Warn if key presses occur when the input window doesn't have focus as the usual key events are not generated then which could be understood as a bug in the sample instead of the correct result. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@72253 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775