272 Customizing the user interfaCe skinning in flash Catalyst A third way to create skins and themes is provided by Flash Catalyst. Flash Catalyst is an interaction design tool that allows us to build interactive projects with no need to write code. It is ideal for designers to build interactive mockups that behave nearly as the final application. Flash Catalyst shows its power when you have a static prototype of a web site or application and you want to make it interactive. One of the key features of Catalyst is the possibility to select graphics and transform them into interac- tive components like buttons, text forms, and so on. This is why it is extremely helpful when we need to create skins for Flex applications. Let's go back for a moment to our scenario. We have built the graphics for a new triangular thumb with Illustrator. Instead of exporting the FXG graphics we open Flash Catalyst and import the Illustrator file (Figure 5.27). This process analyzes the structure of the file, recognizes elements and layers, and prepares the file to be edited in Flash Catalyst. After importation, you should notice we have the stage populated with three layered triangles, as defined in Illustrator (Figure 5.28). If we select the triangles a dynamic menu is activated. This is a key step: You can convert a set of graphical elements into a com- ponent. In this case we want a button (Figure 5.29). figure 5.27 importing an illustrator file into flash Catalyst.