If you are using PSOC 3 then the tool is Creator 3.0, not Designer.
When you start a Creator project there are example projects you can open
and use as the basis. Or if you open a blank project, and place a component,
like ADC on schematic, you can right click component and pick "find example
project", and open it in a new workspace or open it in the current workspace.
Either way you can cut and paste code into your project to get up and running
Oh, sorry for misinformation, just found out it's PSoC 5.
Thank you for fast reply
For both PSoC3 and PSoC5 you need to use PSoC creator.