Except for the EX18A example, each program you've seen so far in this book has had only one view attached to a document. If you've used a Microsoft Windows-based word processor, you know that it's convenient to have two windows open simultaneously on various parts of a document. Both windows might contain normal views, or one window might contain a page layout view and another might contain an outline view.
With the application framework, you can use a splitter window or multiple MDI child windows to display multiple views. You'll learn about both presentation options here, and you'll see that it's easy to make multiple view objects of the same view class (the normal view) in both cases. It's slightly more difficult, however, to use two or more view classes in the same application (say, the outline view and the page layout view).
This chapter emphasizes the selection and presentation of multiple views. The examples depend on a document with data initialized in the OnNewDocument function. Look back now to Chapter 16 for a review of document-view communication.