To get an idea of how the image viewer should look, we will make a rough design that we can follow. The online tool Balsamiq (balsamiq.com) is a good way to rapidly create wireframes that will suit this purpose. Take a look at the following export. It includes a navigation bar along the top, a directory listing on the left, and a full-size image view on the right:

Clearly, this image has a far lower level of detail than the design tool we used in Chapter 4, Walk – Building Graphical Windows Applications (back at the beginning of Section 2, Toolkits Using Existing Widgets) for our GoMail design, but this is intentional. Each toolkit in Section 3, Modern Graphical Toolkits of this book has a very different look, set by its theme definition and by using a rough design we can build an implementation using the best practice for each of them.