HP 3000 Manuals HP 3000 Manuals
Character and Graphical Mode On many UNIX environments, some components of COBOL Toolbox have graphical interfaces as well as menu-driven interfaces. This section introduces the basic concepts for people who are new to graphical interfaces. You need to understand the terms "character mode" and "graphical mode". Character mode is the way computer screens have traditionally worked; the screen display is a rectangle of character positions, typically 24 or 25 rows of 80 columns, and each position can display one character, such as a digit or letter of the alphabet. Typical ways of communicating with a computer in character mode are by typing commands, by pressing function keys, or by using the cursor-control keys to move around a menu. In graphical mode, the screen can display intricate pictures. Often you use a mouse, which is a small hand-held device that you move around on your desk; this makes a pointer, called the mouse pointer, move correspondingly on the screen. Typically an object in the computer, such as a command or a file, is represented by a small picture, called an icon, on the screen. A mouse typically has two or three buttons that you can press; this is called clicking. You select the object by putting the mouse pointer on it and clicking one of the mouse buttons. Often you invoke a function by clicking on a pushbutton, which is a picture of a real pushbutton such as you might have on a radio. Another way is to click on an entry on a pulldown menu, which appears to drop down from the top of your screen when you click on its name on a main menu displayed as a menu bar across the top of the screen. Also, the screen can contain several rectangular areas at once, each acting as if it were an independent physical screen. These are called windows. This is useful in, for example, a multi-tasking system where you are running several programs at once. This kind of user interface is called a graphical user interface (GUI) or simply a graphical interface. We will refer to the menu-driven style of interface as a character mode interface. Within the windows of a graphical interface, you can still use ASCII characters, so an application can use commands and menus where the programmer feels these are appropriate. COBOL Toolbox runs on Motif graphical and character environments.