The Character Coordinate Phrases

In contexts where you can specify LINE, COL, SIZE, or LINES for a control, you may additionally specify CLINE, CCOL, CSIZE, and CLINES (respectively). These phrases let you specify alternate coordinates and dimensions for controls when they are displayed on text-mode systems. The CLINE, CCOL, CSIZE, and CLINES phrases are collectively called the character coordinate phrases. They behave in all ways like their corresponding counterparts, except that they are applied only when the program executes in a text-mode environment.

Because of the physical differences between graphical and non-graphical systems, getting a single screen description to look good on both types of systems is challenging. Sometimes, the best way to account for these physical differences is to use alternate coordinates or dimensions for some screen elements. The CLINE, CCOL, CSIZE, and CLINES phrases allow you to do this easily.

You specify the character coordinate phrases in exactly the same fashion as their regular counterparts (that is, CLINE is similar to LINE, CCOL to COL, and so on). All of the syntax supported by one phrase works in the corresponding phrase. For example, a Screen Section item that has a twin set of column offsets is:

03 entry-field, col + 2, ccol + 1, ...

When run on a graphical host system, the character coordinate phrases have no effect (although in some contexts the values are evaluated, so any relevant table indexes should be set to legal values to prevent access violations). When run on a character-based host, the character coordinate phrases substitute for their graphical counterparts. For example, if you specify both LINE and CLINE for a control, the CLINE specification is used as the line number on a character-based system. Omitting a character coordinate phrase causes the regular counterpart to be used instead. This means that you need to specify character coordinate phrases only for those aspects of the control that must be different between graphical and character-based hosts.

If you specify the CELLS option in either the SIZE or CSIZE phrase, then you must use the CELLS option in both phrases. The same rule applies to the CELLS option of the LINES and CLINES phrases. This rule is necessary because the CELLS option asserts a particular style attribute for the control, and styles work the same under both graphical and character-based systems.