Achieving Happiness?

Happiness seems to be an unequivocal good.  But, what is happiness? Happiness seems to involve pleasure, and the absence of pain, but are there other components of happiness? While a happy life would be a good life, is that the same as a morally good life?  Imagine someone who was secretly stealing from others and who never got caught.  Would such a person’s life be a happy one?  Could one live a happy life that was immoral or is living morally or virtuously a necessary component of a happy life?