Page Positioning
You define sizes and positions for frames and images in output processes just as you do in input and menu processes. The primary difference between screen positioning for a menu or input process and page positioning for an output process, however, relates to the timing of the display. This timing issue is a direct result of the difference in display media for an input process (a screen) versus an output process (a printer).
When displaying an input process, for example, it is a relatively simple matter to add an image that displays before, beside, or perhaps between existing images by refreshing the screen. It is an entirely different matter when those images are committed to paper. You cannot request a printer to back up to print an image beside a previously printed image, or perhaps insert a new image between two printed images.
To overcome this printer limitation, APPX uses a preliminary assembly area for output frames and images called the Print Beside buffer. Various components of the output can be pieced together in the buffer before they are committed to paper. A buffer permits you to insert images before or beside existing images, much as you do when displaying to a screen. See the Print Beside section for details.
If you do not use a Print Beside buffer in your output process, each image is immediately committed to the print file during execution. As a result, each image must print below the previous image (unless, of course, a new page is started).
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