
+_objc = ctypes.PyDLL(objc._objc.__file__)
+_objc.PyObjCObject_New.restype = ctypes.py_object
+_objc.PyObjCObject_New.argtypes = [ctypes.c_void_p, ctypes.c_int, ctypes.c_int]
+def objcify(ptr):
+    return _objc.PyObjCObject_New(ptr, 0, 1)
+kTISPropertyUnicodeKeyLayoutData_p = ctypes.c_void_p.in_dll(
+    carbon, 'kTISPropertyUnicodeKeyLayoutData')
+kTISPropertyUnicodeKeyLayoutData = objcify(kTISPropertyUnicodeKeyLayoutData_p)
+
+carbon.TISCopyCurrentKeyboardInputSource.argtypes = []
+carbon.TISCopyCurrentKeyboardInputSource.restype = ctypes.c_void_p
+carbon.TISGetInputSourceProperty.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
+carbon.TISGetInputSourceProperty.restype = ctypes.c_void_p
+carbon.LMGetKbdType.argtypes = []
+carbon.LMGetKbdType.restype = ctypes.c_uint32
+OptionBits = ctypes.c_uint32
+UniCharCount = ctypes.c_uint8
+UniChar = ctypes.c_uint16
+UniChar4 = UniChar * 4
+carbon.UCKeyTranslate.argtypes = [ctypes.c_void_p, # keyLayoutPtr
+                                  ctypes.c_uint16, # virtualKeyCode
+                                  ctypes.c_uint16, # keyAction
+                                  ctypes.c_uint32, # modifierKeyState
+                                  ctypes.c_uint32, # keyboardType
+                                  OptionBits,      # keyTranslateOptions
+                                  ctypes.POINTER(ctypes.c_uint32), # deadKeyState
+                                  UniCharCount,    # maxStringLength
+                                  ctypes.POINTER(UniCharCount), # actualStringLength
+                                  UniChar4]
+carbon.UCKeyTranslate.restype = ctypes.c_uint32 # OSStatus
+kUCKeyActionDisplay = 3
+kUCKeyTranslateNoDeadKeysBit = 0
+
+kTISPropertyUnicodeKeyLayoutData = ctypes.c_void_p.in_dll(
+    carbon, 'kTISPropertyUnicodeKeyLayoutData')
+
+def createStringForKey(keycode):
+    keyboard_p = carbon.TISCopyCurrentKeyboardInputSource()
+    keyboard = objcify(keyboard_p)
+    layout_p = carbon.TISGetInputSourceProperty(keyboard_p, 
+                                                kTISPropertyUnicodeKeyLayoutData)
+    layout = objcify(layout_p)
+    layoutbytes = layout.bytes()
+    keysdown = ctypes.c_uint32()
+    length = UniCharCount()
+    chars = UniChar4()
+    retval = carbon.UCKeyTranslate(layoutbytes.tobytes(),
+                                   keycode,
+                                   kUCKeyActionDisplay,
+                                   0,
+                                   carbon.LMGetKbdType(),
+                                   kUCKeyTranslateNoDeadKeysBit,
+                                   ctypes.byref(keysdown),
+                                   4,
+                                   ctypes.byref(length),
+                                   chars)
+    s = u''.join(unichr(chars[i]) for i in range(length.value))
+    CoreFoundation.CFRelease(keyboard)
+    return s
+
+codedict = {createStringForKey(code): code for code in range(128)}
+def keyCodeForChar(c):
+    return codedict[c]
+
+if __name__ == '__main__':
+    import sys
+    for arg in sys.argv[1:]:
+        try:
+            keycode = int(arg)
+        except ValueError:
+            print(u'{}: {}'.format(arg, keyCodeForChar(arg)))
+        else:
+            print('{}: {!r}'.format(keycode, createStringForKey(keycode)))
+    if len(sys.argv) < 2:
+        for keycode in range(128):
+            print('{}: {!r}'.format(keycode, createStringForKey(keycode)))