A window consists of four parts: (1) the border, (2) the margins, (3) the , which is the area where information is displayed, and (4) the , which contains the information displayed in the work area. The border and the margins are optional, and create a around the work area. The frame may contain a border, titles, scroll bars, shadows, and margins. The frame is not part of the window contents. The interior work area is where the actual text is displayed.
The interior work area is buffered. The buffer stores information for the window. The buffer is either a memory screen or a memory file.
There are two types of windows that use memory screen buffers: basic windows and virtual windows. Basic windows, by default, have a memory screen buffer that is the same size as the interior work area; virtual windows have a memory screen buffer that may be larger than the interior work area. For the purposes of this chapter, however, the more important difference between basic and virtual windows is the processing function that is assigned to the window when the window is created. The processing function for a basic window puts the window on the screen, waits for the user to hit any key, and then removes the window. The processing function for a virtual window, on the other hand, allows the user to scroll through the memory screen buffer (if the buffer is larger than the work area), and does not take the window off the screen until the user presses the Quit key or Exit key. (For a complete description of the differences between basic and virtual windows, see Chapter 23, "About Windows.")
Video output to a window goes to the window's buffer, and is (by default) visible in the interior work area. By default, if you are writing to a virtual window, Vermont Views will automatically scroll text in the work area, if necessary, so that any output will be displayed on the screen.
