fix OS X alert related to key event (close #98)

src/SFML/Window/OSX/SFOpenGLView.mm

@@ -520,11 +520,13 @@ NSUInteger KeepOnlyMaskFromData(NSUInteger data, NSUInteger mask);
 
 
     // Handle text entred event
-    // We create a new event without command modifiers 
+    // We create a new event without command/ctrl modifiers 
     // to prevent the OS from sending an alert
-    NSUInteger modifiers = [theEvent modifierFlags] & NSCommandKeyMask
-                            ? [theEvent modifierFlags] & ~NSCommandKeyMask
-                            : [theEvent modifierFlags];
+    NSUInteger modifiers = [theEvent modifierFlags];
+    
+    if (modifiers & NSCommandKeyMask) modifiers = modifiers & ~NSCommandKeyMask;
+    if (modifiers & NSControlKeyMask) modifiers = modifiers & ~NSControlKeyMask;
+    
     NSEvent* ev = [NSEvent keyEventWithType:NSKeyDown
                                    location:[theEvent locationInWindow]
                               modifierFlags:modifiers

src/SFML/Window/OSX/SFWindow.m

@@ -32,14 +32,28 @@
 @implementation SFWindow
 
 ////////////////////////////////////////////////////////
--(BOOL)acceptsFirstResponder {
+-(BOOL)acceptsFirstResponder
+{
     return YES;
 }
 
 
 ////////////////////////////////////////////////////////
--(BOOL)canBecomeKeyWindow {
+-(BOOL)canBecomeKeyWindow
+{
     return YES;
 }
 
+////////////////////////////////////////////////////////
+-(void)keyDown:(NSEvent *)theEvent
+{
+    // Do nothing except preventing a system alert each time a key is pressed
+    //
+    // Special Consideration :
+    // -----------------------
+    // Consider overriding NSResponder -keyDown: message in a Cocoa view/window
+    // that contains a SFML rendering area. Doing so will prevent a system
+    // alert to be thrown everytime the user presses a key.
+}
+
 @end