Update control focus flag. Fixes #9915

Parent window must be active for control to draw as focused. This
affects all controls that draw their focus ring using ControlLook
including but not limited to BButton, BCheckBox, and BRadioButton.

I won't pretend to know what is "right" but the behavior now matches
BeOS R5.

src/kits/interface/ControlLook.cpp

@@ -87,8 +87,10 @@ BControlLook::Flags(BControl* control) const
 	if (!control->IsEnabled())
 		flags |= B_DISABLED;
 
-	if (control->IsFocus())
+	if (control->Window() != NULL && control->Window()->IsActive()
+		&& control->IsFocus()) {
 		flags |= B_FOCUSED;
+	}
 
 	if (control->Value() == B_CONTROL_ON)
 		flags |= B_ACTIVATED;