B3270/Graphic rendition

Description
b3270 graphic rendition attributes are a comma-separated list of the following values:

An empty value indicates the default (none of the above properties are set).

When a location has the order attribute, the contents are a visible representation of a 3270 order that would normally be displayed as a blank. This is done when b3270 has the visibleControl resource set to true.

Note that except when the private-use attribute is also set, visible orders should be copied into a paste buffer as a space (U+0020).

When a location has the private-use attribute, it should be treated specially when copied into a paste buffer: the character value should be offset by the value 0xe000 to put it in the Unicode BMP Private Use Area. For example, the * character (U+002a), when marked with private-use, represents the EBCDIC character DUP (X'1C'). It should be encoded in the paste buffer as U+e02a. The Z character (U+005a), when marked with private-use, represents the APL EBCDIC character Underlined Z (GE X'69'). It should be encoded in the paste buffer as U+e05a. This rule applies even if the order attribute it set (normally orders are represented as U+0020 in the paste buffer).

When a location has the no-copy attribute, it should not be copied into a paste buffer. This is generally the case for EBCDIC SO (X'0E') and SI (X'0F') orders, which can be inferred from other data.

So the hierarchy for selecting a value to copy into the paste buffer is:


 * if no-copy is set, do not copy anything
 * else if private-use is set, add 0xe000
 * else if order is set, substitute U+0020
 * else copy the value as-is