The CBL_SWAP_SCR_CHATTRS routine is one of a set of library routines that facilitate reading and writing attributes on the screen. This routine writes a string of characters and their attributes over another character string on the screen.
CALL "CBL_SWAP_SCR_CHATTRS"
USING SCREEN-POSITION, CHARACTER-BUFFER, ATTRIBUTE-BUFFER,
STRING-LENGTH
RETURNING STATUS-CODE
| SCREEN-POSITION Group item | Group item is defined as follows:
01 SCREEN-POSITION.
03 ROW-NUMBER PIC X COMP-X.
03 COLUMN-NUMBER PIC X COMP-X.
On entry, contains the screen position to start writing (the top left corner is row 0, column 0) |
| CHARACTER-BUFFER PIC X(N). | On entry, contains the characters to write
On exit, this data item contains the characters overwritten on the screen. It must be at least the length specified by STRING-LENGTH. Positions in the data item beyond that length are unchanged. |
| ATTRIBUTE-BUFFER PIC X(N). | On entry, contains the attributes to write
On exit, this data item contains the attributes overwritten on the screen. It must be at least the length specified by STRING-LENGTH. Positions in the data item beyond that length are unchanged. |
| STRING-LENGTH PIC XX COMP-X. | On entry, this item contains the length of the string to write. Note that the write stops at the end of the screen.
On exit, this item contains the length of the overwritten string (in cells, that is character-attribute pairs). |
| STATUS-CODE Any numeric type | Returns 1 if successful, or 0 if not successful |
This library routine uses SCREEN-POSITION (in row and column coordinates) to determine where to begin the write operation. On entry, CHARACTER-BUFFER and ATTRIBUTE-BUFFER contain the characters to write and their corresponding attributes, respectively, and STRING-LENGTH contains that string's length. On exit, CHARACTER-BUFFER and ATTRIBUTE-BUFFER contain the characters that were replaced on the screen and their corresponding attributes, respectively. STRING-LENGTH is the length of the string that was overwritten.