Dynapro Technologies Dynapro ET TCS, Application Developer'S Manual

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The Erase a Region command is sent by the host to erase a designated area of the screen.
Each character that is erased is replaced by a blank (a Space character). The attribute of each
character position in the erased region reverts to off, unless the NOCHANGE Attribute Mode is
set.
The region to be erased is defined relative to the cursor position, which becomes the upper-left
corner of the region. The number of lines (height) and number of columns (width) making up the
region are specified by numeric parameters.
The region of the display affected by this command is restricted to the scrolling region if the
Origin Mode is set.
Within a defined region, the host can restrict the effect of this command to one of the following
areas:
•
Inner characters
Only those characters within a region not adjacent to an edge (border) of the region are
erased.
•
Border characters
Only those characters within a region adjacent to an edge (border) of the region are erased.
•
All characters
All the characters (inner and border) in the region are erased.
For the Erase a Region command to produce correct and predictable results, the line type of the
region must be determined. Line type is determined according to the following rules:
•
If the region contains any double-size lines, the entire region is assumed to be composed of
double-size lines.
•
If the region contains any double-width lines, the entire region is assumed to be composed of
double-width lines.
•
If the region does not contain any double-width or double-size lines, the region is assumed to
be composed of all normal lines.
NOTE
Undesirable results may be produced if the Erase a Region command is executed on a region that contains
mixed line types.
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None. (This is a remote command only.)