How to add or modify android graphical layout pale

Question

I want to add set of custom components in Android Graphical Palette with the name given by me and I want to include separate implementation for those components.For example if I drag and drop any component from that particular set one more tab should add apart from Graphical layout and xml_name.xml and that should contain .c code for that xml which I have to write.

Can any one please explain how do these all these things where should I include my code for generating .c code from xml and all.

Thanks in advance.