New skinning architecture of Adobe Flex 4
Spark skins can contain multiple elements (graphic elements, text, images, and transitions). Skins support states, so that when the state of a component changes, the skin changes as well. Skin states integrate well with transitions so that you can apply effects to one or more parts of the skins without adding much code.
You create Spark skins by either editing an existing skin class or creating a new skin class for a Spark component.
