You seem to have forgotten to call setPreviewDisplay() (or, in your case initPreview() ) before calling startPreview() from your restartPreviev() method. Effectively, you're trying to start preview without specifying a surface to render the preview into.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.